# Crank won't spin!!!



## AlanS

Just installed new BB and trying to install Red crankset. The BB instructions said that if the BB shell is 68, then you add the spacers. I did. Otherwise, the cups would not screw in all the way...run out of threads. Put in the crankset, tightened it...totally rock solid, will not budge. I think that without the spacers, it would work, but the BB said to use them, and as I said, the bb cups would only screw in with about 1/8" space left. HELP!


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## AlanS

Could I, maybe have the wrong BB? I have the Truvativ GXP BB Team Cups 07A....???
The spindle can NO WAY reach the width of the length of the BB when installed. The spindle is shorter than the side to side width of the BB+Shell (about 100mm).


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## sixate

Get rid of the spacers.

I believe SRAM and Truvativ cranks use the same GXP BB, but the spacers are only needed on the 68mm BB shell with Truvativ mountain cranks.


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## AlanS

Thanks...NO SPACERS....the threads were kinda stiff, so I assumed I needed the spacers (plus, the tech sheet with the BB said "68- add spacers"...maybe for mtb?). Anyway, just got to torque it down...it spins!


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## a0210817

*Same problem, different problem*



sixate said:


> Get rid of the spacers.
> 
> I believe SRAM and Truvativ cranks use the same GXP BB, but the spacers are only needed on the 68mm BB shell with Truvativ mountain cranks.


I have the same problem with 2010 Force crankset and BB. My BB shell is 68mm. I tried installing with and without the spacers, and nothing seems to work. If I include the spacers, the crank immediately binds up. If I don't include the spacers I cannot get the NDS crankarm to tighten down enough to remove side to side play.

I don't remember having this issue the last time I installed a GXP BB & crankset last fall so I'm really confused...

Any ideas?


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## PlatyPius

You can buy 1mm BB shims. Maybe your BB shell was faced a little too much? I keep the 1mm shims on hand for any such wacky issues.

http://www.universalcycles.com/shopping/product_details.php?id=2241


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## cosmo333

a0210817 said:


> I have the same problem with 2010 Force crankset and BB. My BB shell is 68mm. I tried installing with and without the spacers, and nothing seems to work. If I include the spacers, the crank immediately binds up. If I don't include the spacers I cannot get the NDS crankarm to tighten down enough to remove side to side play.
> 
> I don't remember having this issue the last time I installed a GXP BB & crankset last fall so I'm really confused...
> 
> Any ideas?


Spacers won't fix this. The way the system works is based on NDS arm bottoming on the cup and holding the bearing between the ridge on the spindle and the NDS arm. Take the arm off, regrease and put it on tight-if there is play the arm isn't on far enough. Sometimes it takes an install or two to get the arm up the taper on the spindle enough to eliminate play.

If the shell is crazy narrow (say 67 or less) then you would need to get it back to 68.

A SRAM road crank in a 68mm shell is without spacers. Spacers in a 68mm shell make it bind because the spider hits the drive side cup-drive side arm and cup do not touch.


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## Cyclo-phile

Cosmo is correct.


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## PlatyPius

cosmo333 said:


> Spacers won't fix this. The way the system works is based on NDS arm bottoming on the cup and holding the bearing between the ridge on the spindle and the NDS arm. Take the arm off, regrease and put it on tight-if there is play the arm isn't on far enough. Sometimes it takes an install or two to get the arm up the taper on the spindle enough to eliminate play.
> 
> *If the shell is crazy narrow (say 67 or less) then you would need to get it back to 68.*
> 
> A SRAM road crank in a 68mm shell is without spacers. Spacers in a 68mm shell make it bind because the spider hits the drive side cup-drive side arm and cup do not touch.


Which is why I mentioned the 1mm shims....


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## Kristatos

Not wanting to hijack but also don't want to start another thread...

I finished building up a bike with Red today and during the first ride the cranks started to come loose (they had been torqued to spec). Basically it seems now like if I tighten the 8mm NDS snug then the DS bottoms out and it runs very rough and noisy. If I tighten the 8mm NDS to where there's no play it seems like it's really loose, and will back out and come loose again when riding. Is the fix to tighten the 16mm NDS allen bolt or something else?


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## cosmo333

Kristatos said:


> Not wanting to hijack but also don't want to start another thread...
> 
> I finished building up a bike with Red today and during the first ride the cranks started to come loose (they had been torqued to spec). Basically it seems now like if I tighten the 8mm NDS snug then the DS bottoms out and it runs very rough and noisy. If I tighten the 8mm NDS to where there's no play it seems like it's really loose, and will back out and come loose again when riding. Is the fix to tighten the 16mm NDS allen bolt or something else?


Do you have any spacers installed? On a 68 shell the DS should not bottom out-if you have spacers it will. By your description there are spacers or you're not using a SRAM/Truvativ BB. The 16 is the extractor cap, nothing to do there. 

