Mechanical disc brake problem on Woosh Big Bear

[Justin Fleming]

I've had my bike a year now and it's been excellent. I ride it 16 miles a day, 4 days a week usually.

My front disc brakes aren't gripping the disc. The pads don't need replacing - I've checked and had them checked.
The disc has been cleaned in the shop.

The cable is tight and there is probably 1mm or less gap between the pads and the disc.
I can pull the brake lever on hard and it doesn't touch the handlebar grip.
The pads close onto the disc but barely slow the wheel at all - even if you spin the wheel by hand.

I cannot work it out! Please help.

 

[trex]

Check the contact area first. Does the pads contact the rotor surface properly (flat)? If they do, then take the pads out and check first for traces of oil contamination. Check also the pad's thickness, it should be at least 2mm. Post a picture of the pads if you can.

 

[Justin Fleming]

Yes there is plenty thickness on the pad.
They are all cleaned and degreased.
They make good contact.

 

[trex]

if you have just degreased the brakes, it may need a day or so to bite. Otherwise, it seems that you have ruled out most of the possible reasons. I would suggest you ask Andy @ woosh to lend you a new caliper. Swap it in then return what you don't need.

 

[oldtom]

My front disc brakes aren't gripping the disc.
I cannot work it out! Please help.

My experience of cable-operated disc brakes on two bikes is that they are a pain in the proverbial, needing frequent adjustment.

On one occasion, I popped one bike into my local bike shop and the mechanic spent ages trying to improve the brakes with marginal success. His unsought advice was to ditch them and replace with hydraulic ones. He added that he no longer sold any bikes with mechanical disc brakes as customers were always complaining about them.

On another current bike, I have hydraulic rim brakes which are the best I have had on any of my own bikes. On that basis, I would happily buy a bike equipped with hydraulic discs but I will eschew mechanical discs in future.

Tom

 

[the_killjoy]

I have never found the front disc on my Wisper 905SE particularly effective, keep meaning to replace it with a hydraulic one ~ would a change of pad help?

 

[Deleted member 4366]

Swap the front one for a Hydraulic one that you can get on Ebay for £30 to £40. You'll never look back after doing that. It'll take about 5 minutes to fit and will never need adjusting.Stick to a branded one like Juicy, Tektro, Hayes, Shimano, Avid, etc. You don't need to replace the disc. The lever, caliper and hose come as one unit. After the front one, you'll probably want a back one too, which you can fit, but you'll lose the break cut-off switch, which is not the end of the world.

 

[Alan Quay]

When I've had similar problems it was because of pad glaze. Take the pads out, rough them up on a bit of medium sandpaper, put them back in then do a series of hard stops from 15mph in succession to bed them back in.

 

[footpump]

I find the mech disks do need a fair bit of regular adjustment (levers almost touching handlebars) but its fairly hilly where I am so brakes get a fair bit off use.
I'm on 4th set done nearly 3000 miles, the brakes were not stopping that well lbs noticed the rear pads were wearing unevenly and did not work as they should even after adjustment, (this was the 3rd set) so changed them been ok.

was not aware it was easy to swap to hyd disks which I have had on a mtb and prefer

 

[Benjahmin]

On the wife's Big Bear I have noticed that the outer brake cables are not too good. The ferrule on the end seems to be compressing the body of the cable and there are strands of the outer sticking out. This makes the brake heavy to pull and sluggish to release. Could that be it?