Trek 4300 B/B Size ?

Retro4300

Hello all,

I have been away from MTB for around 8-10 years and am now in the process of building a bike from scratch (With your help !)

I have a Trek 4300 19" frame not sure which year but the frame details I know are :
It's black with silver on the top and down tube front quarter.
V brake bosses
Alpha superlight alu.
Seatpost size 31.6

I need help on getting the right size B/B and Chainset, I have measured the shell width which comes to 72mm measured across from the outside (Is that the right way to measure ?)

So if you can help on the above or link to a B/B and chainset for around £80 that would be great. Im looking to go for Shimano 9sp.

Retro4300

On reading about it seem the first size is going to be 73mm but how do you know the longer lenght needed ?

supersonic

Size of BB axle depends on the crank you choose.

The new external set ups come with the axle attatched, so no need to worry there! Also have spacers to fit 68 and 73mm frames.

Retro4300

http://www.chainreactioncycles.com/Mode ... elID=29944

If I buy the above chainset what axle lenght B/B would be used ?
Would the below B/B be correct ?
I need 73 x ?

http://www.chainreactioncycles.com/Mode ... delID=2962

Thanks for the help

supersonic

Probably a 113: check with CRC or RaceFace.

Retro4300

Tried CR to confirm axle lenght but they was not sure.

If I buy the below Deore and bb set will that be right for my 73mm shell ?
http://www.chainreactioncycles.com/Mode ... elID=22924

Also do I only need this tool for fitting or will anything else be need ?
http://www.chainreactioncycles.com/Mode ... elID=10179

Thanks again for your help !

nicklouse

the deore will fit both 68 and 73mm

and yes plus what ever you need to remobe your old one.

Also the bb shell will need facing by the LBS.

Retro4300

nicklouse wrote:

the deore will fit both 68 and 73mm

and yes plus what ever you need to remobe your old one.

Also the bb shell will need facing by the LBS.

I presume facing means rethreading of some sort to sort the bb ?

Does this always need doing if the bb shell has been used for more convetional bb in the past ?

supersonic

It means the outer faces of the BB shell, which is where the external cups butt against. They habve to be parallel and smooth.

It needs doing for the newer external bottom brackets.

Retro4300

http://www.chainreactioncycles.com/Mode ... delID=7630

Struggling to get a 100% answer on which axle lenght I need so any help would of great help.
If I buy the above CS / BB can I just fit it myself to my 2004 trek frame which is threaded for bb or will it need facing as recommended for the shimano hollowtech ones ?
If it does need facing can you point me in the direction of a bb (Inc which axle lgt) and chainset I can fit myself for around £70 ?
Thanks[/url]

Retro4300

Just been reading more about the fsa gamma drive and it may be to heavy for what I want. (That model anyway but if they have a lighter version ?)
But if you can still help with my axle lenght / BB / Chainset needed ?

supersonic

With external bottom bracket chainsets such as that Gamma Exo and SHimano HT2, the BB axle is integrated into the crank arm or chainset - so the axle is there, and is the correct size. You make minor adjustments to chainline via BB spacers that are included.

All external BB type set ups require the frame to be faced.

You could try this crankset:

http://www.sjscycles.co.uk/product.asp? ... rc=froogle

and this bottom bracket:

http://cgi.ebay.co.uk/Shimano-ES50-Bott ... dZViewItem

The chainset requires a 113 axle for a 47.5mm chainline (pretty standard).

Also look here for some more combos:

http://www.paul-lange.de/produkte/shima ... ettenlinie

Retro4300

Should be able to order a set now with that info and chart.
Thanks