Carbon wheels/changing brake pads

Amoger

(Apologies for the ramble, the question is towards the end).

Been having a good time with my Cannondale SuperSix 105, first road bike in 15yrs+, but knew having bought the 2011 model with RS10s instead of Mavics, that I might eventually, in a couple of years, think about a wheel upgrade.

So.. a few months on so much for self-control, I've splashed the cash on some Mavic Ksyriums. And some GP4000S to go with them. Can't wait to get them on (and the rain to stop). Read all round the forums about lighter inner tubes too, perfectly logical to say "spending £400 on lowering wheel weight 300g, yet can lower it 100g for £20". But sounds like they're just too fragile for me to risk, am ham-fisted putting them in & don't reckon higher chance of blow-outs would be worth it. Others will think differently, & I agree a thinner inner tube probably makes little difference to actual punctures, but it surely does to blow-outs, tears around the valve etc - plenty of stories of people using up 2 or 3 just in fitting.

Reading the Mavic instruction booklet, it says "Never use brake pads that have been used on a metal braking surface, on a rim with a carbon braking surface. They may damage your rims, or even caused them to break."

Really?? Do people switching to all-carbon wheels change the brake pads too? Fortunately the Ksyrium's seem to have a metallic brake surface but it'd never crossed my mind.

estampida

as you said if you have paid £400 for wheels, £20 for latex tubes is a small price for the performance

but how much to replace the rim £100 or more?? for the price and knowing that they will stop the bike in the wet and dry without breaking your new wheels....

http://superstar.tibolts.co.uk/index.php?cPath=22_33

again £25 is a small price

Rule74Please

yep.

Brake pads for alloy rims will pick up bits of metal off the rim, the road and it seems out of thin air. These are harder than the resin in the carbon rims and score it away.

You can run the cork pads on metal rims (many do) as these are designed to break away if "caught" on the rim by inclusions. Do not do this if it rains as you will have NO brakes at all.

Amoger

Thanks for replies.

Hmm, harder job than I realised. Getting the tyres on was OK, following YouTube tutorials. Hadn't realised what was involved with the rear cassette - not got all the tools. Might go the whole hog and switch to an 11-28 from a 12-27, whilst I'm at it.

Questions:

1. Will going from 12-27 to 11-28 require any tricky adjustments, eg longer chain? Shimano 105 CS 5700 is what I've got; instructions say "SS" requires two more chain links, implying "GS" doesn't. Trouble is, no indication which I have.

2. "The end of the quick release skewer must not be sunk more than 2mm in from the outside edge of the adjustment nut". Mine's more like 5mm in, but it's impossible to alter that surely - the tension needed to hold the wheel in place is a fixed thing, can't adjust it.

Monty Dog

Get yourself an extra set of brake shoes and carbon-specific pads - takes about 5 minutes to swap-over with an Allen key. You often need to adjust the brake pad height with different wheels anyway, so not much more hassle.
You should be OK with existing chain length - just don't go putting it on the big sprockets whilst on the big chainring - it's not as mechanically efficient and wears the chain out quicker anyway.
Mavic QRs have quite a light action, so don't need strong-arming to work effectively.

Wrath Rob

Amoger wrote:

1. Will going from 12-27 to 11-28 require any tricky adjustments, eg longer chain? Shimano 105 CS 5700 is what I've got; instructions say "SS" requires two more chain links, implying "GS" doesn't. Trouble is, no indication which I have.

If you've got a 27 on there you'll very likely have the SS, or short cage dérailleur. The GS is the long cage version and can accomodate a larger sized sprocket on the back. I'm not sure what the max gear the SS will take is, i.e. if you can fit a 28 tooth with the SS. Might be time for you to check out the Shimano specs. If not, stick with the 27 or you'll have to replace both the dérailleur and cassette.

Amoger

Hours of Googling later, I've ordered a chain whip, lockring tool (hopefully the right one) and the 11-28 10sp cassette. And some Swarfega..

I've definitely got the "SS" dérailleur. In theory it only copes up to 27T, and needs a couple of extra links in the chain to go to 28, but plenty of people have managed without adjustment so I'll give it a try (and avoid big/big).

Not worrying about the quick release skewer on the front being more than 2mm indented at the end, but an odd instuction, unless there's spacers to come out.

(Ksyrium Elites have alloy rims it seems, so don't need to worry about the brake pads.)

John.T

Amoger wrote:

I've definitely got the "SS" dérailleur. In theory it only copes up to 27T, and needs a couple of extra links in the chain to go to 28, but plenty of people have managed without adjustment so I'll give it a try (and avoid big/big).

You should not need a longer chain. One tooth bigger is only half a link. Just make sure you can get on to the big/big combination safely (do it slow and easy on a stand is best). Only add a link if required. As said you should not use this combination but not being able to safely guarantees that you will go there accidentally one day.

Wheelspinner

Yes if you switch to carbon (brake surface) rims you should swap pads. Takes two minutes to do anyway, piece of cake. I have Swiss Stop yellow pads for the carbon tubs and standard Campag pads for the aluminium rims.

Carbon wheel pads are quite different materials anyway - the rubber ones you normally use just aren't suitable. They are very "grabby" on the carbon. Only downside is the carbon specific ones wear a LOT faster, and are not cheap.

John.T

Wheelspinner wrote:

Yes if you switch to carbon (brake surface) rims you should swap pads. Takes two minutes to do anyway, piece of cake. I have Swiss Stop yellow pads for the carbon tubs and standard Campag pads for the aluminium rims.

Carbon wheel pads are quite different materials anyway - the rubber ones you normally use just aren't suitable. They are very "grabby" on the carbon. Only downside is the carbon specific ones wear a LOT faster, and are not cheap.

Carbon wheel often come with the correct pads anyway. Just don't use the same pads on alloy wheels then put the carbon ones back in. Keep the carbon pads for those wheels only.

Wrath Rob

Wheelspinner wrote:

Yes if you switch to carbon (brake surface) rims you should swap pads. Takes two minutes to do anyway, piece of cake. I have Swiss Stop yellow pads for the carbon tubs and standard Campag pads for the aluminium rims.

As long as the braking track for both sets of wheels is in the same place. My Kysriums are very different to my carbon wheels so I not only have to change pads but move the shoes too. Makes a 2 min job a 10 min job, so not the end of the world but a PITA all the same.

Wheelspinner

Wrath Rob wrote:

Wheelspinner wrote:

Yes if you switch to carbon (brake surface) rims you should swap pads. Takes two minutes to do anyway, piece of cake. I have Swiss Stop yellow pads for the carbon tubs and standard Campag pads for the aluminium rims.

As long as the braking track for both sets of wheels is in the same place. My Kysriums are very different to my carbon wheels so I not only have to change pads but move the shoes too. Makes a 2 min job a 10 min job, so not the end of the world but a PITA all the same.

Easy fix for this..... N+1.