Brakes Upgrade


Senior Member
On my main road bike I have old RX100 side-pull brakes. I'm not super-impressed by their stopping power, and it seems sometimes they become lopsided. I think also my rims are rather old now so braking feels rather bumpy.

Suppose I wanted to upgrade to something newer and better quality, to improve stopping peformance and ride quality, what would be my options? I'm open to purchasing new wheels / rims.

The frame is a late 1990s Orbit harrier, and doesn't have any additional braze ons to support cantilever brakes, but I'd be open to new forks if that would be an option.
Loch side.
Shimano RX 100s are excellent calipers. They are of the powerful dual-pivot type with high mechanical advantage and replacing them will not change anything. They have an adjustment screw that takes care of lobsided positioning. If they feel bumpy, the bumps are coming from the rim, not the brakes.

If you are experiencing poor braking performance you have to look at the fault elsewhere. Firstly, sort out the adjustment problem. Then, replace the brake pads with Koolstop salmon pads. The stock Shimano pads from those days were horrible and picked up aluminium from the rims. Then, see if your rims are still good by placing a straight edge across the brake track to see how concave the rims have been worn. If they are worn by about 0.6mm, replace the rim. If not, sand the rim with fine water paper to clean off any glaze.
Then replace your brake cables - inners and outers.

Further, brakes on bicycles are very misunderstood. If you can skid your rear wheel, your brakes are as powerful as they need to be. A skid means the rim is held stationary and using more force to hold them is of no avail. Dead still is dead still.

Expect rim brakes to take a while to react when the wheels are wet. Better brakes won't improve the number of wheel revolutions required to wipe the rim before the pads can bite.

Cantilever brakes were designed to give mud clearance, not to improve brake force, although they do that. But as I said, enough braking is enough. If you can skid a wheel, you have enough.


Senior Member
Fantastic reply. Thank you. I've been feeling nervous about my brakes, but it's great to know that at core the calipers themselves are sound. I was wondering if there would be any benefit in getting newer 105/ultegra brakes, but it seems that wouldn't confer much advantage.

I'll look out for the screw when I get back to the house (away from home for a few days), but I will certainly replace the pads. The rims are very old - more than ten years, and while of good quality have taken a beating. I'll check those out, but I was expecting to need to replace at least the rims if not the spokes too.

Regarding cables, this leads to a different question. I'm giving serious thought to changing my handlebars to flat. What sort of brake levers would match the RX100?
Loch side.
Rims don't age, but can wear out. Check for problems as I described above. Age is irrelevant.
Shimano makes flat bar brake levers that work with caliper brakes. Look for the model numbers etc on the Shimano website. It depends on whether you want integrated shifters or separate shifters etc. There are many choices, none cheap. Levers made for cantilever brakes will not work satisfactory. They pull too much cable and will give you an On/Off feeling when braking. Technically they "work" but performance is unacceptable in my view. It will be too easy to grab a handful and lock up the brakes.

I think your old bike needs a wash and lube, new cable and pads, and a long ride finished off with a beer. Stop spending money. Ride.
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