Cantilever to Mini-Vee

[robert17]

I have just stumbled across another thread whilst looking for something else which suggested changing cantilevers to a mini-vee to improve braking. This was on a Ridgeback Panorama - I have a Voyage so should be fine. I am sick and tired of the Tektro 720's I have - they require near weekly adjustment and two very good bike shops have tried in vain to help. Can anyone recommend a mini-vee which may be suitable. Also, a member suggested that changing the front only maybe good, however, the back brake on my bike is the one that gives me most hassle.

Thank you,

Robert.

[Brucey]

I have just stumbled across another thread whilst looking for something else which suggested changing cantilevers to a mini-vee to improve braking. This was on a Ridgeback Panorama - I have a Voyage so should be fine. I am sick and tired of the Tektro 720's I have - they require near weekly adjustment .....

....however, the back brake on my bike is the one that gives me most hassle...

what specifically is the problem? Power, 'feel', etc or is it just that you have to adjust the pads often?

The pad wear and adjustment (height, toe in etc) is essentially a function of the pad type and how you use the brakes. With the exception of some 'paralell push' V brakes (which I'm not sure are or were available in mini-V format) there is nothing you can do to alter how the pad articulates around the frame boss, regardless of what shape arm is used.

A mini-V will offer a greater mechanical advantage (MA) at the caliper, so more power, but the brake lever travel will be increased. Brake adjustments to stop the lever from coming back to the bar will need to be carried out more often with a mini-V than with a lower MA canti.

cheers

[CJ]

I'm recently returned from cycling over the Himalayas. Several extremely long and rough descents requiring utterly predictable and sometimes all-the-way-down (with stops to cool the rims) braking. Totally happy with my Tektro 720s.


20120827006 by Chris Juden, on Flickr

What's your problem?

[meic]

Has anybody else noticed that mini-Vs, especially the often recommended Tektro RX5, have become rather unavailable in many/most bike webstores.

They must have caught the public's attention.

[robert17]

I have just returned from my favourite bike shop as I was prompted by a cable broken at the end in the STI lever that I could not fix myself. My man found that my problem was in my levers, not at the brake end [have I been living unknowingly with this for four years?] I have the extra levers on the flats and they were not correctly set up! Put right and hey - a huge improvement. Tsk! Makes me wonder whether I needed to upgrade from the Oryx to the 720's!

Thanks all.

[Brucey]

-good result!

BTW cable fatigue inside the STIs is far from unusual; I have some thoughts on this topic which I will post separately.

cheers

[mattsccm]

Many V's are the same thing re labled.
I'll swap my Generic V''s for your 720's!

[Si]

Many V's are the same thing re labled.
I'll swap my Generic V''s for your 720's!

Are we starting to confuse mini-Vs with ordinary Vs here? This post certainly reads so, and could inspire someone to try ordinary Vs on a none V specific lever with potentially bad consequences.

We should be clear that the idea of mini-Vs is that they require less cable pull and so will work with a lever that was intended for canti or calliper brakes. Ordinary Vs require more cable pull and so need a V specific lever. If you put an ordinary V on a none V specific lever then you will need to set it up with the pads incredibly close to the rims (and need very true rims) otherwise you may find that the lever hits the handlebar before the brake has slowed you any.

A down side of mini Vs can be that their lack of length means that the wire will interfere with the mudguard on some bikes.

[meic]

I have seen V brakes in arm lengths of 105mm, 90mm, 85mm and 80mm.

It is obvious that 80 and 85mm are mini Vs and I think 105 is a normal Vbrake.

A 90mm might be just what you need to clear a 35mm tyre and mudguard but probably needs too much cable for most STIs in real life use. I am not sure if 90mm counts as mini V, ordinary V or just small V.

[531colin]

We keep going round and round this. Theres a long thread here http://forum.ctc.org.uk/viewtopic.php?f=5&t=63112&hilit=brakes&start=60 , including my photo of the tyre clearance with a GENETIC (just 1 finger width away from GENERIC) mini Vee.

[swansonj]

I'm recently returned from cycling over the Himalayas.

Completely off topic, but Chris, I'm going to guess the tandem with child on 25 Aug photo 26 wasn't part of your group? Superb photos as ever btw.

[Si]

including my photo of the tyre clearance with a GENETIC (just 1 finger width away from GENERIC) mini Vee.

I'm afraid that one instance does not make it a rule. As I said, it can be a problem on _some_ bikes. On others it will be fine - the only way to find out is to measure or test. On one of my bikes it caused problems because the tyre was quite large and the distance between drop-outs and bottom of the seat stay bridge was not what it could be.

[Brucey]

I think that the clearance offered with a 35c tyre using mini-V's (85-90mm) is usually OK for road use. With that in mind I'd happily (should that be...heinously....?) reduce the mudguard clearance by adding spacers etc for road use if I had to.

Obviously if rough stuff use/fatter tyres/preference demands greater clearances then it has to be full V's.

If you want V's of any kind that is. Plenty of folk happily using other (usually lower MA) cantis....

cheers

[531colin]

The immutable laws of the universe are against us here.......there are 2 gripes about mini-Vees....
1) not enough mudguard clearance.....to get more, simply move the braze ons up
2) not enough rim/pad clearance ....to get more, reduce the MA by moving the braze ons down

That one ain't gonna fly........

[mattsccm]

Did I spell something wrong?