Wednesday, November 12, 2008

Shiny Brake Bits




Up until this year, the only brakes I really had any experience with were V-brakes and road calipers. When I built my Surly LHT, I decided to try something new and threw on some Tektro cantilever brakes (specifically, the CR720s they sell on VO). The CR720s had a fun retro, frog leg look...and the price was pretty good too.

I had heard all sorts of nightmarish stories about how difficult canti's were to set up and adjust so I didn't really know what to expect. When I finally got them, they weren't so bad. Definitely different from V-brakes and they required an extra tool (10mm wrench), but after a few minutes they came together nicely. For me, I've learned it is best to set the position of straddle cable first (with no tension from the brakes) and THEN pinch bolt the straddle wire to the brake.

I found the stopping power was pretty good, though they were greatly improved (I'd say by 15%-20%) when I swapped the stock pads with Salmon Kool Stops. The brakes definitely cleared the wide tires and fenders with plenty of room to spare.

This brings me full circle to my Bilenky. I ordered it with V-brakes in the back because at that point I had never used canti's. The bike came and was great, though the rear brake always felt mushy. This was due to the really wide fenders in the rear. The V-brakes never fully compressed because they kept squeezing the rear fenders.

I decided a few weeks ago to put canti's on the back (the same Tektros on my Surly). This took a little more fidgeting. There was no built in center stop for the rear cable and many off the shelf cable stops wouldn't work because of the big honking Carradice SQR block on my seat post.



I ended up ordering a Surly Stainless Steel Cable Hanger from VO. It didn't quite work in the center of pinch bolts (I needed spacers and didn't want to go around hunting for some) so I set it off to the side where the head of the bolt presses it against the frame. It worked great, but threw off how the straddle cable hung because it wasn't perfectly centered. This left one brake pad constantly closer to the rim than the other.




Fortunately, the yoke that came with the Tektros had a nifty little feature that I had never used before. On either side of the yoke were two small screws that act like pinch bolts for the straddle wire. I simply centered the brakes and pinched the wire in the yoke, thus keeping the brakes always centered! It's a great elegant solution when you have "problem" brakes, or in my case a cantilever set up that isn't perfectly centered.

Anyone else have some fun brake set-ups?

12 comments:

bmike said...

Russ - you should be able to run that Surly hanger without spacers. I ran it on my CrossCheck that way - just put it on the bolt as I threaded the seat collar together. Worked fine.


Oddly - I just swapped my canti's for some V-brakes. Far more stopping power with the Avid V's off my MTB than I had with the Cane Creeks.

Waiting on an On One Mary bar to make the transformation complete...

RussRoca said...

bmike...i tried it that way at first...but the Bilenky doesn't use a seatpost collar, it's integrated into the frame...and that slot that gets pinched when it's clamped down is a few mm big enough that the hanger won't stay put....

Wayne Myer said...

The last time I had cantis was on my Mongoose Rockadile mountain bike. I loved that frame, but I hated adjusting the cantilever brakes.

I installed a set of Dia-Compe 987 brakes (in purple, no less). These went a long way to easing the pain of adjusting the brakes. But the yoke was still a weak point for me. Then I bought a pair of Straddle Rods. The ability to easily fine tune the brakes is amazing. And the added rigidity in the system is appreciable.

The first time I grabbed a fistful of brake with these, I got launched over the bars. It's my understanding that Paul cantis can still be a bit finicky to adjust; I suspect that Straddle Rods might go a long way to easing that pain. Fortunately, there is plenty of NOS still lurking around, e.g. on eBay.

Jerome said...

Thanks so much for sharing this. I wasn't aware of that nifty little yoke before. As always, I sure enjoy your blog and thanks for your work!

Cheers.

grump said...

I think credit for the little screws is due to Wayne Lumpkin, the original owner of Avid.

twodeadpoets said...

Great stuff! BTW Happy birthday Russ!

Tavis said...

