Friday, October 5, 2012

Park the Gas Guzzler - Scooter Mounted Bike Rack

I admit it - I drive an SUV - a big one.  As painful as it is at the pump these days, its utility necessitates its presence in my garage.  I love the cavernous amount of space inside the rear liftgate, large items being easily enveloped within its weather-proof lockable walls.  A few months ago I even bolted a bike fork mounting block to the floor of the cargo area making trips with the bike a breeze. 

On the eco side of my garage resides my 125cc scooter.  70mpg with a 55mph top speed make the shorter trips a bit less taxing on the wallet.  The far wall of my garage is reserved for green transportation options - yep, the bike wall.  I'm a big bike commuting proponent and would love it if more of my trips could be made that way, and in a perfect world more of them probably would.  But, as a realist, I'll acknowledge that sometimes there's not enough time, too much distance to cover, or it's just too dangerous out in the AZ desert heat to make some of the trips under pedal power - that's why I love my scooter.  Those mid-range non-highway trips are a quick and easy, more fun, and definitely more cost effective on the scooter than rockin' the 15mpg SUV to go pick up a DVD. 

As the fuel costs continued to rise I tried to find more ways to leverage the scooter for my regular trips around the area.  One hurdle always needing acknowledgement was what to do when you couldn't just bungee the stuff you needed to carry to the cargo rack.  A couple of my weekly trips included this conundrum - namely my group road and mountain bike rides.  At 14 miles each way to the ride meeting point, my SUV was costing me over $6 per ride, and as I ride with that group 2-3 times per week the dollars were starting to add up.  How could I make this commute more efficient?  Now, you hardcore types will probably say something like "just ride your bike there!", etc.  That might work for some of the road bike rides (given enough time), but 28 miles of pavement on a mountain bike just hurts my head (and legs) to think about.  Enter the scooter.

I don't know how many hours I spent staring at that scooter, holding bikes up to it at various angles and in various ways, but it took a long time before an idea started to emerge.  I determined that there just wasn't enough space on the scooter itself to mount the bike on the side near the back.  Bikes are too tall and long, interfering with seating position and access to controls on the scooter in that configuration.  That left the only option as the back cargo rack.  Since the route to the bike rides followed quieter back roads and the scooter didn't go THAT much faster than a fast downhill run on my road bike, I thought "why not just tow it?" - and soon after Scooter Bike Rack 1.0 was born. 

A fork mounting block was bolted to the scooter's rear cargo rack, the road bike's fork was secured (rear wheel rolling along behind) and I was off.  It really rode quite well back there - especially once I mounted the fork block so it could pivot vertically allowing for undulation in the road surface so as not to scuff up the bike's fork dropouts.  But, as I was zipping my way at a little over 50mph I began to do some math - focusing primarily on the fact that I had as much invested in my bike's wheelset as I had paid for the scooter and wearing that wheelset out prematurely to save on fuel costs was definitely NOT cost effective.  Return to drawing board.

Alright, so if we need the wheels off the ground, let's just use one of my Yakima roof-top racks mounted to the scooter's cargo rack!  Begin Scooter Bike Rack 2.0.  Yakima has specific guidelines on how close the front and rear rooftop crossbars can be together before you find yourself pushing structural integrity boundaries on their components.  I figured there must be some over-engineering built into the racks, so I managed to mount some crossbar towers to the cargo rack, cut down a crossbar to fit so as not to look crazily wide, mounted the front of my fork-mount tray-style to the crossbar and attached the wheel tray directly to the furthest aft point on my cargo rack.  It looked beautiful. 
I proceeded to mount my 30lb. mountain bike to assess the functionality and noticed a bit more flex in the hugely cantilevered wheel tray than I'd hoped.  Not to be deterred, I took apart a second rack, commandeering its wheel tray which I bolted underneath the wheel tray of the first rack - effectively doubling its strength.  Mounting the bike once more, I was a bit more confident of its adequacy in carrying the heavily leveraged weight.  It's maiden voyage did a bit to reverse my confidence as I watched the shadow of the bike/rack flex to an unnerving extent with every road imperfection I encountered.  After safely traversing the roadways home from the group ride, I removed the mountain bike and replaced it with my 20lb. road bike.  As expected, much less flex.  While challenges still needed to be overcome to transport the mountain bike, at least I could zip cost-effectively to the group road rides... or so I thought. 

