Bent Brake Disk
Discussion
Just over a year ago, I bought a bike from Halfords (I know but it was on a cycle scheme so had no choice!) It was a Carrera Fury 2010 model.
Shortly after I bought it noticed the front brake rubbing slightly. I took it back a number of times and generally it would be sorted for a few more bike rides before starting to make a noise again.
After my one year service it was worse than ever so I took it to an independent that I know and trust a little more than Halfrauds!
They have just called to say the disk is bent slightly. They have used a tool to bend it back a little but it will always be slightly off. A new part if £37 apparently but they recommend trying it first to see if they have fixed it.
Is this a normal thing to happen? Should I be chasing Halfrauds for a new disk? Can anyone recommend a better disk that might mean this doesn't happen again?
cheers
Mark
Shortly after I bought it noticed the front brake rubbing slightly. I took it back a number of times and generally it would be sorted for a few more bike rides before starting to make a noise again.
After my one year service it was worse than ever so I took it to an independent that I know and trust a little more than Halfrauds!
They have just called to say the disk is bent slightly. They have used a tool to bend it back a little but it will always be slightly off. A new part if £37 apparently but they recommend trying it first to see if they have fixed it.
Is this a normal thing to happen? Should I be chasing Halfrauds for a new disk? Can anyone recommend a better disk that might mean this doesn't happen again?
cheers
Mark
It isn't common but does happen.
By far the most common cause is doing a big stop after a long downhill or riding the brakes downhill, so they get very hot... and then stopping. If you get your brakes that hot, it is essential to cool them down before stopping.
If you do stop, the pads will be close to glowing and these will heat and expand the disc in the area that they cover, whilst the rest of the disc cools down and contracts. The result is the disc stresses unevenly and warps.
It will never go back to it's perfect shape and you would be well advised to change the disc.
Don't forget to carefully and slowly bed the new disc in, to get the best results.
By far the most common cause is doing a big stop after a long downhill or riding the brakes downhill, so they get very hot... and then stopping. If you get your brakes that hot, it is essential to cool them down before stopping.
If you do stop, the pads will be close to glowing and these will heat and expand the disc in the area that they cover, whilst the rest of the disc cools down and contracts. The result is the disc stresses unevenly and warps.
It will never go back to it's perfect shape and you would be well advised to change the disc.
Don't forget to carefully and slowly bed the new disc in, to get the best results.
Hmm, should let you know how I ride this bike as I think this is unlikely!
Prior to buying the bike, I hadn't owned a bike in about 4 years or so. When I bought the bike, I wanted a mountain bike but knew that I would riding it on the road most often. This is why I went for a bike with shocks that had a lock-out. I also had road tyres put on before I picked the bike up (not complete slicks but more road like).
I certainly do not ride the bike all that hard. For the first few months it was ridden to the station and back about 3 times a week (about 5 miles each way through residential streets).
Since the weather turned nice I am now riding it to a different place of work which is around 12 miles each way about once or twice a week. This is through the countryside but still on proper roads.
My iPhone app tells me that I have never been above 25mph and generally ride an average of around 12mph for around an hour each time. I haven't really ever ridden offroad as yet. I intend to but haven't got around to it yet!
M
Prior to buying the bike, I hadn't owned a bike in about 4 years or so. When I bought the bike, I wanted a mountain bike but knew that I would riding it on the road most often. This is why I went for a bike with shocks that had a lock-out. I also had road tyres put on before I picked the bike up (not complete slicks but more road like).
I certainly do not ride the bike all that hard. For the first few months it was ridden to the station and back about 3 times a week (about 5 miles each way through residential streets).
Since the weather turned nice I am now riding it to a different place of work which is around 12 miles each way about once or twice a week. This is through the countryside but still on proper roads.
My iPhone app tells me that I have never been above 25mph and generally ride an average of around 12mph for around an hour each time. I haven't really ever ridden offroad as yet. I intend to but haven't got around to it yet!
M
They can get knocked and put out of true - taking in and out of a car, hit by a stone etc. I've seen the guys at Hope true a disc with a tool but you can do the same yourself with an adjustable wrench. Treat it like trueing a wheel, spin the wheel and watch it go through the caliper to see where it's wobbling, or alternatively hold a felt pen so that it's just touching the disc and then spin the wheel which should then reveal high and low spots.
You then put the adjustable wrench on the spot you want to move, clamp it almost shut and then give a few pushes or pulls in the direction you need, don't go mad but don't be afraid to give it a push. It's steel so will need some force to make it move and stay. You may not get it perfect but will be better than when you started, I've done it myself on a couple of brakes in the past
You then put the adjustable wrench on the spot you want to move, clamp it almost shut and then give a few pushes or pulls in the direction you need, don't go mad but don't be afraid to give it a push. It's steel so will need some force to make it move and stay. You may not get it perfect but will be better than when you started, I've done it myself on a couple of brakes in the past
Ironballs said:
They can get knocked and put out of true - taking in and out of a car, hit by a stone etc. I've seen the guys at Hope true a disc with a tool but you can do the same yourself with an adjustable wrench. Treat it like trueing a wheel, spin the wheel and watch it go through the caliper to see where it's wobbling, or alternatively hold a felt pen so that it's just touching the disc and then spin the wheel which should then reveal high and low spots.
You then put the adjustable wrench on the spot you want to move, clamp it almost shut and then give a few pushes or pulls in the direction you need, don't go mad but don't be afraid to give it a push. It's steel so will need some force to make it move and stay. You may not get it perfect but will be better than when you started, I've done it myself on a couple of brakes in the past
+1You then put the adjustable wrench on the spot you want to move, clamp it almost shut and then give a few pushes or pulls in the direction you need, don't go mad but don't be afraid to give it a push. It's steel so will need some force to make it move and stay. You may not get it perfect but will be better than when you started, I've done it myself on a couple of brakes in the past
Interestingly I have the same bike and the front disc did the same thing on mine.
I put it down to me using the brakes too much on descents and bent it back in place with an adjustable spanner, no problems since although its only been a couple of rides since.
£37 is ridiculous for a disc by the way - the first place I looked (superstar components) have the same diameter discs for £11.
Edit :
heres an example of how bad things can get
http://www.singletrackworld.com/forum/topic/ashima...
I put it down to me using the brakes too much on descents and bent it back in place with an adjustable spanner, no problems since although its only been a couple of rides since.
£37 is ridiculous for a disc by the way - the first place I looked (superstar components) have the same diameter discs for £11.
Edit :
heres an example of how bad things can get
http://www.singletrackworld.com/forum/topic/ashima...
Edited by shouldbworking on Tuesday 30th August 21:24
Gassing Station | Pedal Powered | Top of Page | What's New | My Stuff