Bicycle Mechanics - Cranky cottered crank - prognosis?
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06-20-09, 11:54 AM
My dear, trusty transportation bike - a 1974 Raleigh Sports - seems to be wearing out in the bottom bracket department. A little sound each pedal revolution has started to develop into a more full-fledged grinding over the past 10-20 miles. The bike fits me wonderfully, I don't want to part with it, and I'm willing to spend on tools.
I've searched the forums and Sheldon and have read the horror stories, but I haven't gotten a good sense of the typical difficulty of a complete cottered crank overhaul. I know that getting the cotters out can be tough, and I've heard stories about the difficulty of getting the cups out, but what is usual?
I would also appreciate input on how to proceed once I get to inspect the guts. If the spindles are torn up (which seems likely), it sounds like it would be hard to find/kludge a replacement. I'm willing to save up for a Phil Wood/three-piece crankset to go with the Raleigh threading, but it would be nice to be able to continue using the pretty original chrome chainring with the herons on it.
Many thanks in advance! :)
06-20-09, 12:06 PM
first you'll need a cotter pin press to get the pins out, and replacement pins when you go to reinstall your cranks.
you might be able to get away with just replacing the balls and regreasing the assembly, it's worth a try.
a good quality press costs $50 @ http://bikesmithdesign.com/CotterPress/
raleighs i beleive take 9.5mm cotter pins, but don't quote me on that, i have been wrong in the past.
you could check if your LBS has a press and replacement cotters. do not go the hammer and pipe route. please.
the cups shouldn't give you too much difficulty, unless the threads are corroded, but don't remove the fixed cup unless you're sure you need to replace the bb.
good luck, and keep us posted.
06-20-09, 01:03 PM
Removing the cotters is usually the hardest part, particularly if you need to re-use them. A cotter press is the best way, but using a C-clamp to push it and a wrench socket behind the pin so it has someplace to go when you apply pressure is often a suitable low-budget alternative. I don't have any bikes with cottered cranks installed, but here's a crude mock-up of the set up in case you're having trouble visualizing it:
i use a hammer and new cotter pins.
06-21-09, 12:15 AM
but don't remove the fixed cup unless you're sure you need to replace the bb.
I've heard that before many times - but why?
I removed it once just because it made it much easier to clean everything down there.
I haven't experienced any problems... yet.
06-22-09, 09:08 AM
Thanks very much! :)
I will most likely buy the cotter press and take a look. I am encouraged by the availability of Raleigh cottered BBs and parts in reasonable condition on eBay, but we'll see what's needed.
I'll bump with an update once I get it open.
06-22-09, 09:33 AM
A few thoughts
The C-clamp approach is worth a try. It has worked for me - but rarely.
Using the right tool for the job is a joy. However, for the $50 I bought a large bench vice with jaw protectors. It has pushed out numerous pins and is gennerally useful in the shop. Use it to set the new pins also.
No way to tell how bad it is until you ge it apart. Raleigh BB parts are tough, it may not be as bad as you imagine.
06-22-09, 09:38 AM
Another option. Just pour some oil down the seat tube and see if that quiets things up. If it works, just leave it alone. You can adjust the play in the BB with the cranks attached to the bike. I do this now on all my 3 spds.
Removing stuck cottered cranks is probably the most difficult bicycle repair job around. Not for the feint of wrench.
09-05-09, 12:48 AM
Well, this is quite a bump, but it's been a busy summer...
I finally got a cotter press and fixed cup tool from Mark Stonich at Bike Smith Designs along with a Park lockring spanner to round out my cottered crank toolkit. I have to say from my email interactions with him that he's an honest and conscientious person who makes beautiful tools.
His cotter press is a dream. It makes Sheldon's horrific-sounding hammer method seem laughable, because removing my cotters with that tool was as routine as anything - turn the wrench, give it a push if it resists, and out come the cotters. The fixed cup tool is great too. Unfortunately, I didn't use it properly the first time, ripping out a chunk of my fixed cup and trashing one of the two sides of my new tool. I was able to finish the job with the other side of the tool, but damaging my $25 handmade fixed cup tool within a day of getting it made me sad. Whew, those fixed cups really take some pounding! (I was hitting a mallet on the end of a 12" adjustable wrench to finally get the thing to move.)
The races were in fair condition, a little pitted but nothing I'd refuse to ride. The grease fouled by 35 years of rust, muck, and evaporation took lots of scrubbing and soaking in Simple Green to remove. I'm glad I removed the fixed cup, because there's no way I could have gotten the hardened grease out of it while still in the BB.
Once I got it back together with lots of fresh Phil grease and new cotters, the crank was turning quite a bit more smoothly. It's not totally satisfactory, though. The pitting seems to have taken its toll. I'm starting to realize with much sadness that the bike is nearing the end of its life. I will probably let it go the next time it needs major work. I've overhauled or replaced every moving part on the bike but the headset (and some non-moving parts as well), but the wear in the original hub/BB races, the accumulated damage to braze-ons, and the gradual loss of true in the old chrome wheels are keeping the bike from working at its optimum. It will be nice to get a more modern and lightweight commuter (probably a singlespeed or fixed gear). But it will be hard to get over the sentimental attachment to the bike that taught me that not all bicycles come from department stores and are disposable.
Well, thanks for the help, all. This turned out to be a fairly tough job but well within the reach of an amateur like me.
09-05-09, 08:54 AM
Mark Stonich's press is a wonderful tool!
09-12-09, 05:01 PM
Now that I've gotten some commuting in on the Raleigh, I have to say that it feels very good. :) I should remember that what feels rough to the hand on reassembly often feels smooth as butter to the feet in use.
Maybe for reference I should explain how to use the fixed cup tool. Put the square nut within the shell and the hex nut outside. Tighten the hex nut thoroughly with a wrench. Then whale away on the main square body of the cup. Do that, and you might not rip up the tool (and the cup) like I did.
09-13-09, 05:52 AM
I used Sheldon's method with the hammer also -- BUT! I found that it didn't take anything close to "blows from Zeus" to remove the old cotters. Just one good hammer on each one...they came right out.
The hard part is installing new ones that will actually STAY after 30 miles of riding. Those damn things loosen up all the time. Maybe the cotter pin press will keep them in place better though. I just gave up on cotter pins, since I like to stand to pedal on occasion and create a lot of torque on the pedals.....I have absolutely NO faith in cotter pins. They suck.
Use a hammer to fit them in as well, doing the nut up will not get them tight enough.
09-14-09, 05:57 AM
I use the clamping in the vice method.
but I loosen the nut but leave it on. This give more surface area for the vice jaw. Less likely to twist. Also doesnt damage the pin. So it could be reused if its not worn.
I regularly take complete bbs out. I have heard of not taking the fixed cup out as it might not stay tight when it goes back in. Only loosening of cups Ive had are cheap modern bikes that havent had any work on them at all.
I sometimes use the big bolt to hold the adjustable wrench onto the cup. But ussually clamp a frame tube in a vice and tap a drift at the cup flat. The shocking of hammering cracks the bond between the cup and the bb shell
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