Half a dozen trips across town with the bike found me zipping along my regular return route a mile or so from home when I hit a particularly rough patch of pavement.  Snap.  Scraaaaaape.   Sparks.  Not good.  Pulling quickly to the shoulder, I realized a stress point in the rack system had been overlooked in my construction.  The point at which the wheeltray bolted to the fork mounting block had experienced such stress from the cantilevered arrangement that the area around the bolt hole snapped, allowing the wheel tray to pivot freely on its one remaining attachment point, rotating downward until it contacted the pavement below.  Thankfully a minor scuff or two were all the bike suffered for the ordeal and I managed to limp the rig along the last mile home using version 1.0's "towing" style.  Drawing board anyone?

Hmmmm, apparently too much cantilever effect.  So, can't hang the bike fully off the cargo rack and can't tow it because of speed/heat/friction issues.  What if we create a 1-wheeled "trailer" that would support most of the bike's weight?  Scooter Bike Rack 3.0?  When my son was smaller he rode on one of the tag-along or trail-a-bike systems.  Due to my variety of interestingly-shaped bikes/trikes, I had opted to purchase a Burley Piccolo system that attached to a rear cargo rack rather than the traditional seat post attachment point.  This seemed like a good starting point for the design as the tag-along-to-cargo rack attachment was quite secure and it had a built-in two-way pivot allowing the trailing wheel to follow its own arc around a corner or pivot upward if encountering road undulation (plus, it was laying around my garage collecting dust).  I cut one of the tag-along bike cargo racks down to just the attachment interface which I then U-bolted to my scooter's cargo rack allowing the tag-along to be attached or removed quickly without tools. 

The next issue was in mounting a bike rack to this tag-along trailer.  There just wasn't enough length to the trailer to effectively mount a bike, so I made the trailer a bit longer.  Xtracycle makes a longtail cargo bike conversion kit that will turn most any traditional diamond-frame bike into a cargo bike.  I had purchased one of these to use on a TerraTrike Rover (see my earlier post for the details) and it was currently sitting on a shelf, just waiting for a new application.  With a bit of finagling, I managed to attach the kit to the tag-along frame, moving the 20" rear wheel back and extending the trailer by over a foot.  I clamped on a fork mounting block (as low as I could find a mounting spot) and popped the mountain bike on to inspect the finished product.  As I'd hoped, there was very little weight resting on the scooter's cargo rack and the primary forces would be primarily torsional, keeping the trailer upright and in line.  A ride around the block convinced me of the proof of the concept and the next morning I headed for yet another group ride via scooter.

Anyone who has ridden with a child using a tag-along knows that they can exhibit an amazing amount of leverage on the bike making it very important to maintain a tight grip on the handlebars keeping the bike upright and going straight.  You also very seldom exceed 15mph... for a reason.  The trailer did fine at 20mph, and even about 30mph.  When I hit 35+, the trailer began to sway back and forth and begin a resonant wobble from the leverage the high-mounted mountain bike was exerting on the long attachment arm of the tag-along trailer.  After a very slow (and slightly harrowing) drive to the group ride and back, I retired the trailer from its bike carrying days, regaling it to the duty of low-center-of-gravity cargo carrying for nearby scooter trips (e.g. grocery runs).  I'm really starting to dislike this project's drawing board, but back we go.

With the stresses on the bike carrying system I'd encountered, I began thinking I'd need to purchase a small motorcycle cargo trailer or the like in order to safely transport my pedal-powered friends.  Most of these solutions were heavy and/or expensive and weren't easily constructed with materials lying around my garage.  Flipping sadly through a mountain biking magazine, my jaw dropped when I opened to an article reviewing a motorcycle-mounted bike rack!  Amazingly enough it looked suspiciously similar to Scooter Bike Rack 2.0 (though obviously much more solidly built).  2x2cycles ( produces a beautifully designed bike rack for the cargo area of motorcycles, cantilevering the bicycle off the back of the motorcycle.  As I poured over the photos of this design I realized they had incorporated on extremely important thing I had not (beside proper engineering and design) - a load distributing strap countering the effects of the cantilevered mounting position and relieving much of the strain on the arm supporting the bulk of the bike and transferring it to the front fork. 

