new moto x ybb flexing of frame

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new moto x ybb flexing of frame

9 posts from 5 voices

Started 9 months ago by dentlfly
Latest reply from dentlfly

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dentlfly
Member

just built up a new stock 17" ybb. carbon lefty fork and enve carbon wheels. my concern is how unstable the bike feels. it has a lot of lateral flex from headtube back to most of top tube. it is a very unsettled ride; almost scary. shop tried switching to a conventional fork but no difference. anyone have similar issue. i weigh 215 lbs so also wondering if need stiffer tubing. thanks for any input.

Posted 9 months ago #
bowtiguy
Member

wow! I hope this is an isolated case. I've got a new 19" Mooto X YBB on the way, should be here next week. I weigth a tad less at 185. For what its worth, I demo'd a 19" YBB during a local front range demo day and did not notice any flex coming off my 19" MXZ.

However, I did notice that the steering was a little quicker or snappy. Once I adjusted, it was no big deal. I took the bike up to speed ( big ring...down hill) and found it very stable, even under hard corner ( threshold) braking. It railed corners that I may have been bushwacking if I were on the MXZ.

Maybe get your weight back over the rear wheel a bit more. Less stem length with a layback post.

Posted 9 months ago #
JonC
Administrator

dentifly,
In the current 29er models we have gone to 44mm head tubes, and larger tubing both in the top tube/down tube and also have the added stiffness by running a 30.9 post in the RSL models, which when combined really tighten up the bike. The 26'' wheel bikes have not gone through those changes as of yet.

From what you describe above I would say it's a combination of very light parts(wheels)....what else is it built with?..., rider weight and tubing size that are making you feel what you are feeling. How tall are you?

What shop did you order it through?

Thanks,

Jon@Moots

Posted 9 months ago #
dentlfly
Member

jon,

my shop is in charlotte. ben the owner has spent time on phone with cory discussing this issue. build: lefty carbon fork, enve carbon wheels, sram xo 2 x 10. i weigh 220 lbs and am 5'10". this is a medium frame. i also have a 29" inseam. running continental race light tires. frame has the curved top tube. so far we have switched to a conventional fork with no difference. after bens chat with cory today we locked out the ybb to see if that makes a difference. cory said that ybb can cause this problem of flexure. was not able to test today. we also today put longer stem to get more weight forward. i am wondering if the geometry is off with this stock frame and will always be an issue for me. maybe need custom build. also would the full suspension divide be less susceptible to this front end flex? thanks for all your feedback in advance. it is a great looking bike; however i don't feel comfortable on it while riding at least 1/2 the time. i use it mainly for commuting on sidewalks, grass and light trails. i have had several neck surgeries in the last year hence the need for rear suspension. ed

Posted 9 months ago #
dentlfly
Member

jon,

are you there . waiting for a response to my last post. thanks.

Posted 9 months ago #
sbsbiker
Member

Dentifly, Jon's on the road back from a Portland,OR demo thus the slow response.

Posted 9 months ago #
JonC
Administrator

dentifly,
I'm back in the office and talked with Corey here at Moots. From the sounds of it you, Ben and Corey have worked this out?

Thanks,

Jon@Moots

Posted 9 months ago #
Satellite
Member

Ed,

Don't leave us hanging what did you find out and how is your ride now?

Satellite

Posted 9 months ago #
dentlfly
Member

sorry. was unable to access forum for last several days. changed out lefty carbon fork to a standard rockshox fork; no difference. put lefty back on and locked out ybb; not much difference. shop is now going to change out wheels from enve carbon to an aluminum set. will see. i am considering trying a divide mx frame to see if stiffer. for me there is too much flex in the front end of the frame. maybe a custom frame with stiffer tubes will be the answer.

Posted 9 months ago #

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