Stripped crank
11-05-09 | 11:08 PM
#1
Thread Starter
Senior Member
Joined: Sep 2005
Posts: 172
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From: Northern Arizona
Bikes: 1984 Raleigh Super Course, 1997 Cannondale F300
Stripped crank
The drive side Sugino GT crank arm on my '84 Fuji Sundance has stripped pedal threads. I recently got the bike and while cleaning and lubing it, noticed that the threads looked a little buggered up. The threads let go on my way home today and the pedal fell off. Is my only option to get another crank arm? I don't know if bike shops tap these things out and put in some type of threaded insert and, if they do, if it would be more expensive than just replacing the crank arm. I really like the look of the Sugino GT cranks and would like to retain them if possible.
Thanks for any advice.
Thanks for any advice.
11-06-09 | 12:03 AM
#2
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Joined: Apr 2008
Posts: 795
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From: Chicago, IL
Bikes: Schwinn Voyageur
New crank arm. I've heard chatter here and there about inserts, but I've never seen one, and I think it might have just been ghosts whispering at me, or people with silly ideas brainstorming.
11-06-09 | 12:06 AM
#3
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Joined: Apr 2008
Posts: 795
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From: Chicago, IL
Bikes: Schwinn Voyageur
I was going to say you could get weird and get a machine shop to mill and tap your cranks for shimano dyna drive pedals, but you wouldn't have enough meat around the pedal afterwards to ride safely, if there's even enough alloy to cut the threads at all.
11-06-09 | 01:02 AM
#4
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Joined: Jul 2005
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From: New Haven, CT area
Bikes: Trek 7.5 Hybrid, Trek 1.1 Road, Holdsworth touring,Raleigh International,Ritchey Commando,Italvega Speciallissimo,et.al.
Unfortunately it is best to replace the crank arm. Aluminum pedal threads are soft and even if a bike shop re-tapped them, there is a strong possibility of the pedal falling out.
11-06-09 | 04:20 AM
#5
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Joined: Apr 2007
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From: Thunder Bay, Ontario, Canada - burrrrr!
Bikes: 1958 Rabeneick 120D, 1968 Legnano Gran Premio, 196? Torpado Professional, 2000 Marinoni Piuma
Heli-coil...
Just about any machine shop can insert a heli-coil for you and the cost should not be all that great. The whole process would take me less than ten minutes to complete. The amount of material removed would be minimal but the crank would still be a touch weaker. However...
Don't waste your time or money doing this unless the crank in question is a valuable one. Something of more entry level nature should be set aside and replaced with an undamaged crank.
Hope this is a help.
Don't waste your time or money doing this unless the crank in question is a valuable one. Something of more entry level nature should be set aside and replaced with an undamaged crank.
Hope this is a help.
11-06-09 | 08:06 AM
#6
Thread Starter
Senior Member
Joined: Sep 2005
Posts: 172
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From: Northern Arizona
Bikes: 1984 Raleigh Super Course, 1997 Cannondale F300
Thanks for the advice. I kind of figured it wouldn't be worth the cost/trouble to have this repaired. It is a shame this happened because both crank arms and chainwheels are in really nice shape and I like the look of them. Hopefully I can find something similar to replace this with. You guys see many drive side Sugino GT crank arms (175mm) out there for sale or trade?