"Torqued to spec" on the SRAM system means the NDS has been bottomed out and then the bolt torqued. In practice it typically takes more than the spec to bottom the arm out-if you install the arm with a torque wrench it isn't going to bottom out. At the shop I do not use a torque wrench on a SRAM system (oh the horror!!!!!!!!!). Grease everything, 8mm in hand and tight. Never had one with bearings too tight or fall off. It's a really simple system but you have to take a step back and think about how it works (as in, not like everything else).


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## Kristatos

No spacers. I did read the manual and technical bulletin. Shell is 68. DS spider bottoms out on cup before NDS tightens to spec. I've tried adding more grease and repeating per instructions. I will try that a couple more times to see if I can get it to work. I did think about it last night after posting and already came to the conclusion that the 16mm bolt won't do squat here - but I checked it anyways this morning with a 5/8" bolt and it is tight. 

Thanks for the input.



cosmo333 said:


> Do you have any spacers installed? On a 68 shell the DS should not bottom out-if you have spacers it will. By your description there are spacers or you're not using a SRAM/Truvativ BB. The 16 is the extractor cap, nothing to do there.
> 
> "Torqued to spec" on the SRAM system means the NDS has been bottomed out and then the bolt torqued. In practice it typically takes more than the spec to bottom the arm out-if you install the arm with a torque wrench it isn't going to bottom out. At the shop I do not use a torque wrench on a SRAM system (oh the horror!!!!!!!!!). Grease everything, 8mm in hand and tight. Never had one with bearings too tight or fall off. It's a really simple system but you have to take a step back and think about how it works (as in, not like everything else).


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## PlatyPius

The spider should never "bottom out on the cup". It should be very close, yes, but "bottom out" implies that something is grabbing/locking up.

Are you using a SRAM BB?


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## Kristatos

I realize it shouldn't bottom out - maybe it's not so much the spider bottoming out as just the seal getting too tight - nevertheless it starts to bind up and won't spin freely. It is a Red crank/bb. I think I am going to give up and take it to my LBS Monday if I can't figure this out tomorrow. 



PlatyPius said:


> The spider should never "bottom out on the cup". It should be very close, yes, but "bottom out" implies that something is grabbing/locking up.
> 
> Are you using a SRAM BB?


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## Kristatos

Well, got it worked out. I took it apart again and I think the seal went on right the next time I assembled it or something as it now works like a champ. Had a great 70-miler with lots of climbing on it yesterday - great crankset.


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## frdfandc

The Sram cranks sometimes require installing and then removing the NDS crank arm several times to get all the play out of the crank.


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## Joe Nation

I just got in a fritz trying to fit my new Red cranks. I bought a SRAM/Truvativ GXP 2007 BB (that's what it said on the box), and without even getting a cup in the frame, I gave up when I test-fitted the DS cup on the spindle and it hit the spider. Figured I needed a different BB, but having read this thread I guess not.

I'm off to try again, fingers crossed I just need to fit it right and it'll be ok


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## mjdwyer23

This thread just saved me a headache -- I reinstalled my NDS Rival crankarm a few times and eventually it had the correct tolerance.


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## mjdwyer23

Well, I have reinstalled my cranks several times, but I still can't get that last little bit of play out of it. Any final tips?


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## Kristatos

mjdwyer23 said:


> Well, I have reinstalled my cranks several times, but I still can't get that last little bit of play out of it. Any final tips?


As accurately as possible measure your BB shell. If it's 68mm you may just need to torque it down a little. If it's significantly smaller than 68mm you may need a 1mm or so shim on one side like platypus posted below. How are you torquing the NDS 8mm bolt?


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## mjdwyer23

Slept on it and reinstalled it this evening -- fully seated and good to go!


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## Pedaling Pugilist

cosmo333 said:


> Spacers won't fix this. The way the system works is based on NDS arm bottoming on the cup and holding the bearing between the ridge on the spindle and the NDS arm. Take the arm off, regrease and put it on tight-if there is play the arm isn't on far enough. Sometimes it takes an install or two to get the arm up the taper on the spindle enough to eliminate play.
> 
> If the shell is crazy narrow (say 67 or less) then you would need to get it back to 68.
> 
> A SRAM road crank in a 68mm shell is without spacers. Spacers in a 68mm shell make it bind because the spider hits the drive side cup-drive side arm and cup do not touch.


 You are the man! I was trying to figure out this same issue and had problems finding the right answer anywhere.
I was installing a Race Face BB30 into a 2017 Specialized Tarmac Comp with SRAM Red Cranks and Power Meter.
Cranks we’re binding up. I tried the supplied spacers between the cup and frame, didn’t work. Tried spacers on the spindle, no go. 
It came down to math, and having to figure out the spacers I needed between the bearing and the frame, as the ones sent with the BB were just the slightest bit too thick.
It was a game of mm. 
Thanks again for your sound advice and knowledge. You know what you’re talking about.


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