Armed with this revelation, I set out to rebuild Scooter Bike Rack 2.0 - better... stronger... faster... ok, maybe not faster (am I dating myself with Six Million Dollar Man references?), but definitely more robust.  I reused the double wheeltray, but attached the trays to the fork mounting block with a larger bolt/washer combination that would add some strength to the system.  The rest of the mounting system was similar to version 2.0's.  Since building version 2.0 I had acquired a new mountain bike with a front through-axle design.  This required an adapter be added to the fork mounting block.  This adapter also had the added benefit of moving the mounting point for the fork forward a few precious inches.  A couple of additional cantilevered inches were saved by rotating the front fork 180 degrees allowing the wheel mounting point offset to face rearward, in essence shortening the wheelbase.  Then, for the finishing touch, a trusty old ratchet strap was passed over the bike's frame just behind the headset and anchored near the base of the front of the scooter's seat.  The strap was snugged up, each click of the ratcheting mechanism bringing the bike's weight forward onto the fork and lifting away the stress on the wheeltray.  Scooter Bike Rack 4.0 was finished.  Time to hit the road.

As I rolled out with fear and trepidation recalling the last disastrous voyage of this rack configuration.  Eyes darting back and forth between the road in front of me and the shadow cast by the morning sun allowing me to see the movement of the system behind me, I watched as the load distribution strap did its work minimizing the flex of the rack and its wheeltray as I rolled over road imperfections and undulations.  Working my way up to top speed, the rack performed flawlessly - the bike unmoving behind me as I zipped down the road.  I ride with a much greater level of confidence these days, knowing that 4 versions and many hours have (thus far) finally paid off - though I still watch my shadow out of the corner of my eye...  Back to the drawing board again, this time only to smash it to pieces - project complete... done... success.  Next!

Monday, October 1, 2012

Stop the Slapping! A budget-friendly DIY chain guide.

This summer I bought a new mountain bike.  Ok, so it wasn't really "new," in the strictest sense of the word, but I did buy it from an actual bike shop.  I just happened upon a left-over Trek Remedy demo bike with a small frame that only a vertically challenged rider could love.  With a little TLC, it was riding and shifting smoothly, eating up bumps my hardtail would have had me in tears over.  I soon realized that this all-mountain machine with 6" of front and rear suspension travel was a LOT more bike than I was used to, and that it quickly boosted my confidence in quickly descending very rugged terrain. 

As I barreled down yet another boulder-strewn old jeep trail, I noticed how the tranquil sound of rocks bouncing off my spokes was rudely interrupted by the annoying clatter of chain striking chainstay.  I began my investigation with the rear derailleur.  As I hadn't had this problem on my other bikes, I assumed the tensioning system must be askew.  Spinning on the work stand, there seemed to be adequate tension on the chain to keep it in line, so maybe I was mistaken in my previous supposition.  Maybe the problem resulted from my new-found love for rocky descents and technical terrain?  While the cockpit of this new burly all-mountain beast afforded a place of smooth security as the earth undulated underneath, the rear wheel and drivetrain experienced a much more violent interaction with terra-firma.  It would seem that my chain slap symphony was due to hurling my drivetrain mercilessly down the rugged fall line. 

Ok, source located - now, what do I do about it?  My good friend Google had quite a few wonderful solutions to my predicament, but the price tags ranged from a low end of $50 to a high end over $300!  When I added "DIY" to my search engine query, some interesting ideas began to emerge.  Riders were using all kinds of materials they had lying around the house to keep that chain where it was supposed to be as they danced with gravity down the slopes.  Some were using zip ties, others bushings and spacers, some using bolts and a few even fabricating with wood.  The one thing most of these ideas had in common was the basic premise that the shorter the unsupported length of exposed chain, the less deflection the chain will undergo when the driveline deflects rapidly (due to a bump, obstacle, etc).  As I set out to scrounge up some materials for my own version, I began to think about the various recumbent bikes/trikes that I'd owned and how most of them had extremely long chains run across long spans between supports.  Some of the bikes I'd owned were plagued with chain slap issues (my vintage RANS Stratus was one of the worst offenders), while others seemed to manage the chain effectively regardless of how rough the road became.  Many of the quieter drivetrains used chain tubes to support and guide the chain along its long (and sometimes circuitous) journey.  Could it be as simple as adapting a recumbent bike product for a diamond-frame implementation?

