going up in rotor size?

Dog296

Hey all.

Both of my rotors seem to off warped. So thinking of replacing Them.

Weirdly the front one is a superstar floating rotor, which has never really been any improvement. When I went. From 160 - 180.

I have tekro? Brakes, 180 up front and 160 at the rear. I weight 15 stone, and I'm only 5'7".

Id like more braking power, so would I benefit from a 180 rear rotor too?

I'm mainly a XC and trail centre man....

Discuss....

Neal_

A 20mm increase in rotor size is meant to increase stopping power by 10-15% which is about right by my experience. If the rotors aren't true you should bend them back into shape yourself (see how to here) as new rotors will likely need truing from day one anyway. Also from my experience poor braking is down to contaminated rotors and pads which is why I never spray oil anywhere near my bike unless I've remover the wheels and pads and moved them out of the way. Try cleaning your rotors thoroughly with isopropyl alcohol or brake cleaner and a clean cloth until the cloth stays clean and replace the pads. You can try cleaning the pads but it's never been successful for me and pads from Superstars are cheap enough anyway.

Blind Danny Johnson

I've just gone from 160mm front and back to 203mm front and back and yesterday was my first ride with them installed and I have to say I loved it. I don't think I quite got used to it 100% but I'm sure I soon will. The increase in power was amazing and felt a lot more fun because I could brake a lot later and it gave me more confidence in general.

I don't know if this will be the same for you but it's how I felt yesterday. One reason I changed however was because my old, smaller rotors felt terrible. No power at all and sometimes didn't feel like I was braking at all. Maybe yours aren't so bad as this so the change might not feel as dramatic?

YeehaaMcgee

Dog296 wrote:

Id like more braking power, so would I benefit from a 180 rear rotor too?

not Really. because. the rear Brake does not.
do Much apart. from Skidding the rear wheel
when you. really need to slow. Down use the front brake.

Dog296

So shall I increase the front to a 210mm and see how it goes or get better calipers?

YeehaaMcgee

Dog296 wrote:

So shall I increase the front to a 210mm and see how it goes or get better calipers?

Rotors are a cheaper upgrade, and will result in more power for a given brake calliper, so I'd strongly suggest you do that first.
If you still don't have enough power, then consider upgrading the calliper. (Shimanos are my favourite)

Dog296

Yeh ive seen some SLX M666 that I fancy, but don't have the required funds yet.

right, bigger rotor it is, ill get new pads too while I'm there.
What ate organic pads like?

cooldad

YeehaaMcgee wrote:

Dog296 wrote:

Id like more braking power, so would I benefit from a 180 rear rotor too?

not Really. because. the rear Brake does not.
do Much apart. from Skidding the rear wheel
when you. really need to slow. Down use the front brake.

Excellent use of sneaky sarcasm there.

chazkayak

I went from 180 to 203 on my front because I didnt have enough braking effect on the front, TBH I didnt notice the difference too much. But I can stop so thats a good thing !!!

Dont forget different compound pads can have a massive effect on braking. Try different pads aswell as larger discs before you go to new brakes.

Dog296

Sorry to bring this subject back up.

But I think I need better brakes more than going up in size of rotors.

Been looking at a few options:

Hope M4 Hope Tech2 Shimano SLX M666 Shimano Saint

Or any other options anyone else thinks of. budget is approximate £300 without fancy bits like rotors and braided hoses.

YeehaaMcgee

Saints are just bonkers, a more real world solution is to go for either the XT, or XTR.

peter413

YeehaaMcgee wrote:

Saints are just bonkers, a more real world solution is to go for either the XT, or XTR.

They are bonkers yes but perfectly fine when you are used to them though, total overkill for most though, even me but I still love them on the Marin and Rocky.

diy

Make sure your forks are set up correctly for your riding.
Make sure you've got your grippy tyre up front.
Make sure your brakes are well bled and not spongy.
Adjust the position of the levers to work with your postion
maybe upgrade to softer pads (e.g. sintered to kevlar)
practice stopping, see just how much front you can get on before the rear comes up.

After that consider a bigger rotor, but there are downsides, big rotors are more prone to gobble and snatch, don't cope with bad conditions as well and wear your pads out faster.

