SRAM GPX to Shimano Ultegra Chain set

[hondated]

I am trying to build up a Trek Madone 3.5 OCLV frame set and I would like to change the existing SRAM GPX CS to a Shimano Ultegra CS but the problem I have is that the existing bottom bracket looks to me as though its a push fit rather than their version of a Shimano Hollowtech.
So what I would like to ask for advice on is whether I have to drift the SRAM out and if I do to fit the Shimano Ultegra do I have to fit adaptors.
Given my lack of knowledge I am tempted to just leave it and to just fit the Shimano other components.
Please note I am not being lazy here by asking you for this information as I have Goggled it and as yet found nothing.

 

[Hacienda71]

It depends on the frame. If it is a push fit frame then that is the type of crank you need unless you buy an adaptor.

 

[lpretro1]

if press fit then just get adapters - dead easy

 

[hondated]

Thanks Hacienda 71 & Ipretro1
Since posting I have had another look and it is definitely a push fit BB. I also realised that the GPX crank set on the drive side is 24mm but on the NDS is 22mm so the adaptors you mention may not work.
I think I may have found the solution in this though :
http://www.jejamescycles.co.uk/trek...ws5tqVM-IUR39Y4x8o6_BvAh5zkrJRoCQ0bw_wcB#info