Brake issue with RS80 wheels

jrab

I bought a pair of Shimano RS80 wheels last spring, to replace Planet-X Model B wheels which had served well but were getting tired, mostly in view of a Ventoux trip that I did at the end of May '13.

A few weeks before the trip I realised that I wasn't happy with the braking performance (not a good thing before your first trip to a big mountain....!!). I changed the brake inserts, no improvement. I changed the brake calipers from the original unbranded (probably Tektro) to Shimano 105, no real difference. Since then I've changed brake inserts endlessly for different brands & compounds, but have never been happy with the brakes.

My club rode the route of TdF Stage 1 again recently, and again coming down off Kidstones & Buttertubs I had zero confidence - the brakes make a truly nasty scraping noise, the lever feel is completely dead, and there doesn't seem to be much stopping power.

The bike is not used in the wet, and I've regularly cleaned (and replaced) the brake inserts and the rims. My winter/wet bike has very well-used Shimano R500 wheels and Miche Performance calipers, and my "retro" road bike has Mavic Open Pros with Shimano 600 Tri-Colour calipers - I'm happy with the braking performance on both these bikes, despite them being lower-spec.

Anyway, discussing this with my LBS, he suggested trying a different wheel, and maybe cleaning-up the rim with some fine wet-&-dry paper. So, I put the old Planet-X front wheel back in for a quick spin, and hey presto - the brakes worked!! I got some 1000-grade wet-&-dry and gently rubbed-down the front RS80 rim (going "with the grain", so to speak) then cleaned it well with soapy water and disc-brake cleaner.

Went out for a ride on Monday, and the front brake was massively better. At least for the first hour or so, which did include some decent stops. The I had a tight, twisty & gravelly 15% descent which needed some firm & consistent braking - and by halfway down the brakes were back to their old selves.....

Given that I only have the issue with these wheels, the only thing I can think of is that I'm getting some kind of pick-up from the aluminium rims which is getting embedded in the brake blocks? How do I resolve this without ditching some expensive wheels?!

Richard.

DiscoBoy

That is a strange problem indeed, I have no problem with my RS80s and "rubbish single pivot" brakes (planetx forged).

When you say you've tied lots of different pads, have you tried decent ones like the Koolstop Salmon? From what you say about the brakes fading over the ride, it sounds like your pads will certainly play a part, at least.

markhewitt1978

I have RS80 too and while I generally think my braking is bloody awful, it's no different to other wheels I've tried.

jrab

Thanks for the feedback.

markhewitt1978 wrote:

I have RS80 too and while I generally think my braking is bloody awful, it's no different to other wheels I've tried.

That's what's confusing me right now. Popping the P-X wheels in without doing anything to clean up the brake blocks = no noise, nice progressive feel, etc. (And the P-X's are several thousand miles old and have been used in the wet so the rims won't be in tip-top condition.)

DiscoBoy wrote:

When you say you've tied lots of different pads, have you tried decent ones like the Koolstop Salmon? From what you say about the brakes fading over the ride, it sounds like your pads will certainly play a part, at least.

Interesting you say that. I do remember running Koolstops on that bike, what I can't remember is whether I changed them because I wore them out or because I wasn't happy with them either..... I haven't really been scientific enough about it previously to remember which compounds work better than others, except for the fact that the last 3 different sets and the ones used on Ventoux have all been awful. Again, the fact that the P-X wheels work fine is screwing with any science!

On that ride on Monday the brakes worked fine for the 20 miles until that descent, went from ok to horrible in maybe half a mile, and then stayed horrible for the next 20 miles. That has to be related to the amount of brake pressure used on the descent??

Only one of my local shops stocks Koolstop, and they only have one pair in stock. I'm going to try them and see what happens. If they work I'll stick a big label on the bike saying "Koolstop Only"!!

Cheers.

2poc

How are you cleaning your bike? Using GT85? Sounds like there's something on the rims that's causing this.

2poc

Have you swapped your gear cables out?

How Far is too Far

I have a set of RS80 and not really noticed a problem with the breaking but I have found the rims to be very worn after 4500 miles, maybe they are softer alloy?

jrab

2POC wrote:

How are you cleaning your bike? Using GT85? Sounds like there's something on the rims that's causing this.

Good point, but I'm always pretty careful not to get any lubricant etc on brakes & tyres etc. I'd hope that rubbing the rims down with wet-&-dry and cleaning with soapy water then disc cleaner would get rid of this anyway (disc cleaner is supposed to be formulated not to leave residue). And the brakes were much better until I had to use them hard.

2POC wrote:

Have you swapped your gear cables out?

If you mean brake cables, no I haven't. But if it was a cable issue the brakes wouldn't work with other wheels either.....

I picked up the Koolstop inserts from my LBS, they only had one pair of dual-compound salmon-&-black ones, but they did also have a pair of pink Jagwire wet-weather inserts (which were half the price of the Koolstops, by the way...). I didn't have time to fit them before meeting some clubmates for a ride so used the other bike, but when I got back I swapped them out and went for a quick spin. Only had time for a mile or so round the block (and was goosed/starving after a pretty aggressive 42 miles!!) but they did seem better. Will have to give them a proper test, but maybe it is just that the RS80s are quite soft alloy and don't get on with hard pads?

Cheers,
Richard.

DubaiNeil

JRAB - you are not alone in this.

I also have RS80's and use Ultegra brakes. The original pads were not very effective, so I have tried Swissstop Flash Pro Green pads, which haven't made much of a difference TBH.

My other bike has carbon wheels, which I was concerned about (prior to use) when reading (on here) about braking issues with carbon rims, but find the braking to be far, far superior to the RS80's (using carbon specific pads & Campagnolo SR brakes).

I've got used to it, but do find on extremely steep descents in France (steeper & less open than Ventoux) I have come perilously close to running out of braking.

This is not a "I can't brake any harder because I will lock the wheel" feeling, but rather a "no matter how hard I pull on the levers there is no more braking to be had" one.

The wheels have almost never been used in the wet ('cos we don't really get that here!), but I would love to find a solution before this summers rides in France.

I have a spare set of Aksium wheels (well, the wife does!) - I'll give those a go to confirm that it is the rims that are causing my issues.

pirnie

I did find similarly poor braking with my old RS80s, but only towards the end of their life when the rims were worn to hell. I had no problems when they were newer though. As the rims wore out then the braking surface became incredibly smooth and the brake pads just didn't seem to want to grip (Swissstop green pads I think).

I guess this doesn't really help you but thought I'd add my experiences....