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Hi guys I have a 2006/7 marin rock springs with a truvativ power spline bottom bracket which unfortunately is well past its best now. I was planning on getting a new one as to change it would mean changing the chainset aswell.
I was going to purchase the tools to do the job at the same time so i cant remove the current BB to check its size.
Does anyone know what size I require so I can get one ordered and start enjoying the sunshine on my bike. TIA

I have looked at google links and can't find the info
it wil def be 68/73 the easiest way would be to measure the actual shell

Every bloody dimension except the bb width!

http://www.marinbikes.com/bicycles_2006 ... d_tara.pdf

If its external bearings, it will all be done by spacers anyway wouldn't it?

Cheers mate I had this link which is pretty much the same http://www.marin.co.uk/2007/bikedetail.php?ModNo=3733
Thing is on CRC they also list a 108mm, 113mm and 118mm which i would guess is the length, which could be difficult to measure without a crank puller. Im tempted to purchase this

http://www.chainreactioncycles.com/Mode ... elID=47593

or this

http://www.chainreactioncycles.com/Mode ... elID=28019

But Im not sure if id run into more fitting issues..


BTW off topic but did you used to be on E36coupe.com the user name looks familiar?

Surfbum Im pretty sure its not external bearings.

It's a 2007 its unlikely to have an external bb
although one or two specs of it mention a gigapipe and a truvativ but not which one

yes i used to be on e36 coupe had a black 318is, damn now i miss it again

Its definitely a truvativ power spline and not the gigapipe as it only has the blaze chainset.

I know the feeling mate I had ALs old avus blue 328 vert with the silver grey vader interior, got rear ended last year on the way to Danbury and that was the end of it.

ah man not a good way to go!

the bb shell will show you which one you need once you've measured it.
you could try calling marin but i bet they don't know

Iv emailed marin as no one is answering today but im not holding my breath, just curious but how will shell size determine the length apologies if its a daft question.

Well the length measurements would relate to the axle length which will relate to the bb width

you wouldn't need a longer axle if you didn't have a wider bb

So iv stuck a ruler on the bottom of the bike and im getting 68mm for the shell the bottom bracket sits in, how do i work out the length though without taking off the cranks please.

You can't really as the axel length differs by only a few millimeters. If you going to replace it why not take the whole thing out and the measurements should be on the BB shell. Only way to be sure!

Matt just noticed you are in ongar
i have the bb tool at my house in north weald
if you want pop down tonight and i'll pull the bb out for you.
will only take 10mins.
i'll pm you my number and post code