# Specialized vs. Standard BB30 width?



## fallzboater (Feb 16, 2003)

I have a used '09 Tarmac SL Pro BB30 frame on the way, and plan to fit my 7800 cranks. I am looking at using the BB30 bearings and either the Wheels Mfg. or Enduro adapter bushings, but I've read that Specialized is using a different width between the outside of the bearings than other manufucturers. If so, I would have someone cut down the adapters in a lathe, or just have some custom ones made. 

Does anyone know the difference in width? I can measure my frame once I get it, but I'm trying to figure this out and prep the parts first. Also, I don't know the standard BB30 width.


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## cartmaniac (Jun 6, 2007)

Where have you read that Specialized's is wider than standard BB30? First I've heard that. Everything I've heard is that Specialized is BB30, including a comment from knowledable Specialized shop mechanic. He said I could go with SRAM's BB30 crank, no problem, if I wanted to. At the moment I'm quite happy with my Specialized crank, but I like the idea of going to Red when the time comes.

By the way, Specialized explicitly states that their crank is BB30 compatible. I think they started saying this out loud last summer, but it's been true from the beginning as far as I know.
http://www.specialized.com/us/en/bc/SBCEqProduct.jsp?spid=47420
http://www.specialized.com/us/en/bc/SBCEqProduct.jsp?spid=47411
http://www.specialized.com/us/en/bc/SBCEqProduct.jsp?spid=41905

Standard width is 68.0 mm. http://www.bb30standard.com/tech_images/bb30standard.pdf


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## fallzboater (Feb 16, 2003)

I read it starting at post #16 in the thread link, below. I'd be pleased to hear that it's incorrect.
http://forums.roadbikereview.com/showthread.php?t=193081


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## fallzboater (Feb 16, 2003)

Here's my question and the relatively prompt, but brief, response I got from Specialized. They missed, or chose not to answer, the question about other models, so I don't know if all their road models were 68mm wide. If they were, it seems odd that they didn't call it BB30 from the start, but maybe that was a marketing decision, designed to confuse us. I believe that their 30mm MTB BBs are 84.5mm, instead of the 73mm standard. 
---
I will be taking delivery of a 2009 Tarmac SL Pro with BB30, but will be installing a 180mm Dura Ace 7800 crankset. Enduro and Wheels Manufacturing both make adapters to use the standard BB30 bearings with a Hollowtech II crank spindle, which I intend to use. However, I've read that the Speciallized OS BB may be wider than the BB30 standard (68mm). Is that true for the SL Pro, or was it for any other Specialized models, and if so, what was the width?



Specialized said:


> Hello,
> The OSBB has a 68 mm width.
> Thanks
> Xxxx Xxxxxx
> ...


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## Specializin'n'Specialized (Jan 19, 2010)

For clarification... 68 mm width is the width of Specialized's Road OSBB. This includes all Road bikes with the OSBB. Anyone can throw a set of calipers on their OSBB Specialized bikes to verify.

fallsboater:
you forgot to read, or did so and neglected to care about, the part at the base of my response that reads.....
"CONFIDENTIALITY NOTICE: This email, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure, or distribution is prohibited. If you received this email and are not the intended recipient, please inform the sender by email reply and destroy all copies of the original message." :blush2: 

Glad I could help!:thumbsup:


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## fallzboater (Feb 16, 2003)

Specializin'n'Specialized said:


> For clarification... 68 mm width is the width of Specialized's Road OSBB. This includes all Road bikes with the OSBB. Anyone can throw a set of calipers on their OSBB Specialized bikes to verify.
> 
> fallsboater:
> you forgot to read, or did so and neglected to care about, the part at the base of my response that reads.....
> ...


Sorry, I usually don't bother to read the fine print that's automatically attached to some e-mails, but I probably would've neglected to care about it, anyway. Are you normally sending out secret information that shouldn't be shared with the group? I couldn't get a definitive response here, first, so I thought it'd be worth sharing. I still wonder where the confusion came from in the earlier threads. Thanks for your response though. It saved me from having to wait until I got the frame to measure it.

To further clarify then, it sounds like all road frames ever built by Specialized with a 30mm bearing are compatible with BB30 cranks, even though they may not fully comply with the BB30 standard (which specifies non-critical dimensions of the inside of the shell, the circlip part number, etc.). 

I suppose that since the open BB30 standard was developed by Cannondale, Specialized probably doesn't want to use "BB30" name, which would imply that they're following Cannondale's lead in this area (which is true, in any case). Sounds reasonable, from a marketing standpoint, anyway. 

It is nice that Specialized didn't use a purely proprietary geometry for the road cranks, when a good one was available already, although MTB frames with 30mm bearings can use only Specialized cranks. Correct?

