Bicycle Mechanics - Rounded corners on my Peugeots non sealed square taper BB

so i have a SS project slowly taking shape. I road the bike around a but with a lose crank arm (like less than half a mile) and now the square taper spindle is kind of rounded off. Since its not a sealed BB can i just buy a new Square taper spindle for it?

i recently purchased a new crank and dont want to put it on yet since im worried it will get all messed up by the destroyed (almost) spindle...


any ideas?

http://farm6.static.flickr.com/5137/5524180538_ddcfebe08a_z.jpg


i know velo orange has ne BB i could buy for the french bike, but $50 is not what i want to spend right now on this project (i still need wheels)

i did see sheldon browns shop used to carry them, but no more. ANyone?

also, if you think its good to go, no need to worry, that would be a fine answer too, what do you think?

thanks

jim

you can replace it , although the spindles are getting hard to find . just remove it and take it to you LBS and see if they can match it up or even replace it with a seal one , just make sure it match your treads of the BB .

How do you round off a steel spindle with alloy cranks? I have always thought that damage is done to the alloy crank since it is the softer material.

ha, you should sere the crank!!

Yeah, you can just replace the spindle. Make sure you get one of the same length. A mm or 2 off shouldn't matter, unless your cranks are already close to bumping into the frame.

You might have to buy a whole BB. Check ebay, there are lots of spindles for less than $10.

yeah really dont know where to start. i dont know how to remove the spindle to measure it, also dont have a crank puller to remove the drive side crank (non drive side fell off while riding, hence the rounded corners.)

the velo orange bb's are only $50, but if i keep going the new parts route, this will turn into a pricey project that i should have just bought a madison or somehting.

Well, if you dont have a lockring tool you can get it off with a hammer and screwdriver. Use care not to hammer the BB shell... The BB cup will come out with a wrench.

You need a crank puller to remove the other side. Or if you plan on throwing the whole mess in the trash you could unscrew the fixing bolt and just ride until the other side falls off too :rolleyes: Might be hard to ride with one pedal though.

I agree it's not likely the spindle was damaged by the crank but if you want to change the bottom bracket, you might as well go with a sealed cartridge unit. Shimano still makes a fair variety of square taper cartridges and they are quite reasonable in cost. Here is Loose Screws' web page for Shimano bb's in 107 up to 127.5 mm spindle lengths and they are only $22.

http://www.thethirdhand.com/index.cgi?nr=11&b=&c=Bottom%20Bracket&sc=Complete%20BBs&tc=&q=&s=&id=854944332127

Since you ..."don't know where to start..." and have none of the tools, I think this is a job for the LBS.

The chance that the hardened steel spindle was damaged by the aluminum crank arm is vanishingly small. I'd just take a wire brush and remove all the aluminum debris from the spindle before installing the new crank.

The chance that the hardened steel spindle was damaged by the aluminum crank arm is vanishingly small..
+1

I'd need some hard evidence before I'll believe that scenario.

If you are talking about the chamfering on the edges of the spindle they are supposed to be there. If the bearing surfaces are in good condition you can reuse the BB.
The length of the spindle might not work with your new crank.

right on thanks for the help. Ill clean it up and take a closer look, yeah the chamfers should be there, plus i dont think ive seen a new BB for the peugeot that is sealed, being french thread


thanks for all the input, ill post an update when i make a decision.

Jim

Yes, unless the cups and/or spindle are pitted, I'd just put new balls in there and grease it up. But- there are two common square-bottom-bracket tapers (ISO and JIS), and installing the wrong crank on the wrong taper spindle can be a prescription for early crank failure. Google them, and measure to be sure, and get a new spindle if the crank taper doesn't match the BB spindle. I forget which is bigger, but if they don't match, then the crank either bottoms out and the nut won't tighten it, or the crank will only go on a few mm. That may have been the original cause of the failure of your first crank- it could have been loose on the spindle even though the nut was tight.

If it is French threaded then finding a spindle won't be that easy. The Velo Orange sealed French bottom brackets are probably your best bet. You can check on eBay for spindles, but they sell for so much that the Velo Orange BB is usually a better deal.

Have you tried fitting a crank to the spindle? Maybe the damage won't make much of a difference.

If it is French threaded then finding a spindle won't be that easy. The Velo Orange sealed French bottom brackets are probably your best bet. You can check on eBay for spindles, but they sell for so much that the Velo Orange BB is usually a better deal.

Have you tried fitting a crank to the spindle? Maybe the damage won't make much of a difference.

The spindle doesn't care a rip about the threading. As long as the cups are serviceable there should be little difficulty in finding an appropriate spindle.

Actually spindles meant for 68mm English-threaded bottom brackets often don't have enough spacing between the cones. This leads to the left side cone being so far within the shell that the adjustable cup sinks entirely into the frame and the locknut cannot be threaded on to it. This is because many French (and Swiss) cups are thinner than English cups. You can sometimes get away with using an Italian spindle with French cups, as I am doing on one of my bikes.