MooneyBloke

Last night I rear ended a van on my utility bike, a 510 Trek of Ishiwata 022. On close inspection, the down tube has a small crumple at the lower head lug. Interesting point is that the bike used to pull right no-hands, and now it seems better behaved. The question is can I ride this safely, or is it likely to fail and should be sent to the old bikes' home?

Andrew R Stewart 

Only the rider can ascertain if they feel safe when on any bike, crashed previously or not. Now if the question is about the frame cracking and breaking during a ride that is very doubtful. Steel has a wonderful quality of slow crack propagation. So any crack that starts will take some time and miles to grow to a size that affects structure. The stories of someone's steel bike "just failed/broke in two" are from those who don't pay attention to their bike and periodically look it over.

Some here might say that the frame could be straightened but I don't suggest this. That would place more stress and work hardening in the deformed area and one won't know what the OEM head angle really was (as opposed to what a spec sheet might suggest). How do you know when the frame is bent too far in the other direction? If the bike rides well, tracks straight, doesn't have any high speed wobbles and your feet clear the tire's back side I would just ride the bike. But I would check the bent spot routinely. Andy


I might also wonder about the fork's condition as they are often bent too in this kind of incident.

MooneyBloke

Actually, there is some clip overlap, but I have ridden bikes that had that under normal circumstance. It wouldn't surprise me if the fork had been displaced backwards. As far as tracking, I think it actually rides better. As I posted previously, it would pull hard to the right no hands, and it seems pretty neutral now. I've not checked for shimmy, and I'll certainly do that. I briefly had a bike that had speed wobble from 18 to 25mph, and the seller actually took it back without much trouble. I suppose I should also pull the fork and look at the steering tube. [groan]

I may not have that much experience with steel, but I did run a college jewelry/metalsmithing studio many moons ago, and I fully agree about avoiding re-bending the tube based on my knowledge of work hardening.

In any case, this is my beater/utility bike, so I'm not too worried about too many miles.

Awful thing is that early is that I had a perfectly fine 40 mile ride on one of my Peter Mooneys earlier. In this case, the city decided last year to put parking on a very narrow street where it hasn't been for over 58 years, and if you ride as far right as practicible, you may occasionally run into something. It was dark, and it you right so as to clear parked traffic, you're in the opposing lane. Even with my lights, they are set to not blind drivers and show me what my tires are running into. Just a quick trip to pick up laundry detergent turned into a bent bike and a lot of blood. You might guess I'm not the happiest camper.

MooneyBloke

So far so good. It does handle somewhat differently, and most notably when I stand. It's definitely far from unride-able, but it's definitely compromised. Sadly, those are somewhat thin on the ground, but I'm poking around for a replacement.