UCI expected to approve Road Disc Brakes for 2016

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby AUbicycles » Fri Sep 15, 2017 4:06 pm

warthog1 wrote:Are disc brakes decisively better to race on? Apparently not


Just pointing out that disc brakes are better for braking than racing...

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby warthog1 » Fri Sep 15, 2017 5:27 pm

AUbicycles wrote:
warthog1 wrote:Are disc brakes decisively better to race on? Apparently not


Just pointing out that disc brakes are better for braking than racing...


Thanks for that :)

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby Duck! » Sat Sep 16, 2017 6:17 pm

Alex Simmons/RST wrote:
andrewjcw wrote:
Alex Simmons/RST wrote:Link please.


https://cyclingtips.com/2017/08/giant-p ... ils-price/
Image

So it's not a like for like comparison. That was evident at the very start of the article:
The biggest story of the new Propel is that it’s only available with disc brakes. As of right now, there is no rim brake model.

Huh? The initial comment and the article both clearly and explicitly state the improvement is in comparison to the old model, as a complete package.
I had a thought, but it got run over as it crossed my mind.

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby jasonc » Sat Sep 16, 2017 7:58 pm

I've just come back from os where I hired a disc braked tarmac. I was happy when I woke up and it had rained overnight. I got your brakes hard
The trek emonda slr disc is 6.7kgs. (665g frame, 350g fork)
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Re: UCI expected to approve Road Disc Brakes for 2016

Postby Alex Simmons/RST » Sat Sep 16, 2017 8:30 pm

Duck! wrote:
Alex Simmons/RST wrote:

So it's not a like for like comparison. That was evident at the very start of the article:
The biggest story of the new Propel is that it’s only available with disc brakes. As of right now, there is no rim brake model.

Huh? The initial comment and the article both clearly and explicitly state the improvement is in comparison to the old model, as a complete package.

OK thanks. I was perhaps misinterpreting earlier posts claiming a 15W aero advantage for the same bike with disk brakes over comparable rim braked bike.

Nevertheless 15W is, well, a massive difference in aero drag at 38.6km/h for two similar bikes.

For a rider on a road bike position, flat road with average surface, the aero drag of the bike would account for ~50-60W of the total energy demand. What we are being asked to believe is the slight changes to the frame and change to disk brakes has reduced drag of the bike by about ~30%. What that suggests to me is the bikes being compared have somewhat different set ups, probably different wheels.

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby g-boaf » Sat Sep 16, 2017 9:00 pm

jasonc wrote:I've just come back from os where I hired a disc braked tarmac. I was happy when I woke up and it had rained overnight. I got your brakes hard
The trek emonda slr disc is 6.7kgs. (665g frame, 350g fork)


Some guys on day one of Haute Route Dolomites 2017 would have been happy with that bike. Snow and rain that day.

6.7kg is pretty light too.

I had a normal Giant TCR advanced SL (2013 vintage) with Swisstop Blue pads on DA9000 brakes and Bontrager Paradigm Elite alloy wheels and had no troubles with stopping. But some guys with carbon wheels were in all sorts of trouble.

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby Comedian » Mon Sep 18, 2017 1:22 pm

Discodan wrote:FFS, how long can this discussion go on for? There's a couple of mainstream disc bikes at 6.8-6.9 (Izalco Max, S-Works Tarmac) so they can be made light but they'll always be a bit heavier than a rim brake model due to the hardware. Take your choice; I'm a weight weenie but I'll happily lug around half a kg more for the reliability and confidence discs give. If you prefer otherwise that's fine but I don't care either way.

Also a 150g disc at 140mm diameter will have little impact on rotational inertia and will be more than offset by the weight reductions in the rims that are now coming through due to lack of brake track and heat dissipation required

That's the dream that the wheels were going to be lighter... as it turns out it appears that they are panning out as a big source of weight increase. If anything the rims and hubs have to be heavier to withstand braking forces.

Hey any chance of a link to a verified weight of those bikes? Let's check we're comparing apples and apples because I've not seen weights that low. There are lots of claims being made here.. but all I can find is articles saying how light their frame is... not how light the whole bike is. If those weights are indeed right, then somehow it looks as though they have beaten other mainline manufacturers by a solid half a kilo.. which I find hard to believe..
Last edited by Comedian on Mon Sep 18, 2017 1:31 pm, edited 1 time in total.

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby jasonc » Mon Sep 18, 2017 1:29 pm

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby Comedian » Mon Sep 18, 2017 1:36 pm

jasonc wrote:http://granfondo-cycling.com/test-trek-emonda-slr-disc-2018-is-lighter-really-better/
First line of the article....

I'll believe it when I see a verified weight. All I read was that trek thought 6.7kg for a production disc brake bike would be awesesome .. and I agree with them. They then did the usual talk about frame weight but there were no pictures of a complete bike hanging from a scale.. :mrgreen:

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby andrewjcw » Mon Sep 18, 2017 2:14 pm

Listed as 6.92kg on the website atm. https://www.trekbikes.com/au/en_AU/bike ... rey_orange
Paint adds about 100g to a bike doesn't it, so plenty of gains to be made for true weight weenies. I imagine a super expensive set of wheels would get it down to the limit? Next remove toenails, full body exfoliating, ear wax removal, remove molars etc... You'll be flying up hills in no time (we'll leave that losing 20kg of overweight fat till last though).

