Mini-V Brakes and STI Lever woes

[4Rings6Stars]

I've tried this setup twice now, on two different bikes. 105 9s STIs and Ultegra 9s STIs, both times to Tektro Mini-V brake calipers with stock pads. I have never liked cantilever brakes and I read all over the place that mini-v style brakes work great and are easy to set up and maintain.

The first time I tried (about two years ago), I used generic lined brake cable housing (the spiral kind). I had to set the pads up VERY close to the rims to get them to work, and they were still very squishy. I replaced the front with a canti and added a travel agent in the rear, works OK now but the rear is still soft.

Tonight I got some Ultegra STIs in the mail and decided to get my touring bike back on the road. This time I thought I would solve the problem and use better housing--Campy, the kind that has metal wires running parallel and is supposed to compress less. The result? SQUISHY brakes! The pads are lined up maybe 2mm from the rims and the brakes are still very soft.

These are my only two bikes with STI shifters (cross bikes), would I have better luck with Ergo shifters? The quick release on the lever would be nice for removing wheels since the pads are so close to the rim.

Anybody make Mini-V brakes and STI levers work well?
Am I just spoiled by my Campy dual pivots and BB7 road discs on my other bikes or should mini-v's work just as well?
Do I need more expensive brakes like TRP CX9/8.4?
Anybody have a disc fork for a 26" wheel Surly LHT so I can actually stop?

Sorry for being so longwinded, but at least the thread isn't about Lance...

[DRZRM]

Try the TRP 9.0s, they seem to work better. Though they may feel a bit mushy at the bar, you can lock up your wheels easily, which was never the case with cantis for me.

[bcm119]

I have TRP 8.4 and Ultegra 9s levers on one bike. They work well, in terms of leverage/stopping power... too well in fact. Not much modulation. I run the pads about 5mm from the rims, which puts the levers pretty close to the bar at full braking. For loaded touring, this would be a pretty good set up. For gravel roads or dry cross conditions, the lack of modulation makes it a little sketchy on bumpy descents.

[EricEstlund]

Feels mushy on the stand, or while actually riding the bike?

I have found set ups that had a squishy feeling in the stand were bomber on the ground.

You may also try replacing the stock Tektro pads with something stiffer and of better rubber. Koolstops are a generally good choice.

[93legendti]

I just put the Mini V's on my new Pocket Crusoe, they work great with Ultegra STI 10 speed levers. I'm using Jagwire. I am adding the travel agents only because its is hard to open the brakes to remove the wheels.

http://forums.thepaceline.net/showpost.php?p=1214565&postcount=18

[holliscx]

Eric which Kool-Stop pads work with the TRP 9s? I see a lot of different ones at Kool-Stop's site?

http://www.koolstop.com/english/rim_pads.html

[oldpotatoe]

Feels mushy on the stand, or while actually riding the bike?

I have found set ups that had a squishy feeling in the stand were bomber on the ground.

You may also try replacing the stock Tektro pads with something stiffer and of better rubber. Koolstops are a generally good choice.

Yep, what I see as well..powerful brakes, sometimes so much so they can flex the seat stays..but riding, and stopping, they really work well.

[Aaron O]

I've yet to use mini-v's, but I don't have the hatred for cantis that you seem to have. Are you using just the more CX style cantis, or also the older wider profile arm cantis? The touring style, wide armed cantis work very well and have a lot of stopping power. I've had no problem stopping a fully loaded tourer at moderate speed.

Thanks for posting something that had nothing to do with Lance.

[nooneline]

re: above comment - I don't know all the science behind it, but wide-profile cantis have the reputation of being far weaker than low-profile/tall cantilevers.

And a glance at a visual mechanical advantage calculator confirms this -
http://www.circleacycles.com/cantilevers/

[oldpotatoe]

re: above comment - I don't know all the science behind it, but wide-profile cantis have the reputation of being far weaker than low-profile/tall cantilevers.

And a glance at a visual mechanical advantage calculator confirms this -
http://www.circleacycles.com/cantilevers/

What he said..second gen XT and XTR, low profile, were some great stoppers. High profile, like the really unadjustable TRP(seen on a lot of sponsored CX bikes, cuz they are sponsored) to the older Myfac, are less powerful, by design.

Plus many CX racers dig high profile brakes into their back when carrying or hit heels on them or interfere with panniers...low profile much better brakes.

Mini Vs better still.
Origin 8 makes some 9cm mini Vs, about $12 per end..swap the pads for Clark's cross pads..using road slide ins..great brakes for less than $20, $40 per bike.

[rice rocket]

Try the TRP 9.0s, they seem to work better. Though they may feel a bit mushy at the bar, you can lock up your wheels easily, which was never the case with cantis for me.

That would make it more squishy. The longer the arm length, the more mechanical advantage you have on the pad, which will make any flex even more apparent. I went with the shortest one available (BMX setup from Tektro, 8.0 cm arms) to get the most pad travel per distance pulled at the levers, and less mechanical advantage (and thus the stiffest). On a setup w/ 7800 levers, it's more power and just as stiff as my 7800 calipers + stock shimano pads.


OP: Did you try a new pad? Koolstop's CX pad is pretty good. I have a setup w/ road-BB7s and this mini-V setup (on two different cross bikes) and the mini-V setup is by far the stiffest (not that the BB7 setup is super mushy either, it stops with confidence and modulates well).

