Fitting Truvativ cranks to Specialized frames

[ManicCycles]

Been trying to find a solution but still no success, perhaps somebody on this forum has a solution.

 

On most of the latest Specialized frames, they have a Shimano pressfit bearing that fits into the BB (not BB30, a size specific only to Specialized as far as I'm aware).

 

Any Shimano or compalable Crankset fits this system.

 

BUT, we've yet to find a solution for customers that wan't to fit X-0 or XX (TRUVATIV cranks).

 

Even tried a AEROZINE BB adapter that converts std shimano type bb to fit a Truvativ style crankset, but no success.

 

Only solution for the XX customers has been to fit ROTORBIKE's 3D XC2 crankset with Q-rings.

 

While this works perfectly fine, and I'm a huge fan or Rotorbike's stuff, I do have a customer that would prefer the "bling" of an XX crankset.

 

Other problem is Rotor only offers a 39 in Double cranks option, where as XX offers a 40 or 42 option.

 

Anybody outthere with a suggesiton or solution?

[Aurora]

how about getting the sram internal BB system??

 

 

 

Sram red uses this bb so im pretty sure the xx will work with it

[Aurora]

i mean press fit BB, not internal. You get the drift though.

 

 

 

Works on the Trek road frames

[ManicCycles]

i mean press fit BB' date=' not internal. You get the drift though.

Works on the Trek road frames[/quote']

 

NOPE, alreay tried that option. Thanks for trying. (These seem to work with BB30 style frames (like Merida & Cannondale and probably others too)

[Johan Bornman]

I think you are going to have to wait until someone makes a special adapter for that problem.

 

As a matter of interest, what is the OD of the pressfit bearing and the OD of the compatible axle?

[ManicCycles]

I think you are going to have to wait until someone makes a special adapter for that problem.

 

As a matter of interest' date=' what is the OD of the pressfit bearing and the OD of the compatible axle?

[/quote']

 

I've been nagging the local Sram agents for a few months now...... but hopefully they will come up with something.

 

As for the OD, not sure & not in the shop today, but will get back to you on Monday.

[Wyatt Earp]

Sram have a pressfit BB, sadly the diameters aren't up to spec, they are soon to launch a compatible BB.

 

Till then the Rotor or the Specialized crank are your only options.

 

If you can get the Specialized crank you can get the blades with adapter to fit on to the crank.

[Johan Bornman]

Sram have a pressfit BB' date=' sadly the diameters aren't up to spec, they are soon to launch a compatible BB.
.[/quote']

 

I dont understand that statement. Could you please elaborate?

 

Thanks

[Wyatt Earp]

Currently they offer a pressfit 30 bottom bracket and speak quite excitedly about a BB 30 bottom bracket.

 

To date we have not seen one yet, this is why the original poster started this thread.

 

The BB 30 has a 41 mm. outer diameter(I think) where it presses in to the frame.(I will double check that od. with a vernier)

 

The pressfit 30 has a larger OD , could be 46mm. again I could be a little off with my accuracy. Anyways this is a mew standard by Sram and bike companies have to make sure that their BB shell diameter can accommodate this BB.

 

Specialized uses the osbb ,according to what I was told is that this bb. was developed for a 73 mm. width bottom bracket.

 

LaPierre bikes also do their own thing.

 

To be quite frank it all gets very confusing especially for the dude who wants to build a new bike and when the parts arrive he is without crank.

 

There should be some sort of standard.

 

 

 

Just another matter of interest, Sram don't recommend the use of a 166 mm. Q factor XX crank to be used with a BB 30, but rather with the pressfit 30.

 

 

 

Confusing to no end

[ManicCycles]

Thanks Dangle.

 

Let me know when you receive any news on a compatable pressfit bb.

 

I'll do the same.

[Johan Bornman]

I think I now understand the OP's problem.

 

I found some useful info here:

 

http://www.parktool.com/repair/readcalvinscorner.asp?id=231

 

 

It is pretty sad that the industry could not agree on a single standard. I see nothing wrong with BB 30. Why put us through this nonsense all over again?

[Wyatt Earp]

I think I now understand the OP's problem.

 

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I found some useful info here:

 

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http://www.parktool.com/repair/readcalvinscorner.asp?id=231

 

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It is pretty sad that the industry could not agree on a single standard. I see nothing wrong with BB 30. Why put us through this nonsense all over again?

