More disk brake in the peleton problems

More disk brake in the peleton problems

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JustinF

6,795 posts

202 months

Monday 27th February 2017
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millen said:
JustinF said:
you did research and settled on cable operated?!
Yep - Spyres have both pads pivoting symmetrically, unlike the older-design Avids where one pad does the work and the other floats freely, supposedly requiring frequent adjustment. They were good enough for Emily Chappell in the TCR. I've used Jagwire compressionless cable which improves feel (though threading the rear brake cable through the frame was a real pig of a job!).

Cost was indeed a factor. Managed to find a near-new Ultegra set (sans callipers) for £350. Buying new hydraulic shifters would've added a lot to the cost. Yes I know you get better modulation with hydraulics but I suspect that's more crucial for gnarly off-road runs, descending over slippery tree trunks etc.

A guy I rode with in the cycle club this morning runs TRP HyRDs - the hybrid cable operated hydraulic callipers. He likes them - they exert more stopping force I gather.
OK things have moved on since I looked at cable ones, last I knew they worked on a single piston, effectively bending the disk towards the static side.

Big Rod

6,198 posts

215 months

Monday 27th February 2017
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JustinF said:
OK things have moved on since I looked at cable ones, last I knew they worked on a single piston, effectively bending the disk towards the static side.
I have two bikes with brakes like that and I will admit to being a little uncomfortable with them in that respect but if you keep your eye on them and adjust them, (one click with an allen key from time to time), you can minimise the bending of the disc.

They'll never be as good as full hydro but the hybrid set on my road bike is a great compromise especially when considering gear upgrades in future.

SteveSteveson

3,209 posts

162 months

Monday 27th February 2017
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TPR HYRDs are a good compromise between cable and hydro. They push both pads and with compressionless cables you get quite close to the feel of hydro brakes.

donfisher

793 posts

165 months

Monday 27th February 2017
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SteveSteveson said:
TPR HYRDs are a good compromise between cable and hydro. They push both pads and with compressionless cables you get quite close to the feel of hydro brakes.
Agreed.

My current commuter came with some promax mechanicals. One pad moves and one pad is fixed. They were fine when new then started to play up and were a PITA to get the old pads out when they needed changing.

I swapped the front one for a HyRd and it’s brilliant. Occasionally it needs a bit of adjustment/resetting when replacing the pads but most of the time the new pads just go in and it works brilliantly again.

My new commuter came with Spyres and the first thing I’ll do when the current one dies and this takes on the daily duties is swap the front Spyre for the existing or a new HyRd.

A mate has had loads of problems with his Spyres (noise and issues with pad replacement) so I’ll stick with what I know works. Keeping the back one isn’t too much of a problem and at least they’ll both use the same type of pad. Currently one is rectangular shimano compatible and one round Avid.

yellowjack

17,065 posts

165 months

Monday 27th February 2017
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Hmmm?

Discs are dangerous in a crash?

Probably BS, because plenty of larger diameter rotors are used in mass-start MTB XC/Enduro races. And there are plenty of crashes on much worse terrain for bike handling than in a road race.

What will discs cut?

Well, my fingers and knuckles for one thing. But that was during maintenance when I wasn't concentrating properly on what I was doing.

Does anyone really need them?

Probably not. I certainly don't, and although I've looked at the idea of a 'Green Laner' or 'Gravel Adventure' bike, with drop-bars AND disc brakes, I don't have any urgent need to jump ship from rim brakes on road bikes just yet.


If you want them, have them. No business of mine, and there'll be a long while before we see any end to rim brakes on road bikes available to buy. I just don't get some of the arguments against that are coming out of the pro peloton. Sure, campaign against them because you don't like them, or because you think that a mixed peloton with some on rims brakes and some on discs will result in more crashes caused by later braking by those on discs. But this "danger" from getting cut by the spinning disc rotor is plain silly. It might happen, but then again deaths have happened in the peloton from crashes involving no-one else. No-one is calling for an end to bike racing because an unintended interface with scenery is potentially fatal.

I'd be quite happy to see the peloton stick with rim brakes, and equally not too bothered if they permitted discs. It just seems like a bit of an odd argument to get bogged down by. Far more pressing issues for the UCI to be trying to solve, I think...

Your Dad

1,924 posts

182 months

Wednesday 1st March 2017
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From GCN twitter feed:


Don1

Original Poster:

15,936 posts

207 months

Wednesday 1st March 2017
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hehe

jamiebae

6,245 posts

210 months

Wednesday 1st March 2017
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Cable discs are fine if properly set up in my experience, but do require fairly frequent tweaking.

