Road bike - poor brakes

Rotor

Wife has got a Decathlon road bike. It has xenon QS 10 speed lever clusters (from my research this is campagnolo entry level) but the brake calipers have nothing on them so I'm guessing decathlon have used unbranded to save a little money.


I think this is a caliper problem because, after cleaning and sanding wheel rim to no avail I swapped her front wheel and pads to my bike and my bike still stopped fine whilst hers was still poor.


So, do people agree it's the calipers and, if so, which cheapish ones do I change to?


I confused myself reading up about it as there seems to be different leverage ratios between manufacturers so some are not recommended with other makes.


Thanks

Weird_Nev

Weir-d... Brakes should perform OK if new and properly set up. You should be able to stop the bike fine from the hoods position using your forefingers, and stop the bike quickly from the drops with a full grab of the lever.

(Just a word of caution - rims often have coating or anodisation on their braking surfaces to help them brake properly and stay durable... taking sandpaper to them isn't the best idea).

There are a number of things to check out.

Brake pads bed in over time. It could also have been a matter of adjustment. If the pads aren't hitting the rim flat, they won't perform well.

There's also some adjustment on the cable at the calliper, and you need the lever to be set so that you're getting good mechanical advantage. It's possible to pull the level to the bar if it's not set up right, meaning that your brakes don't work.

It's also possible that there was some contamination on the blocks or rim, but you seem to have eliminated that as an issue by swapping them to your bike.

Before spending any money, I'd really go over the brakes and ensure everything is in order. It could be down to weak calipers, but it's unlikely IMO as they should be adequate.

Out of interest, do the calipers operate off of a single central pivot, or is each arm mounted to a separate pivot either side? It looks like some of their bikes do use a centre pivot design which... isn't the best.

gnvqsos

Rotor wrote: »

Wife has got a Decathlon road bike. It has xenon QS 10 speed lever clusters (from my research this is campagnolo entry level) but the brake calipers have nothing on them so I'm guessing decathlon have used unbranded to save a little money.


I think this is a caliper problem because, after cleaning and sanding wheel rim to no avail I swapped her front wheel and pads to my bike and my bike still stopped fine whilst hers was still poor.


So, do people agree it's the calipers and, if so, which cheapish ones do I change to?


I confused myself reading up about it as there seems to be different leverage ratios between manufacturers so some are not recommended with other makes.


Thanks

Buy some used quality brakes and nothing cheapish will do -its your life.

Norman_Castle

It could be a mismatch between the caliper and lever. If you bought the bike recently try asking Decathlon.

Nebulous2

Good pads are said to make a big difference. A lot of people on forums rate either Kool stop or Swiss stop pads.

I've never had Compag gears/ brakes, so wouldn't know, but one of the biggest differences I ever made was upgrading my Shimano calipers even with stock pads.

Rotor

Thanks guys.
Nev - yep 1st thing I did was clean rim with meths, then changed pads, then swapped pads between the bikes.


Didn't get the bike new and not sure how old it is. I think it was a sprint triathlon purchase that then sat in shed gathering dust as it is very low use when we got it. (10x3 speed, 6061 ali frame)


Having looked, they are dual pivot brakes , same shape as these
http://www.ebay.co.uk/itm/281421293204?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


So if I bought something like the brake above are the caliper and lever likely to be matched- i.e. are Campy xenon levers and Veloce calipers interchangeable or do I need a Xenon caliper only?

Weird_Nev

If the brakes are dual pivot, I would:

Buy new pads. Shimano if compatible, Campag is not. Spend about a tenner, that's all I've ever spent on pads.

Pull the brake cable through the liner, grease it, and re-insert it. If you can't remove the nipple, work grease back and forth through by disconnecting the cable each end and working it back and forth applying grease to each end. you lose a remarkable amount of efficiency if it's dry/corroded.

Finally, re-assemble. Pay close attention to brake block position and to brake lever positioning - it's possible they're just not positioned right on the bar, and again you need mechanical advantage working in your favour as you grip them to get full stopping power. Check brake tension is good, I.e. even with full on panic braking you cannot pull the lever to the bar.

If they're dual pivot, with new pads and well set up, they should be as effective as road bike brakes get.

jbainbridge

From what you say everything points to the calipers. The cheap no name ones you have may not be working with the amount of cable the levers are pulling.

As far as I can see the correct ones are the Veloce as there does not appear to be a Xenon caliper. A pair would be around £27 from Ribble or you might get some on ebay.

Rotor

Just an update for those interested and for others who may find the thread on a search.
I put some Campagnolo centaur calipers on the front and this made a significant improvement so I think there must have been some flex with the cheaper ones.
Then I changed the pads to some Kool-stop Dura 2 and these have transformed the braking- I thoroughly recommend them.


I have only done the front as the back wasn't as bad and if only mild braking is required they are fine and under severe braking the back one plays a much reduced role anyway.


Thanks all