Suddenly no Front Brake!

karl101

Pedelecer
Aug 2, 2011
87
7
Hello,

The front disc brake on my Wisper 905 SEL has failed. It was alight when I got to work, but going out this lunchtime I pulled the lever only to hear a clunking noise from the brake mounting.

The cable is OK, the lever on the disk brake, where the cable is attached, levers up as it should, but when it gets to the top, there is a soft click/clunking noise and no movement on the pads.

Any ideas for what to look out for to repair it once I've gotten the bike home this evening?

Thanks

Karl.
 

kitchenman

Esteemed Pedelecer
Jul 9, 2010
1,309
7
Aberaeron, West Wales
I've just started riding a bike with disk brakes so will be interesting to find out what has happened here. Go careful on the way home Karl.
 

Mussels

Esteemed Pedelecer
Jun 17, 2008
3,207
8
Crowborough
I reckon it's a high chance the pads need replacing, they can break up or just fail fairly quickly when worn out. Also the adjustment on the non moving caliper can go past the end of the thread, if this has happened it may have moved past the end of the thread (think about when you unscrew a bolt and keep turning it, there's a little click and jump backwards on each rotation). There isn't a lot else to go wrong like that.
My pads need replacing fairly often but I ride a lot through town.
 

karl101

Pedelecer
Aug 2, 2011
87
7
Mussels, the bike is about three months old. I'd hope the brakes would of lasted longer. Will Check though.

Karl.
 

Blew it

Esteemed Pedelecer
Jun 8, 2008
1,472
97
Swindon, Wiltshire
Hello,

The front disc brake on my Wisper 905 SEL has failed. It was alight when I got to work, but going out this lunchtime I pulled the lever only to hear a clunking noise from the brake mounting.

The cable is OK, the lever on the disk brake, where the cable is attached, levers up as it should, but when it gets to the top, there is a soft click/clunking noise and no movement on the pads.

Any ideas for what to look out for to repair it once I've gotten the bike home this evening?

Thanks

Karl.
The 905 SEL is one of this years new models, so it can't be very old. It sounds as though the cam mechanism that moves the outer pad towards the rotor is reaching the end of its travel before the pad contacts the rotor. The most likely cause is the inner pad is too far away from the rotor and should be adjusted inwards using an alan key.

If your not sure how to do this, have a look at the service instruction PDF.

TEKTRO NOVELA SUPPORT PDF

If you can't fix it yourself, I would return the machine to the retailer, the warrantee should cover the brakes. Alternatively, take the bike to a local bike shop where they will set the caliper up properly.

Sorry link is not working as intended, it will take you to the Tektro website.

Click on 'SUPPORT' Then 'downloads', You will find the english instructions for Novelo about halfway down.

Have fun.
 

Mussels

Esteemed Pedelecer
Jun 17, 2008
3,207
8
Crowborough
My 906 came with (I think) organic brake pads, good round town but in a hilly area they can overheat and wear out very quickly. I changed to semi-sintered after that.

As Blew it said it could be badly set up giving the same symptoms as worn pads.
 

karl101

Pedelecer
Aug 2, 2011
87
7
The most likely cause is the inner pad is too far away from the rotor and should be adjusted inwards using an alan key.
Hello Blew It.
Yes, that was the problem. I was able to adjust the inside nut and brakes were restored. It'll also explain why I've been having to make cable adjustments on the arm, the nut has been shaking loose.

Thanks.
Karl.
 

Mussels

Esteemed Pedelecer
Jun 17, 2008
3,207
8
Crowborough
Hello Blew It.
Yes, that was the problem. I was able to adjust the inside nut and brakes were restored. It'll also explain why I've been having to make cable adjustments on the arm, the nut has been shaking loose.

Thanks.
Karl.
I've had that problem before, it will get worse. I'd forgotten about that one.
My solution was to use threadlock designed for RC car builders, works a treat but doesn't sieze the thread.