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Help me understand - BB30 Crankset in a BB30A Frame

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Help me understand - BB30 Crankset in a BB30A Frame

Old 01-30-17, 02:16 PM
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benshares
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Help me understand - BB30 Crankset in a BB30A Frame

Hi gang,

I've got a SRAM Force BB30 crankset that I'm hoping to use in a BB30A CAAD12 Frameset that is in the mail to me.

I've done some research that leads me to believe the you can use BB30 Cranksets in BB30A frames? That doesn't make sense to me, unless you're just screwing the cranks in 5mm less than you would on a BB30 frame. Is that right? I've read that the BB30A are just spaced differently? I'm having a really hard time figuring it out, and I can't find any diagrams that help.

Any clear advice would be appreciated.
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Old 01-30-17, 02:26 PM
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https://pardo.net/bike/pic/mobi/b.bot...standards.html
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Old 01-30-17, 02:29 PM
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That is not super helpful. I understand what BB30A is, a 73mm spindle instead of the 68mm that BB30 has.

1. That site doesn't even have BB30A information
2. Listing of specs does not answer my question, which is about BB30 cranksets in BB30A Frames.
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Old 01-30-17, 02:35 PM
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The BB guide article on BikeRadar ( Complete guide to bottom brackets - BikeRadar USA ) claims that some will work, which means some (probably many) don't. I hope it's not a make/break matter for this bike. If it is, it's probably something best verified before purchasing the frameset.

This BB business is getting even more ridiculous isn't it? I thought after the original BB30 "standard" was introduced and things got a little crazy, the industry would tire of the chaos and settle down a bit. That appears not to have happened at all.

I'm on the market for a bike for my wife right now, and I won't even look at bikes that spec BB30 crank sets due to the fact that they are the least compatible option on the market. All of the 24mm cranksets (shimano/FSA) can be fairly easily adapted to fit most frames...With BB30/PF30 cranks, you have so much less wiggle room.

I hope it works for you. Please let us know once you have a chance to test it.

-Jeremy
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Old 01-30-17, 02:57 PM
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Thanks Jeremy -

It's not a make/break although I'd rather not have to buy a new crankset - The CAAD12 is really the anchor of the build, as I was able to get it new frame/fork/bb/seatpost/saddle/headset for around $500 - The SRAM crankset is just sitting around and I hoped I could use it to save some more money for the build, but if I can't it's just another problem to solve (not a bad thing). From what I can figure out, some BB30 cranksets have a 5mm preload ring on the spindle that can be removed, making it compatible with BB30A. I'm not home right now so can't look at mine, but guessing that if it doesn't have that ring, I'll be out of luck.

Coincidentally I'm also making this bike for my wife - good luck to you!
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Old 01-30-17, 03:06 PM
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Just found this on Koegel

"Both standards are based on the standard BB30 or PF30, but with 5mm added, only on one side. Hence the ‘A’ stands for Asymmetric. The official word is that it helps build frames with better chain lines, the result is that it only fits a PF30A specific crank set. That’s right. Any Shimano, Sram, FSA, Campagnolo or Rotor will not fit unless you load up a bunch of spacers."

This is where my confusion comes in - how would spacers help in this situation (wider BB than your spindle) wouldn't you need like...negative spacers?
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Old 01-30-17, 05:22 PM
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Maybe this is of use to you:

Cannondale BB Technical Info
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Old 01-30-17, 07:33 PM
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I think Force 22 BB30 Crank will work with a spacer, but older Force and any Red or Rival will not. It might be though that if your BB30 crank has the "preload adjuster" you could remove it entirely and use a wavy washer and it would fit.

scott s.
.

Last edited by scott967; 01-30-17 at 07:37 PM.
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Old 01-30-17, 08:46 PM
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Originally Posted by benshares View Post
I've done some research that leads me to believe the you can use BB30 Cranksets in BB30A frames?
No you can't. BB30A needs a crank with a longer spindle. Only BB30A, PF30A , BB386 EVO, Cannondale BB30A specific SI, SiSL cranks will fit. Other options are buying 24mm spindle crank and using an adaptor.


Originally Posted by Tunnelrat81 View Post
I'm on the market for a bike for my wife right now, and I won't even look at bikes that spec BB30 crank sets due to the fact that they are the least compatible option on the market. All of the 24mm cranksets (shimano/FSA) can be fairly easily adapted to fit most frames...With BB30/PF30 cranks, you have so much less wiggle room.

