Saturday, May 17, 2014

My next bike: a VB-R-027 from 梅 辉辉

Over the last couple of years Heather and I have been riding together more, and we've been doing more rides with the kids on the tandems. More riding inevitably makes me start thinking about how much fun it would be on the latest new bike. Last year Heather upgraded her old aluminum bike to a new one with a carbon fiber frame, and she thinks it's a substantial improvement in ride quality over the old one. I'm not going to be able to buy my dream bike any time soon, but I've become curious enough about carbon fiber frames to look around at some of the less expensive carbon frames. People who ride and write about the super expensive bikes are all convinced the extra cost buys a better quality ride, but carbon fiber frame construction has advanced so much that I think even the inexpensive ones may now be well ahead of where any type of frame was 10-15 years ago, including my current road bike, a 2004 Fuji Roubaix Pro.

At some point in the last few months I became aware of a whole new world I didn't even know existed: cyclists who buy bike frames direct from the manufacturers in China. I first stumbled into this when looking for tandem frames, thinking that if I could buy just a frame I could upgrade one or both of our tandems at a lower cost than buying the whole bike. It turns out that hardly anyone sells tandem frames except for expensive custom builders, and a few Chinese frame shops that will sell direct to consumers (in addition to the frames that get resold under other brand names). The process of buying a custom titanium frame from China is well documented by the Spanner Bikes blog, which is a fascinating read. I'd like to do that some day, but titanium is beyond what I can spend right now, so I started looking at carbon fiber frames from China.

Since I have a birthday coming up, I've decided that this year I'm going to get a carbon frame (thanks, family!). To keep costs down I'm going to (for now) put the aging Shimano 105 group off my Fuji on it. After doing a fair bit of research I concluded a few things. First, there are a few sellers that seem reputable and are even willing to offer warranties nowadays, but the process of sending a broken frame back to China is probably slow and expensive, so I'm still accepting a bit of risk doing this. Second, I decided I don't want a frame that tries to imitate a brand name frame. There are outright counterfeits and frames that are just similar looking to famous name frames, but I want to respect the R&D those companies put into their designs and I'm not doing this to pretend it's something it's not. Third, it appears the main benefits of ordering direct from China are selection and customization. You can now get a generic carbon frame from a US distributor like Bike Nashbar for as little as $500. I decided to buy from Velobuild Mall, which offers a dozen carbon fiber road frames in the range of $320 to over $500, but shipping from China is $80, so the cost is not that different, but with more frame options and custom paint jobs.

The majority of frames offered by Velobuild only go up to 58 cm, while my existing road bike is a 61 cm frame. However, some of the frames have top tube and head tube lengths that are similar to my existing frame, so I should be able to replicate my fit with the right length seatpost. I'm not interested in aero frames because they are generally considered to have a harsher ride. Those constraints left me with two or three frames that could work and I went with the "VB-R-027" model, currently selling for $349. In addition to being less expensive than the other frame I was considering, it had slightly longer chainstays, which will hopefully give me the biggest possible tire clearance. I'm happy with the 25 mm tires I'm using now, but I'd like the option of bigger tires if they will fit. Since I'm going to the trouble, I decided I might as well get a custom paint job. I went with 3 colors for $70 (1 or 2 colors cost less). I put the frame, seatpost collar, and custom paint in my cart, and proceeded to checkout, at which point the shipping and some tax (I'm not sure which government is getting that) were added. A few seconds later I got a confirmation email from PayPal saying:

You sent a payment of $517.96 USD to 梅 辉辉.

So there you have it. I just bought a bike frame from China. The checkout process didn't provide a way to specify what I wanted in my paint job, so I sent an email to chris@velobuild.com to ask. Chris advertises his email prominently on Velobuild.com, and he responded within minutes. He asked me to just email him a picture of the paint scheme I had in mind. I had already prepared artwork for my proposed paint scheme using Inkscape, so sent it off. The drawing includes a head tube logo I designed, but apparently doing that level of detail would have added extra cost, so I told him to skip that part. The finished product should look something like this, minus the head tube logo:

New shifters and derailleur on the Bike Friday tandem

Last year I switched the Bike Friday tandem to road-style drop handlebars. The Sachs (now SRAM) Dual Drive system has a 3 speed internally geared hub with 7 speed rear derailleur. The system came with Grip Shift shifters, which work great, but are for flat handlebars only. At the time, I had read a couple of sources that I consider to be reliable claiming that any 7-speed Shimano drop bar shifter is compatible, so I found a set of 1990s vintage Shimano RSX 3x7 shifters on eBay. The triple left shifter worked great on the internally geared hub, but the 7 speed right shift lever never seemed to work quite right despite several efforts to readjust it. It seems that the cable wasn't pulling the derailleur far enough to get all 7 gears, so it would work OK for 2-3 gears but not the rest.

Initially, I assumed that one possible reason for the poor shifting was that the RSX shifter mechanism was simply wearing out due to its age. At some point recently I discovered that in the last year or two, Shimano has started selling a 3x7 drop bar shift lever set for the first time in many years. The 7 speed Tourney group appears to have been available for a few years and is found on various low-priced bikes, but only last year was a drop bar shifter made available. So, my first solution was to try swapping out the RSX shifters for a brand new set of Shimano Tourney 3x7 shifters.



These shifters sell online for about $90. Amazingly, after buying these I sold off the old RSX shifters on eBay for $65, so this swap ultimately only cost me about $25. I'm constantly amazed how much some vintage bike parts will sell for. The Tourney shifters have the thumb lever like Shimano Sora did until about a year ago. I prefer the "behind the brake" location for the upshift lever, but this works fine. These also have the "indicator" that shows you what gear you're in, another feature I associate with lower end Shimano road groups, and which I always assumed I didn't need. As it turns out, it's actually been nice to have the gear indicator on a tandem because it's not as easy as it is on a single road bike to know how many gears you have left just by looking down.

The Tourney shifters didn't solve my shifting problems. At this point, I started measuring how far the shifter pulls the cable compared to the original shifter that came with this bike, when it finally dawned on me that the rear derailleur on this bike was expecting a different cable pull (known as "actuation ratio") than the shifter was pulling. I had assumed that because the spacing of the 7 rear cogs was identical to Shimano 7 speed systems, a 7 speed Shimano shifter would work with this, without giving any thought to the rear derailleur.

The original derailleur is labeled "Sachs Centera". I can't find any documentation on this old shifting system. Sachs was bought by SRAM in 1997, so I'm assuming this bike and Dual Drive system was made around that time, because I don't think it's much older than that.


Regardless of the technical details, I was pretty sure the derailleur was the problem, but didn't want to spend a lot of money on trial and error. All I needed was a derailleur that's compatible with Shimano road shifters. For $15 on Amazon, I got this "SunRace R80", which claims to be Shimano-compatible.


This is designed for an 8 speed system, but Shimano 7, 8, and 9 speed all use the same cable actuation ratio, just with the clicks spaced closer together, so in theory this derailleur should work with any of them as long as the shifter is compatible with the spacing of the cogs. With the new derailleur installed, I can now finaly reach all 7 gears! Shifting is still a little sluggish sometimes. The derailleur hanger is slightly misaligned, so I'm going to try fixing that, but it could also be that this is just how a $15 derailleur shifts. In any case, I'm happy enough with this setup that I'll stop messing with it for now.