 

 

 

That Park Tool link is very useful, it gives a very nice detailed installation but unfortunately they don'y have the info on everything.

 

Sram are the boys that made it difficult, the shorter spindle has made BB choices that much more difficult.I understand their reasoning, they want 2 by 10 users to use the entire cassette regardless of their choice of blade on the front.

 

The Q factor gets wider from the carbon molding whilst the spindle length stays unchanged.

 

They offer 3 Q factors, a 155mm. 164mm and a 166mm.

 

 

 

I agree with you 100 % that a single standard would be great.

 

I somehow think that as long as we have two rival companies, there will always be one who will try and make their mark.

 

 

 

I can say thumbs up to Shimano for making a specific BB for Specialized bikes, they could easily have turned around and told them to re-design their BB shells.

[Johan Bornman]

We need to clear up some terminology here.

Q-Factor is the distance between your two feet on a bicycle. From what I understand here you are referrng to the width of the BB and axle and crank setup. Correct me if I'm wrong here. BB width may or may not affect Q-factor, depending on the crank's curve.

Q-Factor is limited on the inside by chainstay clearance which in turn is limited by tyre width and tyre position in the rear triangle.

 

I also don't understand the issue with 2 x 10 setups. If your chainline is neutral, all that's required to use all the blades without rubbing on the FD is a wide enough FD. Q-Factor or indeed, BB axle width doesn't play a role here.  10-speed cassettes are just as wide as 9-speed cassettes? Yes?

 

What am I missing?

 

[Wyatt Earp]

 

 

There is zip zero and no terminology to clear up.

 

The Q-factor changes form a 156 to a 164 and 166 by Sram doing the molding of the carbon differently.

 

The spindle length stays the same UNCHANGED, which limits it's usage to a wide range of bikes, especially 29'ers, thus the three different Q factors on offer.

 

So the reason for the shorter spindle is to keep a STRAIGHTER chain line.

 

I can see where this is heading, yet again.

[Johan Bornman]

There is zip zero and no terminology to clear up.
The Q-factor changes form a 156 to a 164 and 166 by Sram doing the molding of the carbon differently.
The spindle length stays the same UNCHANGED' date=' which limits it's usage to a wide range of bikes, especially 29'ers, thus the three different Q factors on offer.
So the reason for the shorter spindle is to keep a STRAIGHTER chain line.
I can see where this is heading, yet again.[/quote']

 

No, I think you're just looking for an argument. I'm trying to understand what's happening with new developments in the industry.

 

Questions:

 

1) "The molding of the carbon" - does that refer to the width of the BB shell?

2) By changing the Q-Factor but keeping the spindle length the same, you are simply changing the curve in the cranks? Yes?/No?

3) I don't understand how the shortle spindle (BB Axle?) keeps a straighter chainline. I understand chainline, on a geared bike, to be the line between the middle of the two front sprockets to the middle one of the rear sprockets. That's perfect chainline and is achievable on today's bikes quite easily. What is changing?

 

 

 

 

 

[Wyatt Earp]

There is zip zero and no terminology to clear up. The Q-factor changes form a 156 to a 164 and 166 by Sram doing the molding of the carbon differently. The spindle length stays the same UNCHANGED' date=' which limits it's usage to a wide range of bikes, especially 29'ers, thus the three different Q factors on offer. So the reason for the shorter spindle is to keep a STRAIGHTER chain line. I can see where this is heading, yet again.[/quote']

 

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No, I think you're just looking for an argument.I'm trying to understand what's happening with new developments in the industry..

 

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Questions:

 

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1) "The molding of the carbon" - does that refer to the width of the BB shell?

 

2) By changing the Q-Factor but keeping the spindle length the same, you are simply changing the curve in the cranks? Yes?/No?

 

3) I don't understand how the shortle spindle (BB Axle?) keeps a straighter chainline. I understand chainline, on a geared bike, to be the line between the middle of the two front sprockets to the middle one of the rear sprockets. That's perfect chainline and is achievable on today's bikes quite easily. What is changing?

 

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I disagree with you, I think you are the one looking for an argument, that was my impression in any case, why did you not just say what you said in your second post in the first place(as I highlighted in black),the approach from my side might have been different.

 

I am quite done here, cheers.