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Old 01-17-07, 11:18 AM   #1
jim10040
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Steel Rims + Canti Brakes = NO STOP POWER

I have steel rims under my cantilever brakes (I'm very sure they're steel...polished and very shiny). Does this combination REALLY take away stopping power, or is this just guessing? Would it help to scrub the rims with a scotch pad (scratching them like crazy) or is that a rumor? This bike is a mid-late 90s Univega Grand Tourismo. Should I change the rims out entirely? I already changed out the pads. Maybe I should get new cantilever brakes entirely (about $20 Nashbar)?
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Old 01-17-07, 11:25 AM   #2
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Doesn't matter what type of brakes, stopping with steel rims is not good. If you value your physical integrity replace them.
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Old 01-17-07, 11:26 AM   #3
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yes it's true they are a bad combo. Not sure of what type of combo. Inexpensive bike=cheap parts.
Chrome rims are so slick that it takes a good gripper to get the pads to stop the wheel from spinning. And depending on your canti's they and the type of lever you have may be the true culprit. As for the Scotch brite technique, I doubt if you can even scratch the chrome with a plastic Scotch brite pad. Try a sand paper in the 100 grit catagory and cross sand the braking surface. It may help it may not, but what it will do is expose the metal underneath to the elements. Remeber chrome is for protecting raw metals...good luck
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Old 01-17-07, 11:45 AM   #4
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Check the rims with a magnet to be sure they're steel. On that bike, I doubt they are unless the original wheels were switched out at some point. Assuming they're aluminum, new pads (preferably kool stops w/salmon compound) might help.........if the rims turn out to be steel, replace them. Steel rims are no good for braking, you can clean them, replace the pads, etc. and it will make little or no difference. And if they get wet, you will have virtually no braking at all. Been there, done that, and it's scary-
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Old 01-17-07, 11:52 AM   #5
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And if you get somewhat reasonable stopping power on the rims while dry... it is a whole new ballgame if they ever get wet.
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Old 01-17-07, 11:58 AM   #6
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If those wheels are original, I would bet anything that they are aluminum. jim
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Old 01-17-07, 12:12 PM   #7
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Quote:
Originally Posted by jim10040
I have steel rims under my cantilever brakes (I'm very sure they're steel...polished and very shiny). Does this combination REALLY take away stopping power, or is this just guessing? Would it help to scrub the rims with a scotch pad (scratching them like crazy) or is that a rumor? This bike is a mid-late 90s Univega Grand Tourismo. Should I change the rims out entirely? I already changed out the pads. Maybe I should get new cantilever brakes entirely (about $20 Nashbar)?
Hmmm... aluminum rims can be polished and shiny too. The best way to make sure they're steel is with a magnet. If it sticks, steel, if not, aluminum.

There is nothing special about canti brakes with steel rims. Steel rims give very poor stopping power when wet... with any type of brake.

The thing about canti brakes is, they can give excellent stopping power, but they are quite tricky to adjust correctly. Changing the angle and extension of the brake pads a little tiny bit can alter the stopping power drastically, by changing the mechanical advantage of the brake. This is difficult to get right, since old-style canti pads have threadless posts that sit on a rotating block, meaning that you can't adjust the angle or extension of the pads without changing the other two.

The cheap version of the Nashbar canti brakes uses this same type of pad. They will be no easier to adjust than your 1990s canti brakes!! However, they also sell Nashbar deluxe cantilever brakes, $40 for a front and back set. I have used the latter model and can highly recommend them (they are knockoffs of the Avid Shortys). This modern type of cantilever brake is much easier to adjust because it uses threaded V-brake pads and because the arms are held at a steeper angle. This makes them just about as easy to adjust as V-brakes, and you'll have a wider selection of pads as well.

Conclusion: if you have steel rims, they should be replaced (Aluminum rims are a whole lot lighter too ). As for the brakes, I doubt there is anything mechanically wrong with them. Either practice adjusting them carefully (can be frustrating), or upgrade to the modern canti brakes. If you go with the upgrade, look for prices on Avid Shortys or Tektro cantis, because these name-brand models are sometimes cheaper than the Nashbar version.
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Old 01-17-07, 12:29 PM   #8
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There used to be some leather-surfaced brake pads made by the UK's "Fibrax" which were alleged to improve braking on steel rims. I know they were made in a threaded-post form for caliper brakes, not sure if there was a cantilever/Mafac style.
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Old 01-17-07, 12:41 PM   #9
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Kool-stop salmon pads will work just fine for dry conditions. In fact, I find them to be a tad too grippy, even on steel rims. The problem probably isn't your brakes or even the rims, it's most likely the set-up. If you're getting hardly any stopping power the first thing to do is try to set up the brakes as optimally as possible. One of my wife's bikes has steel rims with centerpull brakes- which are less powerful than cantis- and it stops on a dime, thanks to the kool-stop continental pads (they're salmon compound) on it. Even in slightly wet conditions it stops decently.

Unless you're riding around in wet conditions all the time I wouldn't worry about changing the rims, just try dealing with the brakes first.
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Old 01-17-07, 12:50 PM   #10
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Oh yeah- whatever you do, don't purposely scratch up your rims, you'll ruin them if you take off the chrome, and I think all that would happen is you'd have some rims that eat up brake pads. Try messing with the brakes first and if that's not satisfactory get new rims.
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Old 01-17-07, 01:40 PM   #11
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Steel rims are so bad for stopping that back in the day they were textured to help.....
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Old 01-17-07, 02:39 PM   #12
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+1 to everyone's points about magnets and how steel don't stop

Just to clarify why (didn't see it already posted), steel has a lot lower coefficient of friction with most materials compared to aluminum which has a pretty high cf. Aluminum is pretty abrasive.
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Old 01-18-07, 02:39 PM   #13
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Hi again...thanks for all the answers! Haven't had a chance to stick a magnet on the rims yet, but as for adjusting the brake mechanism, ain't gonna happen. NOTHING about the brakes can adjust except the angle (up-down) & distance of the pads...the v-cable is fixed length, and there is no way to adjust the toe-in. Just by carrying the things around, the wheels are VERY light, so if they are steel (I am beginning to doubt it), they are VERY thin and should have bent a few rides ago when I was trying to bunny hop (imagine how gracefully a Clyde can bunny-hop a road bike) over ruts in the road. So...Next Task...Stick a magnet on the rim and know For Sure, and check out the $40 Cantilever brakes from Nashbar and the Avid & Tekro setups.
Again, Thanks!
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Old 01-19-07, 04:40 AM   #14
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Toe-in is set with a big-ass crescent wrench or similar... bend the arms. I'm sure you can change the length of the cross (straddle?) cable somehow, which in my undesrstanding is a very important thing with cantis. And of course changing the distance of the pads from the brake arm (and then compensating for the change by adjusting the cable length) can also change things a bunch.
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