[Aaron O]

Not my experience, but use what you like. I don't think I've ever seen anyone argue that the CX style cantis had more stopping power (and they don't). As for the digging in your back, I'm not racing cross, and neither is 4ring. A long armed canti with low straddle gives a lot of power.

Paul doesn't seem to agree either:

Neo-Retro
A modern twist on a classic design. The Neo-Retro is a high profile cantilever brake based on the famously powerful Mafac Tandem brake. Our sealed pivots and modern adjustable brake pads prove that some things only get better with time.


Touring Canti
Looking for long-armed power of the Neo-Retro but want something low profile? The Touring Canti brings the brake arms in toward the wheel, offering much more clearance without sacrificing too much power.

[oldpotatoe]

Not my experience, but use what you like. I don't think I've ever seen anyone argue that the CX style cantis had more stopping power (and they don't). As for the digging in your back, I'm not racing cross, and neither is 4ring. A long armed canti with low straddle gives a lot of power.

Paul doesn't seem to agree either:

Neo-Retro
A modern twist on a classic design. The Neo-Retro is a high profile cantilever brake based on the famously powerful Mafac Tandem brake. Our sealed pivots and modern adjustable brake pads prove that some things only get better with time.


Touring Canti
Looking for long-armed power of the Neo-Retro but want something low profile? The Touring Canti brings the brake arms in toward the wheel, offering much more clearance without sacrificing too much power.

whatever, not looking to argue.

The heel and pannier 'issues' are some of the things my customer's mention, with high profile cantis.

[Aaron O]

whatever, not looking to argue.

The heel and pannier 'issues' are some of the things my customer's mention, with high profile cantis.

Hence my suggestion of using low in the back and high in the front ;)

For what it's worth, I have size 12 feet and don't have strike issues with my Koga Miyata...but that bike also has very long chain stays. I suspect this would only be an issue for people using racks on bikes not really designed for them, or designed poorly.

[4Rings6Stars]

I'll start with new pads, I guess.

If that doesn't work I'll probably spring for some 8.4s.

Aaron, I might be PMing you for canti suggestions eventually... or buying a disc fork for all my CX bikes. :eek:

[bcm119]

That would make it more squishy. The longer the arm length, the more mechanical advantage you have on the pad, which will make any flex even more apparent. I went with the shortest one available (BMX setup from Tektro, 8.0 cm arms) to get the most pad travel per distance pulled at the levers, and less mechanical advantage (and thus the stiffest). On a setup w/ 7800 levers, it's more power and just as stiff as my 7800 calipers + stock shimano pads.


OP: Did you try a new pad? Koolstop's CX pad is pretty good. I have a setup w/ road-BB7s and this mini-V setup (on two different cross bikes) and the mini-V setup is by far the stiffest (not that the BB7 setup is super mushy either, it stops with confidence and modulates well).
That is a very smart idea. I have the 8.4s, and wish the arms were a bit shorter. The 8.4s have too much leverage and not enough pad travel with the 9s STI levers... but they are better than the TRP 9.

[EricEstlund]

Any compatible pad- in the case of the TRP and Paul that would be any "V type" threaded variety. The Thinlines are always popular and have a metal inner body that runs about 3/4 of the pad length.

Other nice options are the Cross- a bit shorter/ stiffer, and the V-type "holder" (for replaceable inserts). The aluminum carriers add stiffness to the pad, and you can mix and match breaking compounds to your hearts content. If you have issues opening the brakes because the pads hang up on fork legs or seat stays, go Cross. Otherwise the mtb type should be fine.

Just as a point of interest, most Paul brakes come with Thinlines.

[GRAVELBIKE]

Mini-v-brakes come in several different lengths. How long are the author's brakes (measure from center of mounting bolt to center of where cable attaches)?

If the brakes are too long, you'll have too much leverage, and they can feel soft (especially on a flexible frame/fork). Something in the 80-85mm range will usually work fine with conventional road levers/shifters.

And as others have said, use good pads and compression-free housing.

[45K10]

I have a set of TRP's, worked great but the spring adjustment screw threads stripped out. Alum housing, steel bolt; kind of a bad design.

Anyone else have this problem?
I was thinking of trying to chase the threads and see if I could restore them.

[William]

Curious as to how many folks are using the Travel Agents? Pros or cons?




William

[Aaron O]

I'll start with new pads, I guess.

If that doesn't work I'll probably spring for some 8.4s.

Aaron, I might be PMing you for canti suggestions eventually... or buying a disc fork for all my CX bikes. :eek:

I have some old Deore DX Cantis that I think worked OK that you can have for shipping...they'll need pads, but you're welcome to try them out.

[carlineng]

Not a fan of travel agents, as they just add another piece of complexity to the picture, and I've heard a lot of people complain about them. Squeaky, add friction, etc. etc. If a component isn't designed for a your specific use case, better just switch to something that is rather than force it.

I'm surprised by Paul's stance that the wide profile brakes are stronger, as Sheldon lays out a pretty convincing argument here:

http://sheldonbrown.com/cantilever-geometry.html

Note that he also mentions that while squishy brakes can be disconcerting, they don't necessarily mean lesser braking power.