Bicycle Mechanics - Is there a suitable replacement for this bottom bracket?

Hi,

The bike is a mid 1980s Raleigh road bike, the bottom bracket is on its way out and needs replacing. Its stamped "Japan Tange 1.37 x 24T K1". The spindle is square but I cant see any other markings which might indicate how long it is. Does anyone on here have any idea what is available these days which will fit, if anything? I dont mind if the spindle is a different shape as I'd like to fit lighter cranks anyway.

Thanks for any info.

Chris

it's English thread, probably 68x115.

As always, check with Sheldon:
http://sheldonbrown.com/bbsize.html#shimano

Could be any length - no way to tell without measuring. You'll need to measure and buy a cartridge BB with the same size spindle (within a mm or two).

Hello, I certainly agree with you. Thank you very much for sharing your information. It was really very helpful for me.

Many thanks for the info so far, would I be best getting the cartridge type BB with "matching" crank set? Or I should say, does the crank dictate the spindle length? I just took a rough measurement of the BB in situ (as I havnt removed it yet), and its 68mm.

I was assuming you were reusing the old crankset; I misunderstood. You need to buy a matching crankset and BB, as you deduced. It sounds like your were measuring the BB shell - 6t8 is the right number for that. The spindle is dictated by your crankset.

If youve got the cranks off the bike.
you can measure the width of the axle by putting the bike in a door way and closing th door on the axle.
then measuring the gap with a ruler

If its a cheap old bike. It may be 127mm. Better if its shorter.
does depend on your cranks.
For instance Suntour cranks need a slightly longer axle than Shimano ones

If youve got the cranks off the bike.
you can measure the width of the axle by putting the bike in a door way and closing th door on the axle.
then measuring the gap with a ruler.



With that vintage Raleight-this might be one of the crank-nut securred BBs instead of the crank bolt securred types- the nut versions had extra thread beyond the taper that would give an unusual measurement.




If its a cheap old bike. It may be 127mm. Better if its shorter.
does depend on your cranks.
For instance Suntour cranks need a slightly longer axle than Shimano ones

It's a road bike. 127mm is unusually large. I doubt its 127 even if its a triple, probably more like 120-113 if a triple. If a double, probably about 108.

1) Are you replacing the cranks or not
2) Spindle length speculation is irrlevant, either you are only replacing the bb and not the cranks in which case just measure the length or you ARE replacing the cranks and you need to tell us WHICH ONE

One of my bikes uses a spindle as long as 127mm (or so). It's a crappy late-80's touring bike. The quickest thing to do would be to take the spindle to you LBS. They can tell you how long it is and if you are likely to find a replacement. But, as Operator pointed out, if you want to change your cranks this is all moot.

1) Are you replacing the cranks or not
2) Spindle length speculation is irrlevant, either you are only replacing the bb and not the cranks in which case just measure the length or you ARE replacing the cranks and you need to tell us WHICH ONE

Hi,

Yes indeed, after some thought I've decided to replace the cranks as I'll try and upgrade from the old 6 speed to a 9 speed cassette, which I believe will need a new thinner chain, so would require 2 new chainrings to match. I'll go for new crankset rather than try and replace just the chain rings. Its all getting pretty complicated to me (being new to bike upgrades) trying to work out which parts are compatible!

Meb is quite correct... "With that vintage Raleight-this might be one of the crank-nut securred BBs instead of the crank bolt securred types- the nut versions had extra thread beyond the taper that would give an unusual measurement." ..... It does use crank nuts, so the taper does make the overall length something near 130mm. Eitherway, I realise that I dont need to worry about this now.

Thanks for all the info, its slowly becoming clear now!