Idea hatched - time for parts gathering.  The core of this idea involved a chain tube.  These are typically made from PVC or Teflon tubing (1/2"?) and can be found either on recumbent bike supply websites or in the yard irrigation aisle at your local home improvement store.  I wanted a length short enough to minimize friction, but long enough to ensure a smooth chain entry/exit impervious to twisting and binding - in my case, I guessed about 2" long.  Now, one thing I learned riding recumbent bikes with chain tubes: they are not the easiest things to secure.  The up-side to this type of tubing is that it is quite low-friction.  The down-side is that this low-friction property makes it a pain to securely affix.  I've had more than my fair share of chain tubes sucked into my front derailleur when the zip tie I had securing it slowly slipped further and further down the tube's length.  I thought about using a hose clamp, but the thought of an unsightly silver clamp on this beautiful bike was more than I could bear.  As I rummaged through a parts drawer I came across a piece leftover from the installation of a rear cargo rack on one of my other bikes.  Some racks come with universal C-clamps to wrap around the seat stays and anchor the cargo rack in cases where the bike doesn't have rack mounting bosses brazed on.  These small metal clamps have most of their surface coated in an anti-slip rubber or vinyl material - perfect for our implementation. 

Once the chain tube was securely bolted in the C-clamp, the attention turned to securing the apparatus to the chainstay.  Since I'm not one of those single-speed-riding monsters I've been passed by on the trail, the chain guide had to be able to move and pivot to accommodate my triple front crankset and 10-speed rear cassette.  Enter my ever-present pals, the zip ties.  The simplest part of the project, one zip tie around the chainstay and another from that zip tie to the bolt securing the chain tube's C-clamp.  The tie around the chainstay should be secured VERY tightly so it doesn't allow the tube to "migrate" forward along with the chain and risk contacting the front derailleur.  The tie connecting the chainstay tie with the chaintube c-clamp bolt should be left as an open circle, in my case about 1" in diameter.  This allows the chain tube to pivot on the zip tie and to deflect left and right as the chain is shifted through the various gears. The optimal size of this connecting zip tie "O" will depend on the specific bike geometry and how far the chainstay is from the lower return path of the chain from crankset to rear derailleur.  Some contact with the chain tube in all but the smallest of gears (granny gear + smallest rear cassette cog) quiets the chain, but too much (i.e. tube pulled too far up toward the chainstay) creates additional friction and noise when in the large chainring and could limit lateral deflection, creating difficulty in shifting smoothly between the front three chainrings.

I will include a side note about guide positioning fore-n-aft.  Some DIY-ers reported issues with the guide deflecting sideways and contacting spokes or knobby tire treads, sometimes with not-so-great consequences.  I anchored my guide so as to bump into the smooth sidewall of the tire, should the chain & tube ever deflect sideways to that extent.  Chain slap most likely would be further minimized by moving the guide further aft toward the center of the chainstay, but I didn't want to risk that positioning for a prototype run.

Last step: threading the chain through the tube.  I was in luck as I had a removable master link in my chain - popped that open, threaded the chain through the tube and snapped it back together.  No master link?  Get out the chain tool, I guess.  Theoretically I suppose one could cut the chain tube down one side along its axis allowing it to be wrapped around the chain before attaching the C-clamp, but I'd worry that the tubing would spiral in on itself, coming out of the C-clamp and lodging itself in the rear derailleur - probably at the most inopportune time.  If I hadn't had a master link in my chain, I would probably have removed a link from my chain and put a master link in - but that's just me.

Maiden voyage: success.  A couple rides around the block and it was off to the trail.  The thing that struck me was how unnoticeable the chain tube apparatus was.  In many gear combinations I couldn't hear the chain passing through the tube at all, and in others it was just perceptible.  Going up the trail the bike performed as usual - shifting as smoothly as ever through the range of gears.  At the top, I opened the rear shock up to its full range and began the descent.  The difference was immediately evident.  I would estimate an 70-85% decrease in chain clatter, the rest of which can probably be attributed to drive-side chain slap (to which I have no solution thus far).  My descent was now (mostly) peaceful and serene again, the gentle ping of displaced stones rocketing off the tensioned spokes (and occasionally the aluminum frame) and the chain silently and dutifully propelling the bike downward.

A final note on durability.  In any system - especially one of inherent contact and friction between two surfaces (chain and chain tube) one would expect one or both components to exhibit wear.  The soft plastic of the chain tube will need periodic inspecting and eventual replacement.  The time between tube replacements (at a cost of about $0.05 if you bought the 20' irrigation tubing roll!) can be extended (probably up to 400%) by periodically loosening the C-clamp and rotating the chain tube 90 degrees.  Simple, basic, cheap and effective.  Probably one of my favorite "little" projects yet.

Happy riding!

*** Disclaimer: Once again, if you use this idea or a part of it in a project of your own, you do so at your own risk!  If your chain tube breaks loose, jams in your rear wheel causing you to fly off a cliff, don't blame me - I've lost plenty of perfectly good bike components (and skin) to hairbrained ideas such as these.

