BB30 Adapter for Shimano Cranks

Discuss light weight issues concerning road bikes & parts.
mattfrogy
Posts: 4
Joined: Thu May 17, 2012 4:04 am

by mattfrogy

The reason the rotor adaptor works Better than bb30 is it is basically a gxp style setup. But instead of having to thread into the frame they thread into the opposite cup so the bearings are square to each other lowering the friction.

Track bb's use a similar concept but by using loose bearings over sealed they can spin for we over a minute.
Just comes down to what you want with your bike, save 50grams or have cranks that spin.

by Weenie


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JesseD
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Joined: Mon Jul 21, 2008 10:20 am

by JesseD

All I want is a functioning bottom bracket set up that doesn't creak every 5 minutes, the Praxis setup looks good as does the KCNC version, anyone had any issues around noise or performance with either of them?

AptosBigRing
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by AptosBigRing

Hey JesseD,

Just wanted to chime in on ours for some insight.
Ours is a patent pending design so the Left and Right cup are connected together so neither bearing can walk/wiggle/slip out of the frame. This keeps the bearings perfectly concentric at all times and exactly on Shimano CL. We also went further and designed it using a collet system that wedges itself tightly inside the shell with even pressure throughout to minimize any chance of noise.

We spent a great deal of time on it and think you'll be impressed.

If any questions just chime us.

Adam@Praxis
Santa Cruz County
Praxis Works
Manufacturer
Santa Cruz, CA
www.praxis-works.com

petal666
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Location: Brisbane, Oz
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by petal666

AptosBigRing wrote:Hey JesseD,

Just wanted to chime in on ours for some insight.
Ours is a patent pending design so the Left and Right cup are connected together so neither bearing can walk/wiggle/slip out of the frame. This keeps the bearings perfectly concentric at all times and exactly on Shimano CL. We also went further and designed it using a collet system that wedges itself tightly inside the shell with even pressure throughout to minimize any chance of noise.

We spent a great deal of time on it and think you'll be impressed.

If any questions just chime us.

Adam@Praxis
Santa Cruz County
Pity shipping outside of the US is ridiculously expensive. :)

mattfrogy
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Joined: Thu May 17, 2012 4:04 am

by mattfrogy

Thanks Aptosbigring

It is a great innovation

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Tinea Pedis
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by Tinea Pedis

Guess that rules out Praxis for me :(

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Rick
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Joined: Sat Aug 29, 2009 4:30 pm

by Rick

Q:
With the Praxis adapter in BB30:
The instructions say to press the non-drive cup in until the O-ring just barely touches the frame.
Then, the drive cup is threaded in until it bottoms on the non-drive cup and is flush with the frame.

At that point, has the O-ring been crushed further (the non drive side cup pulled in further) ? How much ?
Is the O-ring then still visible on the non-drive side after final assy ?

I presume you use the O-ring to allow for a compliant layer to compensate for width tolerances of the bottom bracket areas ?

Is the non-drive side cup a press-fit into the non-drives side BB30 bore ?

Your system looks good. But how does this differ from the KCNC bottom bracket adapter ?

Are the bearings 24mm ID or 25mm ID with a sleeve (like Shimano) ?

Thanks.

musk3t
Posts: 38
Joined: Thu May 10, 2012 11:43 am

by musk3t

The Praxis BB uses a sleeve over bearings, the NDS is pressed in with a headset or bearing press. The DS threads in to the shell which is part of the fixed NDS cup with terminates in a collet which expands as the DS is fitted. The KCNC threads together, but no expansion (which is the purpose of the collet) occurs to further secure the BB.

With the Praxis units I've fitted, the o-ring / gasket did not compress further.

Best way to see all this is simply visit the praxis site and watch the install video.

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Rick
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Joined: Sat Aug 29, 2009 4:30 pm

by Rick

musk3t wrote:The Praxis BB uses a sleeve over bearings, the NDS is pressed in with a headset or bearing press. The DS threads in to the shell which is part of the fixed NDS cup with terminates in a collet which expands as the DS is fitted. The KCNC threads together, but no expansion (which is the purpose of the collet) occurs to further secure the BB.

But BOTH cups of the KCNC are toleranced such that they are a snug sliding fit into the BB30 bore, aren't they ?
Is the KCNC O-ring visible after installation ?
With the Praxis units I've fitted, the o-ring / gasket did not compress further.
Best way to see all this is simply visit the praxis site and watch the install video.

I did, but the resolution/magnification is not high enough to actually see the final state of the O-ring.

When the Praxis cup is pressed in until the O-ring "just barely" contacts the shell, is that intended to compress the O-ring slightly for sealing ?
About what is the thickness of the O-ring and what percentage is it compressed ?

Sorry to be a pest, I am trying to invision exactly how both these BB adapters work and end up looking without having to buy both.

musk3t
Posts: 38
Joined: Thu May 10, 2012 11:43 am

by musk3t

The KCNC's are toleranced to fit some std measure - the beauty of the Praxis is they will take up whatever tolerance the FRAME has been built with / without.

The gasket is c.2mm and basically contacts, so compression as a percentage is negligible.

AptosBigRing
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by AptosBigRing

Hi guys...
Thanks for the interest!

Yep...you got it.
The Tolerance O-ring is just there due to all the different frames out there that have variances in the shell width and it will always visible.

It's there visible on the ND side just to take up any slack if frame shell is short, or it's compressed if the frame shell width is a shade too big.

See Attached. Hope this helps.
*And yes...we're talking to EU distributors right now. We do ship anywhere in the globe from our store. Fed Ex Int'l Econ is who we use as USPOSTAL has lost too many of our orders and UPS is way too expensive.

Adam@Praxis
Santa Cruz County, CA
Attachments
ConvKit View.png
Praxis Works
Manufacturer
Santa Cruz, CA
www.praxis-works.com

melbnut
Posts: 18
Joined: Sun Jan 23, 2011 1:54 am

by melbnut

I have just had the praxis installed in my Z1 after a few failed attempts at different kits. I believe it has been customized to some degree to cater to internal di2 wiring. Only one ride so far and it seems miles better than the previous hawk racing converter I was using.

I'll update after the weekend.

But I'm keen to know when a dedicated di2 solution will be available :)

gsxrawd
Posts: 4
Joined: Mon Aug 11, 2008 7:57 am

by gsxrawd

I used that on my mountain bike with zero issues. It don't look as pretty as the sleeve type adapters but it gets the jobs done and the price is right.

JesseD wrote:http://wheelsmfg.com/bb-30-shims-shimano.html" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

Anyone using these successfuly with no creaking issues that a lot of people have experienced (including me).

I am swapping from Campag to Shimano and am torn between putting a converter sleeve in or using these.

Thanks

Jesse

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vmajor
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by vmajor

We only ever use this for full Shimano builds: http://www.bikepedia.com/pa/Item.aspx?itemid=104873

Pressing it in is simple, but taking it out may be tricky due to general lack of removal tools in the market. The FSA official way to remove it is to use a levered bench mounted press with a special tool bit.

However. You do not need to remove it, ever, if you do not intended to run BB30 again.

V.

by Weenie


musk3t
Posts: 38
Joined: Thu May 10, 2012 11:43 am

by musk3t

There are quite a few frames not warrantee'd if that or the sram equivalent sleeve is used.

I agree they work well, but definitely check you're covered.

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