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Question about Rotor 3D+ crank on SL3 'OSBB' Specialized
http://weightweenies.starbike.com/forum/viewtopic.php?f=3&t=113525
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Author:  lyot [ Sun Mar 10, 2013 6:15 pm ]
Post subject:  Question about Rotor 3D+ crank on SL3 'OSBB' Specialized

I've recently bought a SL3 equipped with a OSBB and a Specialized Fact CT crankset. The latter has been removed, and I'm now trying to mount a Rotor 3D+ cranckset. The frame currently has some "C-bear BB30-46 Road" bearings press fitted into it. I've installed the two spacers (11.5mm) provided with the Rotor 3D+, but still, there's about 5mm of 'space' left to be filled. The crankset is also able to move in the bottom bracket if you push it. Anyone in the know what more I need ?

Author:  Weenie [ Sun Mar 10, 2013 6:15 pm ]
Post subject:  Question about Rotor 3D+ crank on SL3 'OSBB' Specialized


Author:  KWalker [ Sun Mar 10, 2013 6:40 pm ]
Post subject:  Re: Question about Rotor 3D+ crank on SL3 'OSBB' Specialized

I used a normal pressfit 30 with my 3D+ crank and the two spacers. Does your BB come with the extra bearing shields that most Sram and Cannondale BB's come with (the red and green ones at this link: http://www.cannondaleexperts.com/assets ... /ka021.jpg ?

If not, get some of those. Again, Sram includes them with their BBs and most shops should have them. After that you will need to adjust the preload washer, but that should do it.

Author:  lyot [ Sun Mar 10, 2013 7:04 pm ]
Post subject:  Re: Question about Rotor 3D+ crank on SL3 'OSBB' Specialized

Thanks for replying, KWalker. There are indeed two plastings bearing shields provided by Rotor 3D+, but they can't make up for the space that's left.

Excuse my shallow knowledge of the English language, but what is a preload washer ? Google didn't help.. :-)

I think I might need the OSBB 62-86 C-Bear -as found on this overview http://www.c-bear.com/image/bbchart-print.pdf - instead of the C-Bear BB30-46 that's mounted right now. I'd still be interested to see what others are using though.

Author:  KWalker [ Sun Mar 10, 2013 8:56 pm ]
Post subject:  Re: Question about Rotor 3D+ crank on SL3 'OSBB' Specialized

Rotor doesn't include these. You need these shields in addition to what they provide.

Author:  lyot [ Sun Mar 10, 2013 9:50 pm ]
Post subject:  Re: Question about Rotor 3D+ crank on SL3 'OSBB' Specialized

KWalker wrote:
Rotor doesn't include these. You need these shields in addition to what they provide.


So the shields you posted (Cannondale image), are they at least 5mm in width ?

:beerchug:

Author:  TwiggyTN [ Sun Mar 10, 2013 9:58 pm ]
Post subject:  Re: Question about Rotor 3D+ crank on SL3 'OSBB' Specialized

The SRAM bearing shields are 2.5mm in width IIRC.

Sent from my Galaxy Nexus using Tapatalk 2

Author:  thisisatest [ Mon Mar 11, 2013 4:05 am ]
Post subject:  Re: Question about Rotor 3D+ crank on SL3 'OSBB' Specialized

C-Bear makes two bottom brackets with 46-30 designations. One is a pure pf30, the other is for carbon osbb frames (which are 61mm wide as opposed to 68mm wide). You probably have the wrong one.
wheels mfg makes spacers that go between the cup and frame to space the bearings out to the proper width. this would be a reasonable option. Another route, my preference, would be to ditch the C-Bear bb and get some ROAD OSBB cups from a specialized dealer. If you want, you could pull the ceramic bearings out of the C-Bear cups and put them in the OSBB cups.
you could conceivably also add 3.5mm of spacers to the spindle on both sides of your current arrangement, but I wouldn't, as the bearings will be resting on an interior portion of spindle, not as intended and not designed to support the load.