Friday, October 21, 2011

Bearing Some Resemblance to a TerraTrike Rover

I've had a recumbent trike or two over the past couple years, and some months back I convinced my better half of the benefits of 3 wheeled transportation.  She didn't like the ultra-low seating position some of the tadpole-style (two front wheels, one back wheel) trikes were sporting, so we settled on the design of the relatively new TerraTrike Rover.  Its seating position is higher than most of its class brethren while still remaining stable enough for cornering at our regular cruising speeds (without lifting the inside wheel off the ground).  My initial issue with the model was its lack of wide range gearing.  It was available only in a 3-speed or 8-speed internally geared hub configuration which didn't give quite the desired range our hilly area requires.  After some searching I ran across a custom build being done by Utah Trikes: the Rover 8 DL.  Basically they pull the internally geared rear wheel and replace it with a standard rear wheel with 8-speed cassette and rear derailleur.  What's the benefit of that, you ask?  This allows the single front crankset to be replaced with a triple crankset giving more gearing options than you could ever need.  Utah Trikes will even install the triple crankset option complete with bolt-on front derailleur post for a modest $150.  Convinced we now had a winner, I placed the order and waited with baited breath until the day of the huge box delivery arrived.  The trike shipped almost completely assembled and it was up and running in very short order.  The Rover is a great recreational riding trike - very maneuverable, easy to get in and out of, and above all very fun to zip around the neighborhood on.

The great build configuration by Utah Trikes left me wonderfully content... for about a week.  It was about that time that the economy-level drivetrain components and tires left me yearning for better ride quality and crisper shifting (the trike came configured with very modest level SRAM X-3 components which shift a bit imprecisely).  With a few flicks of an allen wrench (and turns of a cassette lockring tool, chain whip, channel lock, wire cutter, and even a few squirts of hairspray to slide grips on and off), the Rover was now sporting a 9-speed rear cassette, Deore rear derailleur and SLX trigger shifters. 
Soon after, the cheap no-name low-pressure tires were replaced with a trio of beastly Maxxis Hookworm tires better capable of handing the suburban jungle in which we reside.  Better shifting?  Check.  Better ride?  Check.  Ahh, content again... sort of.

A few minor tweaks ensued.  Bolted on a rear rack for the pannier bags, added a bike computer and added a chainring guard (the ICE Trice Chainring Guard fit wonderfully).  As I mentioned in previous posts, I'm a big fan of shorter cranks on recumbent bikes, so I swapped the front crankset for a Sugino XD600 152mm triple crankset.

Amid the modifications, I had noticed there was a great deal of room ahead of the 20" rear wheel.  Poking around online I also found other Rover builds that were sporting rear wheels up to 26".  This was just too much of a temptation not to be attempted.  As there is no rear brake needed on a tadpole trike (the left and right brake levers typically work the left and right wheel brakes rather than front and rear), the swap was an easy one.  There isn't much clearance for a large volume tire, but a 26 x 1.5" fit in the frame spacing without any trouble.
Riding was surprisingly unaffected with the exception of a bit higher top end due to the larger wheel circumference and a bit of a forward tilt that could be generally negated by adjusting the seat recline angle.  The only detriment to this configuration was that I lost the advantages of my higher volume tires.  In the end, ride quality trumped top speed and the 20" rear wheel returned home.

It wasn't long after that an interesting piece of hardware found its way to my local craigslist: an Xtracycle FreeRadical.  Xtracycle ( makes a spectacular longtail conversion system allowing a bike to become a very cool and utilitarian device - even allowing the transport of passengers on the back!  I had some experience with the Xtracycle system (will post more on that later), and instantly visions of an Xtracycle-equipped trike began dancing in my head.

The FreeRadical installation was really quite simple on the Rover and the only truly invasive part of the project was drilling a mounting hole in the Rover's frame just ahead of the rear wheel.
The system attaches in three locations - the two rear wheel dropouts and one point where the chainstays typically attach to the bottom bracket (and where a kickstand typically would be mounted) on a traditional diamond frame bike.  The location of the anchor point on the FreeRadical lined up almost perfectly with the point the chain stays attach to the main square tube frame of the Rover and simply had to be anchored to the frame in some way.  I decided the most secure (yet still reversible) mounting method would be using a bolt passed through the FreeRadical and both sides of the square frame tube.
To maximally distribute the load the Xtracycle system would exert on the frame, I used one of the brackets that came with the FreeRadical kit.  Two of these brackets can be used to sandwich the chainstays on a diamond frame, but one of them did a spectacular job of distributing the load forces and protecting the Rover's frame.

