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View Full Version : Shimano and MegaExo BB compatibility

thwart
12-14-2008, 12:21 PM
I don't deal with non-Campy stuff too often...

Can you run a Truvativ crank, meant for a MegaExo BB, in a frame with an already mounted (and very similar appearing) Shimano external model BB? I assume so, but have no experience with these.

Thanks in advance for any assistance.
Marcusaurelius
12-14-2008, 01:00 PM
Nope truvativ use a different design for their crank (mega exo is usually an fsa bottom bracket).

This is the main reason I stick to shimano cranks (very easy to find bottom brackets).
thwart
12-14-2008, 01:18 PM
This particular crank actually says MegaExo on it...
scottie
12-14-2008, 07:15 PM
I used to run an FSA Crank with a Shimano BB and there was not an issue, I also ran the Dura Ace Crank with the Mego Exo BB and it worked fine, they are exactly the same thing in a different box... And both will work fine with each other!

Cheers,

Scottie.
PaulE
12-14-2008, 07:27 PM
Lennard Zinn just covered a lot of this stuff in a column over at velonews.com.
Marcusaurelius
12-15-2008, 12:25 AM
Well I'm a bit puzzled because my truvativ crank would only work with a truvativ gxp bottom bracket. I've never seen a truvativ crank with Mega Exo written on it. Mega Exo is a brand name of FSA and I suspect it's been copryrighted so I can't see truvativ putting it on their cranks.

As someone indicated truvativ makes their cranks a little different from everyone else (FSA and Raceface etc.)
Michael Maddox
12-15-2008, 09:52 AM
That's my experience, too. Truvativ has the GXP bottom bracket (one came with my Carbon Rouleur a few years ago). Of course, this is a SRAM thing, so all the SRAM bits work with it, too.

My Dura Ace bits will not work with a GXP bottom bracket, it appears. There seems to be a slight difference in spindle diameter on the non-drive side.

According to Zinn, both use a 24mm spindle, but the SRAM components step down to 22mm on the non-drive side. He does offer some advice concerning modification here:

http://www.velonews.com/article/85783
Volant
12-15-2008, 10:48 AM
I used to run an FSA Crank with a Shimano BB and there was not an issue, I also ran the Dura Ace Crank with the Mego Exo BB and it worked fine, they are exactly the same thing in a different box... And both will work fine with each other!

Cheers,

Scottie.

Same here. Running a DA with a Mega Exo right now and it works fine.