Praxis BB30A for road - could I buy the 73mm MTB option.

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diegogarcia
Posts: 571
Joined: Sat Apr 24, 2010 7:31 pm

by diegogarcia

After having installed praxis 68mm adaptor to my evo and being hugely impressed, I bought another one as building a Synapse. But, I realise this is 73mm, so I googled praxis options who advise that they do not adapt or support the 73mm BB30A option.

However, looking at the webpage I realise that 73mm is MTB standard and they do this, in hollow tech II for Shimano cranks. Has anyone used this as a work around or option for BB30A as makes sense to me ?!?!? Would it work, or am I missing the point as assymetric bb area ?

https://praxiscycles.com/wp-content/upl ... ConvBB.pdf

Thanks in advance.

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breezerboy
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Posts: 279
Joined: Fri Jun 22, 2007 8:14 pm
Location: Bristol, UK

by breezerboy

MTB 73 mm is symmetrical, BB30a is asymmetrical, so while the bb will fit, the cranks will then be offset, upsetting the chainline, your pedalling, or may not even clear the frame.

by Weenie


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ourmanflint
Posts: 39
Joined: Mon Sep 08, 2014 4:12 pm

by ourmanflint

I think it's more likely your NDS will be out rather than affecting chainline on drive side. My Wheels MFG adapters are almost flat on NDS and protrude quite a lot on drive side.

Tenlegs
Posts: 289
Joined: Wed Jul 16, 2008 10:37 am

by Tenlegs

They do make it quite clear in that .pdf link you posted-

"CANNONDALE
SuperSix EVO -It is our understanding that this frame comes in 2
versions. A version for mechanical cable routing, and one specifically
for Di2 internal wiring. The Conversion BB mounts great in both.
*However* if you have the Mechanical version and you’re trying to route
Di2 inside, the inside of that frame is different and is closed off to the
chainstay. Please call Cannondale.

Synapse ’14 w/BB30A - This is a fully custom 73mm ROAD
Asymmetrical BB shell. This FRAME is NOT compatible with the
Conversion BB. This frame can only run a Cannondale crank."

Chainline will OK but L/h crank won't fit -5mm too short on the Shimano spindle

grover
Posts: 1302
Joined: Mon Jul 26, 2004 1:06 pm

by grover

As has been said.

With the 73mm MTB Praxis bb in Cannondale BB30A road shell the drive side crank will be in the correct position and chainline will be correct. However not enough of the spindle will protrude from the non drive side for the non drive arm to mount securely (and if you did attach it, it would be 5mm wider than intended).

Look at Kogel, C-bear or Wheels Manufacturing instead in order to use a Shimano crank in BB30A road shell.

jeffy
Posts: 1325
Joined: Sun Oct 05, 2014 11:51 pm

by jeffy

This FRAME is NOT compatible with the
Conversion BB. This frame can only run a Cannondale crank.


it is a shame that praxis state that, when what they mean is with their product.

c-bear clearly works.

CBRE
Posts: 219
Joined: Mon Dec 08, 2003 1:37 am
Location: Pittsburgh, PA
Contact:

by CBRE

Infinite BB makes a 73 for the new EVO I just got one, waiting to install with Etap so I don't have to deal with the stupid rear derailleur cable running through the BB
Curt Brown

2016 Cannondale EVO Etap 13.8#'s
2012 Cannondale Supersix EVO etap 13.7#'s
2017 Cannondale SUPER X Force 16.0#'s
2016 Cannondale FatCad2 28.1#'s
2011 Cannondale Carbon Flash 1 17.9#'s

diegogarcia
Posts: 571
Joined: Sat Apr 24, 2010 7:31 pm

by diegogarcia

Sorted, great comms with Bart at c-bear. BB adaptor was shipped Friday morning from Belgium.

https://www.c-bear.com/en/products/bott ... face-rotor

by Weenie


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