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby Comedian » Mon Sep 18, 2017 2:44 pm

andrewjcw wrote:Listed as 6.92kg on the website atm. https://www.trekbikes.com/au/en_AU/bike ... rey_orange
Paint adds about 100g to a bike doesn't it, so plenty of gains to be made for true weight weenies. I imagine a super expensive set of wheels would get it down to the limit? Next remove toenails, full body exfoliating, ear wax removal, remove molars etc... You'll be flying up hills in no time (we'll leave that losing 20kg of overweight fat till last though).

Wow! Trek claim their $10,000 super disc bike is only half a kilo heavier than my 3k Ultegra Scott with alloy training wheels was in 2013. I guess that's progress for you. :mrgreen: Let's wait and see what it actually weighs in at.
Last edited by Comedian on Mon Sep 18, 2017 2:47 pm, edited 1 time in total.

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby biker jk » Mon Sep 18, 2017 2:46 pm

Comedian wrote:
Discodan wrote:FFS, how long can this discussion go on for? There's a couple of mainstream disc bikes at 6.8-6.9 (Izalco Max, S-Works Tarmac) so they can be made light but they'll always be a bit heavier than a rim brake model due to the hardware. Take your choice; I'm a weight weenie but I'll happily lug around half a kg more for the reliability and confidence discs give. If you prefer otherwise that's fine but I don't care either way.

Also a 150g disc at 140mm diameter will have little impact on rotational inertia and will be more than offset by the weight reductions in the rims that are now coming through due to lack of brake track and heat dissipation required

That's the dream that the wheels were going to be lighter... as it turns out it appears that they are panning out as a big source of weight increase. If anything the rims and hubs have to be heavier to withstand braking forces.

Hey any chance of a link to a verified weight of those bikes? Let's check we're comparing apples and apples because I've not seen weights that low. There are lots of claims being made here.. but all I can find is articles saying how light their frame is... not how light the whole bike is. If those weights are indeed right, then somehow it looks as though they have beaten other mainline manufacturers by a solid half a kilo.. which I find hard to believe..


The Enve 3 4 wheelset is 87 grams heavier in the rim brake version based on a DT240 hub. The disc brake rims are 84 grams lighter for the two. So the disc brake hub/extra 4 spokes add 3 grams.

Enve 3.4 rim brake wheelset weight is 1508 grams. Disc brake wheelset weight is 1421 grams. Even with a lighter Chris King R45 hub on the rim brake wheelset it's still heavier at 1477 grams.

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby warthog1 » Mon Sep 18, 2017 11:46 pm

That is a point I hadn't thought about. When you remove braking force from the rim and move it inboard to the hub will greater forces be imparted to the spoke bed where it meets the rim, or are the forces still there on a rim brake? The bike is slowing either way, does cross lacing resolve it and that's it?
Will it mean more material needs to be placed there offsetting the losses from the removal of material at the brake track?
Apparently not from the example above.

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby Nobody » Tue Sep 19, 2017 7:20 am

To my knowledge the front requires more spokes and cross lacing than the minimum front rim brake setup. As far as I can see the rear doesn't change since it needs to be cross laced for drive forces, the braking forces are lower and it needs to carry more weight anyway.

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby warthog1 » Tue Sep 19, 2017 11:21 am

Thanks Nobody.
I think I've asked the question before and braking forces imparted on the wheel are lower than the force applied by irregularities in the road surface.

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby BJL » Tue Sep 19, 2017 12:07 pm

My 2 cents (as this interests me)

Re the braking forces, I'm guessing that with disc brakes, the braking force is transmitted from the rotor to the tyre via the spokes.

With rim brakes, the braking force from the brakes is directly applied to the fork/frame rather than to the hub.

You can see the difference when people convert rim brake forks to disc braked forks and don't do a very good job of it. I've seen a couple of photos of forks bent just above the upper disc brake mounting point from poor conversions.

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby jasonc » Tue Sep 19, 2017 12:38 pm

http://road.cc/content/news/154249-firs ... -road-bike
The new Focus Izalco Max Disc comes with the claim of being the world’s lightest production disc-equipped road bike, and with a SRAM Red-equipped model coming in at 6.8kg for a size 56cm, it nudges the Specialized S-Works Tarmac Disc I tested last year off the top spot.
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Re: UCI expected to approve Road Disc Brakes for 2016

Postby jasonc » Tue Sep 19, 2017 1:59 pm

Lightweight have just released one. 6kgs.
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Re: UCI expected to approve Road Disc Brakes for 2016

Postby fat and old » Tue Sep 19, 2017 2:10 pm

biker jk wrote:
The Enve 3 4 wheelset is 87 grams heavier in the rim brake version based on a DT240 hub. The disc brake rims are 84 grams lighter for the two. So the disc brake hub/extra 4 spokes add 3 grams.

