front tire "flex"?

pygmypony

Well-Known Member
#1
hey all...i have a 2012 trek xcal, with a rock shox reba fork. i've got a DT swiss C1800 wheel / hub with a wtb 2.3 vigilante tire on it.

i've started getting a good bit of front tire "flex" if i stand up on the pedals and really push hard side to side (going up a super steep climb for example)

is this just because i have too much powah! or is this something mechanical afoot?

my old wheel was bontrager mustang that also had flex.

when i got the new wheel put on at halters (thanks J!) there was no flex for the first 100 miles or so...but it has recently crept back in.

i tried adjusting my fork settings, both pressure and damping but nothing seems to work.

any tips / suggestions?

thanks in advance!

joe c
 

shrpshtr325

Infinite Source of Sarcasm
#4
if the wheel only has 100 miles on it and your feeling this id take it back to have the trueness checked and the spoke tension, threaded fasteners have a way of loosening up as they are cyclically loaded, and tension members have a way of stretching, (minuetly but still)
 

pygmypony

Well-Known Member
#5
if the wheel only has 100 miles on it and your feeling this id take it back to have the trueness checked and the spoke tension, threaded fasteners have a way of loosening up as they are cyclically loaded, and tension members have a way of stretching, (minuetly but still)
cool - thanks! i'm overdue for a trip there anyway.
 

jimvreeland

Shop: Hilltop Bicycles
Shop Keep
#9
Flex that transfers into tire rub generally isn't a loose wheel. Quite the opposite. A stiff wheel will transfer input from the ground into the top of the wheel while a soft will will flex and the top stays centered. It's more than likely the new wheel is stiffer than the old QR fork can take so like Ninja Monkey says, upgrade the axle.
 

pygmypony

Well-Known Member
#11
1) Pull off your QR/QR end caps
2) Install 9mm thru caps and RWS 9mm through axle
3)...?
4) Profit
Flex that transfers into tire rub generally isn't a loose wheel. Quite the opposite. A stiff wheel will transfer input from the ground into the top of the wheel while a soft will will flex and the top stays centered. It's more than likely the new wheel is stiffer than the old QR fork can take so like Ninja Monkey says, upgrade the axle.
thanks guys...can i upgrade the axle without upgrading the fork?

here's a couple of pix as reference...
 

Attachments

Santapez

Well-Known Member
Team MTBNJ Halter's
#14
1) Pull off your QR/QR end caps
2) Install 9mm thru caps and RWS 9mm through axle
3)...?
4) Profit
This. Went from flex and brake disc rub on turns on my QR release cross bike to nice stiffness. Luckily I run Stan's wheels and the 9mm through axle end-caps are a cheap upgrade.
 
#15
hey guys...quick update on this...

i went to halters for a wheel tensioning over the weekend (thanks cody!), and then got the new end caps and 9MM thru axle in the mail today (thanks amazon!).

i did the install today as per @Karate Monkey excellent step by step instructions provided above, and the flex is gone! thanks for all of the input!

i had a little trouble getting the non-drive side end cap off since i didn't have the end cap vise highlighted in this video. so i tried removing it with a pair of channel locks/shop rag as per this video

that didn't go so well, as i basically destroyed the old QR end cap (see idiot amateur mechanic pic below - it's the one on the bottom). so, after a few minutes of mangling that side, i just put the QR skewer back through from the drive side, and since i had crimped the non-drive opening with my shoddy mechanics skills, it popped right out!

i then used the paint brush handle in the photo to pop out the drive side end cap! (once i had properly removed disc brake lock ring, etc...)
IMG_7870.jpeg


here's a pic of the finished product
IMG_7869.jpeg
 
#16
For future reference for the 5 billion sets of QR DT hubs out there, you can usually pop the caps off by slyly getting the QR off kilter through the center, and hitting the cap from the other side. So, what you wound up doing, without mashing it.

Unior makes an end-cap pulling tool, now, though it doesn't work for QRs.