I've been using the cr720s on my crosscheck for a while and I like the nice hanger straddle wire hanger they come with, however, the cr720s give me a lot of shudder on my front wheel, so I'm going to try the new 2009 avid shorty 4 on the front. It came with the shimano-style link wire, so I think i might give that a try unless someone can convince me not to.

RussRoca said...

tavis...what's your setup?

using road or mtn. brake levers?

have you tried the usual suspects of adjusting toe-in? are you using the stock pads?

R

bmike said...

tavis -

i have shudder as well on my cross check. was hoping to alleviate that with the switch to v's... but alas still here.

toed in, fidgeted, changed pads. (still awaiting some kool stop salmons - no one in town seems to carry them! aztec red pads suck!) i suspect its something misaligned with the canti-studs. left front brake wobbles a bit when i grab it, more than the rest. so the stud is too long or the brake is missing something. might try to add a washer or space.

but - it did this with my cane creek canti's too. headset is tight... maybe its the cc forks?

Tavis said...

I'm using road levers with mine. Kool-stop mountain pads. I've tried everything as well. Last weekend I cleaned the rims really, really, really well with rubbing alcohol and that seems to have helped. The new shorty 4 have redesigned arms to help with shudder, so I hope it helps. It may just be the fork. If only I could afford a wound-up commuter fork.

Mr. Beattie said...

I've run many different cantilever setups on several different cyclo-cross racing & touring bikes (Kona Jake the Snake, an old steel lugged Specialized Expedition, a front Tange 'cross fork on my Gitane commuter, I setup a friend's Koga-Miyata aluminum touring bike, and my newest rig is a Trek XO2):

What I've found is that the old Shimano low profile cantilevers from the mid-90's, just prior to the release of linear pull V-brakes, work the best. The cheap Alvio's are slightly lighter than the Avid Shorty 4's and work better. The LX version (in black) was probably the most robust, the XT version unfortunately had a plastic washer on the front when you tightened down the bolt. I've seen the XTR version but haven't bought them as last I looked they could for go up to $100 on eBay, and you need to be sure you have all the washer parts.

The wider / higher pull brakes Russ is using (like the vintage Mafac style ala Froglegs, Spooky, and various Dia Compe versions, also TRP) tend to have more mud clearance but less actual power / mechanical advantage. In a cyclo-cross race when you simply need to scrub speed and keep your rim clear of mud I don't doubt that the Spooky / Froglegs are the best there are, nearly all racers run them. But for actually touring and day to day use on a commuter I think the older lower profile which Shimano basically perfected with it's LX, is the commuter's best bet.

I'm sure everyone has read Sheldon Brown's article on the topic (http://www.sheldonbrown.com/cantilever-adjustment.html) but it bears repeating that the biggest difference with center-pull canti's versus linear pull cantis (V's) is that you can adjust the mechanical advantage by changing the height of the center-pull anchor. In practice, using the Shimano style link-wire, sizes A & B are probably the most effect, though remember going with an even lower adjustable straddle point gives more power (mechanical advantage) albeit with more "mush" in the feel of the lever. Fortunately that mush = stopping quicker, so long as the lever doesn't bottom out.

I rode about 10,000 miles on a pair of black LX's that came with my Jake the Snake when I bought it in 2000. I'm serious when I say they work, especially when paired with a set of Salmon Kool-Stop smooth stud pads. Also, some brake levers work better than others when it comes to canti's. I've used the Diacompe 287 C's (now discontinued I think) as well as Campagnolo Ergo Levers and I've found both to pull slightly more cable and work better than Shimano aero-levers and STI's.

GhostRider said...

The cable carrier hanger (the Surly bit, in this case), doesn't need to be tightened into place. It can be free to rotate on the seat binder bolt, and cable tension will keep it oriented correctly. The old aluminum "hockey stick" shaped ones worked this way...I don't see why the newfangled one would be any different.

And, for the record, this "Avid" style straddle wire yoke has some controversy behind it. It is possible that a company called Joe's Yokes may have been the first to market with this type of device, but certainly the Avid one (Tri-Dangle) is the one everyone remembers.