campy bb's and what I can use with them

[10timesbetter]

just the background for my story, I got a road bike with a campy bb and cranks, but shortly after I got it the right pedal came loose and I noticed the threads have been stripped out, so I'm working on getting it back together, but the bb is so short it's hard to find cranks that will even let me use a double without scraping against the chainstay, let alone a triple like it had when I got it. I know the taper is different and you're supposed to use campy cranks with a campy bb, but the cranks I just got have the same problem, that they don't let me use an inside chainring. I'm going to try and find a smaller one, but the 42 on it now is too big. I have a set of shimano 600 cranks that are spaced good enough that I can use two chainrings on them, but I don't want the spindle to mess up the crank arms. the other problem with it is my pedals don't thread in smoothly all the way by hand, and I don't want to force them. so my questions are:

how different is the taper? I know I can make other crankarms fit on it, but will the different sizes eventually warp the crank arms?

do I need to use campagnolo pedals in the campagnolo cranks because of some special threading i'm not familiar with?

why did my bike come with a triple, and now I'm having a hard time even fitting on a double?

 

[John M]

just the background for my story, I got a road bike with a campy bb and cranks, but shortly after I got it the right pedal came loose and I noticed the threads have been stripped out, so I'm working on getting it back together, but the bb is so short it's hard to find cranks that will even let me use a double without scraping against the chainstay, let alone a triple like it had when I got it. I know the taper is different and you're supposed to use campy cranks with a campy bb, but the cranks I just got have the same problem, that they don't let me use an inside chainring. I'm going to try and find a smaller one, but the 42 on it now is too big. I have a set of shimano 600 cranks that are spaced good enough that I can use two chainrings on them, but I don't want the spindle to mess up the crank arms. the other problem with it is my pedals don't thread in smoothly all the way by hand, and I don't want to force them. so my questions are:

how different is the taper? I know I can make other crankarms fit on it, but will the different sizes eventually warp the crank arms?

do I need to use campagnolo pedals in the campagnolo cranks because of some special threading i'm not familiar with?

why did my bike come with a triple, and now I'm having a hard time even fitting on a double?

Suggestions: Do not put shimano cranks on campy BB or vice versa. The taper is the same on both (2 degrees), but the beginning spindle width is different and the shimano crank will slide on too far and bottom out on the campy BB.

The record and chorus cranks use shorter BBs than the other campy lines and an asymmetric BB for the triple--did you remove the BB and reinstall the spindle backwards such that the short side is now on the crankside.

One advantage of campy is that you can easily order individual parts. Get a right sided campy crankarm to match your old BB or get a shimano BB that matches your 600 crank-it will work with the campy derailleurs. Or get a campy BB that matches your new campy crank.

All current pedals use the same thread. The threads probably got damaged when the loose pedal twisted around in the crank arm.

Good luck.

 

[10timesbetter]

I'm not trying to be difficult, but if there's only one thread size, why would they take the time to print the thread size on the crank arms right where the pedals go in? I've never seen any other cranks have that.

The one that was on there was a mirage. I tried to get the bb out a while ago, but it's in there tight, and it's a carbon frame, so I was worried that I'd crank the frame before it came out. I bent the bb tool trying to get it out, and it still didn't budge, and it was a good park wrench with a couple feet of cheater pipe. the shimano 600 cranks work fine on it, they didn't bottom out or anything, I was just worried something would happen. Hopefully I can find a campy chainring somewhere that's small enough that it won't rub the chain stay, and if I can everything should work out ok.

 

[boudreaux]

I'm not trying to be difficult, but if there's only one thread size, why would they take the time to print the thread size on the crank arms right where the pedals go in? I've never seen any other cranks have that.

The one that was on there was a mirage. I tried to get the bb out a while ago, but it's in there tight, and it's a carbon frame, so I was worried that I'd crank the frame before it came out. I bent the bb tool trying to get it out, and it still didn't budge, and it was a good park wrench with a couple feet of cheater pipe. the shimano 600 cranks work fine on it, they didn't bottom out or anything, I was just worried something would happen. Hopefully I can find a campy chainring somewhere that's small enough that it won't rub the chain stay, and if I can everything should work out ok.

Dude!! How dense can you get? There is a different pedal thread size,but it's typically found on wally mart types bikes.Some makers put the thread size on the cranks,and others don't. Are you sure you were turning the BB the right way to get it out? English thread if left hand on the drive side,and the left side neds to be loosned or removed first.Cranks have specific requirements for spindle taper and spindle length. Sure you can cram a shimano 600 on there, but dollars to donuts the chainline won't be right. I'd suggest you take the whole mess to LBS, have them remove the BB and get you a replacement cramkarm.

 

[John M]

I'm not trying to be difficult, but if there's only one thread size, why would they take the time to print the thread size on the crank arms right where the pedals go in? I've never seen any other cranks have that.

The one that was on there was a mirage. I tried to get the bb out a while ago, but it's in there tight, and it's a carbon frame, so I was worried that I'd crank the frame before it came out. I bent the bb tool trying to get it out, and it still didn't budge, and it was a good park wrench with a couple feet of cheater pipe. the shimano 600 cranks work fine on it, they didn't bottom out or anything, I was just worried something would happen. Hopefully I can find a campy chainring somewhere that's small enough that it won't rub the chain stay, and if I can everything should work out ok.

I sympathize with you on your caution with the carbon frame. One of my own bikes has a carbon frame and I flinch a bit whenever I have to put any force on the wrench in removing any part screwed into the frame for fear of stripping or cracking something.

You may already know this, but English threaded BBs have a left hand thread on the drive side and a right hand thread on the non-drive. Turn clockwise to remove the English drive side BB cup. Italian threaded BBs are right hand thread on both side. Could it be that you were turning the wrong way and in fact were tightening the BB. See this link on the Park tool website for pictures:
http://www.parktool.com/repair_help/FAQcartdg.shtml

By bottoming-out, I mean that the crankbolt is fully tightened but the crankarm is not on as far as it can go. The problem with the shimano crank on the campy BB is that even though it feels tight by hand, under the increased forces of riding, the crank may move a bit and over time the square tapered hole may become distorted and the crank arm will be damaged and will loosen.

I don't' know why that crank would have the pedal thread marked. The pedal thread should be a 9/16" X 20 which is the standard.

I believe that 39t is going to be the smallest chainring that will fit the 135mm bolt circle diameter of the campy crank. If that works, great. If it doesn't you'll have to try one of the other solutions.

Good luck and I hope you are back on the road soon.

 

[John M]

Dude!! How dense can you get? There is a different pedal thread size,but it's typically found on wally mart types bikes.Some makers put the thread size on the cranks,and others don't. Are you sure you were turning the BB the right way to get it out? English thread if left hand on the drive side,and the left side neds to be loosned or removed first.Cranks have specific requirements for spindle taper and spindle length. Sure you can cram a shimano 600 on there, but dollars to donuts the chainline won't be right. I'd suggest you take the whole mess to LBS, have them remove the BB and get you a replacement cramkarm.

Boudreaux, I know that the single piece cranks use a 1/2" thread. The issue here is that all of the pedal threads for modern three piece cranks are the same 9/16" X 20. I think it is fair to assume that none of the participants here are going to be putting cheap rattrap pedals on campy cranks.

I agree with you about chainline issues with using the wrong crank/BB combination.