Crux 2021

[stlrider]

So I'm kinda hating my CruX for CX racing.

Having some weird shudder with the front brake I can't seem to get rid of. Changed pads, different rotors, tightened the headset preload a bit more beyond just removing play, doesn't matter.

Only happening on cx races when I'm braking hard into corners.

Anyone else have a similar experience?


Also cannot for the life of me get the front mech to work right. Running a GRX DI2 front with a Power2Max NGEco Gravel 48/31. It's either set correctly and often refuses to shift, or set with it out a bit further and shifts up every time but occasionally throws the chain off.

Same mech and spider (46/30 rings) on my Diverge and that shifts perfect every time. I'm thinking it's because the CruX BB shell flexes so damn much coupled with the 1 extra tooth of difference. I need to try a proper GRX crank.

[yinzerniner]

. I need to try a proper GRX crank.

Winner winner chicken dinner. Pretty sure all documentation points to the Crux requiring both wide chainline cranks and FDs when running 2x. The diverge has no such requirement.

As for front brake shudder that's way more concerning. Possible it's due to the somewhat long axle to crown of the fork? Or maybe that ocmbines with the fork flex profile/design?

[Pyotrump]

So I'm kinda hating my CruX for CX racing.

Having some weird shudder with the front brake I can't seem to get rid of. Changed pads, different rotors, tightened the headset preload a bit more beyond just removing play, doesn't matter.

Only happening on cx races when I'm braking hard into corners.

Anyone else have a similar experience?


Also cannot for the life of me get the front mech to work right. Running a GRX DI2 front with a Power2Max NGEco Gravel 48/31. It's either set correctly and often refuses to shift, or set with it out a bit further and shifts up every time but occasionally throws the chain off.

Same mech and spider (46/30 rings) on my Diverge and that shifts perfect every time. I'm thinking it's because the CruX BB shell flexes so damn much coupled with the 1 extra tooth of difference. I need to try a proper GRX crank.

1. about wheel
Have you checked the NDS side spokes tension? Put another front wheel and try to replicate the shuddering.

2. Shitty F shifting
It should be connected with the support plate and support bolt.
Check this out: https://si.shimano.com/en/dm/RX815/temp_fix_fd
"When there is a mounting boss on the seat tube". 2. (3)

[tonytourist]

My Crux with a 50/34 and Ultegra 8050 FD shifts perfectly. Maybe the issue is the 17t difference? Try the 48/31 on the Diverge.

[stlrider]

Winner winner chicken dinner. Pretty sure all documentation points to the Crux requiring both wide chainline cranks and FDs when running 2x. The diverge has no such requirement.

The Power2Max Gravel uses the GRX spacing, but they're Rotor chainrings, as opposed to Shimano's proprietary ramps. So it's not a spacing issue, but I suspect it might just be the 17t jump + flexy bike + shift ramps that aren't Shimano. The crank is, for all intents, a 48/31 GRX, just with third party rings.

1. about wheel
Have you checked the NDS side spokes tension? Put another front wheel and try to replicate the shuddering.

2. Shitty F shifting
It should be connected with the support plate and support bolt.
Check this out: https://si.shimano.com/en/dm/RX815/temp_fix_fd
"When there is a mounting boss on the seat tube". 2. (3)

1. Good thought. I'll double check tension and try a different wheel set, though I'm about to just go back to my Boone for CX.

2. Yep, I always set that bolt. I angle the mech in a bit, tighten the main bolt and drive the adjustment bolt in until the cage is straight. I have height set to a 2mm gap between big ring and cage. I have high limit set to about a 1mm gap between the plate and the chain in big/little. Setting the high limit any further out makes the shifting better, but then I occasionally throw the chain completely off.

My Crux with a 50/34 and Ultegra 8050 FD shifts perfectly. Maybe the issue is the 17t difference? Try the 48/31 on the Diverge.

How'd you get 50/34 on the bike? Add a spacer on the DS?

I think that's what I'll try next, just swap chainrings over.

[cycleboyco]

Will be interested to see if swapping chainrings fixes the problem-I'm running the same P2M setup with the 46/30 Rotor-made rings and GRX FD on my Crux without any issues. I was considering seeing if P2M would sell me just the Rotor 48/31 rings for a little more top end and had not heard that there may be an issue with that combo.

[tonytourist]

How'd you get 50/34 on the bike? Add a spacer on the DS?

I think that's what I'll try next, just swap chainrings over.

I just have a SRAM DUB bb installed, no extra spacers. Quarq Dzero pm. No clearance issues. I posted these before somewhere before but can't remember.

[kgcx]

How'd you get 50/34 on the bike? Add a spacer on the DS?

I think that's what I'll try next, just swap chainrings over.

I just have a SRAM DUB bb installed, no extra spacers. Quarq Dzero pm. No clearance issues. I posted these before somewhere before but can't remember.

I've got a 36 inner to fit, used a 1mm spacer but it works.

Also, I have used my Ultegra front derraileur with grx rings, 31-48, and it will shift it on my crux. Did you use the correct screws with the front hanger? My shifted horribly with the standard screws that came on the bike since they weren't tapered, didn't realize that installed the wrong screws on accident.

[BikeTyson]

Looking to lighten up my Crux. Currently running GRX Di2 2x with 48/31t up front. I can get a really good deal on a SRAM Red crank arm. Is there a way to run subcompact rings (either 48/32 or 48/31) with the Red cranks? I can get a DFour power meter to run Shimano rings, but unsure if they'd work.

[uppis]

How'd you get 50/34 on the bike? Add a spacer on the DS?

I think that's what I'll try next, just swap chainrings over.

I just have a SRAM DUB bb installed, no extra spacers. Quarq Dzero pm. No clearance issues. I posted these before somewhere before but can't remember.

Are these chainrings made by SRAM?

[tonytourist]

They're 50/34 BOR rings. Oh yeah, just mounted my Schwalbe G ONE RS or whatever yesterday in 700x45. Looking forward to trying them out today on the road

[Matte86]

They're 50/34 BOR rings. Oh yeah, just mounted my Schwalbe G ONE RS or whatever yesterday in 700x45. Looking forward to trying them out today on the road

Beautiful with the 45c.. I know they come up skinnier than other tyres, but they stand out
What is the rim depth of those MCFK?25 or 35?

[tonytourist]

Thanks! The MCFK wheels are the GRV spec and are 25mm deep. I just used my calipers and the Schwalbes are sitting at 47mm on a 24mm internal rim.

[Matte86]

Thanks for your reply and checking the actual width..I mentioned it because the 40c were measured skinnier on 25internal..and on 24 of the Mcfk I was kinda expecting the same..maybe the 45 are more true to their size
Did you have the chance to try them?
Would have you thought of getting the Mcfk in 35?
I ask as I’m debating which rim depth my upcoming crux

[robbosmans]

They're 50/34 BOR rings. Oh yeah, just mounted my Schwalbe G ONE RS or whatever yesterday in 700x45. Looking forward to trying them out today on the road

That looks so clean. If only they put fender mounts on this thing…