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Just how stuffed is my drivetrain?


Rudi Pollard

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I'm assuming the OP bike is a TREK Superfly, if he is running a 2 X 10 with 39 big ring on a GXP crank then that gap looks about right.

 

The only spacer you will need is the 2.0mm spacer on the chainring side which slides on first, then the wavy washer and then the rubber seal. The spacer has nothing to do with moving the crank over it is there to increase the presuure on the wavy washer which holds the seal against the bearing keeping out dirt.

 

Trust me I rode my superfly without the spacer for months and the cranks were not loose and the position of the chain ring is the same now that I have installed the spacer.

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I agree with the shops, the spacing is alright. The press fit BB needs a tapered/stepped spacer to run on the inner race of the BB bearing. I use one when I run a 36 tooth on my DS frame.

 

Chain suck should never be a problem, as the guide/protector plate should be enough to keep the chain from sticking in the small ring.

 

On a 34 tooth have 3-4 mm clearance, on the 36 its 1-2mm, I run a 1.5mm stepped shim to prevent the 36 from grinding on the plate. Don't forget as your suspension squats, the chain stay moves away from the chain ring. Your clearance looks like a 3-4mm.

 

Clearance without the spacer is 1mm if it is that much... Where do you get these tapered spacers you are referring to?

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I'm assuming the OP bike is a TREK Superfly, if he is running a 2 X 10 with 39 big ring on a GXP crank then that gap looks about right.

 

The only spacer you will need is the 2.0mm spacer on the chainring side which slides on first, then the wavy washer and then the rubber seal. The spacer has nothing to do with moving the crank over it is there to increase the presuure on the wavy washer which holds the seal against the bearing keeping out dirt.

 

Trust me I rode my superfly without the spacer for months and the cranks were not loose and the position of the chain ring is the same now that I have installed the spacer.

 

Oops my bad!!!! the wavey washer goes on first and the 2.0mm spacer on second then the rubber seal

 

post-2304-0-82299000-1396345797_thumb.jpg

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I'm assuming the OP bike is a TREK Superfly, if he is running a 2 X 10 with 39 big ring on a GXP crank then that gap looks about right.

 

The only spacer you will need is the 2.0mm spacer on the chainring side which slides on first, then the wavy washer and then the rubber seal. The spacer has nothing to do with moving the crank over it is there to increase the presuure on the wavy washer which holds the seal against the bearing keeping out dirt.

 

Trust me I rode my superfly without the spacer for months and the cranks were not loose and the position of the chain ring is the same now that I have installed the spacer.

 

Good to know that it looks the same on your bike as well. When I took the crank off there was no spacer in there, just the rubber seal thingy.

 

Thanks for the help

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Good to know that it looks the same on your bike as well. When I took the crank off there was no spacer in there, just the rubber seal thingy.

 

Thanks for the help

 

you need to get part numbers 1 & 2 in the pic or you gonna be changing your Bb drive side bearing soon

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Oops my bad!!!! the wavey washer goes on first and the 2.0mm spacer on second then the rubber seal

 

post-2304-0-82299000-1396345797_thumb.jpg

 

Yip so the spacer sits right against the chainring.

 

I have just checked it again with and without the spacer.

 

Without the spacer I can tighten the crank nicely but thenb the chainring touches the chainstay

 

With the spacer I cannot tighten the crank to the suggested setting but then it does not touch the chainstay... If I tighten it all the way the crank does not move...

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Ill ride it as is till a week before MTN Clarens and then replace everything in time for that race as well as Sani. I will have a look at the spacing this afternoon. Thanks for the help guys
Make sure you get a few good rides in before the race after changing everything.
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Yip so the spacer sits right against the chainring.

 

I have just checked it again with and without the spacer.

 

Without the spacer I can tighten the crank nicely but thenb the chainring touches the chainstay

 

With the spacer I cannot tighten the crank to the suggested setting but then it does not touch the chainstay... If I tighten it all the way the crank does not move...

 

No the wavey washer sits against the chainring (spider) then fit the spacer and then fit the rubber seal. torque the crank to specified torque setting (40Nm) I think (sitting in my office not near the bike) and you should be sorted.

 

If the crank tightens up or doesn't spin at the correct torque with all the hardware correctly fitted, then you have another problem with the press fit bearings not being correct or not fitted properly.

 

Your crank should spin freely after you tightened everything up

 

You will note in the picture that the "Non Drive side" bearing is different from the drive side as it has a boss on the inner race which faces inside the BB. I've seen many fitted incorrectly by LBS, either facing out or bearings fitted on opposite sides.

