Cottered BB/crank problem

FWIW I really don't get how TeeTee's problem could have arisen. Curious (probably a simple explaination).

I think it's a case of poor workmanship on the crank: the hole for the pin on the drive side just isn't straight and that's what's throwing it out.

I've tried filing one of the modern pins down - and it does make a few degrees difference - but to get it there I had to file so much off that the pin pretty much went right the way through the crank.

I've tried a different crankset on this axle and the cranks were straight, and this crankset on a different axle and the cranks were misaligned. So, the problem definitely seems to be the crankset.

The pins definitely will only go in from one side, and they go in the same way on both. I was surprised by that too - I thought they'd go in from opposite directions, but no.

This is how it looks. Any more suggestions??

Looks like a nice bike, would use a cotter press. That ball joint splitter tool that olik pointed out looks promising. I always use automotive bearing tools to remove crown race and a couple of other jobs that tend to be cheaper than buying some park doodad. I was lucky and picked up one of the Park Tools cotter press tools from the 80s, it was overpriced but was in love with my cotter cranks. I've tried the hammer approach too and it does work but it was awkward holding the bike up like that and yes, Like Brickman says, you must support the crank and have no pressure on cups and bearings etc.

There are also differnt size and shapes of cotter. So when you get that one loose you can use it as a specimen. I think SJS may stock cotters but I could be wrong -- yeah they do. 77p each but maybe not he right size but could be worth a shot.

Is the left hand crank on the correct way round - remove pedal and rotate crank 180 degrees - put pedal back on but from what was the inside of the crank.

looks like the flat of the cotter isn't quite on the flat of the spindle. they need to be flat against each other. Could be the wrong cotter size... do you have the original pin? Take it with you to an old bike shop - a kid at cycle works said "a cotter what???" to me once.

you should be able to wiggle the cotter into position by jiggling the crank. tap lightly with hammer if you need to get it in there snugly. tighten, tap, tighten, smash it with hammer, then tighten. Don't over tighten, unless you want to repeat the process. Cotter pins are no fun.

Tumbleweed. I modified my BJS slightly by drilling a small depression (with a half inch drill) into the curved arm in order to locate end of the cotter positively.

One problem with using a hammer is that you can damage the entrance to the actual hole and if it gets out of round, or slightly preened over, you may have great difficulty getting any pin inserted. Missed hammer blows also frequently damage the chain-wheel itself. Seen plenty of those in my time!

I wouldn't put a hammer anywhere near a good Williams chainwheel...

On the plus side, steel chainrings are pretty easy to hammer flat again.

Wouldn't be good for the chrome though: )

semi-unrelated note......what chain is that??? Lovely.

Hi, Brand new to fixed gears. Been keen to do a little project for a while and finally bought a frame to start my project and have a few questions.

Frame i purchased is a 1978 raleigh and is 22ich by 23, and my first question is do people think i can get away with 700c wheels on this ? Also any help on what bottom bracket set up i should go for ? Any links would be great :) And also any tips on getting fixed bottom bracket cup out as im having a mare getting it to shift. lol. Just help and suggestions in general would be really appreciated :) Thanken you :)

Hi, Brand new to fixed gears. Been keen to do a little project for a while and finally bought a frame to start my project and have a few questions.

Frame i purchased is a 1978 raleigh and is 22ich by 23, and my first question is do people think i can get away with 700c wheels on this ? Also any help on what bottom bracket set up i should go for ? Any links would be great :) And also any tips on getting fixed bottom bracket cup out as im having a mare getting it to shift. lol. Just help and suggestions in general would be really appreciated :) Thanken you :)

UTFS for all the answers, but yes, 700c wheels will fit the frame but if your frame was designed for 27" wheels, your brake pads will have to drop by 4mm to reach the rims.

Shimano UN54 bottom bracket is a good cheap choice so long as your frame threads are ISO/British (that is 24tpi). If your bike came with cottered cranks (some Raleigh town bikes still had them in 78... and even in 88) then the threads are probably Raleigh (26tpi), in which case either keeping cottered cranks or finding a suitable cotterless axle is the best solution. You need to work out what axle length you need before buying a BB or axle.

If your bike already has a BB installed then there's not much point in buying a new one - modern sealed ones aren't necessarily better than the old ones (although they are less maintenance). You can remove the fixed cup by using a bloody massive spanner, or by putting the fixed cup in a vice and turning the frame. Soak it in oil first though, otherwise you could damage something.

OK, many thanks for all the advice.

I did have the crank on the right way round. The cotter pins were sitting flat against the axle. I had put them in the right way round (or the only way the cranks would let me). I'm pretty sure I have the right size pins.

So, in the end I just decided to live with it. The cranks are slightly misaligned but it doesn't make too much difference and, as I said, they were like that when I got it so it isn't just me who's had the problem. I'm almost 100% that the hole for the cotter is askew and that's what throws it out. I didn't bother with the press, just very carefully piled books to support the cranks and BB then whacked it with a hammer. Carefully, if that's possible.

semi-unrelated note......what chain is that??? Lovely.

It's a 1950s Coventry made by Renold. It is very nice. It has "The Coventry" and "Made in England" stamped on the links.

The full bike is here, if you're interested.