The incident at Pugsleyville

A few days ago (Monday, May 22 to be exact) I decided to ride the Pugsley to work. It seemed like a good idea at the time. I’d not been riding it much lately and I could tell it was growing lonely parked in the basement bike area where there’s no dirt (or not much anyway) and no curbs, children, or small animals to roll over without noticing. And, I figured it would level the field a bit for my wife, who hasn’t ridden much yet this year; she is a mostly-transportational cyclist and doesn’t ride in the winter like the rest of us idiots.

At the end of the previous week, I’d dreamed up (quite literally) and installed the crankbolt fork-end spacers that finally meant that I could ride it with the rear fender installed. I rode it several times over the weekend–all short hops for errands to the library, the hardware store, the LBS, and the liquor store. What more does one need than books, tools, bike bits, and beer? Steak, perhaps–but I digress.

The what

We woke a little too early (one can only take so much early morning birdsong) and took off after lazing around the house and taking the dog for a short walk. It really did seem like the week was getting off to a decent start.

That ended after about 3.5 miles.

As I was pulling up to a stop, the back wheel somehow went loose from its moorings, rotated out of the Pugsley’s horizontal fork ends and moved sideways until the fat Endomorph tire was lodged against the drive-side chain stay and the disc rotor was rammed back against the rear face of its own caliper. The disc rotor stuck fast against the caliper, took all of my weight, and taco’d itself. The shifting wheel also caught the home-made PVC sheet fender, buckled it into a multi-layered broken mess under the brake bridge, and generally rendered it completely fubar.

The bent rotor in situ

As as I was coming to a stop anyway, my left foot was unclipped. Unfortunately, the way the wheel shifted caused me to fall to the right. I wasn’t able to get my right foot unclipped in time, and went down very slowly. As falls go, it was low-impact and mildly clown-like. I lost only a little bit of skin on my right knee–and a certain amount of dignity. It was, after all, the morning rush period in a heavily traveled bike/ped corridor at a street crossing where there are lots of bikes, pedestrians, and cars. I’m sure that thirty or more of my fellow citizens were privileged to start their workweek by thinking “I’m glad I’m not that moron.” The Wife got to watch from close up, and was concerned for my well-being. Everyone else went about their business.

After I picked myself up from the pavement, I managed to get the rear wheel back in the fork ends, but this only make it possible to carry the bike in one piece instead of two. The taco’d disc rotor rendered the wheel immobile for at least 90 degrees of rotation. There was nothing to do but carry it across the street, lock it up, and run to catch a bus–which I missed. I ended up walking another mile and half (and confirming what I first learned in the Almanzo 100: SIDI Dominators are not as bad for walking as their stiffness would lead you to believe) before I caught another bus that took me to work. That evening, Friend Bob gave me and the injured Pugsley a lift in the dad-van, for which he was rewarded with two bottles of Baltic Porter, sparkling conversation, and a loan of the Azor (all his bikes are in Minneapolis).

Last night, I removed the remaining fender hardware and the damaged disc rotor, which looks like this:

The bent rotor solamente

As luck would have it, I have a spare 160mm 6-bolt disc rotor–the one formerly on the Albatross’ rear wheel (which is now wearing a VeloSolo cog). The hub itself appears to none the worse for wear, and the wheel is still straight and true–but then I don’t know what would harm the Large Marge rims when fully shod (a sledgehammer, perhaps). There are a few nicks on the non-driveside edge of the rim–no doubt caused by banging into the frame or the disc caliper. The rear disc caliper appears to be functional and the mount appears to be straight. There are a few scratches on the caliper face where the disc rotor met its end, though these appear to be entirely cosmetic, however ugly.

The Pugsley is now back together, though without fenders, and awaiting another chance to prove that I should just sell it off so that I can buy something without disc brakes.

The why

Now, the real question is why this happened–and why it happened when it did (since I did ride about 10 miles or so since I’d last touched it). I figure there are two main options:

The fender, which was somewhat flexible and bouncy, caught on the rear tire and was driven into the brake bridge. This in turn jammed the rear wheel in place while my forward momentum pulled the wheel out of the fork ends, which in turn destroyed the disc rotor and so on. This is possible, though less likely.

The quick-release on the rear hub either failed or was not cranked down tightly enough. As I engaged the rear brake, the torque on the disc caliper as it was moving forward and being stopped caused the wheel itself to rotate backward, which overcame the clamping force of the quick-release and spat the tire out of the fork ends. Chaos ensued. This explanation is more likely, though it still raises some questions.

I lean toward option 2, but wonder why (regardless of whether it was my own fault for not tightening the quick release adequately) the quick released failed when it did. I’d ridden at least ten miles over some very rough pavement and bumpy non-pavement during the weekend prior. During the commute in question, we have ridden on nothing but smooth bike path. I was running about 20 psi in both tires, which makes for very plush pavement riding. Perhaps I had just before ridden over a bump in just the right way, or perhaps I’d just been very lucky in the previous 10-12 miles. Or perhaps I’d not clamped the rear brake down hard enough in all that time to overcome the clamping force of the quick release.

If you have any better ideas, be sure to let me know.

The what next

At this remove, I can only surmise–and try to take precautions that it does not happen again. I’ve replaced the stock with another Shimano quick-release from the parts bin. I removed the fork end spacers; the fenders are gone and they are no longer needed. I roughed up the paint on the fork ends a bit to give the quick release a little more purchase. And, I cranked the quick release down very tightly–so much so that it will be hard to open when the need next arises.

Updates

May 27 (am): When I took the bike down from the stand to ride it to work, I noticed another rather serious problem.  The rear wheel now has a serious amount of side-wise play–no doubt as a result of the incident itself. Perhaps the Pugsley doesn’t like commuting. In any event, it’s time for a complete overhaul.

May 28 (am): After pulling the rear hub apart, things don’t look bad–just poorly adjusted. Thankfully, I am not the idiot who assembled this bike–though I am now the idiot who keeps fixing it. I’ll leave the complete overhaul until some later date, pending some test riding.

May 30 (am): After adjusting the rear hub (and the brakes once again), I’ve ridden the Pugsley about town on several occasions and everything seems to be working as intended. Still not happy with the tune-ability and performance of the disc brakes–and I absolutely hate the Shimano mountain brifters that came with the bike. A complete overhaul and partial rebuild with different shifters, brake levers, and perhaps rim brakes is in the offing. But I’ll ride it awhile first.

May 31 (am): The Pugsley has now allowed itself to be ridden to work. Note to self: must replace the oddly slippery short pins in the Crank Brothers 50/50 pedals with something that actually grips my shoes.

June 1 (am): The Pugsley (which apparently needs a name of its own) survived another commute. I’m going to tempt fate and call this incident report closed.

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