Uninstall of Praxis Works BB30/GXP bottom bracket

Discuss light weight issues concerning road bikes & parts.
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engelke
Posts: 3
Joined: Sun May 27, 2018 8:20 pm

by engelke

Hey guys,

I have a Praxis Works conversion BB (bb30 to gxp, https://praxiscycles.com/product/conv-bb-sram-gxp-road/) installed on my Specialized Tarmac SL6 which I want to uninstall. The drive side is already removed.

For the non drive side the manual says the headset removal tool will catch the „outside edge“ of the left cup. An older video (https://m.youtube.com/watch?v=Eory8iw2BqU) says there is a machined lip inside the cup. In my installed bb I cannot see any „stop“ inside the cup. Question: should the headset tool really be placed against the very end of the cup where the threading ends?

Thanks for your help.

Dominik

by Weenie


flying
Posts: 1550
Joined: Mon Dec 19, 2005 9:16 am

by flying

I wouldn't worry & would likely just give it a tap with a socket or a piece of wood from the drive side

I have a similar BB type (but Wheels Mfg) & find if I just grab the non drive side & rotate a bit it just pops out.
(But my non drive side has tooling to grab)
So if you dont have the ability to grab that side a tap from the other will likely pop it out.

If not & you have the headset tool I would imagine grabbing either spot you mentioned
would be fine as they usually pop right out & don't need much pulling force

Good Luck :thumbup:

alcatraz
Posts: 1342
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Does your tool expand to the necessary 42mm diameter? If yes then go ahead. :)

Whatever gives you better leverage without slipping is a good place to tap. Use a piece of wood or a rubber mallet.

If the bearing seals are exposed then be careful not to touch them as they damage easily.

/a

engelke
Posts: 3
Joined: Sun May 27, 2018 8:20 pm

by engelke

Thanks for the hints!
Looks like the cup sits very tight. Moving it from the outside by hand didn't work. Tried the headset removal tool and some gentle hits but nothing moved so far...Maybe I need to hit harder ;)

sungod
Posts: 1685
Joined: Fri Dec 24, 2010 9:37 pm
Location: it's raining, it must be uk

by sungod

can't you screw the ds in just 2-3 turns, then tap on that to drive the adaptor out a bit?

once it's moved, unscrew the ds and the rest should be easier to remove fully

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Calnago
Posts: 6739
Joined: Sun Nov 07, 2010 9:14 pm

by Calnago

It’s pressfit and if any retaining compound was used it takes a good solid whack. It should take a good whack regardless unless it’s a very poor pressfit. Use the Park RT-2 (or equivalent) to catch the lips on the non drive side piece. Make sure it’s sitting square and evenly. Put a target on the opposite wall and make a game of it. 10 points for hitting the bullseye first whack.
Do not try threading in the drive side part way and using that as the removal tool. The threads are fine and the collet expands. You’ll likely just damage the threads doing that with the left side still in the frame.
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engelke
Posts: 3
Joined: Sun May 27, 2018 8:20 pm

by engelke

sungod wrote:
Mon May 28, 2018 8:14 pm
can't you screw the ds in just 2-3 turns, then tap on that to drive the adaptor out a bit?

once it's moved, unscrew the ds and the rest should be easier to remove fully
Update: I asked Praxis Works about that approach and they said it might be ok to do it. So I tried and it worked perfectly. I screwed in the DS some turns and hit the DS cup with a pice of wood between the cup and the hammer. After some hits I could remove the NDS by hand. After that I cleaned an reinstalled everthing without problems.

Dominik

by Weenie


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