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No the wavey washer sits against the chainring (spider) then fit the spacer and then fit the rubber seal. torque the crank to specified torque setting (40Nm) I think (sitting in my office not near the bike) and you should be sorted.

 

If the crank tightens up or doesn't spin at the correct torque with all the hardware correctly fitted, then you have another problem with the press fit bearings not being correct or not fitted properly.

 

Your crank should spin freely after you tightened everything up

 

You will note in the picture that the "Non Drive side" bearing is different from the drive side as it has a boss on the inner race which faces inside the BB. I've seen many fitted incorrectly by LBS, either facing out or bearings fitted on opposite sides.

 

Thanks, I think the best thing will be I take it to a TREK dealer, because I have checked it and made sure everything is fitted correctly and it is still tightening up.

 

I think you might me right regarding the non drive side bearing. I noticed that it looked different than the drive side, and that it has a little step down but it is facing outward. You are saying that it should be facing inward correct? Ill take a pic of it and PM it to you to help me out

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Thanks, I think the best thing will be I take it to a TREK dealer, because I have checked it and made sure everything is fitted correctly and it is still tightening up.

 

I think you might me right regarding the non drive side bearing. I noticed that it looked different than the drive side, and that it has a little step down but it is facing outward. You are saying that it should be facing inward correct? Ill take a pic of it and PM it to you to help me out

 

therein lies your problem!!

 

Yes if you look at the pic its item 7, that step must face inside. You need to turn that bearing around.

 

Pressfit BB is actually easy to replace with a few homemade tools, I've changed mine twice already.

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Madmarc has you covered. Check the assembly of your BB first

 

AS for spacers, they come from the press-fit kit. PF92/PF95 and PF30/BB30. If you get a full kit, they normally supplied with spacers. I have plenty left overs from various kits and most decent bike shops should have them around.

 

Remember to check your logic, outer bearing race stays in the frame, shouldn't move, the seal should be tight on the outer, the inner bearing race should carry all the clamping forces, if not your assembly has gone astray.

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Madmarc has you covered. Check the assembly of your BB first

 

AS for spacers, they come from the press-fit kit. PF92/PF95 and PF30/BB30. If you get a full kit, they normally supplied with spacers. I have plenty left overs from various kits and most decent bike shops should have them around.

 

Remember to check your logic, outer bearing race stays in the frame, shouldn't move, the seal should be tight on the outer, the inner bearing race should carry all the clamping forces, if not your assembly has gone astray.

 

Bike shops will always have them laying around because they don't know where to install them or forget to install them :ph34r:

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Just some feedback regarding this.

 

I went to Cyclelab this morning and spoke to Andrew Mclean regarding the issue. The bikeshop which installed the bearings on my bike pressed the non drive side bearing in wrong way round and then conveniently left out the spacer and the wavy washer in order for everything to work.

 

Andrew's technician quickly sorted everything out and installed the crank correctly with the spacers and washers and he didn't charge me a cent for the job.

 

The clearance between my chainstay and chainring is a lot better now as well.

 

I just want to say thanks to Andrew and his team at cycle lab for helping me out even though they did not cause any of the problems to start with. Great service like that means that I will definitely use them in the future!!!

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I replaced my XT jockey wheels with aluminium ones. doesn't make too much difference I don't think. They were only around R150

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I would say about 3500 - 4000km

I am just getting half of that out of my group sets.

But I am obese and heavy on my bike.

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Just some feedback regarding this.

 

I went to Cyclelab this morning and spoke to Andrew Mclean regarding the issue. The bikeshop which installed the bearings on my bike pressed the non drive side bearing in wrong way round and then conveniently left out the spacer and the wavy washer in order for everything to work.

 

Andrew's technician quickly sorted everything out and installed the crank correctly with the spacers and washers and he didn't charge me a cent for the job.

 

The clearance between my chainstay and chainring is a lot better now as well.

 

I just want to say thanks to Andrew and his team at cycle lab for helping me out even though they did not cause any of the problems to start with. Great service like that means that I will definitely use them in the future!!!

When I removed the crank on my last bike(s) I discovered the wavy washer had broken into 3 pieces (this happened on 2 bikes with 2 new BB's). I emailed the SRAM suppliers to order a new one and a spare one and no-one ever came back to me so I just wound up carrying on without it! I think it just keeps the seal tight up against the face of the BB?

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