disc brake problem
Post new topic   Reply to topic    MTBE Forum Index -> The Workshop
View previous topic :: View next topic  
Author Message
connell83



Joined: 19 Feb 2009
Posts: 4

PostPosted: Thu Feb 19, 2009 4:54 pm    Post subject: disc brake problem Reply with quote

I recently bought a decathlon 8.1 mtb.
its my first ever (proper) mountain bike so my knowledge is not too good.

at the decathlon shop i noticed that when i span the wheels around, front and back, the disc brakes were slightly rubbing on the disc of the wheel, and causing friction, so that the wheel cannot spin freely.
When I questioned them about this the lady, who said she knew all there was about mountain bikes as she was a serious rider said this is very common and after a short while it won't do that anymore. Is this true? I bought the bike on her word, but I am not sure about this.
Although the wheel can still spin, it slows a lot quicker and you can actually hear the noise of the friciton.

Thanks anyone who may help
Back to top
View user's profile Send private message

Register & log in to remove these advertisements!
badblood



Joined: 01 Jun 2008
Posts: 510

PostPosted: Thu Feb 19, 2009 5:31 pm    Post subject: Reply with quote

If it is really bad, it may just be a case of a poorly aligned caliper. Take the wheel out and check that the disc isn't bent.

While the wheel is out take a thin flat bladed screwdriver and wrap a CLEAN cloth around the blade a couple of times- now insert between the pads on the brake caliper and GENTLY push them apart into the caliper -as if you are prying them apart.

Pop the wheel back in and loosen the bolt that secure the caliper to the frame/forks, then while they are loose get somebody to pull the brakes on really hard - this will have the effect of centering the caliper on the disc.

While the brakes are on like this, tighten the bolts up again and you should notice a definite improvement - It may not go away completely but is should improve and get better as the pads wear in.

Make sure that you do not tough the disc or the pads as they can contaminate easily this can affect braking performance.

It is not as scary as you may think, just get everything you need laid out in advance and take your time.

_________________
Back to top
View user's profile Send private message Facebook
connell83



Joined: 19 Feb 2009
Posts: 4

PostPosted: Thu Feb 19, 2009 5:54 pm    Post subject: Reply with quote

thanks a lot badblood, I will give this a go being very careful as you mentioned. Thanks again for the advice
Back to top
View user's profile Send private message
tomlevell



Joined: 13 Apr 2008
Posts: 989

PostPosted: Thu Feb 19, 2009 6:23 pm    Post subject: Reply with quote

It is normal that you will get a scraping noise as the tolerances are very tight. You should be able to set them up so they don't noticably slow the wheel when span but still have a noise.
Back to top
View user's profile Send private message Visit poster's website
connell83



Joined: 19 Feb 2009
Posts: 4

PostPosted: Sun Feb 22, 2009 6:14 pm    Post subject: Reply with quote

you won't beleive this...

I said this bike was brand new and it has broke already!

I have rode it once. Basically, the axis that the rear gear rings are placed on has fractured at the end.

I went to (try) to ride it today and as I pedaled whilst the chain was on the smallest gear ring, the ring just span around and did not turn the wheel.
So I took the rear wheel off and as I did, a few small peices of fractured metal fell out and when I look closer, it was from the central acis that the gear rings are placed on to stop them spining, and actually cause the wheel to spin when you pedal. (i'm not sure what this component is called, sorry)

I will have to go back to sheffield (long drive) to take the bike back. This is rediculous, after only one ride!

Is this a common thing or...?

Surely not! So annoyed right now
Back to top
View user's profile Send private message
Gunner



Joined: 15 Apr 2007
Posts: 29331
Location: Under Whitestone-Cliffe on the Lake.

PostPosted: Sun Feb 22, 2009 7:16 pm    Post subject: Reply with quote

Is this the bike.............

http://www.decathlon.co.uk/EN/rockrider-8-1-34963132/


Certainly shouldn't have happened.

Note that the spec. sheet says, "Guarantee: 5 years on frame, 2 years on fork, shock and parts (excluding wear parts)."

However, I would feel a bit put off the Brand, and the shop by your experiences...............

How do you think you will play it............ Question

_________________
Your poison letter, your telegram, just goes to show you don't give a damn!!!
Back to top
View user's profile Send private message Visit poster's website
mr-marty-martin



Joined: 30 Jun 2008
Posts: 3778

PostPosted: Sun Feb 22, 2009 7:30 pm    Post subject: Reply with quote

Confused Confused Confused


defantly somin up there...
Back to top
View user's profile Send private message
connell83



Joined: 19 Feb 2009
Posts: 4

PostPosted: Sun Feb 22, 2009 9:49 pm    Post subject: Reply with quote

Gunner wrote:
Is this the bike.............

http://www.decathlon.co.uk/EN/rockrider-8-1-34963132/



How do you think you will play it............ Question


Hi Gunner,

Yes thats the bike. Its quite unbelievable that this has happened, I didnt even ride over any bumps on it yet, but I got the feeling right from the strart something was up with it.

Even if you threw a bike at a brick wall it shouldnt break there, its an inherant problem I think, must have been broke before.

I'm going to have to take it back and get a replacement bike or my money back.
Do you know what this particular component is called? So I can explain it to them on the phone.
Its the cyclindrical part that the gear rings slot onto on the rear wheel.
Thanks
Back to top
View user's profile Send private message
Gunner



Joined: 15 Apr 2007
Posts: 29331
Location: Under Whitestone-Cliffe on the Lake.

PostPosted: Sun Feb 22, 2009 10:19 pm    Post subject: Reply with quote

Is this any help in identifying your part:

http://www.parktool.com/repair/readhowto.asp?id=48

Wink

_________________
Your poison letter, your telegram, just goes to show you don't give a damn!!!
Back to top
View user's profile Send private message Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    MTBE Forum Index -> The Workshop All times are GMT + 1 Hour
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum