glowdon

So, I'm rebuilding a 70's-ish Peugeot Mixte, maybe 80's I'm not sure, and I guess at some point someone decided to put this aftermarket crank on, and screwed it up royally. I had a hell of a time getting the cranks off, and when they finally came off, the crank arm tread came off with the pedal bolts. This is after soaking for hours in TriFlow and hitting it with a torch. The pedals were very very rusted and seized. I was able to hit the pedal screws with a torch and tap the metal out of the threads, but the crank arms are pretty bad. Also, the crank set seems to be permanently attached to the chainwheel, so I can't just get new cranks it seems.

Is it feasible to drill out and retread the crank arms, then shim some thin metal in there to hold the current pedal bolts? Or is that silly? It might be cheaper to get a new crank set I thought, but those run in the hundreds of dollars from what I've seen, and I only paid $50 for this bike, and have already spent like $200 on various parts and tools (new cables, tires, tubes, derailleurs, chain, bearings, grease, chain whip, flat wrenches, freewheel tool, misc tools, etc... It has a Maillard Normandy freewheel and the tool to remove that cost the same as what I paid for the bike. However, I found out the freewheel goes for at least $60-$70 on ebay, and I'm tempted to sell the freewheel and tool for at least $100 or so, since it's in pretty good condition considering it's 30+ years old, and the tool is pretty rare. That being said, what's the best, cheapest crank set to put on this thing if I can't fix the one I already have? It currently has the square crank mounts with a loose bearing bottom bracket.

What are my options? I'm still waiting on the freewheeel tool to arrive, but would it be worth selling and purchasing a new one? Otherwise, the existing freewheel is in pretty good condition, and is probably better built than anything I could buy these days, since it's lasted 30+ years already... and is still in good condition, where-as most people and shops these days treat freewheels as disposable, which is insane IMO. I'll probably be throwing on some alloy wheels at some point later also since we live in Seattle and it rains here a lot, and I hear it's hard to stop on steel rims.

I have tons of tools, and am pretty mechanically inclined... I'm just new to bikes, so any advice is greatly appreciated. Can anyone source the original parts for this bike? I'm open to throwing on newer parts, I just picked up a few sunlite derailleurs to replace the existing ones, so I'm open to aftermarket crank sets too I suppose, and freewheel, though I'm not sure if it's reverse threaded yet since I haven't got the freewheel tool yet.

Here's some photos to give you an idea as to what I'm dealing with.

dabac

A good shop should be able to repair the pedal axle thread in the crank arms by installing some heli-coils. Can't be any mechanic as one of them is a left-hand thread. An improvised job with shims in an oversized thread would indeed be silly. And futile.
Or just get any square-taper road double. Might be cheaper.
Why are you so sure it's an after-market crank? Looks like it'd fit the era from here.
And I'm not so sure about "screwed up" either. Decades of ignorance can do nasty stuff to most things, even if correctly assembled way back when.
Freewheels aren't reverse thread. If they were, pedalling torque would spin them off.

cycle_maven

Yeah, get another crank- you can probably find a used period-correct square-taper unit at your local co-op. Get some other pedals while you're at it. You already know that the derailleurs need replacing (well, the front one certainly).

I like modern freewheels since they have the ramps and cutouts that make shifting much easier and more positive- so I usually ditch an old freewheel unless it has some collector value.

glowdon

Ahh, I'd already read the info on Sheldon Brown's site. I guess I meant to say I'm not sure if it's French threaded, or ISO. My mistake. Since it's currently got the old Normandy freewheel, I'm assuming it's French threaded. Would I have to switch out the wheel hub to use an ISO freewheel then, or are the old French threaded style still made?

glowdon

Was able to find a used freewheel from a guy on Craigslist, nearly matches the one I had. Woo!

jyl

A bike shop can install helicoils in the crank arms, these are threaded inserts than are used to repair stripped pedal threads in crank arms. I think it costs around $30-40.

Note that helicoils only come in ISO (standard) pedal thread. There is a slight chance your pedals are French thread. If they are marked "G" and "D" they are French thread, if they are marked "R" and "L" they are ISO (standard) thread, if they are unmarked they are probably ISO thread given the '80s vintage of the bike. (Not for sure, though; I just finished tapping a crank from a 1986 Peugeot from the original French thread to ISO). In that case you'll need new (used) pedals. Which will cost $5 maybe.

You're in Seattle? Have you looked in the used parts bins of Recycled Cycles in the U District? They will have every part you could possibly need to rebuild that bike, used and for cheap. Derailleurs, freewheels, cranksets, pedals, etc. And their mechanics should know old bikes too.