If you just want the take-aways, skip down to the bottom.
The failure occurred while I was riding along a path shared by cyclists and pedestrians, and I had just maneuvered to avoid a group of people standing still and talking in the middle of it. I thought, at the time, the wheel failed because the spokes had clipped one of the many obstructions jutting into the path.1 In hindsight, I'm not so sure. Either way, the next day, I bought a new wheel from Reid (only available in a set of front and rear, back then, $40) and kept riding. Easy fix.
|Reid's target market|
for these bikes:
rider weighs less than 80kg.
So, when several months later, I experienced the same periodic dragging and saw another broken spoke, I was less inclined to blame myself. Rather than go through the waste and inconvenience of replacing wheels a couple of times a year, I was prepared to spend more to get a better-quality wheel. (I summarily dismissed learning to replace spokes as a process more fiddly than I was prepared to undertake, and my growing concerns about the quality of the wheel made me think I'd be doing this often).
As I searched for a compatible replacement, I learned about wheels, their sizes, and about the difference between freewheels (as fitted to this bike) and freehubs (fitted to most other bikes for the last few decades). Sheldon Brown's article "Freewheel or Cassette?" was a great summary for me.
My take-away from all this was that there was no simple, drop-in solution for my problem. That is, I couldn't find a decent-quality 700c-sized wheel designed for either a freewheel or for a 7-speed cassette. Road bike wheels were the right size but designed for 10- or 11-speed cassettes; and mountain bike wheels were different sizes and designed for 8- or 9-speed cassettes. And while I noted some decent-quality mountain bikes fitted with freewheels, the wheels didn't seem to be easily available separately.
Since I rely on my bike for daily transport, expediency prevailed, and I elected just to buy yet another set of wheels (which this time had nearly doubled in price to $70 per set!)
Clearly, it was time for a change, even if it proved difficult.
Making the switchTo keep the same size wheel, I figured I'd need to make the switch to a freehub and cassette. After a bit of research, I knew that I would need:
- a new wheel (duh)
- a cassette that would work with the shifter and derailleur on the bike, since I didn't want to replace them as well. To be safe, I would aim for as close a match to the freewheel as possible
- a quick-release skewer to mount the wheel to the frame
- tools: the tool for tightening and loosening the lock ring on the cassette, and a chain whip in case I needed to get the cassette back off again (which I assumed I would, given my lack of experience and the experimental nature of what I was doing.) I bought Park Tools' FR-5G for the lock ring and their SR-11 chain whip.
|Note the 0.5-mm gap between|
the top spacer and lockring
I ordered one, but in the meantime, figured that the 0.5-mm difference was going to be within the tolerances of the drivetrain components anyway and proceeded to mount the wheel on the bike. A test-ride established that the shifting was terrible — so terrible that I ended up having to extract the chain from where it had wedged between the largest cog and the wheel spokes. Twice.
How to Adjust Shimano Rear Derailleurs". With this help, a complete novice like me not only corrected the chain-eating problem described above, but had this bike shifting smoother and quieter than I remember it ever shifting in its life. And all in under 10 minutes!
Project costWheel: $20
Spacers: $25 ($18 for the right one, including international postage, plus $7 for the almost-right one)
Tools: $65 ($27 for the lock-ring tool, plus $38 for the chain whip)
If I could distill the lessons and give them to my past self, they would be:
- You're swapping contemporary components with similar characteristics from the same manufacturer. Don't overly stress about compatibility with the derailleur and shifter. Assume they're going to work until they don't.
- Fitting a 7-speed cassette onto a hub designed for a larger cassette just requires a spacer. Put the parts together and then measure for the spacer you'll need rather than trying to figure it out from published specs.
- Don't be afraid of adjusting the rear derailleur. No matter how complex the mechanism appears, there's a logical sequence to adjusting it, and it's easy to do.
1 A staircase! The City Reach Boardwalk is a truly, truly stupid and dangerous design, and I can only assume that whoever thought it was suitable as a shared path to accommodate bicycles (and to use it to link other significant, high-traffic shared paths) was not deeply familiar with the concept of "bicycle". There should be a website for "world's stupidest bicycle infrastructure" and this should get a look-in.
2 Note that they describe their 4.5-mm spacer as "for 7-speed cassettes on 8/9-speed freehub bodies", and there's no way the gap I need to fill is 1.5mm, although the Shimano spec sheet for the WH-R550 (or, at least, one variant of it) specifically states it is for use with a 8/9-speed cassette.