Compatibility of brake upgrade
 

Hi everyone, I'm restoring a Specialized Tricross and looking for new rim brakes. I really like the Shimano Ulegra BR-R8000 and the R8010, but am unsure which one would fit. I believe I need the R8000s since, as far as I can tell, I currently have Tektro 992 cantilever brakes.

Thanks for any input and let me know if more info is needed!

As the OEM brakes are cantis and this bike has clearances for significantly larger tires then common racing short reach calipers are made for I would assume that the proposed brakes won't fit. A measurement from the brake mounting hole to the rim brake track's center will give you the "brake reach" that a caliper will need to reach the rims. Compare with what Shimano lists for the 8000. The 8010 uses different attached to frame pivot bosses then a canti does.

Why the want for a change? Many people don't manage to set up their cantis it get complete advantage. Andy

Ah too bad. I've got roughly 70mm reach right now - maybe a bit more or less when I get the new wheels.

Any recommendations for this application? Mostly road use for me. Just a quick look around and the Avid Shorty Ultimate's seem pretty good. $180 for front + rear.

As for why I'm replacing, old ones are rusty and never worked too well.


https://cimg9.ibsrv.net/gimg/bikefor...44fd6c70f3.jpg

https://cimg9.ibsrv.net/gimg/bikefor...2eb32fa1c1.jpg
Given all the rust it seems that this bike is either out in the elements all the time, it sees a lot of salt, it rarely gets servicing or all three. Know that chain life is significantly reduced when running it with an abrasive coating it (as in iron oxide).

The pads look pretty work and dried out. When was the last time they were replaced? Maybe placing the thicker concave spacer between the pad and canti arm will bring the arm angle out to come closer to a right angle with the straddle cable when the pads contact the rim.

Since brakes are simple levers comparing canti arm lengths and the angle the straddle cable sits at (when pads touch the rim) is an easy thing to do. See included diagram for specs. Andy

All three, although the rare servicing only because it's been out of commission for quite a while until I replace the destroyed front wheel. Normally just elements and salt. It was sitting outside a bit more than usual during some garage renovation work - has a nice home now. I wouldn't ride with the chain that bad! Pads are probably about 3 years old.

NB [# 3] that's just a 5mm Riv nut; fit mudguards maybe , not brake center bolts....

Rust on parts your issue?, take them apart paint the rusty ones,
put it back together , put in new pad inserts...


Or,
Go with a Mini-V , long enough to clear the tire, brakes,
or convert to proper V brakes..



Avid ultimate cantilever brakes are certainty pretty..


http://cdn.mos.bikeradar.com/images/...au9-700-80.jpg
there are others..; Pauls comp
https://www.paulcomp.com/wp-content/..._gallery_1.jpg
https://www.paulcomp.com/wp-content/..._gallery_1.jpg


....

I would advise ditching that link wire setup and using a straddle cable instead. I use the Problem Solvers Wide Cable Carrier https://problemsolversbike.com/produ...arrier_-_16460 with similar Tektro CR-720 brakes and they work great. You will need to provide something to catch the cable if the main brake cable breaks or comes loose, lest it foul the tire; a reflector bracket or even a loop of twine will work. I second the suggestion to replace the pads; Kool-Stop Salmon compound pads are frequently recommended. I

Good to know about the nut, thanks! I'm not a big fan of colors on details, but the Avid's do make it hard to complain much haha. I'll choose performance over aesthetics every time though. Between restoring and the three you pictured, do you have a preference for best performance? I'd say I have about $200 max I'm willing to put toward brakes so I imagine that covers most cantilever options.

Definitely agree about the link setup, thanks for the link! I'll check out those pads too.

the link was a safety improvement , on front brakes,
done for people who ignored their brake cables fraying..
cable from lever broke, then...
on the front , with mountain bike knobbies ..
transverse cable with the power of both return springs
came down between tire knobs stopping the tire .. face plant time..

Power = math - leverage.. cable pull shorter is more longer is less
MA, Mechanical Advantage..
https://en.wikipedia.org/wiki/Mechanical_advantage







....

The just get a set off Kool Stop pads, new brake cables and housings - that will be the best performance achievable.

Don't you think there's a lot to be gained through better geometry? Just looking at mine vs the Avid's, it seems pretty clear that you can apply more pressure and do so more easily.

There is no "better geometry" - the straddle cable and brake pad adjustment control it all. You can duplicate the geometry of the Avids with your current brakes.

See Sheldon's treatise on cantilever brakes.

I might be misunderstanding things, and my wallet would be glad if I were, but reading that seems to confirm brake geometry differences. It says mechanical advantage is determined by:

1. Brake lever
2. PC/PS length ratio
3. Yoke angle

1 is a different matter and PS is determined by the frame and wheel.

PC and yoke angle seem to be at least partially dependent upon Attachment Point to Pivot Point length and the angle between PA and PS which are determined by the geometry of the brakes.

First time reading all this though, so I might be very wrong.

The geometry of the calipers themselves look fine. (I love the old Mafac and near copy old Shimanos with their horizontal arms. You have nearly that.) But I would can that cable. Get a standard brake cable and a cantilever bridle that has a ball or puck on one end and just bare cable on the other plus the triangular straddle piece that clamps to the brake cable. Set it up leaving all cables long. Ride it. Play with the bridle cable length and the amount of post on the brake pad showing. You will find you can get quite different powers and feels. (I find I often like my bridles long. Not as crisp feeling but lots of power to dry wet rims. And in panic stops, I don't go over the handlebars; just stop really fast.)

And as other said, get KoolStop pads. Yes, there are other good pads. But with KoolsAtop you know you are getting good pads. Also that if you still cannot stop, the issue is elsewhere.

Ben

The straddle cable length and the pad to arm distance the main controlling factors.

And as noted by [MENTION=391685]Andrew R[/MENTION] Stewart "...placing the thicker concave spacer between the pad and canti arm will bring the arm angle out to come closer to a right angle with the straddle cable when the pads contact the rim."

Your current brakes offer all of the adjustment you need to make them perform as well as any rim brake possibly can.

These might be nice (VO offers the same thing, Polished) ..


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