S-Works Amira bottom bracket question

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villahidalgo
Posts: 22
Joined: Tue Oct 19, 2010 8:25 pm

by villahidalgo

Just bought a used 2010 S-Works Amira frameset for my wife, which has the 42mm alloy OSBB. The previous owner had a dura ace crankset installed with the shimano SM-BB91 cups. I will be installing an S-Works BB30 crankset.

Does anyone know what I will need to purchase for a bottom bracket? Specialized compatability chart and bottom bracket types are confusing to me. Specialized compatability chart mentions only circlips are needed.

http://service.specialized.com/collater ... racket.pdf

Will I be able to use the same bearings currently installed? If I buy BB30 bearings will the circlips be included or do they come with the frame?

Thanks for your help.

by Weenie


socratease
Posts: 169
Joined: Thu Oct 13, 2011 5:25 pm

by socratease

Is the crankset new? If so, it comes with the bearings you would need. Possibly the circlips as well.
If not, you just need some bb30 bearings and the circlips. From memory (though it may be flawed memory) the older OSBB is basically "true" bb30.

thisisatest
Shop Owner
Posts: 1980
Joined: Sat Jun 13, 2009 4:02 am
Location: NoVA/DC

by thisisatest

i personally dont see how bb91 cups could have been used. those press into a different type of frame (like Giant frames, not bb30) and ive never seen an adapter for bb30-to-bb86/90/91/etc.
i believe you likely have specialized's own 24mm adapters. they look like wheelsmfg ones but aluminum:
Image
if that's the case, your bearings and circlips are already in there. may need some bearing dust shields and wavy washer.

villahidalgo
Posts: 22
Joined: Tue Oct 19, 2010 8:25 pm

by villahidalgo

socratease wrote:Is the crankset new? If so, it comes with the bearings you would need. Possibly the circlips as well.
If not, you just need some bb30 bearings and the circlips. From memory (though it may be flawed memory) the older OSBB is basically "true" bb30.


The crankset is not new, but it did come with a wavy washer, and others. Do you nkow if the circlips are readily available? I haven't found them online.

villahidalgo
Posts: 22
Joined: Tue Oct 19, 2010 8:25 pm

by villahidalgo

thisisatest wrote:i personally dont see how bb91 cups could have been used. those press into a different type of frame (like Giant frames, not bb30) and ive never seen an adapter for bb30-to-bb86/90/91/etc.
i believe you likely have specialized's own 24mm adapters. they look like wheelsmfg ones but aluminum:
Image
if that's the case, your bearings and circlips are already in there. may need some bearing dust shields and wavy washer.


I have a photo that does show "Shimano SM-BB91-42A" on the cups currently, I just don't know how to post photos here.

aaric
Posts: 439
Joined: Thu Jun 09, 2011 4:10 pm

by aaric

If you buy a bb30 bearing kit, it should come with the clips, wave washer, bearing shields, and some extra spacers.

(http://www.competitivecyclist.com/produ ... n=Datafeed" onclick="window.open(this.href);return false;)

Or you can buy the ciclips online for less than 10 bucks shipped in a pinch.

(http://www.google.com/products/catalog? ... CGkQ8wIwAQ)

What you need really is going to depend on what the crank has hanging off of it. Sometimes the bearings and washers are all included, sometimes not. Rarely are the circlips included from what I've seen, since they almost always are left in the frame.

The safe play is to just buy the kit for ~$35, and follow the instructions. You can probably save a bit by just buying the bearings individually and the circlips, but IMO its not worth it if you aren't familiar with the technology - you might end up missing the wave washer or shields and spend more.

thisisatest
Shop Owner
Posts: 1980
Joined: Sat Jun 13, 2009 4:02 am
Location: NoVA/DC

by thisisatest

villahidalgo wrote:I have a photo that does show "Shimano SM-BB91-42A" on the cups currently, I just don't know how to post photos here.

shrink your photo to 160kb or less, put it somewhere obvious on your computer (like the desktop), then under the UPLOAD ATTACHMENT area, look it up by clicking BROWSE.
i just have to see this picture.

goodboyr
Posts: 1391
Joined: Wed Jan 10, 2007 10:56 pm
Location: Canada

by goodboyr

thisisatest wrote:
villahidalgo wrote:I have a photo that does show "Shimano SM-BB91-42A" on the cups currently, I just don't know how to post photos here.

shrink your photo to 160kb or less, put it somewhere obvious on your computer (like the desktop), then under the UPLOAD ATTACHMENT area, look it up by clicking BROWSE.
i just have to see this picture.


Its amazing what you can do with a dremel and a big mallet.

villahidalgo
Posts: 22
Joined: Tue Oct 19, 2010 8:25 pm

by villahidalgo

thisisatest wrote:
villahidalgo wrote:I have a photo that does show "Shimano SM-BB91-42A" on the cups currently, I just don't know how to post photos here.

shrink your photo to 160kb or less, put it somewhere obvious on your computer (like the desktop), then under the UPLOAD ATTACHMENT area, look it up by clicking BROWSE.
i just have to see this picture.


Here is the photo
Attachments
DSC08193.jpg

villahidalgo
Posts: 22
Joined: Tue Oct 19, 2010 8:25 pm

by villahidalgo

aaric wrote:If you buy a bb30 bearing kit, it should come with the clips, wave washer, bearing shields, and some extra spacers.

(http://www.competitivecyclist.com/produ ... n=Datafeed" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;)

Or you can buy the ciclips online for less than 10 bucks shipped in a pinch.

(http://www.google.com/products/catalog? ... CGkQ8wIwAQ" onclick="window.open(this.href);return false;)

What you need really is going to depend on what the crank has hanging off of it. Sometimes the bearings and washers are all included, sometimes not. Rarely are the circlips included from what I've seen, since they almost always are left in the frame.

The safe play is to just buy the kit for ~$35, and follow the instructions. You can probably save a bit by just buying the bearings individually and the circlips, but IMO its not worth it if you aren't familiar with the technology - you might end up missing the wave washer or shields and spend more.


this is what I needed to know, thanks!

by Weenie


thisisatest
Shop Owner
Posts: 1980
Joined: Sat Jun 13, 2009 4:02 am
Location: NoVA/DC

by thisisatest

thanks for the photo-makes sense now that i think of it. the "-42a" part is what i missed. you just dont see that particular shimano adapter on road bikes, or at least i dont. it was mostly used on specialized mountain bikes with their 84.5mm wide "mountain OSBB" bottom bracket... actually all shimano data i can find lists it as mtb only. i dont see too much of a problem being used as you had it, besides the bearings sitting too far inboard. your dura ace cranks used some spacers as well?

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