YeehaaMcgee

diy wrote:

maybe upgrade to softer pads (e.g. sintered to kevlar)

Pad hardness or softness has nothing to do with it's performance in stopping, and also, sintered pads stop better than resin or kevlar, because they generate heat much faster.
(the downside being that they tend to squeal, and can overheat most lesser braking systems when used heavily)

diy

YeehaaMcgee wrote:

diy wrote:

maybe upgrade to softer pads (e.g. sintered to kevlar)

Pad hardness or softness has nothing to do with it's performance in stopping

It affects the feel though and they will perform differently in different conditions. Confidence in braking is as much about how they feel and bite as it is about technical ability to stop you.

I must admit having had very disappointing experience with Kevlar in the wet (typically I use sintered in the winter/wet month) , my latest batch of SS kevlar have lasted ages. Might be down to a dry winter though.

YeehaaMcgee

clickmaster wrote:

Dude, Increasing the front by 210mm I think is not a good idea, just my two cents.

Yes, a very very bad idea. He already has a 180 front, so that would give him 390mm front rotor, and then the only calliper adapters would have to be bespoke, custom made, one-off units.
A silly idea indeed.

mrmonkfinger

yeah, but just think about how good them brakes would be, you could do endos and all sorts

leaflite

Dog296 wrote:

Sorry to bring this subject back up.

But I think I need better brakes more than going up in size of rotors.

Been looking at a few options:

Hope M4 Hope Tech2 Shimano SLX M666 Shimano Saint

Or any other options anyone else thinks of. budget is approximate £300 without fancy bits like rotors and braided hoses.

Merlin have a great offer on formula r1s at the moment:
http://www.merlincycles.co.uk/Bike+Shop/MTB++Parts/Brakes/Disc+Brakes/Formula+Disc+Brakes/Formula+R1+Disc+Brakes+-+Front++Rear+Set+-+2012_1928.htm

Works out at £270 inc rotors and everything once 10% discount is applied. Very light and powerful. They are quite a faff to set up though, and there has been some reliability issues.

I have the last model hope tech x2s atm. They arent the most powerful brakes out there, but the reliability has been excellent-no issues in over 1 year, havent even needed bleeding, and the modulation is great. The newer versions are more powerful too. If you do go down the hope route, I would probably consider getting an m4 caliper front and a x2 caliper rear to increase power further.

The SLX/XT brakes seem very popular on here too.
The best option is probably to try several bikes with different brakes on and see which ones you like best.

Dog296

I'm not sure if ive read into it too much, but the shimano's seem to be lacking in spares like new seal kits?

I like the look of the hope brakes, plus my LBS is a hope agent, hence why I have hope hubs in blue, with white ztr rims lol.

Nice idea about mix and matching brakes, but would the levers be different?

1mancity2

I have hope M4 with 203mm rotors, they are really good brakes, had them 2 years not needed any maintenance apart from cleaning, new pads when worn.

Only time I thought they were under powered is when doing DH but that could just be my braking technique.

garylythgoe

From what I've experienced, the smaller the rotor the more 'grabby' and 'snatchy' the brakes can feel. The larger the rotor, the more modulation you gain/have. Now this obviously doesnt take into account the caliper type etc.

I currently have 2010 XT's on mine with 180mm rotors, and they work great and very easy to bleed. I'm looking to try a 203mm rotor on the front because I'm scrubbing too much speed off on runs I think. I want to experiment anyway! A Shimano RT75 203mm rotor is £19-24 and the caliper mounting bracket is £5-7 so a reasonably inexpensive experiment.

HTH.

leaflite

Dog296 wrote:

I'm not sure if ive read into it too much, but the shimano's seem to be lacking in spares like new seal kits?

I like the look of the hope brakes, plus my LBS is a hope agent, hence why I have hope hubs in blue, with white ztr rims lol.

Nice idea about mix and matching brakes, but would the levers be different?

Hope do 2 levers, tech and race, and 3 different calipers, x2, m4 and v2. As long as you get the same lever for both brakes, the levers will be the same just with different calipers.

YeehaaMcgee

garylythgoe wrote:

From what I've experienced, the smaller the rotor the more 'grabby' and 'snatchy' the brakes can feel.

I asked Physics. he says you're wrong - you must have changed something else apart from the rotor.

Dog296

Oh brilliant.

Hope are what I'm going for then, just need to actually decide what's the most powerful up front.

Chunkers1980

Clearly the bigger the more powerful, all other things equal.

Dog296

So V2 up front and X2 on the rear?

leaflite

Dog296 wrote:

So V2 up front and X2 on the rear?

I would go m4 up front as the v2 requires a different rotor iirc which is much heavier