1990s Gazelle Formula Race - fitting modern BB

[speedingsnake]

Hello all!

I am about to go about putting a new chainset on my 1990s. This will most likely be the modern Shimano 105 5700 model cranks. Now, I am having some difficulty discerning the BB type of the Gazelle. I think I have discovered that it will be of the English (BSA) variety, yet internet talk of a variety of shell lengths is leaving me confused.

I would be very grateful if anybody could clarify what type of BB is required?

ALSO - I might end going for an FSA crankset, which makes the type of BB even more confusing. Anyone got an answer for that?

Many thanks guys,

Matt

 

[NeilM]

Re:

Unless you go with an external bearing bottom bracket, then axle length is determined by the crankset, not the frame. Somewhere on line there will be an instruction manual for the crankset you are after and in the specification will be the preferred axle length.

Once you have found the axle length and bb type, square taper, ISIS etc, then you can search for the best priced item to do the job.

 

[speedingsnake]

Re:

Thank you for your reply.

Another query - I measured the external diameter of my seat tube and divided it by pi to find the diameter, which was very close to 31.8. However, I did do this in the dark with a sewing style measuring tape. Will this be the correct size in which to purchase a front mech for the Gazelle? I see a lot of front mechs stating 28.6/31.8 in one size, is this because it comes with a shim in order to fit both sizes?

Many thanks,

Matt