SRAM Red keep GXP or sell and get BB30

brettjmcc

So, I am in the process of building myself a TT bike and I have been slowly gathering bits together over the past few months.

Originally, I thought I was going to get a Carbonzone frame or something similar that used an English BB, so took the opportunity to pick up a new set of SRAM Red GXP cranks.

However, like a magpie, when someone offered me a Quintana Roo Cd01 frame at a very reasonable price, I really couldn't help myself. Needless to say the wife isn't amused...

So my question to all my fellow forum members is... stick with the GXP cranks and get SRAM's conversion kit; or sell them and buy a set of BB30 cranks (especially as the frame comes with a set of bearings.

Thanks much in advance for the advice

hopper1

brettjmcc wrote:

So, I am in the process of building myself a TT bike and I have been slowly gathering bits together over the past few months.

Originally, I thought I was going to get a Carbonzone frame or something similar that used an English BB, so took the opportunity to pick up a new set of SRAM Red GXP cranks.

However, like a magpie, when someone offered me a Quintana Roo Cd01 frame at a very reasonable price, I really couldn't help myself. Needless to say the wife isn't amused...

So my question to all my fellow forum members is... stick with the GXP cranks and get SRAM's conversion kit; or sell them and buy a set of BB30 cranks (especially as the frame comes with a set of bearings.

Thanks much in advance for the advice

Well, I love all things SRAM, so I vote you keep the GXP. Didn't realise thay did a conversion kit.
Their ceramic bearings are superb...

AidanR

Seems a bit silly to put an adaptor and BB in - that's quite a bit of unnecessary weight. Depends on how much money's at stake though!

brettjmcc

hopper1 wrote:

Well, I love all things SRAM, so I vote you keep the GXP. Didn't realise thay did a conversion kit.
Their ceramic bearings are superb...

Ah, me not being clear. I meant keep the GXP and conversion kit (see here: http://www.wiggle.co.uk/sram-truvativ-b ... apter-kit/) or get a set of SRAM Red BB30 cranks.

AidanR, I guess that is the million dollar question! I know the conversion kit and a BB will cost me another £60 ish on top of the cranks. I'll have to see what I can get for the GXP ones!

petemadoc

I went through the same dilemma and decided it was worth getting the BB30 cranks, if only to put my mind at rest knowing I had the right cranks for the frame. You'll need BB30 bearings as well.

I don't know if it makes any difference but there was a significant weight saving. The one thing I do notice is the ankle clearance, a small thing but worth mentioning.

Pokerface

If you are only going to use the chain set on that one bike, go for the BB30 specific chain set.

brettjmcc

Thanks everyone. I'll wait for the frame to arrive and then you'll be seeing a brand new sRAM Red GXP Chainset appearing on the for sale secti on within a day or two... off I go hunting for a BB30 chainset 8)

petemadoc

Just a note,

BB30 bearings for road frames are these ones

http://www.evanscycles.com/products/sra ... gn=froogle

not these ones

http://www.chainreactioncycles.com/Mode ... roducts-UK

I bought the wrong ones first time DOH

brettjmcc

Another question that segues in... crank length

I am not the tallest guy in the world being only 5'7" and an inside leag of 77cm.

Now when I put that into the computer on competitive cyclist it says for an Aero fit, my cranks should be 172.5mm; however, if I use the L(mm)=2.16xl(cm) I should be using cranks of 166mm!

My current bike has 172.5mm cranks and it feels fine, and I can regularly spin up past 110. So what is the benefit of going the other way, or even if I got a crank of 175mm would it really matter?