Brake pad touching tyre on road bike

[quezi]

I'm trying to fit new front and back caliper brakes to my road bike as the original cheap Tektros have busted after 4 years or so.

I bought a 2nd hand pair of tiagras, which proved to be too short drop-wise. So I did some research and picked up a pair of Miche brakes off wiggle - a relatively long drop on them - 57mm.
The front break now works fine, connects with the wheel rim spot on, but the back brake is still connecting with the tyre wall, must be at least 6mm off still. I can't realistically drill out a further 6mm as there isn't space on the drop.
I've tried re-seating the rear tyre numerous times, but it is positioned fine and is lining up with the groves where paint has been worn off in the past.

Beyond that I'm out of ideas? The bike is a Claud Butler Roubaix 2007 - I can't understand why the back would require such a long drop.

After some more googling the only realistic option I have is the Tektro R559, which is an extra long drop to 70 odd mm. Does anybody know of any other (ideally cheaper) options available in the 60 odd mm region?

Cheers.

 

[RecordAceFromNew]

If I were you I would measure the rim size. I think you have a wrong sized rear wheel.

 

[quezi]

Both wheels are the same size, measuring (approx) 63cm diameter from outer rim to outer rim.

 

[RecordAceFromNew]

Both wheels are the same size, measuring (approx) 63cm diameter from outer rim to outer rim.

In that case the distance to measure (it is a little tricky to be 100% accurate) is the centre of the fixing bolt to the centre of the rim's braking surface. That is the distance that corresponds to e.g. the Tektro's 55mm to 73mm and whether it is enough or too much for your bike.

Some bikes are designed to use longer drop brakes to provide better mudguard clearance.

 

[craigwend]

are your wheels fully in your dropout /ends?

the original spec? http://www.evanscycles.com/products...-2007-road-bike-ec015419?style=71307#features

 

[Supersuperleeds]

I am no expert, but on my brakes, I can move the block up and down (and spin it) by loosening a bolt over the blocks. I can easily move the block by 6mm. If this is a silly answer then please ignore!

 

[quezi]

In that case the distance to measure (it is a little tricky to be 100% accurate) is the centre of the fixing bolt to the centre of the rim's braking surface. That is the distance that corresponds to e.g. the Tektro's 55mm to 73mm and whether it is enough or too much for your bike.

Some bikes are designed to use longer drop brakes to provide better mudguard clearance.

It (very roughly) measures 56mm to both front and back rim.

are your wheels fully in your dropout /ends?

the original spec? http://www.evanscycles.com/products...-2007-road-bike-ec015419?style=71307#features

Yeah, I've tried re positioning rear in the dropout numerous times, it makes no difference. There is a ring of worn off paint at the end of the rear axel where the wheel sits, and the hub matches up to that ring perfectly (if that makes sense), suggesting it is in ok.
Stuff has been chopped and changed since I've owned it. The front wheel got vandalized and bent so was replaced, but the problematic rear wheel is original as far as I know (bought it 6 months used).

I am no expert, but on my brakes, I can move the block up and down (and spin it) by loosening a bolt over the blocks. I can easily move the block by 6mm. If this is a silly answer then please ignore!

Nope not a silly question! But the brake blocks are right at the end of these 'grooves', so unfortunately can't move them down anymore.


I may just blow the cash on the long reach brakes for ease. The problem makes no sense to me!

 

[RecordAceFromNew]

The problem makes no sense to me!

According to the spec here that bike is supposed to have long drop brakes. Why not measure the original you took off too?

 

[quezi]

According to the spec here that bike is supposed to have long drop brakes. Why not measure the original you took off too?

They were so broken that I (stupidly) decided not to keep them, so that's not possible - lesson learnt!

Does anybody know any alternative extra long reach brakes to the Tektro R559s?
I can't seem to find any at all really!

 

[RecordAceFromNew]

Does anybody know any alternative extra long reach brakes to the Tektro R559s?
I can't seem to find any at all really!

Depends on what drop you need, see this. Also sjs stocks different Tektro, Dia-Compe (and even one Shimano to 57mm). Harris might give you some idea too.

 

[quezi]

Ok I tried a pair of R559s and they don't really work, too big.

I managed to find the original broken brake that was taken off in a rubbish bag yesterday. It fits/lines up fine if I fit it back onto the frame, suggesting the wheel is seated fine.
Imprinted on the arms is 'hj-402aq'. Googling brings up a generic Taiwanese make, and there is nothing on the brakes to suggest they are Tekro, as the original bike spec suggests. The brake spec, here, shows a max drop of 57mm. The miche brakes I ordered have the same quoted drop, yet are coming up short.

I can't for the life of me work out what the problem is

They do appear to have slightly different profiles/shapes compared next to each other, but should both have the same reach overall based on those figures.

 

[accountantpete]

The drop is measured from the middle of the bolt hole to the centre of the wheel rim.

Have a look at this page http://velo-orange.blogspot.co.uk/2011/10/27-wheels-and-measuring-brake-reach.html

 

[mickle]

Its pretty simple - your new brake doesn't have enough drop.

A 6mm rat-tail file *might* lengthen the slot if there's enough material available. But the proper solution is a brake with enough drop.

Its not a common problem these days but back when every Tom Dick and Harry was trying to upgrade their 27" bike to 700c we used to see this all the time.

 

[quezi]

Its pretty simple - your new brake doesn't have enough drop.

A 6mm rat-tail file *might* lengthen the slot if there's enough material available. But the proper solution is a brake with enough drop.

Its not a common problem these days but back when every Tom Dick and Harry was trying to upgrade their 27" bike to 700c we used to see this all the time.

Both are long reach brakes.
Both the original rear and new Miche rear measure approx 56-57mm drop (slight error/variation). Original fits fine front and back. Miche fits OK front, but not on the rear. It's about 5-6mm short of the rim.

If the brake doesn't have enough drop why is the front OK but not the rear? Considering that both rear drops measure up very similar.

 

[Globalti]

I had this problem recently with my son's Triban 3; have a look at these pictures:

http://www.cyclechat.net/threads/strange-triban-3-brake-problem-pictures.109471/