Replacing bottom bracket on '88 Marin Pallisades Trail

[vspike]

Hi-

New to this board and newly bitten by the cycling bug. I've been using an old Marin bike that looks exactly like this one viewtopic.php?t=166860 ... except mine has a different saddle, and the handlebars are red. My parents bought this new when I was a kid!

I've been trying to keep it going - replaced the chain, re-adjusted the gears, tightened brakes. My maintenance skills are rudimentary, but I'm learning.

The bottom bracket on this bike is totally shot. Friends at work are encouraging me to chuck it and get a new or newer second-hand bike, but having seen the love some people give their old bikes I'd rather try to repair it.

I tried to research how to replace the BB but it seems like a complex topic - partly because I can't get details on what the bike has, and partly because there are so many sizes and types.

Could anyone give me some pointers on what I need to buy? I'm ordering one of these http://www.planetx.co.uk/i/q/TOJW41PCTK ... -swap-shop so I have at least some of the right tools.

Thanks in advance for the help!

John

 

[Stiff_Orange]

Hi John,

You can replace it with something like these:
http://www.chainreactioncycles.com/shim ... -prod34652

http://www.chainreactioncycles.com/shim ... -prod71369

However you need 2 measurements. The first it the width of the Bottom bracket on the frame itself, don't include any bits of the bottom bracket itself. The second is the width between the 2 ends of the square taper ends. So if the Frame bottom bracket is 68mm and the width of the square tapers is 113mm then you need a 68x113mm.

On old bike the BB could be stuck, looks like there is the right tool in that set, however a tip is, if there is a hole all the way through the tool you can fasten it too the bottom bracket using a long bolt (and large washers) that threads into the square taper (or a bit of threaded bay and a nut) you can then whack the BB tool with mallet to shock release it.

 

[JackN]

Re:

Hi John. One of the bottom bracket threads is "opposite" i.e. clockwise to loosen it. Watch a couple of You Tube videos on how to change a square taper BB. Before you start soak the BB with WD40/GT85 or any penetrating oil, it may make the job easier.

 

[vspike]

Thanks for the excellent info. Toolkit arrived, cranks came off pretty easily. I've measured 68x118 so that's clear enough.

The existing BB tapers have a threaded bolt sticking out, and to remove the cranks I had to remove nuts. It looks from the photo like the replacement UN-55 requires bolts. Would these be the thing?

http://www.chainreactioncycles.com/clar ... prod120387

 

[Vinevo]

Re:

Welcome John, you've come to the right place loads of good advice and help here, those bolts will work fine.

Good to see another one still in existence, get some pics up sometime