Cross-threaded crank arm thread - my options?
10-03-17, 12:44 PM
#1
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Cross-threaded crank arm thread - my options?
I posted a similar thread in the hybrid section but wanted to broaden the discussion to see what options I have.
I have a driveside cross-threaded crank arm. At the second attempt, I managed to screw the driveside pedal in at the correct angle. What are the potential issues. Could this become a safety issue? The pedal is screwed in tight but the crank thread is cross-threaded as it went in at an angle at first but I didn't notice until I rode the bike a few yards and could feel the pedal was at an angle. So, I refitted it and it seems to have gone in at the correct angle.
I could just leave it and see what happens in the future, but that presents a potential safety issue I imagine.
I could get my bike shop to replace the crankset. I guess this would involve costs for the crankset, bottom bracket and labour costs.
What other options do I have? Or which option would you go for in this situation?
I have a driveside cross-threaded crank arm. At the second attempt, I managed to screw the driveside pedal in at the correct angle. What are the potential issues. Could this become a safety issue? The pedal is screwed in tight but the crank thread is cross-threaded as it went in at an angle at first but I didn't notice until I rode the bike a few yards and could feel the pedal was at an angle. So, I refitted it and it seems to have gone in at the correct angle.
I could just leave it and see what happens in the future, but that presents a potential safety issue I imagine.
I could get my bike shop to replace the crankset. I guess this would involve costs for the crankset, bottom bracket and labour costs.
What other options do I have? Or which option would you go for in this situation?
10-03-17, 12:54 PM
#2
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Often, threading the pedal in from the back side of the crank can restore damaged threads. Failing that, a helicoil repair or new crank arm are your best options.
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10-03-17, 01:11 PM
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If you were able to re-thread the pedal on correctly and it is in place now you can ride it as is and see if you have an issue. A few things could happen.
The pedal could completely fall off. This should be able to determine by yanking on the pedal a few times and see if it gives way.
The threads could be ruined in such a way as the pedal will work loose quickly. Again easy to determine by riding it a bit. The pedal will get loose and floppy before it completely falls off.
The pedal will stay seated and you are good to go. Only way to know is to ride it.
The pedal could completely fall off. This should be able to determine by yanking on the pedal a few times and see if it gives way.
The threads could be ruined in such a way as the pedal will work loose quickly. Again easy to determine by riding it a bit. The pedal will get loose and floppy before it completely falls off.
The pedal will stay seated and you are good to go. Only way to know is to ride it.
10-03-17, 01:16 PM
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You may be OK for an indefinite time as danmyersmn states, but if it does fail a Helicoil repair will be stronger than the original threads.
10-04-17, 10:38 AM
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If the pedal is tight now, odds are that it'll stay put, but you want to keep an eye on it to be sure. Other than the risk of loosening, which may be marginally more likely, all is good now.
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Just because I'm tired of arguing, doesn't mean you're right.
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10-04-17, 02:21 PM
#9
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@AnkleWork - yes I did - it was very obviously in at the wrong angle when I test rode the bike. My right foot was wobbling on the pedal slightly and it was easy to feel that there was an issue with the pedal rotation. I aborted the ride I could actually see a couple of exposed thread on one side and none on the other side as I rotated the crank which confirmed the wrong angle. After I took the pedal off I could see that the threads in the crank arm were not good. I cleaned up both the crank arm and pedal threads, re-greased and carefully fitted the pedal back on and this time it went in at the correct angle.
After a ride today it's still on tight so I'm just going to do as some previous posters have suggested: forget about it and ride the bike! I'll just remember to give the pedal a quick check once a week or so to see that it's still screwed in tightly.
After a ride today it's still on tight so I'm just going to do as some previous posters have suggested: forget about it and ride the bike! I'll just remember to give the pedal a quick check once a week or so to see that it's still screwed in tightly.
10-04-17, 05:11 PM
#11
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I would say that you are fine where you are. Just check both pedals every once in a while to ensure they are both tight and ride on. FWIW; The post about running the pedal in from the backside is credible and I have done that a couple of cases. But as your pedal is in and tight, leave it alone and ride
10-04-17, 05:45 PM
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...generally speaking, this is not the sort of thing that will fail catastrophically. If it does start to fail, it will loosen and give you some warning.
Just don't ignore the warning if it happens and you should be fine. the threadsert repair is usually the easiest and cheapest fix, but you need someone locally that does them. You might want to call around to see if anyone does for future reference, but riding it as it is now does not make that repair any more difficult or expensive.
...generally speaking, this is not the sort of thing that will fail catastrophically. If it does start to fail, it will loosen and give you some warning.
Just don't ignore the warning if it happens and you should be fine. the threadsert repair is usually the easiest and cheapest fix, but you need someone locally that does them. You might want to call around to see if anyone does for future reference, but riding it as it is now does not make that repair any more difficult or expensive.
10-04-17, 09:05 PM
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11-13-19, 06:36 PM
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I did this a few years ago and am still enjoying riding my bike without issue.
11-14-19, 08:13 AM
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11-14-19, 12:32 PM
#16
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Even though 2 years old, I'll add my 2 cents. If this is a common crank, like a Shimano of almost any type, it would easy enough to find a replacement of the same model. They are so common. It is easy to pop off one crank arm and replace it with another of the same type, much easier than drilling and tapping, and likely cheaper too than having someone do it. If this is some rare or super expensive crank then I'd consider repair. Based on the OPs description though it was from a hybrid and unlikely to be anything uncommon. As it stands, the OP didn't update the thread with his ultimate results and I'm assuming it just worked as is.
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