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Technical & Reference Section => Tech and Restoration => Topic started by: tricknuts on February 21, 2006, 03:38 AM

Title: Bottom bracket thread sizes
Post by: tricknuts on February 21, 2006, 03:38 AM
Ok, so i bought  myself a new school Mongoose 1 piece crank, and while trying to bolt on my chainwheel, found that  my bottom bracket set doesn't screw on. Its close, but obviously the wrong thread.  I haven't got any new school stuff, and don't know about when they changed thread sizes etc. Who can tell me if I buy a new bottom bracket set,  will the bearings fit into old school cups that I've already fitted into my 1988 Haro sport, or have they went and messed around with bearings sizes as well?

Why can't these young uns just leave things as they were?. Things were certainly different before the changes...rant: :LolLolLolLol:
Title: Re: Bottom bracket thread sizes
Post by: revcore on February 21, 2006, 03:41 AM
The cups should be the same size. As far as I am aware there are only 2 different thread sizes for one piece cranks..... 24 and 28 tpi. The 28 tpi was what Mongoose used on their original one piece cranks. 24 tpi is the standard size found on most common one piece cranks.
Title: Re: Bottom bracket thread sizes
Post by: YGT on February 21, 2006, 08:44 AM
If I remeber corectly, mongose had there own strange thread system on there cranks so kids used to have to buy replacement mongoose parts for mongoose products.
muddy fox i think also did the same a few years later when mtb bikes came in.
Title: Re: Bottom bracket thread sizes
Post by: daz bmx it! on February 21, 2006, 09:20 AM
Hey Tricks,think its rudewheels on the bay? got what your lookin for  28tpi b/b £15 buy it now! :daumenhoch:
Title: Re: Bottom bracket thread sizes
Post by: tricknuts on February 23, 2006, 04:36 AM
Cheers Thanks guys for your help. I'm over in the States, so will have a look around here before trying the bay.  I even saw a Monngoose complete bike at the charity shop at the weekend. Ok it was crap, but could even be cheaper than postage on a BB!

Or  might treat myself to a new crank... 
Cheers Ross
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