[AScott_user]

Hi. Recently i got some problems with my bike. Basically the problem is that when braking my front wheel wobbles like mad. I also noticed that my front wheel and rim got pulled to the left (towards the disc brake direction). I checked and realised the skewer had came loose. I tightened it back, making sure its rly tight without it coming loose again.

However, during the journey back home, on the road , the wheel still vibrate and wobble slightly under braking as well, this time the skewer is still tightened, not loosened as in the previous case, while the vibration and shaking isnt that severe as the former one as well.

What are the possible causes? Loose headset? Faulty headset? Rotor warp? Disc caliper severely misalligned?

Bike specs : Scott Aspect 2008. Currently using Rockshox Recon 351 coil U-turn fork. Using disc brakes (Shimano mechanical stock) and A2Z 160mm rotors. Using A2Z Titanium Skewers.

 

[highdelll]

can you move the wheel side to side by grabbing the rim? if so, check to make sure your cones are tight on the axle

 

[lyndonchen]

Like you said, a loose skewer would cause wobbling and a pull to the left. Only happens under braking? If the skewer really is tight, then it could be a warped rotor.

You can test the loose headset theory. Hold your front brake and rock the bike back and forth. If the headset is loose you'll hear a clunking sound. Put your hand on the headtube to confirm it's coming from the headset.

One last thought: ti skewers are inherently more flexible than steel ones. Try swapping in a steel skewer and see if the issue goes away.

 

[MikeyLikesIt]

cam you move the wheel side to side by grabbing the rim? if so, check to make sure your cones are tight on the axle

X2. The axle cone nuts probably worked loose.

 

[highdelll]

it also should be mentioned that a properly closed skewer simply will not come loose by itself. either it was knocked open or not secured properly---either way it's a great way to come home w/out teeth.

 

[AScott_user]

Like you said, a loose skewer would cause wobbling and a pull to the left. Only happens under braking? If the skewer really is tight, then it could be a warped rotor.

You can test the loose headset theory. Hold your front brake and rock the bike back and forth. If the headset is loose you'll hear a clunking sound. Put your hand on the headtube to confirm it's coming from the headset.

One last thought: ti skewers are inherently more flexible than steel ones. Try swapping in a steel skewer and see if the issue goes away.

The skewer is real tight now.

I just tested the headset. No clunking sound. No sound at all.

I see. I didnt know about this. Thanks for the info. :thumbsup:

Btw, i forgot to state that the wobbling and vibration comes and goes when the skewer is tight. As in, now that the skewer is real tight, my front wheel will only wobble under braking
at some point, not everytime i brake then will it wobble. My bad that i forgot to state this.

 

[AScott_user]

X2. The axle cone nuts probably worked loose.

I see. Since the hubs were pointed out, im currently using a Commencal DELUX TD-7F.

 

[retro83]

Check the calliper is fitted tightly and the cones on the hub are correctly setup (with the locknut fitted nice and tight).

it also should be mentioned that a properly closed skewer simply will not come loose by itself. either it was knocked open or not secured properly---either way it's a great way to come home w/out teeth.

Vibration + disc brakes can cause even a properly tightened skewer to undo.
More info here
Plus I have anecdotal evidence of finding my own Shimano deore skewers loose after fitting the wheel myself before I set off. I am 100% certain it was installed tightly enough, it simply could not have been tighter without using a lever on the QR handle. The forks were Kona P2s, used with Shimano LX disc brakes. This is why I switched to thru-axle forks.

 

[AScott_user]

Check the calliper is fitted tightly and the cones on the hub are correctly setup (with the locknut fitted nice and tight).

Vibration + disc brakes can cause even a properly tightened skewer to undo.
More info here
Plus I have anecdotal evidence of finding my own Shimano deore skewers loose after fitting the wheel myself before I set off. I am 100% certain it was installed tightly enough, it simply could not have been tighter without using a lever on the QR handle. The forks were Kona P2s, used with Shimano LX disc brakes. This is why I switched to thru-axle forks.

I'm not going back to Shimano skewers. Dump them if you have them. For 3 times, they came loose after i used them with many vibrations and lots of braking. I'm also 100% sure that they were tight enough. Any tighter and i cant close the skewer.

 

[highdelll]

...
Vibration + disc brakes can cause even a properly tightened skewer to undo.
More info here
....

i checked it out and he raises some good points. i'm fairly new to disc brakes [no probs so far] so i'm gonna try the experiment of marking and noting the angles. lord knows if anything can vibrate a qr open, it's the trails in upper bidwell park here in chico . who knows, i may have to re-evauate my position

 

[Bikinfoolferlife]

I'm not going back to Shimano skewers. Dump them if you have them. For 3 times, they came loose after i used them with many vibrations and lots of braking. I'm also 100% sure that they were tight enough. Any tighter and i cant close the skewer.

Shimano's skewers are among the best, so I'd look elsewhere for the problem. Is there play in your hub or not?

 

[AScott_user]

Shimano's skewers are among the best, so I'd look elsewhere for the problem. Is there play in your hub or not?

Guess its my great fault this time. my very bad. I checked and the skewer isnt a Shimano's skewer. Stupid me. :madman: Pardon me for that. Its a Formula skewer. I used a Formula front hub the last time, which was my bike's stock hub. But i changed the wheelset as my stock rims became severely untrue as it was only single-walled.

 

[AScott_user]

Busted headset

Okay. Heres the verdict. My headset is busted.

My friend , who is of bigger size and build than me, tested my bike. He pushed my bike forward with front brakes on much harder than me, and the headset makes the clunking sound. Sigh. Gonna replace the headset. :madman:

 

[highdelll]

whoa cowboy

Okay. Heres the verdict. My headset is busted.

My friend , who is of bigger size and build than me, tested my bike. He pushed my bike forward with front brakes on much harder than me, and the headset makes the clunking sound. Sigh. Gonna replace the headset. :madman:

double check your preload. true, you can ovalize your head tube or something [bigger prob], but , as far as i know, headsets don't usually 'break' - it's more likely to be maladjusted.
loosen your stem bolts enough to spin freely on the steer-tube. then tighten the preload using the top-cap bolt. not too tight...just snug-your forks should rotate freely w/out binding. then align and retighten your stem - use the f. brake as before and rock back n' forth.
hopefully you won't have any play...good luck!!

 

[lyndonchen]

Agree with highdelll. Before you get rid of the headset, play with the preload and see if that doesn't solve the problem. Insufficient preload is the usual cause of a loose headset.