I did order the Enduro BB30 to Hollowtech II Adapter Kit today, so I should be good to go when I get my Tarmac frame next week. Maybe Specialized could evaluate this part, and endorse its use, or offer a similar adapter themselves. Right now I think there's only the Italian-threaded BB shell sleeve adapter, which was probably made so that Specialized could offer a bike using a Campy BB and crank. 
http://enduroforkseals.com/id286.html


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## Specializin'n'Specialized (Jan 19, 2010)

^^^^
We are not trying to keep secrets..... Just our names off of forums

You are correct.
Currently our mtn. bikes with the OSBB will only accept our cranks or shimano cranks with an adapter. Who knows what the future will bring.
I


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## fallzboater (Feb 16, 2003)

Specializin'n'Specialized said:


> ^^^^
> We are not trying to keep secrets..... Just our names off of forums
> 
> You are correct.
> ...


Sounds reasonable. Thanks for participating in the forum. There's a lot of bad information available, so it's helpful to have an insider straighten us out.

That's good to know about the MTB cranks, too. My buddy is enjoying his new Stumpy FSR 29er, although I imagine that one just has the threaded BB shell.


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## PJ352 (Dec 5, 2007)

Specializin'n'Specialized said:


> ^^^^
> *We are not trying to keep secrets..... Just our names off of forums*
> 
> You are correct.
> ...


Slightly off topic, but IMO relevant to the Spec forum in general; it's completely understandable to want to keep identities secret (most here do the same), but it would be in both parties best interest for you to (in some way) identify yourself as a Spec rep (or whatever you may be  ). I think having such a (credible) resource available to this forum is highly desireable.


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## vartuz (Jan 5, 2010)

I echo that 200%, this is after all Specialized Thread. Having a manufacturers rep providing us accurate information IMHO is not only great for this thread but also great for Specialized brand.


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## cornas (Sep 19, 2008)

Specializin'n'Specialized said:


> For clarification... 68 mm width is the width of Specialized's Road OSBB. This includes all Road bikes with the OSBB. Anyone can throw a set of calipers on their OSBB Specialized bikes to verify.


Not true! My new SL3 came with a bb shell that is 62mm wide and with a diameter of 46mm.


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## CodyatSpecialized (Jan 26, 2010)

The SL3 has removable cups that house the BB bearings. 
Your new SL3 has those dimensions because it is being measured without the cups in.
The previous S-works OSBB bikes had the cups built into the frame. The new SL3 will have the same measurements as the SL2 and all other BB30 bottom brackets when the cups are pressed in.


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## cornas (Sep 19, 2008)

Yes, you are right! My bad, sorry! The shop forgot to give me those cups. I have to say that I was quite puzzeld  About the cups, is there an aluminum version also?

And btw, the bike is absolutely awesome :23:


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## CodyatSpecialized (Jan 26, 2010)

There is only the version of the cups that your shop provided for you. I believe they are plastic.
Glad you enjoy the bike.


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## cornas (Sep 19, 2008)

Yup, they are plastic. Just that I have seen other bikes which seem to have an aluminum version. But I guess those bikes are older.

Tanks for the quick response! :thumbsup: :thumbsup:


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## EricTj (Jun 6, 2007)

Got a Roubaix SL3 frame with the express intent of installing Dura Ace 7803 - the dealer thought the frame was OSBB = BB30, which was incorrect - its some version of PF30, and the plastic insert/bearing holders DON'T make the frame equivalent to BB30, as the bearings apparently sit further outboard than "normal" BB30. The got Wheels Mfg PF30 adapters and gave the bike to me with the non-drive crank like half way onto the spindle.

The correct dimension for traditional Shimano external bearing BB when installed on 68mm shell is ~90mm. PF30 adapters made by Wheels Mfg. installed on the frame were 96mm. The Wheels Mfg BB30 adapters make it 93mm. Since the Wheels adapters are made of Delrin, and so are easy to machine, I ground off ~1.5mm from the outside face of each of the BB30 adapters, and wound up with a correct width. Don't have a chain-line checking gizmo, so I'm not sure if one side should have been reduced more than the other to get that just right, but at least the I now have full engagement of the non-drive crank onto the spindle!!

Has anyone tried fitting a road bike (68mm) with the MTB "press-in threaded adapter cups" that Specialized makes for using outboard bearings in PF30 MTB frames?


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## ukbloke (Sep 1, 2007)

EricTj said:


> Got a Roubaix SL3 frame with the express intent of installing Dura Ace 7803 - the dealer thought the frame was OSBB = BB30, which was incorrect - its some version of PF30, and the plastic insert/bearing holders DON'T make the frame equivalent to BB30, as the bearings apparently sit further outboard than "normal" BB30.


There is something strange going on here, and it warrants more investigation in my opinion. PF30 and BB30 use the same cranks so they _have_ to be the same width when fully installed on a bike. I wonder if you were provided with the wrong "plastic insert/bearing holders"?


