XTR BR-M970 V-Brake worth it?
 

Got a friend who has a singlespeed, and where the existing V-brakes on it very cheap -- they stop OK, but barely so. Modulation is pretty sucky even when adjusting the cables.

Upgrading the bike to discs is out of the question, just due to cost.

He wants to get something with top-notch stopping power, so he is looking at upgrading what he has on there to XTR BR-M970s, Shimano's best V-brakes.

I'm telling him consider Avid SD Ultimate or something along those lines and save the $10-$50.

Is the price premium for the '07 XTR stoppers worth it?

What's he using now, Promax? Those really are awful. I would recommend the basic Shimano Alivio-level v-brakes. The fancy ones just add unnecessary bells and whistles and reduce the weight a bit. They don't offer any significant improvement in stopping power. If he's already using low-end Shimano or Tektro brakes, he probably needs new pads (Kool Stop are great!) or better set-up or better cable routing, or some combination of those things. You're right, XTR v-brakes are a big waste of money.

If it's improved modulation you want, the levers may have more to do with it than the brakes. Shimano's servo-wave v-brake levers (currently available in XTR, XT, and LX) are very good for this, follow the directions for setup (i.e., remove all "adjustment blocks") and you'll be able to feather the brakes more affectively, as well as increase your braking power because of better leverage than with typical v-brake levers.......beyond that, the highest end v-brakes (Shimano XTR, Avid Ultimates) are about saving weight and bling factor, not increasing braking power. The one thing the Shimano XTR and XT have (not sure about LX but I don't think so) that the others don't is Shimano's "parallel push" design. It adds some complexity to the brakes, but from my experience it works great at keeping the pads parallel with the rim surface instead of traveling in an arc. Of the Shimanos and Avids, if you want really good linear pull brakes, I'd look at the Shimano XT's and Avid SD-7's. Combine those with some Shimano servo-wave levers and your friend will definitely have better brakes-

edit: if you do go with servo-wave brake levers, be prepared to also invest in some brake boosters, for the rear of the bike particularly. The increased power with the servo-wave levers will likely cause your seatstays to flex noticeably, which not only defeats the purpose of the increased braking power and modulation, causing fade, but it's also probably not so good for a frame. With brake boosters, the stays will be rock solid and the brakes will provide predictable modulation, as well as excellent power-

Three questions about the single speed:

1. Does it have steel rims? If so, forget about braking in wet weather.

2. What brake pads does he have? Some pads are very hard, so they last a long time... but they hardly brake in dry weather and don't brake in wet weather. Replace the pads with Kool Stop Salmon and you'll see improvements.

3. No cable kinks anywhere?

I don't have a ton of experience with this sort of thing, but it seems likely that it's not so much a stopping power issue as it might be adjustment and wear. I have the cheapo shimano with cheapo pads, alu rims, and if it's adjusted and not too worn I can stop a lot faster than I can... not fall of the bike? So I'd say, start by getting some better pads and recabling them, oiling the cables when you do.