Awful braking ability after expensive bicycle fitting

General cycling advice ( NOT technical ! )
cyclefitt
Posts: 8
Joined: 27 Jan 2018, 11:36am

Re: Awful braking ability after expensive bicycle fitting

Postby cyclefitt » 18 Feb 2018, 7:07pm

Excellent, thanks for all the posts. I am getting cross tops but also looking into changing my STI brakes for Ergo(n?)s/Tektro.

niggle
Posts: 3200
Joined: 11 Mar 2009, 10:29pm
Location: Cornwall, near England

Re: Awful braking ability after expensive bicycle fitting

Postby niggle » 18 Feb 2018, 8:51pm

cyclefitt wrote:Excellent, thanks for all the posts. I am getting cross tops but also looking into changing my STI brakes for Ergo(n?)s/Tektro.

What speed of gearing do you have, i.e. how many sprockets on the rear? The Campagnolo Ergos were never made to work with Shimano gearing, only other Campag components, but can be made to in certain combinations.

My touring bike has a specific variety (Ultrashift) of Campag Ergos for Campag 10 speed which just happens to work perfectly with Shimano 8 speed gears. Some other variants of Campag 10 speed Ergos apparently won't cooperate in the same way so it is a bit of a minefield really.

cyclefitt
Posts: 8
Joined: 27 Jan 2018, 11:36am

Re: Awful braking ability after expensive bicycle fitting

Postby cyclefitt » 18 Feb 2018, 9:47pm

Ah, I see. I'd rather not be fiddling around with things if I'm being honest. I'd like to be using compatible parts.

I have 3 gears on the front and 9 on the back.

Brucey
Posts: 30364
Joined: 4 Jan 2012, 6:25pm

Re: Awful braking ability after expensive bicycle fitting

Postby Brucey » 18 Feb 2018, 10:25pm

cyclefitt wrote:..... yes they are cantilever brakes......


it is possible to set cantilever brakes up so that they don't work at all well, and the only way to slow down appreciably is to get on the drops and squeeze as hard as you can.

It is also the case that some manufacturers fit combinations of parts that don't work that well.

If you can provide details of your brakes (pictures and/or details of components used) this may help

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

cyclefitt
Posts: 8
Joined: 27 Jan 2018, 11:36am

Re: Awful braking ability after expensive bicycle fitting

Postby cyclefitt » 25 Feb 2018, 12:07am

Hi, thanks for the follow ups. It is true that I have always found it a bit difficult to adjust the brakes well as the "v" of the brake cable fouls the mudguards slightly.

Here is a photo of the front brakes:

front.jpg
front brakes


and the rear:

rear.jpg
rear brakes

Brucey
Posts: 30364
Joined: 4 Jan 2012, 6:25pm

Re: Awful braking ability after expensive bicycle fitting

Postby Brucey » 25 Feb 2018, 3:34am

the straddles are about as low as you can get them which is good, but

a) if the brake blocks are worn, the straddle angles may be unfavourable by the time the brake blocks contact the rim and
b) those brake cables look about a million years old; the ends don't become frayed and/or rusty in short order.

The fact that they have gone rusty also means they were cheap galvanised inners anyway.

You could easily be losing over 50% of your brake effort in the cables without knowing. I would suggest that you replace the cable set with good quality outer cables, fitted with well-lubricated polished stainless steel inner cables.

Cheap cables that are averagely well prepared will work OK for about a year and then they usually need to be replaced if you want your brakes to work properly.

Your photos don't show what brake blocks are fitted or what the height setting in the arms is, or the clearance to the rim. All these things can affect the brake power too.

The brakes you have also benefit from having a drop oil applied to the pivots on a regular basis, without which they can even seize solid in the winter. Yours have clearly not been oiled for a long time; this won't by itself make the brakes awful but it will further degrade the action.

If you have more than enough mudguard clearance to the tyres, consider lowering the mudguards slightly so that the straddle cable can be lowered further. I would recommend that you fit a separate straddle and yoke,
Image
rather than keep the arrangement that you have; this will allow you to space the brake blocks differently, spread the arms further apart and this will allow the brake MA to be increased.

But most of these things are probably going to be the icing on the cake; the brake cables look cheap and ancient, they are almost certain to be corrupting whatever chance your brakes have of working properly.

hth

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

Samuel D
Posts: 2235
Joined: 8 Mar 2015, 11:05pm
Location: Paris

Re: Awful braking ability after expensive bicycle fitting

Postby Samuel D » 25 Feb 2018, 9:40am

I agree with Brucey that new cables and housings, the latter carefully cut to length per Sheldon Brown’s instructions and filed square at the ends, would likely transform the braking.

Is it my imagination or does the straddle of the rear brake rest on the mudguard, leaving the main cable slack and unseating its housing from the stop? If so, you must have next to no pad clearance.

cyclefitt
Posts: 8
Joined: 27 Jan 2018, 11:36am

Re: Awful braking ability after expensive bicycle fitting

Postby cyclefitt » 25 Feb 2018, 1:34pm

Some great tips here. I will order the Tektro triangle yoke thing. I've always had problems with the Shimano yoke as it is poorly designed to do asymmetrical braking force. I am replacing the inner cable right now as I am fitting cross levers at the same time.

The rear brake V cable does rest slightly on the mudguard. I'd really prefer not to adjust the mudguards as they have served me well and I have had so many problems in the past with them. Here is a photo of the front brake cantilever position:

front.jpg


I have the brake pads quite close to the rims by the way - I regularly adjust this so the clearance is small and the brake arm (?) is at right angles to the wheel rim.

Brucey
Posts: 30364
Joined: 4 Jan 2012, 6:25pm

Re: Awful braking ability after expensive bicycle fitting

Postby Brucey » 25 Feb 2018, 4:04pm

you do seem to have lots of clearance between the tyre and the mudguard (although I suppose it could be just the way the photo looks); I'd guess you could lower the mudguards a few mm, and see if the lower straddle makes much difference .

Note that if the inner cables are bad enough, you should change the brake housing as well; the liner will be worn and may well generate high levels of friction if it has crud embedded in it. Still, new inners are easy to fit and this will at least tell you if you are going in the right direction or not.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~