But a crank is much cheaper to switch out than a frame ?

Looking at it the other way. BB30 frames (and other pressfit bb's) actually have more crank options available than a BSA threaded frame.
BB30 can be converted to Hollowtech II, GXP, Megaexo, Campy Ultra/Power Torque, BB386EVO, PF30 (A), BB30A (with a spacer). Rotor bb.

a bike with a traditional BSA threaded bb, can only work with Hollowtech II, GXP, Megaexo, Campy Ultra/Power Torque, JIS square taper

The majority of road bikes today are pressfit bb's. Only entry level bikes, aftermarket alloy and steel frames still use BSA threaded bb's. So you limit your range bike model options.

Originally Posted by benshares View Post
Just found this on Koegel

"Both standards are based on the standard BB30 or PF30, but with 5mm added, only on one side. Hence the ‘A’ stands for Asymmetric. The official word is that it helps build frames with better chain lines, the result is that it only fits a PF30A specific crank set. That’s right. Any Shimano, Sram, FSA, Campagnolo or Rotor will not fit unless you load up a bunch of spacers."

This is where my confusion comes in - how would spacers help in this situation (wider BB than your spindle) wouldn't you need like...negative spacers?
It's slightly confusing info, but semi true.
BB30A can be converted to 24mm hollowtech II, GXP, Megaexo, Ultra Torque because those adapters fit inside the shell. Normal BB30,PF30 cranks have a spindle that is too short and too fat so there is not enough room to fit an adapter.

Originally Posted by scott967 View Post
I think Force 22 BB30 Crank will work with a spacer, but older Force and any Red or Rival will not. It might be though that if your BB30 crank has the "preload adjuster" you could remove it entirely and use a wavy washer and it would fit.
This is correct info. Only Sram Force 22 BB30 crank has the longer spindle.

Last edited by trailflow1; 01-30-17 at 10:34 PM.
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Old 01-30-17, 09:24 PM
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Very illuminating Trailflow - thanks for the help.

So if I'm understanding the preload ring issue - this crankset might work if I remove the preload ring? (ignore the worn teeth, just looking at the spindle)
SRAM Force 22 BB30 Carbon Road Crankset 11-speed 52/36T 175mm | eBay
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Old 01-30-17, 09:26 PM
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Yes, or there is another 2 spacers behind the preload adjuster that can be removed. You'll probably will want to keep the adjuster on there to take up any side-to-side play easier.

You may need to play around with those spacer configurations to get it right.

Last edited by trailflow1; 01-30-17 at 11:30 PM.
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Old 01-30-17, 09:47 PM
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There is also a 13mm spacer that should come with that Force 22 crank, it goes on the driveside spindle, say If you ever wanted to fit it to a normal BB30 frame.

So if you do buy that crank, ask the seller to include it in case you ever need it.

Last edited by trailflow1; 01-30-17 at 11:30 PM.
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Old 02-01-17, 08:43 AM
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Originally Posted by trailflow1 View Post

But a crank is much cheaper to switch out than a frame ?

Looking at it the other way. BB30 frames (and other pressfit bb's) actually have more crank options available than a BSA threaded frame.
BB30 can be converted to Hollowtech II, GXP, Megaexo, Campy Ultra/Power Torque, BB386EVO, PF30 (A), BB30A (with a spacer). Rotor bb.

a bike with a traditional BSA threaded bb, can only work with Hollowtech II, GXP, Megaexo, Campy Ultra/Power Torque, JIS square taper

The majority of road bikes today are pressfit bb's. Only entry level bikes, aftermarket alloy and steel frames still use BSA threaded bb's. So you limit your range bike model options.
This is precisely why I said that I'm not looking at BB30 "cranksets." Most frames use pressed in bearings,yes, but not all of them are spec'd with BB30/PF30 cranksets. Any bike that is shimano but spec's a non-shimano (BB30) crankset is on my bad list. But there are plenty of options still. For example, Trek often specs full shimano groupsets. This is because the frames are BB86(.5) or BB92, and they have to spec 24mm cranksets.

Cranksets are cheaper, true, but framesets are more likely to have problems and need replacement. So owners looking to maintain as much future compatibility as possible will look for bike spec'd with the longer spindle that will fit most frames.

In my opinion, one of the best options for BB/crankset is the PF30 frame running with a shimano 24mm spindle crank. This way you can use a thread-together Wheels MFG or Praxis BB and your squeaky/short life BB problems come to an end.

-Jeremy
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