I contstantly hear about "clearance issues" when going from cantis to v-brakes. I'm not really sure what that is referring too. Is this clearance between the pad and rim? Is is clearance when they're opened up for changing wheels? Is it a worry that the brake arms/cable/noodle provide a smaller opening and therefore may catch more mud?
As I see it, the distance between the pad and the rim wouldn't be all that different between brake styles, unless I'm missing something about pull ratios, where perhaps the pads on a v-brake have to be set up closer to the rim than cantis to properly work.
As far as changing wheels, I already run long pads on my Paul cantis, so when I open them, they hit the frame - I assume it's the same with most v-brakes - so no difference there.
And as far as the arm clearance, etc - it wouldn't seem like the "opening" of the brake would be any more restrictive that the area between the seatstays and the bridge between them, if that make sense. And there's definately less clearance around the fork itself than the front brake.
So... talk me out of v-brakes. I've been seriously considering them to get rid of shudder (yes, I've tried all the usual remedies, which work for a while, but then it comes back as the pads wear in). I just want to know if the "downfalls" of v-brakes are real, or exagerrated. Also, which models work best with the previous generation Shimano levers (7800, 6600, 5600)?
I think that the major problem with running V-brakes on a cross bike is that most dual control brake/shift levers don't pull enough cable to make the brakes travel as far as they're supposed to.
To remedy that problem the brake pads have to be set closer to the rim, thereby limiting your brake clearance. I have a friend who set up his bike with V-brakes this past season and said they worked great but we had a very dry fall here in the midwest and we didn't get to ride any mud. Muddy rims and small brake clearance could be a problem. There is a part called a Travel Agent which is a cam that mounts on your brake that increases your mechanical advantage, I've heard they work well but sometimes you can catch your leg on the rear one when dismounting. My $0.02
I've switched to 8.4's on both of my bikes (paired with SRAM red shifter on one and Rival on the other) and will never go back to cantis . I live and ride in the Pacific Northwest, where thick gooey mud is the norm, and I haven't noticed any difference in pad clearance when thing get nasty. The only real difference that I've noticed since the switch, is actually having stopping power in wet and muddy conditions.
That's exactly what I was hoping to hear. I live in the PNW as well, and mud is my concern. If it doesn't seem to be a big problem, I may give them a go!
You'll have slightly less pad to rim clearance once set up but overall, they work great. You'll want to run the TRP CX9s with Shimano. The 8.4s are better matched to SRAM/Campy pull.
I've been doing some more research, and it appears that this is partially true. If you run the newest generation of Shimano (7900, 6700, etc) you need a brake with 90 mm arms like the CX9's or Tektro's RX6. The newest generation of Shimano has a different pull ratio than all of their previous generations, and different than SRAM or Campy.
If you use the older generations of Shimano (10 speed 7800, 6600 - as I do - or any 9 speed stuff) or SRAM or Campy, then you're better off with brakes with 85-84 mm arms, like CX8.4's or Tektro RX5.
That seems to be the general consensus, anyway.
TRP has tried hard to make it clear to us that this really is not true about their brakes...it's mostly a matter of how much mechanical advantage vs. pad clearance you are looking for. They will all work with each other, although you'll get the most power with a SRAM/Campy/Non Super SLR brifter and a CX9 but it'll have the least pad clearance. You'll get the most pad clearance with a Super SLR and a CX8.4. Other combos fall in the middle. Or you can even go budget with a Tektro version that is a bit heavier and doesn't have the nice brake shoes (they have both lengths) or opt for even more pad clearance with 80mm, ultra short budget Tektro 926AL brake that performed really well on our CXM Labs $643 Cheap Bike project.
Definitely try to get some of the cable adjuster noodles unless you have a Campy/Tektro/Cane Creek/TRP brake lever that has a quick release. That will make wheel removal and cable adjustment a lot easier. Good luck!
I'm using the 926s on my bike right now. Cheap, and they work really well. I've had at least one bike with cantis on it for most of the past 30 years, going back to BMX. These work as well as any canti I've ever had, less adjustment, and no readjustment.
Granted, these were purchased for temporary use, since I'd heard these were coming out...
I just bought a set of these for the monster crosser because I just was never happy with the wide-profile old Shimano cantits. I was egged on by the cheap bike project (jusst my speed!). Probably will eventually put Kool Stop Salmon's on but we'll see how it goes for now.
I actually recently purchased a pair of the TRP CX8.4s to replace an annoying set of KORE Sport+ cantis. I did everything I could to adjust the KOREs up until replacing all the cables and hangers and still could not get them to NOT drag.
Then enter the CX8.4. Total setup time with installation of new brake cables and learning how to tune them took me a total of about an hour. Best of all they have LOADS more stopping power than the cantis. Now I realize that with CX you dont need to stop on a dime or lock the rear up like say in XC MTBing but it does come in hand if you use the bike for commuting like I do. I have seriously fallen in love with these brakes, a breeze to tune and the stopping power allows me to modulate and slow myself down slowly, or if needed (like the other day) I can slam on the brakes and come to a skidding halt (with enough time to slap the back of some crackheads van as he cut me off to get to the local bar).
The centering screws for the CX8.4s do a TON and coupling that with the barrel adjusters you can really fine tune the pull to whatever your liking is. Now the 926A and RX5 are similar Mini-V brakes but with the only real difference being; 1) price, 2) weight, and 3) length of arm. I wanted the slightly longer arms of the 8.4 (84mm) to allow for fender use on my bike when things get wet.
All in all a great buy!
I also tried the 926's since they were so inexpensive. Much better power but pad-to-rim clearance is less than with canti's. I can't see forking out the money for the expensive versions, especially since I'm patiently waiting for discs...