Bicycle Tutor

Hi,
Does anyone know if Saracen 6061 Aluminium bike MTB frames(approx 4 or 5 years old) , only take a specific make/model of crankset and chainset please?
i believe there are only 2 or 3(max) types of bottom bracket standards so i was thinking that maybe the manufacturer,Saracen, adopted one standard only?
thanks regards,
NewbieAM-England

The chances are that Saracen used Shimano or Suntour chainsets.
(at least that's the spec' on various websites.)
You could, in theory, use any chainset as long as you stick to the same dimensions. ie approximate ring size and chainline.
If you look on the rear of the crank arms, there is usually the make, model and crank length stamped.
Again the BB will probably be Shimano cartridge type, but as long as you use the same size you could fit other manufacturers.
Be aware though that there are differences between BB,s such as taper and threads.
See: http://www.sheldonbrown.com/gloss_bo-z.html
(page down to bottom bracket)
And: http://www.parktool.com/repair/readhowto.asp?id=94

Hi CyclerUK,

Thanks for that info from my research i think your spot on with the shimano suntour info. I cannot refer to any existing crank parts as i am building the whole bike from just the frame up the only part on it is the bottom bracket which is sort of splined -(see attached photo) Could you possibly try and identify the type of BB it is from the photo please?

i did look before on sheldons bottom bracket but thanks for that reference anyway?

thanks regards,
NewbieAM-England

   

I believe that is a standard Shimano type square taper BB. The splined part just requires the proper tool to remove, it doesn't affect the crank. It uses a "square taper" spindle which does affect what kind of crank you get.
Note that it looks like maybe the BB was not the proper size for the frame. There is an awful lot of threads showing on the left side. But can't be sure without seeing in person.

As a back up to DaveM's comment.
There shouldn't be that amount of thread showing with a "cartridge" BB.
Looking at the photo' there is a "68" showing.
This will probably be the width of the "bottom bracket shell". (68mm)
You then need to determine the axle length to match the chainset you are using.
If you get the chainset from a bike shop then ask them what size BB is required.
If you look at "Spa cycles" website they advise the BB to match their chainsets.
Such as :- http://www.spacycles.co.uk/products.php?plid=m2b0s109p3
** recommends a 110mm BB **
Again, as Dave says, you will require a matching tool to remove and re-fit the cartridge BB. If you use a different manufacture BB then the matching tool may be different.