Crankset and BB advice please!

John Sanderson · Post by **John Sanderson** » 03 Mar 2012 13:59

Ok - here's the situation: I have a TIME frame fitted with a Bontrager Crankset with what appears to be an SRAM(?) 'GXP' bottom bracket. English threaded - 68mm wide. I'm a bit vague on the details - as the BB just has GXP moulded into the plastic sleeve but doesn't have any manufacturer details on it. Looking at the crankset axle it has clearly been sitting on a bearing on the drive side (i.e. taking the load vertically), but on the non-drive side it hasn't - so I assume the non-drive side bearing is taking the load horizontally like a Shimano Hollowtech style setup. From the research online this sounds like the Giga-x-Pipe Truvitav standard to me....

Anyway - the BB bearings are shot and the crankarms are a state as the alloy covering is peeling off. To confound things it looks like Bontrager don't do cranks anymore, although I do wonder if they are just rebadged SRAM parts anyway?

Is there any reason why I need to stay with the 'GXP' setup - or could i easily just replace the whole lot - i.e. bearings and crankset - with a Shimano Hollowtech II set up?

dweben · Post by **dweben** » 21 Mar 2012 19:44

No reason to stick with it no. From a MTB point of view GPX and HTII were more or less the same when I went through them. If you're replacing the whole lot then there's no reason at all to not change the lot. I binned Truvativ Style/ISIS style cranks due to them using bearings which were too bloody small

It would probably even be the same HTII style tool to remove the BB..

Guess the only other thing to consider is if you want to change the chain/cassette too!

pprince3145 · Post by **pprince3145** » 23 Mar 2012 07:51

Gxp and HT2 same principle but incompatible due to axle width. No reason to keep it just go with a compatible BB for the chainset you choose