Crank bolts keep becoming loose.
06-26-08, 01:05 AM
#1
Senior_Member2
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Crank bolts keep becoming loose.
My crank bolts become loose after only 20min. Whats going on?
Also the cranks creek when using oposing forces.
I think it might be a iso/jis, or what ever they are called, conflict.
Also the cranks creek when using oposing forces.
I think it might be a iso/jis, or what ever they are called, conflict.
06-26-08, 02:39 AM
#2
oldsprinter
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I think you're right. Although I've had it happen lately on lots of crank/bb combinations. My Campag Chorus cranks were working loose on a Campag Record bb - changed the bolts and all was OK again. Then bolts on a Suntour Superbe cranks with TA Titanium started coming loose - this time it was down to the crank and bb not being the same taper. Also had a problem with Tune cranks coming loose on Campag Record bb - nothing seemed to work until I got some titanium bolts with a big 10mm allen bolt head and bought a massive 10mm allen key with lots of leverage. Did em up really tight and they've been fine since.
I have a theory that if you can track down some old bolts with the 15mm head on them (old Campags etc) they hold better than newfangled 8mm allenkey bolts with self-extracting washers etc.
I have a theory that if you can track down some old bolts with the 15mm head on them (old Campags etc) they hold better than newfangled 8mm allenkey bolts with self-extracting washers etc.
06-26-08, 06:42 AM
#3
Spawn of Satan
What kind of cranks?
If you go to the manufacturers website, most of them have torque specs. Even if you don't have a torque wrench you can get a pretty good idea of were you need to be.
If you go to the manufacturers website, most of them have torque specs. Even if you don't have a torque wrench you can get a pretty good idea of were you need to be.
06-26-08, 07:13 AM
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It says paul spirit on them, or dual sprint. No idea what mani. And it has the gimpemme(sp) bird on it.
Outa luck.
Outa luck.
06-26-08, 07:24 AM
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These are square taper cranks? Have you tightened them with a torque wrench? Is it the right type BB for the cranks? assuming it is, and assuming they are square taper cranks,
Here's what I'd do.
1. pull them, and inspect the taper holes. The should not be rounded out.
2. check the BB, it should not be rounded
3. dry the BB spindles
4. Clean the crank taper holes, install the cranks
5.Torque to 25 pounds
If they come loose then, the cranks are worn out. After being removed/installed alot a square taper cranks bore wear enough to be non useful. Or from riding them loose, you have worn them out.
Here's what I'd do.
1. pull them, and inspect the taper holes. The should not be rounded out.
2. check the BB, it should not be rounded
3. dry the BB spindles
4. Clean the crank taper holes, install the cranks
5.Torque to 25 pounds
If they come loose then, the cranks are worn out. After being removed/installed alot a square taper cranks bore wear enough to be non useful. Or from riding them loose, you have worn them out.