Enve 3.4 rim brake wheelset weight is 1508 grams. Disc brake wheelset weight is 1421 grams. Even with a lighter Chris King R45 hub on the rim brake wheelset it's still heavier at 1477 grams.


Shouldn't the weight of the disk be included when comparing? You don't exactly remove the brake track from a wheel when checking the rim brake version, disks are essentially the brake track aren't they? Overall weight of the wheel/braking surface is apples with apples?

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby andrewjcw » Tue Sep 19, 2017 2:20 pm

Technically yes, but the logical take away is we'll have to come up with something new to complain about. The list is getting a bit short... :(

Safety
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Ugly
What stinky hairy legged mountain bikers use

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby biker jk » Tue Sep 19, 2017 2:25 pm

fat and old wrote:
biker jk wrote:
The Enve 3 4 wheelset is 87 grams heavier in the rim brake version based on a DT240 hub. The disc brake rims are 84 grams lighter for the two. So the disc brake hub/extra 4 spokes add 3 grams.

Enve 3.4 rim brake wheelset weight is 1508 grams. Disc brake wheelset weight is 1421 grams. Even with a lighter Chris King R45 hub on the rim brake wheelset it's still heavier at 1477 grams.


Shouldn't the weight of the disk be included when comparing? You don't exactly remove the brake track from a wheel when checking the rim brake version, disks are essentially the brake track aren't they? Overall weight of the wheel/braking surface is apples with apples?


My response was to an argument that a disc brake wheelset needs to be heavier due to rims/hubs/spokes. This is clearly not the case. Nobody is denying that that disc brakes make a bike heavier, but this isn't because of the need for a beefed up wheelset. Indeed, even accounting for the weight of the rotors, the Campagnolo Super Record EPS disc brake groupset with Bora One 35mm tubulars is 9 grams heavier than the rim brake version.

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby MichaelB » Tue Sep 19, 2017 2:39 pm

andrewjcw wrote:Technically yes, but the logical take away is we'll have to come up with something new to complain about. The list is getting a bit short... :(

Safety
Aerodynamics
Weight
Ugly
What stinky hairy legged mountain bikers use



Love it !!! :D

At the end of the day, I'm happy with my discs.

I don't race, so can't slice anyone up, not fast enough to worry about aero, weigh over 90kg :( , so an extra couple of hundred grams is SFA, and I'm more of a form over function, and couldn't car what MTB'ers use, as they are just a baggy shorts brigade that occasionally bug me with their whirring & noisy tyres and ridiculous helmets.

Just glad I didn't buy the last Propel, as I'd be feeling ripped off by my extra 15W that it takes to pedal at a speed I can't typically get to !!!

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby warthog1 » Tue Sep 19, 2017 2:48 pm

MichaelB wrote:
Just glad I didn't buy the last Propel, as I'd be feeling ripped off by my extra 15W that it takes to pedal at a speed I can't typically get to !!!


You'll need to read Alex Simmon's comment to place that 15w figure in perspective. It appears to be heavily on the marketing side of factual.

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby biker jk » Tue Sep 19, 2017 3:24 pm

warthog1 wrote:
MichaelB wrote:
Just glad I didn't buy the last Propel, as I'd be feeling ripped off by my extra 15W that it takes to pedal at a speed I can't typically get to !!!


You'll need to read Alex Simmon's comment to place that 15w figure in perspective. It appears to be heavily on the marketing side of factual.


Speaking of marketing bs, don't you own a Zipp wheelset? :lol:

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Re: UCI expected to approve Road Disc Brakes for 2016

Postby fat and old » Tue Sep 19, 2017 3:42 pm

biker jk wrote:
fat and old wrote:
biker jk wrote:
The Enve 3 4 wheelset is 87 grams heavier in the rim brake version based on a DT240 hub. The disc brake rims are 84 grams lighter for the two. So the disc brake hub/extra 4 spokes add 3 grams.

Enve 3.4 rim brake wheelset weight is 1508 grams. Disc brake wheelset weight is 1421 grams. Even with a lighter Chris King R45 hub on the rim brake wheelset it's still heavier at 1477 grams.


Shouldn't the weight of the disk be included when comparing? You don't exactly remove the brake track from a wheel when checking the rim brake version, disks are essentially the brake track aren't they? Overall weight of the wheel/braking surface is apples with apples?


My response was to an argument that a disc brake wheelset needs to be heavier due to rims/hubs/spokes. This is clearly not the case. Nobody is denying that that disc brakes make a bike heavier, but this isn't because of the need for a beefed up wheelset. Indeed, even accounting for the weight of the rotors, the Campagnolo Super Record EPS disc brake groupset with Bora One 35mm tubulars is 9 grams heavier than the rim brake version.


Comprende. So a Bora One 35mm tub rim brake version is 4.5 grams lighter than a Bora One 35mm tub disk brake version with disk? Cool. Quintana will be beside himself!

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