For those mentioning the Etape du Tour, discs were un-banned before the event so you could use them in the end. The safety benefit of discs on that ride is absolutely clear to anyone who was actually there. It was a HOT day, and on the descents there were crashes everywhere caused by tyres blowing out after overheating from brakes being dragged, I even saw a few where carbon rims had totally delaminated and broken apart. With discs there is no transfer of heat from the brakes into the tyre so the risk of a blow out is massively reduced. Although these were amateurs dragging brakes in some cases the pros still suffer from this on occasions.

As for the pro debate, you have to remember it's in the interest of certain riders/teams to get them banned as there are scenarios where they offer a benefit but many bike brands don't have a high end aero disc frameset available. Canyon and Specialized are in a strong position, the likes of Cervelo and Pinarello not so much and if you can brake 5% later on a descent with discs then that's a big benefit on an alpine descent.


Kawasicki

13,041 posts

234 months

Wednesday 1st March 2017
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jamiebae said:
Cable discs are fine if properly set up in my experience, but do require fairly frequent tweaking.

For those mentioning the Etape du Tour, discs were un-banned before the event so you could use them in the end. The safety benefit of discs on that ride is absolutely clear to anyone who was actually there. It was a HOT day, and on the descents there were crashes everywhere caused by tyres blowing out after overheating from brakes being dragged, I even saw a few where carbon rims had totally delaminated and broken apart. With discs there is no transfer of heat from the brakes into the tyre so the risk of a blow out is massively reduced. Although these were amateurs dragging brakes in some cases the pros still suffer from this on occasions.

As for the pro debate, you have to remember it's in the interest of certain riders/teams to get them banned as there are scenarios where they offer a benefit but many bike brands don't have a high end aero disc frameset available. Canyon and Specialized are in a strong position, the likes of Cervelo and Pinarello not so much and if you can brake 5% later on a descent with discs then that's a big benefit on an alpine descent.
dragging brakes with discs will lead to brake fade too, and easily if you are talking about alpine descents

IroningMan

10,154 posts

245 months

Wednesday 1st March 2017
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Kawasicki said:
jamiebae said:
Cable discs are fine if properly set up in my experience, but do require fairly frequent tweaking.

For those mentioning the Etape du Tour, discs were un-banned before the event so you could use them in the end. The safety benefit of discs on that ride is absolutely clear to anyone who was actually there. It was a HOT day, and on the descents there were crashes everywhere caused by tyres blowing out after overheating from brakes being dragged, I even saw a few where carbon rims had totally delaminated and broken apart. With discs there is no transfer of heat from the brakes into the tyre so the risk of a blow out is massively reduced. Although these were amateurs dragging brakes in some cases the pros still suffer from this on occasions.

As for the pro debate, you have to remember it's in the interest of certain riders/teams to get them banned as there are scenarios where they offer a benefit but many bike brands don't have a high end aero disc frameset available. Canyon and Specialized are in a strong position, the likes of Cervelo and Pinarello not so much and if you can brake 5% later on a descent with discs then that's a big benefit on an alpine descent.
dragging brakes with discs will lead to brake fade too, and easily if you are talking about alpine descents
Quite. I thought that one of the barriers to the adoption of discs for the road was the extent to which early models were prone to fade - you get much longer descents on the road than you do off it and carbon forks don't conduct heat away from the caliper very well.

The wheels might not break up, but you still won't be able to stop. Presumably the manufacturers have been able to address this, but I very much doubt they're fade proof.

yellowjack

17,065 posts

165 months

Thursday 2nd March 2017
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Out of interest only, because I've not yet needed them on my MTB, but...

Do road disc systems have options such as 'floating' or IceTech rotors, and finned backing to pads? All are designed to cool the braking system and reduce brake fade, but so far when looking at the new road bikes that come with discs as standard I don't recall seeing finned pads or anything other than one-piece rotors. Just curious really. I know that road disc rotors tend to be a size or two smaller than MTB rotors to keep weight down and reduce the need for caliper adapters. I hadn't really considered the potential problems of brake fade and overheating until I read the last few posts on here. Up until now the pro-peloton's "against" faction seems to have argued primarily on the "danger to other riders of sharp edges" aspect.

I'm sure it won't be long before we see the UCI sanction disc brakes in the peloton. Shimano and the other component manufacturers have a lot to gain, as do the bike brands who have led the way with early adoption of discs on specifically developed frames. There must be one hell of a lot of lobbying going on behind the scenes. I'm assuming the politics is complicated, that each team and manufacturer isn't regarded as holding equal sway over the debate, and that the actual riders' opinions are largely irrelevant in the grand scheme of things. The tip of a rather ugly iceberg, if you will...

neenaw

1,212 posts

188 months

Thursday 2nd March 2017
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yellowjack said:
Out of interest only, because I've not yet needed them on my MTB, but...