The front of the FreeRadical is designed to rest on top of the chainstay brackets (or kickstand bracket), but on the Rover this caused the Xtracycle platform to slope as well as raise the overall height of the Rover's rear assembly.  Because of these issues I chose to mount the FreeRadical underneath the frame instead.  To make sure the hardware would be equal to the task, I went down to my local hardware store and bought a nice heavy-duty Grade 8 bolt and thick washer to bear the load.
Hardware in hand, the rest of the assembly was fairly straightforward.  The two aft mounting points on the FreeRadical slid smoothly into the Rover's horizontal dropouts and the new bolt secured the system at its forward third point. 

The rear derailleur (removed prior to assembly) was relocated to the derailleur bracket on the FreeRadical, an extra handful of links was added to the Rover's loooooong chain, and a new longer rear shift cable (tandem cables are long enough) was run to the new rear derailleur position.  The rear wheel slid into the FreeRadical's dropouts and we were ready for the maiden voyage.

The first thing you notice after this type of conversion is how LONG the trike has become.  I could no longer turn the trike around in a single lane width.  It now took a full two lanes to turn this stretch limo 180 degrees.  Once the initial acclimation took hold, the ride really wasn't all that different than stock and stability wasn't affected particularly one way or the other.  One problem that became apparent a few pedal strokes in was that the chain had a tendency to rub against the chainstay when in the smaller cog and against the FreeRadical frame in the largest cog.

I found some resolution to this by adjusting the position of the rear power-side idler wheel to one of its upper mounting positions.  This didn't resolve the chain rub in the largest climbing gear, but did make downhill runs rub-free.  With the front triple crankset and small rear wheel, I found I really never needed the largest gear on the rear cassette so I "fixed" the issue by adjusting the set screw and limiting the rear derailleur's maximum range - effectively changing the rear cassette to a 8-speed configuration.  I would venture a guess that the chain rub would not have been an issue had I been using a closer spaced rear cassette rather than the wide range cluster which included the offending 32 tooth gear.
Strange noises quelled, I returned to the streets for some additional testing.  The new configuration proved very functional and usable with a few caveats.  For one, the rear shifting was not as precise as it had been prior to the conversion.  I attribute this to the many mm of additional shift cable needed to reach the rear derailleur.  A higher grade low-friction cable would most likely improve the shifting performance and return it to its former crisp shifting glory.  The second thing I found a bit unsettling was in the feel under heavy loaded conditions.  I have used the FreeRadical systems on upright bikes as a seating area for my 80-ish pound child.  Xtracycle makes a great seat cushion and foot-shaped floorboards for the FreeRadical which make it a very stable and efficient child carrier.  When my son mounted up on the back of the converted Rover I noticed a distinct amount of torsional frame flex.   As we cornered and he shifted his weight while riding I continued to notice the frame flexion.  As the Rover has a strong square-tube frame, it was not overly concerning from a structural perspective, but definitely added a bit of an odd feel to the ride.  Also, the center of gravity became markedly higher with a rear rider and necessitated greatly reduced cornering speeds.  With this type of behavior, I limited two-rider trips to short jaunts to the park rather than longer commutes in higher speed situations.

Overall the design and versatility of the TerraTrike Rover has proved admirable.  While it will never compete with the likes of its low-slung ultra-reclined brethren (think Catrike 700) from a performance perspective, it is by far the easiest to climb on for a bit of fitness, a ride around the neighborhood or a short commute.  Its seating position make it both more visible to automobile traffic and easier to see "out" of to enjoy the scenery and maintain situational awareness of traffic around you.  It really is the trike most of us SHOULD be riding even though many of us envision ourselves aboard performance trikes rocketing down the road cheating the wind and passing the roadies in their pacelines.  It all goes back to the saying that the best bike/trike is the one you actually USE; and the TerraTrike Rover is definitely in that category.

UPDATE (10/21/2011): While a cargotrike was my idea of the ultimate configuration of a Rover, my better half found she didn't agree.  Her typical trips didn't require the extensive cargo-carrying capacity of the FreeRadical, and thus the longer turning radius and increased weight were unmerited.  As I already had an Xtracycle-equipped bike that I used for errand-running and child-carrying, we had little need of a second similarly-equipped machine.  We have since removed the FreeRadical kit, returning the Rover to its shorter and more maneuverable configuration, while the standard rear rack still affords a wealth of carrying space with trunk bags and panniers.  Once again the old adage applies as the current configuration is the one that will be the most used.

