Disc brake performance

MrSweary

Dinyull wrote:

I've started to notice that when the bike isn't used over the weekend - or for a couple of days - the brakes are terrible, and don't start working properly until half way into my commute after VERY heavy braking.

Clearly vigilante mice are invading your garage and weeing on your pads and rotors. Whatever you've done I'd be making amends pretty quickly otherwise it will just escalate. Do you own a cat?

ugo.santalucia

VRSMatt wrote:

However the comment above about never feeling under-braked on your v-braked mtb means that frankly you ride like a 5 year old girl, and/or exclusively in the dry....

....i have MTB'd for over 25 years and ridden road bikes for 15 years...

you cant argue with physics....

You are so great, we could do with more of your insightful posts...

whyamihere

Just to add extra fuel to the fire... I rode my racier road bike outside for the first time in a few months yesterday. It's the only one of my bikes to still have rim brakes (2 mountain bikes and the other road bike are all on hydraulic discs), and the braking power was as excellent as it's always been - Campagnolo Centaur brakes and levers with Koolstop Salmon pads are pretty damn good. Where it falls short is in the feeling and modulation. They're much more on or off than the disc brakes. This led to me getting it all locked up and sideways in an emergency stop situation (I held it due to being awesome, naturally). Now, obviously I can't say for certain that I wouldn't have locked up the disc brake bike in exactly the same circumstances, but knowledge and experience of similar circumstances suggests that I'd have held it together a lot better.

Something to consider if you're not using hydraulic discs - You need to have a decent match between the levers and calipers. When I first built up the disc brake road bike, I used Campagnolo levers and TRP Spyres. The lever throw was so long that I took them off after 2 rides. I changed to Juin-Tech R1s, which were slightly better due to more adjustability, but I still considered them almost unrideable, so they again lasted only a couple of rides. I was in the fortunate position of being able to drop a load of cash on a full Sram Apex HRD drivetrain, so I did that, but I'm aware that both types of caliper I tried have great reviews, but that they seemed to be fundamentally incompatible with the Campagnolo levers. Maybe I'd have had a different experience if on Sram or Shimano levers, which I believe have a slightly different cable pull ratio, but going hydraulic basically ensures that the levers and calipers will work properly together.

I also agree with all the comments about leaving the brakes alone as much as possible. I've been using hydraulic discs on my mountain bikes for 10+ years, and in that time I've used most of the big brands of brakes. In all those years, I can count on one hand the number of times I've had to touch them once they're set up, other than to change pads. They are as close to 'fit and forget' as you can get.

tim_wand

I ve just taken TRP Spyres off my Kinesis GF Ti and Fitted Shimano BR 805s . The spyres were fitted with Goodrich Compressionless Cables and the Braking performance was Excellent.

I don't know if I ve not allowed the 805s long enough to bed in , But man do these things squeal!!!!!!!! and the braking performance isn't as good as the Spyres at the moment.

I m still running the original 160 Front TRP Rotor ( this is the brake that squeals the most ). I ve taken some 180 grit to the pads and the rotor and I ve bled the system a couple of times.

The Noise is reducing but the lever throw is still a lot longer than I expected and a lot longer than with Spyres.

The next step I am going to try is to get the Proper Shimano Ice tech rotors, But so far it seems like good money after bad.

And before any one asks " Why did I change brakes (Spyres ) that were performing well ? Because I am a vain and silly man ( and they are flat mount and look nice :? )

DeVlaeminck

OK so having bought a set of pads for my front Trp HyRds can someone advise. The rotors "look" clean but is it worth buying a can of bicycle rotor cleaner and using that before fitting them.

Moonbiker

Whats wrong with soap & water?

whyamihere

Soap can leave residue. Isopropyl alcohol is what you want.

bendertherobot

Juin Tech's R1's have been updated to X1

https://www.edgesportsuk.com/store/juin ... ss-cx.html

Much more expensive, more even than a TRP HY RD, but you do get floating rotors.

No idea if better but look to have a bigger reservoir.

meanredspider

bendertherobot wrote:

Juin Tech's R1's have been updated to X1

https://www.edgesportsuk.com/store/juin ... ss-cx.html

Much more expensive, more even than a TRP HY RD, but you do get floating rotors.

No idea if better but look to have a bigger reservoir.

Do you know what the F1 is? Just say something on Juin's FB page

bendertherobot

meanredspider wrote:

bendertherobot wrote:

Juin Tech's R1's have been updated to X1

https://www.edgesportsuk.com/store/juin ... ss-cx.html

Much more expensive, more even than a TRP HY RD, but you do get floating rotors.

No idea if better but look to have a bigger reservoir.

Do you know what the F1 is? Just say something on Juin's FB page

It's a flat mount R1

kajjal

DeVlaeminck wrote:

OK so having bought a set of pads for my front Trp HyRds can someone advise. The rotors "look" clean but is it worth buying a can of bicycle rotor cleaner and using that before fitting them.

Yes, if the rotors are heavily contaminated they will simply contaminate the pads when you put them in. If you clean the rotors with disc brake cleaner and kitchen roll, once the roll stays white you know the rotors are clean.

It is rare the rotors need replacing.

veronese68

whyamihere wrote:

Soap can leave residue. Isopropyl alcohol is what you want.

IPA is also much cheaper than disc brake cleaner.

BelgianBeerGeek

Veronese68 wrote:

whyamihere wrote:

Soap can leave residue. Isopropyl alcohol is what you want.

IPA is also much cheaper than disc brake cleaner.

Greene King IPA OK?

graeme_s-2

BelgianBeerGeek wrote:

Greene King IPA OK?

I'd rather use it for cleaning rotors than drink it!

veronese68

There are better IPAs out there, in this case isopropyl alcohol is best, you could rinse the rest of the bike with Greene King.

ugo.santalucia

Of course you can drink isopropanol, it is not toxic*... gets you drunk quicker than ethanol and there is no duty on it... what's not to like?

*unless it's cut with something else like methanol

orraloon

Back on the mechanical TRP Spyres, I got better performance this time out after seriously abusing the pads with coarse sandpaper and cleaning the rotor, again. Had to back off the pads as bleepin' LBS (I blame them but no way of proving) had bent the rotor slightly while wheel was in for rebuild. Even so, stopping much better, could even lock up the rear, which is first in a long time.

New rotor arrived today, good work CRC, fitted but not taking the good bike out in this peeing weather so tbc.

vrsmatt

If getting new pads then i'd advise a disc clean with proper disc brake cleaner then follow the bedding in process as if it was all new.

If changing discs and not pads.....buy new pads too you tight bugger and bed in as new.

vrsmatt

ugo.santalucia wrote:

VRSMatt wrote:

However the comment above about never feeling under-braked on your v-braked mtb means that frankly you ride like a 5 year old girl, and/or exclusively in the dry....

....i have MTB'd for over 25 years and ridden road bikes for 15 years...

you cant argue with physics....

You are so great, we could do with more of your insightful posts...

Glad to be of help.

You should market these MTB rim brakes that you never feel under braked with as i reckon you'd sell a shed load

First.Aspect

ugo.santalucia wrote:

Of course you can drink isopropanol, it is not toxic*... gets you drunk quicker than ethanol and there is no duty on it... what's not to like?

*unless it's cut with something else like methanol

Strictly, all alcohols are toxins, including ethanol. I think isopropanol is marginally more toxic than ethanol, but significantly less toxic than methanol.

So if you are going to get drunk and give yourself brain damage in the park on the cheap, I'd recommend isopropanol over meths. Plus it tastes better and isn't pink.