Author:  lyot [ Mon Mar 11, 2013 10:53 am ]
Post subject:  Re: Question about Rotor 3D+ crank on SL3 'OSBB' Specialized

Thanks so much for all the answers. I'll be weighing my options.. :-)

Author:  lyot [ Mon Mar 11, 2013 5:36 pm ]
Post subject:  Re: Question about Rotor 3D+ crank on SL3 'OSBB' Specialized

Thanks to your help and the input of fellow ww'er Pcrispey, the problem is almost completely solved now. I got some OSBB Road cups which were installed. The bearings from the C-Bear were removed and installed in the OSBB Road cups. There's still some free space left, but that can be left out by adjusting the screw on the Rotor 3D+ crank (non-drive side). Ideally, I should still install a bearing shield because the cranck screw seems stretched to the limit.

:beerchug:

Author:  thisisatest [ Wed Mar 13, 2013 5:20 am ]
Post subject:  Re: Question about Rotor 3D+ crank on SL3 'OSBB' Specialized

Yes in that system, bearing shields should be installed on both sides.
I apologize for not making that clear.

Author:  lyot [ Wed Mar 13, 2013 9:41 am ]
Post subject:  Re: Question about Rotor 3D+ crank on SL3 'OSBB' Specialized

thisisatest wrote:
Yes in that system, bearing shields should be installed on both sides.
I apologize for not making that clear.


No problem! I appreciated your help. Does anyone know where to buy such bearing shields online ? A quick google search didn't provide much help

Author:  KWalker [ Wed Mar 13, 2013 3:05 pm ]
Post subject:  Re: Question about Rotor 3D+ crank on SL3 'OSBB' Specialized

Where are you located? I have 2 Sram shields in my toolbox. PM me your address and if you're in the US I can send for free.

Author:  weekapaugin [ Mon Sep 16, 2013 11:44 pm ]
Post subject:  Re: Question about Rotor 3D+ crank on SL3 'OSBB' Specialized

After reading this and a few dozen other threads on Specialized osbb, specialized carbon osbb, bb30, and pf30 compatibility I'm now more confused than when I started.

I have a 2011 tarmac sl3 pro now, with the stock specialized cranks, which the speci website specs as the OSBB frame and crank, http://www.specialized.com/us/en/bikes/archive/2011/tarmac/tarmacsl3prom2red#specs.
I understand that this is not the same as the carbon osbb that is used in the s-works models. Where I am now confused is some of the threads state the sl3/sl4 pro frames use standard bb30, like this http://weightweenies.starbike.com/forum/viewtopic.php?f=3&t=103618&start=15 which is not osbb? :noidea:

At the end of the day, I'm looking to order a power2max unit - I think the rotor 3d+ is the correct option, but am unsure and want to try and keep the installation as clean and simple as possible and avoid using cups and spacers and conversions if I can.

I apologize in advance if I am thread jacking, but I know there are a lot of threads on this topic and did not want to start another.

Author:  weekapaugin [ Tue Sep 17, 2013 9:46 pm ]
Post subject:  Re: Question about Rotor 3D+ crank on SL3 'OSBB' Specialized

to further clarify my confusion:
This http://service.specialized.com/collateral/ownersguide/new/assets/pdf/Bottom-Bracket---Oversized-Road-Bottom-Bracket.pdf document from Specialized indicates that the 2011 tarmac sl3 pro has a 46mm carbon osbb shell

Whereas http://service.specialized.com/collateral/ownersguide/new/assets/pdf/Bottom-Bracket---Oversized-Road-Bottom-Bracket.pdf indicates the 2011 tarmac pro has a 68x42 osbb.

Does anyone know which one is in fact correct, and what that means as for as if it is bb30, pf30, or a modified version of either, and what I will need to use one of the rotor power2max models on this frame?

Author:  Herb5998 [ Tue Sep 17, 2013 9:51 pm ]
Post subject:  Re: Question about Rotor 3D+ crank on SL3 'OSBB' Specialized

68x42 is the Original BB30 Standard, using Circlips and 61806 Bearings. 68x46 is the PF30 Standards, using press in cups (46mm Diameter) with bearings installed in the cups. Measure what the ID of your BB Shell is and that will tell you what you need to use.

Author:  Weenie [ Tue Sep 17, 2013 9:51 pm ]
Post subject:  Re: Question about Rotor 3D+ crank on SL3 'OSBB' Specialized


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