Thursday, August 4, 2011

Bargain Bin Special - Huffy 626 Road Bike

A few years ago I became intrigued by the idea of drop bars.  Yes, I know, they've been around since the dark ages - but I hadn't ridden a bike with anything of the sort since I was 12.  I stopped down to my local bike shop and wandered the aisles, dazed by the number of digits in the price tags.  Not sure I wanted to be quite so committed to a style of riding I'd never experienced, I went to my next favorite store: craigslist.  $10 later I was the proud owner of a beat-up but mostly functional Huffy 626 10-speed.

A little spit and polish, some cheap bar tape and a couple tire tubes later I was off to the races.  The first thing that struck me was the aerodynamics of the drop bar position.  The second thing was that riding in the drops was not entirely comfortable for my level of flexibility (or lack thereof).  The old-school 27" wheels definitely smoothed out the road a bit nicer than the 26's I'd been riding on other bikes, and as I rode along the not-so-smooth pathways in my neighborhood I realized probably the best feature of this particular bike: the very flexible steel fork which visibly absorbed a great deal of the path imperfections.  One other feature of note on this particular machine is that the rear dropouts are slotted relatively horizontally.  This makes it easy to convert the bike over to a single speed or fixie configuration as you can use the horizontal dropouts to slide the rear wheel fore and aft to tension the chain properly.  I don't have much else good to say about that bike except it opened my eyes to new frontiers of riding.  Bad brakes, old un-true-able wheels, extremely stiff and finicky stem mounted shift levers and a creaky one-piece crank all made this bike worth every penny of the price I paid for it, but it served well as a campus commuter for a short stint.  Plus, at that price point it gave me a wonderful peace of mind knowing that I spend more at the local coffee shop in a given week than I had invested in that bike, should someone be foolish enough to steal it.

Tuesday, August 2, 2011

Evolution of a Vision R40 SWB Recumbent

For a first post on a new blog, it would seem prudent to choose a project bike that had some interesting options and results. 

I don't think any of my bikes have seen much more of a renovation than my pair of 1994 Vision R40 recumbent bikes, purchased in 2009.

The Vision R40 came in two configurations: short wheelbase and long wheelbase (sometimes called mid wheelbase).  Both have a 26" rear wheel and 16" front wheel.  One issue I had right away with the bikes was that they have the shortest wheelbase of any bike I've ever ridden (at least since I left training wheels behind)!  This makes them what you'd call "very responsive", or probably better described as "twitchy".

Interestingly enough, the short wheelbase version can be converted to a long wheelbase just by swapping the front boom for the style that has a head tube ahead of the bottom bracket.  The front fork can then be relocated to the forward position and a steering linkage ties the fork and the handlebar together.  One such longer boom was included in the box of parts that came with the pair when I purchased them, so I converted it to its longer configuration.  This made the ride much more stable at speed, and the added length smoothed out the ride noticeably as the chromoly frame soaked up the bumps.

On the whole, both bikes rode very well.  They have full mesh seats which are comfortable and extremely breathable.  Adjustable recline angle, pivoting handlebars and rackmounts make them very versatile machines.  They are on the lighter side for steel-frame recumbents, and their drivetrain is very simple and efficient with no power-side idler and only one idler wheel on the non-power side.  They can be set up as over seat steering over under seat steering, whatever your preference happens to be.

For cruising and touring the LWB seemed well-suited, but I had speed comparisons on my mind and the added weight of the boom and steering linkage seemed counter-productive... so I began working with its SWB sibling.  Handling was definitely an issue over 25mph, but nothing too worrisome - plus, I don't spend a great deal of time at that speed anyway.  What I was more concerned with was the flatland performance.  In my estimation there were a couple things working against this machine.  First, the 16" front wheel did not do very well with bumpy surfaces, and some of the trails I was riding were bumpy enough to cause me to slow measurably.  Secondly, the riding position was not terribly aerodynamic - even with the seat quite reclined.  The bottom bracket (where the front crankset resides) was just too low for the seating position and presented too much surface area to the wind. 

I decided to solve both problems with one solution - a larger front wheel.  I picked up an inexpensive steel (1" threaded) fork, had it cut to the right length, and found a used 20" front wheel that was still fairly true and rolled adequately.  This conversion was quite quick and easy as the new fork positioned the brake pads of the old brakes nicely in line with the new wheel's rim.