Do road disc systems have options such as 'floating' or IceTech rotors, and finned backing to pads? All are designed to cool the braking system and reduce brake fade, but so far when looking at the new road bikes that come with discs as standard I don't recall seeing finned pads or anything other than one-piece rotors. Just curious really. I know that road disc rotors tend to be a size or two smaller than MTB rotors to keep weight down and reduce the need for caliper adapters. I hadn't really considered the potential problems of brake fade and overheating until I read the last few posts on here. Up until now the pro-peloton's "against" faction seems to have argued primarily on the "danger to other riders of sharp edges" aspect.
Yes.
Shimano rotors are IceTech but you'll probably find that on lots of bikes they'll spec cheaper one piece rotors to keep costs down.
Finned pads also came standard on my Ultegra hydraulic brakes but I've still never seen a replacement set of finned pads, just the normal ones. I'll probably try to get hold of some new finned pads before I go to the Alps later this year as they'll be due replacement by then.

JustinF

6,795 posts

202 months

Thursday 2nd March 2017
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I have finned replacement pads for my Shimano 685's, spent a week and a half in the alps last year on a fully laden bike ~(95kg bike+rider) got the rotors pretty hot a few times, no fade.

jamiebae

6,245 posts

210 months

Thursday 2nd March 2017
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Kawasicki said:
dragging brakes with discs will lead to brake fade too, and easily if you are talking about alpine descents
Not as easily as you'd think in my experience. I've managed to get the discs hot enough on my old bike that I could feel the radiated heat from them with my hands on the bars but they still didn't fade (Avid BB7 with the standard Avid rotors).

I still maintain most of the anti-disc sentiment in the pro ranks is related to not wanting someone else to gain an advantage. In particular, riders on Specialized bikes with Shimano groupsets are likely to have an advantage in equipment over most other teams (Bora, Quick Step). Equally though, Specialized are pushing very hard in favour of discs - they've invested a lot in development of the bikes and want to sell them to the general public but they also want to win bike races. There were a few stages last year where absolute balls-out mental descending made the difference to the stage winner and with better brakes that could really make the difference.

thiscocks

3,126 posts

194 months

Thursday 2nd March 2017
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IroningMan said:
Quite. I thought that one of the barriers to the adoption of discs for the road was the extent to which early models were prone to fade - you get much longer descents on the road than you do off it and carbon forks don't conduct heat away from the caliper very well.

The wheels might not break up, but you still won't be able to stop. Presumably the manufacturers have been able to address this, but I very much doubt they're fade proof.
Pretty sure they can make them almost fade proof with special pads. Its not exactly a lot of weight to stop. Im sure if you compare heat dissipation of a bike with a car disc it is pretty minimal.

Kawasicki

13,041 posts

234 months

Thursday 2nd March 2017
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jamiebae said:
Not as easily as you'd think in my experience. I've managed to get the discs hot enough on my old bike that I could feel the radiated heat from them with my hands on the bars but they still didn't fade (Avid BB7 with the standard Avid rotors).

I still maintain most of the anti-disc sentiment in the pro ranks is related to not wanting someone else to gain an advantage. In particular, riders on Specialized bikes with Shimano groupsets are likely to have an advantage in equipment over most other teams (Bora, Quick Step). Equally though, Specialized are pushing very hard in favour of discs - they've invested a lot in development of the bikes and want to sell them to the general public but they also want to win bike races. There were a few stages last year where absolute balls-out mental descending made the difference to the stage winner and with better brakes that could really make the difference.
That's if you think discs are an advantage.

Compare the time a pro spends struggling against aero drag to the time spent braking in the wet.

jamiebae

6,245 posts

210 months

Thursday 2nd March 2017
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Kawasicki said:
That's if you think discs are an advantage.

Compare the time a pro spends struggling against aero drag to the time spent braking in the wet.
It's not just in the wet they help, if you're braking from 90kph a disc brake will slow you more effectively and can be modulated much better than a rim brake, within the limits of the tyre.

Also, wasn't there some research that showed that flat mount disc brakes make no difference at all to aero drag?

Don1

Original Poster:

15,936 posts

207 months

Thursday 2nd March 2017
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I think discussing the drag between different brake set ups is insane. The rider aero will impact far more than brakes. Yes, I know every little helps, but the link attached shows just how little it matters.
http://www.slowtwitch.com/Tech/Disc_and_Rim_Brake_...


Kawasicki

13,041 posts

234 months

Thursday 2nd March 2017
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Don1 said:
I think discussing the drag between different brake set ups is insane. The rider aero will impact far more than brakes. Yes, I know every little helps, but the link attached shows just how little it matters.
http://www.slowtwitch.com/Tech/Disc_and_Rim_Brake_...

did they use the same front wheel for each test.

discs need cross spoked wheels, rim brakes can use radial spokes and less of them.

Magic919

14,126 posts

200 months

Thursday 2nd March 2017
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That's the third time that link has been posted in this thread.