Stripped Crank Arm
 

My friend didn't properly install his non drive side pedal and stripped the threads completely. He took it to 2 bike shops on his ride route the day it happened hoping they could get the whole crank arm off and unfortunately the 8mm crank bolt is frozen in and got stripped in the process. I told him to bring it to me to check it out. Is there any reason why I can't simply take the drive side crank off and remove the non driveside by removing the Bottom bracket? Obviously, I'll have to trash the bottom bracket but thats fine, i have a cheap replacement crank/bb combo for him. If for some reason the bottom bracket is frozen in there, is his only other option just getting a new frame and swapping components?

yeah as long as you can get the drive crank off then you can remove both the fixed and adjustable cups - assuming you still cant get the bolt off - you'll need a new non drive crank arm, spindle and adjustable cup

edit: hardest part will be getting at the fixed cup - they can be tough to get off

i don't know why the crank bolt wouldn't come off, the drive side bolt came off no problem whatsoever. i'm really hoping the BB cups were better greased than that crankbolt was!

heh right - i just tried to take off the drive side cottered crank from my raleigh - got the pin out no problem but the arm would not release from the spindle - well - i got the other arm off i was able to overhaul / regrease the BB anyway but as much as i pounded the spindle with a hammer and thick punch - it would not release from the crank - after i figured i could overhaul it anyhow and still put i new pin in i said meh - why bother - its tight without the pin it'll be tight with it - so the BB is back together overhauled, etc

your situation is different though because as much as u need that crank bolt off - more important is that you are able to sufficiently tighten it after the overhaul - probably u are gonna just go w a new BB and cranks but i dont know - if u have spare parts around you might be able to work around this as i mentioned above

Try a hardware shop. Perhaps they can get the bolt off

+1 if you can be patient u might find someone or the right type of tool to remove the bolt - which would save alot of headaches for ya

If the bolt head is stripped, simply drill the head off.

its a crank bolt, it's recessed into the crank, you can't just drill the head off. I don't know if there is a bottom bracket removal tool that is open ended like shimano octolink one is so removing the cups may not be an option, I may have to hacksaw the damn crank arm off!

Yes, I'm well aware of what a crank bolt looks like. And you can easily drill the head off one. Start off with about a 1/8" bit and work your way up to 5/16". Either at that time or maybe even one size before, the bolt will give out and the head will pop off. The remainder of the bolt will come out by hand. No need to hacksaw any perfectly good bike components.

Drilling sounds like the best plan to me. Easier to replace a bolt then the whole 9 yards.

u need the proper size headset wrench - u'll be able to get purchase with that - its open ended

One of the worst suggestions ever. Not only is it ignoring the obvious simple answer to this problem of drilling the head off the bolt, it's also suggesting using a tool entirely not designed for the type of torque required to loosen a bottom bracket cup. It's like suggesting a cone wrench to remove pedals. Fixed cups are hard enough to remove with good access and the right tools. Using a head wrench will leave you with a damaged headset wrench and possibly rounded edges on the fixed cup.

well its worked for me - and i dont think the OP wants to drill - he may damage the tool and the cup - but if he doesnt get that bolt off - he's getting a new cup and possibly a whole new BB / crankset as well - as for the tool - meh - u're out 15$ - myself - i havent damaged the tool when doing this - to label it 'one of the worst suggestions ever' - well - i think that might be a bit overboard no?

Perhaps the OP doesn't understand my suggestion to drill the head off. All it takes is a few drill bits ranging from 1/8" to 5/16". Start small and work your way up. By 5/16" you'll have drilled through all of the diameter of the bolt so the head will come right off, if not before that point. The only thing you need access to to do this is the hex recess in the bolt. The bottom of that recess will actually help you align the drill bit in the center of the axis of the bolt. Note that you don't need to drill any deeper than the head of the bolt. Square taper cranks leave the bolt head at least a few millimeters shy of the bottom bracket spindle so the chances of hitting it will the drill bit are slim to none. Chances of damaging a bottom bracket cup are nil, unless you completely misunderstand my suggestion.

Given all the problems you read about where people are desperately trying to remove a fixed cup without success, I find it hard to believe that a headset wrench will work in all but a few cases. Yes, my comment about your suggestion being the worst was a bit overboard and I apologize for that. The OP is welcome to try and maybe it will work. He'll still need to remove the damaged bolt from the crank though and the best way to do that is still drilling the head off. Much cheaper to sacrifice an already damaged bolt than a crank arm and bottom bracket.

no its cool - i think the suggestion u gave is also good and honestly i might be inclined to try that as well next time i'm in a similar situation - and u're right - the crank bolt is the major issue so if addressed directly it will save alot of headaches, components, and $

Since everything is stripped and shot, why not weld the pedal on, use the bike and worry about the major surgery down the road?