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## ukbloke (Sep 1, 2007)

EricTj - you should check the assembly diagrams that I posted over here. The "press-in cups" should be 15.65 mm wide, and you might want to check that.

One possible source of this mistake is if you could have the BB30-SRAM adapters instead of the BB30-SHIM adapters from Wheels Manufacturing. I wonder if there is a 3mm difference between the Shimano crank standard (90mm) and the SRAM crank standard (93mm) measured at the crank (outside of the BB)? If that's the case you should get the dealer to order the BB30-SHIM adapters and install them for you at their cost, and then keep your modified ones as spares. I know for sure that SRAM and Shimano cranks/BBs are not interchangeable so there is presumably some difference in width.


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## ukbloke (Sep 1, 2007)

The easy way to tell if you have the BB30-SRAM adapters is if the ID sizes are different because of the SRAM tapered spindle:



> Sram / Truvativ cranks have a TAPERED SPINDLE (24mm to 22mm)
> 24mm BB30 Sram shim is for Drive side (right)
> 22mm BB30 Sram shim is for Non Drive side (left


If this is the mistake, you definitely want the Shimano ones not modified SRAM ones.


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## vs779 (Feb 22, 2005)

I assume the Wheels MFG BB30 and PF30 spacers are different to allow for the lip of the PF cups on a PF30 frame. I use Shimano cranks on my 2011 S Works Tarmac SL3 OSBB which is PF30 with PF30 spacers and it works fine.


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## ukbloke (Sep 1, 2007)

vs779 said:


> I assume the Wheels MFG BB30 and PF30 spacers are different to allow for the lip of the PF cups on a PF30 frame. I use Shimano cranks on my 2011 S Works Tarmac SL3 OSBB which is PF30 with PF30 spacers and it works fine.


What are these PF30 spacers that you mention? Where did you get them from? It sounds like they serve the same function as the Wheels Mfg adapters. The purpose of these is simply to adapt from the width/ID of the BB30 standard to the width/ID of the Shimano crank standard.


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## EricTj (Jun 6, 2007)

The PF30 (part # PF30-SHIM) and BB30 (part # BB30-SHIM) spacers by Wheels Mfg. are both intended to adapt the two different "standards" to a Shimano crankset. The difference being an additional lip on the inside edge, and a bit more overall width between the bearing face inside the frame and the "virtual" bearing face against which the crankset is installed. 

Sounds like vs779's rig is working as it should. 

I'm thinking that the dealer probably installed the wrong press-in cup and bearing set for the frame. Regardless, I got it working and the bike otherwise is easily the best I've ever ridden - HTC colors are now a collector's item I guess....


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## ukbloke (Sep 1, 2007)

OK, thanks. I understand vs779's post now - I didn't parse the first sentence properly. Here's the page at the Wheels Mfg web-site showing all 3 adapters that they make. In EricTj's case, I am surprised that using BB30-SHIM instead of PF30-SHIM would lead to as much as 3mm difference in width though.

Enjoy your limited edition HTC frame!


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## stiffnezz1 (Feb 5, 2013)

*hawk racing osbb- shimano adapter*

Has anybody heard of or tired the Hawk-Racing BBS bottom bracket? i have an sl4 and i wanted to run di2 on it. I have tried the praxis rings, the specialized rings and the s-works specialized rings, none of them offer the same shifting performance as the sl3 with english threaded cups and DA cranks and rings. some ring combos on the specialized crank caused me to drop the chain, get it jammed between the rings,all kinds of nightmares! I then found this.Its made to adapt the 46x61mm OSBB carbon shell down toshimano 24mm. no spacers no glue. just light press fit into frame followed by the cranks. Machined 1 piece out of delrin in the USA. they are only $119 had mine in for 3 weeks no noise no complaints and DA CRANKS AND RINGS


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## roadworthy (Nov 11, 2011)

cornas said:


> Not true! My new SL3 came with a bb shell that is 62mm wide and with a diameter of 46mm.


There is so much confusion in this thread so I had to chime in. No, Specialized doesn't make it easy.
Summary:
Specialized has two OSBB's:
Carbon OSBB which is a 61mm like you show. But..and here is the thing...with Delrin bushings pushed in which protrude 3.5mm per side, overall BB width measures 68mm.

Alloy OSBB: OP...that is what you have with your Tarmac Pro bike. Both Roubaix and Tarmac Pro bikes have BB30 = 68mm wide.

In summary, the Specialized cranks...and other BB30 cranks out there can't tell the difference between either OSBB type...spacing is the same.

As to mounting DA cranks, standard Wheel Mfg. spacers work the same for both OSBB's.

OP...I hope that clears it up for you. You have BB30 with standard 68mm spacing.


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