Front brake locking on by itself?

[Danny]

I was recently on a long ride with lots of steep decents and found I was regularly getting a loud vibrating sound from my front wheel which was like a brake locking on even though I wasn't touching the brake lever. . I also only got the sound when I was going above 17 mph. Often this started if I hit a small bump in the road and usually went on for about 30 seconds or until I hit another minor bump.

As this was mostly happening when I was going down quite steep and technical descents I was reluctant to lean over too much to try and work out if it was really caused by my brakes locking on somehow or was the result of something else vibrating or rubbing.

I was riding a Cannondale Synapse with a Shimano 105 groupset.

Any ideas about what could have caused this?

 

[Webbo2]

I was recently on a long ride with lots of steep decents and found I was regularly getting a loud vibrating sound from my front wheel which was like a brake locking on even though I wasn't touching the brake lever. . I also only got the sound when I was going above 17 mph. Often this started if I hit a small bump in the road and usually went on for about 30 seconds or until I hit another minor bump.

As this was mostly happening when I was going down quite steep and technical descents I was reluctant to lean over too much to try and work out if it was really caused by my brakes locking on somehow or was the result of something else vibrating or rubbing.

I was riding a Cannondale Synapse with a Shimano 105 groupset.

Any ideas about what could have caused this?

Have you checked whether your front wheel is fastened tight.

 

[Danny]

Have you checked whether your front wheel is fastened tight.

Well it was fastened as tight as it normally is. By which I mean you feel some obvious resistance when you close the quick release lever but not so tight that you really have to push on it to get it closed.

 

[ColinJ]

Can you pull the top of the wheel sideways?

I have had wheels with lateral movement due to hub problems .

Is the wheel true?

 

[figbat]

Disc or rim brakes? Hydraulic or cable?

 

[Ian H]

Disc or rim brakes? Hydraulic or cable?

The fundamental first question.