Bikes > Computers

Three out of my last four posts (four out of five if you count this one) have been about bikes, instead of computers! I have just spent the last 4 or 5 hours reading about various bike stuff online, culminating in the purchase of my TomiCog. I have been riding bikes for a long time, and I even occasionally race them badly. Although I took a four year hiatus to row, the bike is back! I attained higher cycling fitness in 2007 than I have had since high school, or perhaps ever. I rode the L-train to victory in the 2007 Grass Roots Racing Sprint Series, solely as a result of our mountain biking skills. I have already crashed more times in 2008 than I did in all of 2007. I now own a pink single-speed, and I can blame Bianchi warranty if too many big dudes start making fun of it. I built a wheel, though I haven’t ridden on it yet. I almost killed Mullen and myself on the way to Quebec Run due to resonating childish exuberance overpowering my ability to see red lights, and I got pulled over on the way home and escaped with only a warning!

This evening’s literary selections have included BikeSnobNYC and Mark Weaver’s Road Rant, as well as the discovery of 63xc, even if it has been disbanded and I didn’t learn much except a lot more people ride fixed gears off-road than I thought.

Aspirations for the year include acquisition of enough weight training and protective equipment to allow my 27-year-old nerd’s physique to survive the beating it’s going to receive, as I intend to introduce more frequent skinnies, stair gaps and try my hand at a downhill race or two. This may finally be the year of the open-ended wheelie and manual, as well as the open-ended backwards fixed-gear riding. Open-ended with respect to my own balance, though I remain woefully subject to the whims of yinzer motorists.

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TomiCogs

I’m supposed to be a clever fellow, given the nearly completed PhD and all. However, I’ve been fussing internally about how to get a fixed rear mountain bike wheel without spending a bunch of money. Even if I want to build it with junk I have lying around, I’ll have to shell out for spokes. Enter TomiCOG. I already have disc brakes, and this cog bolts on right where the disc does. Just flip the wheel. Why I didn’t come up with that on my own is cause for rumination and mental anguish. I’ll have to make sure I have the bike nearby when those thoughts creep up. I have a feeling that descending fixed in Frick Park is an effective way to sharpen one’s focus.

For maximal cheapness, I could take the conversion approach and drill a sufficiently metal cog from a low-end cassette or coaster brake. I read something somewhere about a good source of cogs for this. However, embarrassed by my own lack of creativity, I opt to reward TomiCOG for his innovation.

I built a wheel (White Industries hub + Deep V rim)

Many years ago I built a few wheels, but I haven’t sat down with a pile of spokes and nipples in a long time. This particular wheel is composed of a White Industries hub from the late 1990s; I believe it is a “Speed Racer” (it shares the identical measurements of the Speed Racer). This is a nice lightweight hub with a nice loud freewheel and cartridge bearings. I’ve had it long enough to have worn through the braking surface of two rims and at least one set of cartridge bearings on my mountain bike. To this hub I have laced a brand new Velocity Deep V 700c rim, using DT Swiss double-butted (2.0/1.8) stainless steel spokes, using the traditional 3-cross pattern.

Spoke Length

The issue that concerned me most going into this was selecting the right spoke length since I was lacing a hub previously used for mountain biking to a 700c deep-V rim for my ‘cross bike. Dan Halem’s Spoke Length Calculator actually has entries in its drop down menus for both my hub and rim, which made entering the necessary measurements trivial. My Velocity Deep V has an Effective Rim Diameter (ERD) of 582.0mm, while the White Industries Speed Racer has symmetric flange diameters of 55.0mm, with a Left Center to Flange measurement of 34.5mm and a Right Center to Flange measurement of 21.5mm. Using a 3-cross pattern and with 32 spokes, the left (non-drive) side spokes should be 282.5mm and the right (drive-side) spokes should be 281.2mm. As spokes tend to be sized every 2mm, I settled on 282mm spokes for both sides.

Building the Thing

To jog my memory I read through Sheldon Brown’s Wheel Building page, which is a great source of information. Lacing the spokes to the hub and rim is straightforward, if painstaking, and I didn’t have any issues. I then started gradually tightening up the spokes. I tried to leave the same amount of thread showing all the way around, tightening spokes in order around the rim until the threads just started to disappear into the nipples. This gave me a fairly tight wheel with terrible dish, which is to be expected since it’s a rear wheel and I tightened everything evenly. I then started tightening only the drive-side spokes until the dish got close. I had actually over done things a bit, and I ended up backing out some of the non-drive side spokes by 1 to 1.5 turns. In the end, some of the threads are visible on the non-drive side spokes. I’m not sure that an extra 0.5mm of spoke would have made much of a difference here.

Final Truing

When building a wheel, one must monitor vertical true, horizontal true, spoke tension, and dish. With my truing stand, I can take care of everything except for spoke tension. I did my best to pluck the spokes and try to get them all, at least on the drive side, to make similar-sounding musical notes. I don’t know anything about music, so my ability to tension-by-ear may well be awful. I haven’t decided yet whether to get a second opinion on whether she’s road-ready or to just give’r and pick up the pieces if I’m wrong.

Riding the Thing

I haven’t put the wheel on my bike yet. The hub is older, and is pre-9-speed, which is the type of cassette currently on my ‘cross bike. My plan is to select and unlucky cog from the cassette and just get rid of it. I’ll readjust the deraillier to cope and just have an unused “gear” at the low end of my index shifter. Nothing I can’t handle, hopefully.