Technique for Removing Cotter Pins?

[JtB]

I need to maintain the bottom bracket on my 30 odd year old Carlton and I was wondering if anyone had any advise on removing the cotter pins. I remember when the bike was new that they were extremely difficult to remove then, but now they've been left un-touched for 30 years I would imagine they will be near impossible.

Also, I recently changed the brake blocks and they don't look anything like the old ones. Have I got them the right way up?

 

[Young Un]

Brake blocks look upside down to me?

 

[lazyfatgit]

Brake blocks are upside down.

If you plan on replacing the cotter pins, then remove the nut, support the crank on a block of wood and just whack them out with a hammer.

 

[Davidc]

30 years ago the technique was basically to hit them!

If they didn't budge easily then penetrating oil (plus gas) left to get at them overnight usually worked.

The last resort was to carefully drill them out. The problem with that is that one side is flattened so as you get to the bigger drill it's very easy to damage the flat on the bottom bracket spindle. The positive side is that the cotter pins used on that type of bike are soft (aluminium if I recall correctly).

Sometimes the beasts stuck part way out and needed to be hit remotely. Then the hardest steel bolt of a size which just fitted down the hole was neded. A cheap bolt would sometimes itself get stuck.

Cotter pins are certainly one thing I don't regret seeing pass into history.

I'd have offered you some unused cotter pins a few weeks ago, but I chucked them in the recycling skip.

 

[JtB]

Thank you all for your very prompt responses.

 

[andrew_s]

The other method for cotter pins is to press them out with a G-clamp. Put an oversize nut round the back end of the pin to give it somewhere to go.

 

[Davidc]

The other method for cotter pins is to press them out with a G-clamp. Put an oversize nut round the back end of the pin to give it somewhere to go.

Good thought - I'd forgotten that one. Guy at my local LBS did much the same with an old bench vice (off the bench!)

 

[theboytaylor]

As ever, Sheldon has the answer

 

[Davidc]

As ever, Sheldon has the answer

Don't think we missed anything except the heating with a blow torch one. Do let us know how you get on Shaun

 

[theboytaylor]

Don't think we missed anything except the heating with a blow torch one. Do let us know how you get on Shaun

Do you know what, I posted the link, sat down to have my dinner and the same thought struck me as well. Made a mental note to add a comment to the effect that it had all been covered already, but clearly you beat me to it!

 

[JtB]

Wow, it looks like I'm going to have an action packed weekend and I'll either get the job done or the bike will end up on a skip.

 

[Ian H]

Don't remove the nut. Just loosen it a couple of turns then hit it hard. If necessary loosen it again and hit. this prevents the end of the cotter pin mushrooming.

 

[jimboalee]

You've just missed a cyclejumble at Rowlands Castle.

Next one there is scheduled 16th Feb 2010.

 

[Davidc]

Good luck! And keep your fingers out of the way or it'll be .

With that operation a good pair of protective gloves and eye protection goggles are highly recommended.

 

[ChrisKH]

Possibly a bit late, but get a piece of wood to put between the floor and the crank to make sure that any force applied to the cotter pin is going through the cotter pin and not the bike frame and then wack it with a hammer. It will come out if wood technique is used (or similar). It will take much longer if you don't and possibly damage the crank, etc.

Tips about hitting the nut are all good, but be sure to remove it once the pin is moving downwards otherwise the pin cannot come out.......