Ive just fitted 780mm renthal fatbar on my bluepig and there seems to be flex in the fox float 32rl 140mm qr forks that ive got fitted. At the moment im running a 90mm stem as its the only one i have. The renthal has replaced a 685 easton ea70 so im guessing the extra 95mm lenth of the renthal is exagerating the flex. i will be buying a shorter stem in the near future so hopefully thats the problem. Any help/advice or agreement to put my mind at rest would be appreciated.

Cheers

Nick

140mm qr forks? Probably the forks.

780mm is a pretty big bar, I’d imagine there would be a bit of flex there too.

can you modify your hub to accept a 9mm thru axle?

Nah, you’re probably right. The 150mm Float 32s i used to have were like noodles as soon as it got rough and that was with the 15mm axle. Also use a fatbar run at the full 780mm for reference. Quite tall and broad and it fits me well so i never cut it down. Reputation for being a stiff bar as far as i know.

Dont think i can modify it. Its a standard hub fitted to mavic crossrides and a quick google search to see if i can go larger says it cant be done. Would a shorter stem help? I didnt have any problems when running the easton ea70 bar (685mm length).

Cheers

Possibly as you’re just reducing the amount of leverage on the fork. That’s tenuous though and could probably be proved wrong by some good math. Would it possibly be that you’re hitting rough stuff harder as you have more confidence because of the extra stability provided by the wider bar? As result you’re now noticing the flex?

I have 140mm QRs and don’t think i’ve detected any flex – maybe I’m just a wussy rider

What does flex from the fork feel like?
I would have thought tyres and wheels deform and flex before forks?

Everything flexes! To me fork flex feels like the bike’s being deflected off line by bumps.

I noticed the fork flex when i put the front wheel between my legs and turned the bars slightly when doing up the stem plate. Ive checked the qr and thats tight enough so maybe it is just the extra bar length that exagerates the leverage. Just a concern as riding llandegla on sunday and didnt want any problems. I might switch back to the easton bar until i get a shorter stem

Nick

Cut 47.5mm off each end of your bars….that’ll cure it 🙄

Cheers Rorschach, makes perfect sense now 🙂

Nick, it won’t cause you any problems, just ride the wider fatbars and enjoy it. If thats the only time you’ve felt flex then you may not even notice it on the trail. How many times is your front wheel locked in place whilst you twist the bars when you are riding?! You could have mentioned thats how you noticed it at the start! Its a combination of a QR front wheel and the actual forks. You can get stiffer forks but your riding may not warrant them and anyway the flex is not going to cause them to explode and throw you over the bars, they just won’t hold a line as well through rough rooty and rocky sections as something stiffer.

Cheers Gotama. Your right about the wheel being locked in place. Just thought it might’ve been a problem on drops and jumps. Cant wait till sunday now

Nick