The new wheel definitely appeared to improve the aerodynamics by raising the bottom bracket up and bringing the pedal circle more in line with the wind shadow of the body, which hopefully would translate into lower wind resistance.  The first ride out brought about some realizations.  First of all, I'm not a tall rider at 5'6", the new wheel and fork had raised the bottom bracket height enough to make flat-footed stops and starts a bit less comfortable than they had been with the smaller wheel.  Once moving, though, the position certainly felt better.  The second observation was a pleasant one after analyzing the ride data - the bike was 5-10% faster.  Now, I could go into the comparison rides and methods, but we all know that comparing bikes to one another across days/weeks/energy levels is virtually impossibly to fully quantify.  I'll leave it to say my numbers were quite a bit improved.

This successful modification led to more theorizing on what to improve upon next.  Before I jumped into any other radical innovations, I first upgraded the drivetrain.  A new rear wheel w/ 9-speed wide-range (11-34) cassette, new 9-speed chain, new Shimano Deore rear derailleur and Shimano integrated brake/shift levers made shifting more precise while expanding the gear range (from the original 7-speed drivetrain).  I also changed out the front crankset for a Sugino XD600 triple (24-36-50) with 152mm crank arms.  I have found that my short legs prefer a shorter crankset on recumbent bikes than on diamond frame bikes.  I ride with a 165mm crankset on my road bike, but that length bothers my knees on the 'bents.  I've had good luck with the Sugino cranksets, they're moderately priced ($110-ish) and it's hard to find a wider range triple unless you customize.  I find that my speed doesn't change much with the shorter crank arms, but the comfort level is much improved.

After a number of rides under my belt with this 26/20 configuration, I once again felt the need to push the speed limits of this machine.  I first tried another size jump in front wheel diameter.  I tracked down a larger fork that would fit a 26" front wheel and swapped it out.  With the dual 26" wheels, the pedal circle moved further upward and almost fell in line with the body of the rider just as I'd hoped.  What I hadn't hoped for is as much height difference in the seating position for my short stature.  What had been a stretch to stop/start with flat feet before turned into a stretch to even reach the ground tiptoed.  On top of that, the wheel diameter was large enough that the tire actually overlapped the circle of the crank arms.  This meant that if I turned the wheel more than a few degrees while pedaling the crank arm (or my foot) would hit the front wheel.  Now, recumbent riders are generally accustomed to "heel strike" because of this positioning and it can generally be mitigated by kicking your heels out to the side when turning sharply.  Crank strike, on the other hand, is a big problem and can stop you dead in your tracks if not extremely careful.  I eased the bike out for a couple of time trial rides and found that the benefits (3-5% speed gain) didn't outweigh the drawbacks (paranoia when turning).  Time to click the "undo" button.

Back at the drawing board with the bike safely back to its 20" front wheel configuration, I decided to try another method to mitigate wind resistance: a fairing.  As luck would have it, I found a Vision Lexan or Plexi or some kind of clear plastic fairing with mounting hardware on craigslist.  It was a bit heavier than I'd imagined, but it had a lot of surface area as well.  Riding with a fairing is a bit different as vision is a bit impaired even with the clear plastic - it was a bit hard to see the pavement closer than 5 feet in front of the bike.  The fairing also made it warmer to ride - nice on a cool crisp fall morning - not so nice on a humid summer day.  Time-trial-wise, the fairing added another 5-10% to the flatland speed when the wind was light or off the nose/tail.  Cross-winds necessitated "fighting" the bike a bit because of the large surface area of the fairing and caused speeds to dip to levels at or even below those of the unfaired bike.  Climbing also slowed a bit (5-10%) with the fairing as the added weight worked against it.  None of my routes were terribly long and straight, and coupled with the midwest's proclivity for moderate-to-high winds, this was not an ideal faired bike environment.  Having not been quite as impressed with the performance gains as I'd hoped, I left the bike in the unfaired configuration for the bulk of the time unless comfort dictated its use (primarily cooler weather).

At this point I decided the unfaired 26/20 configuration of the Vision R40 was the most efficient possible while still being useable for someone of my stature.  Overall the bikes both rode wonderfully and were great recumbents.  I rode the SWB model on two long charity rides and it performed perfectly and made the trips much more comfortable than any diamond frame would have.  But, with the projects exhausted the addiction set in and I parted with the pair in search of something new to explore.