[Stef Marazzi]

Hi all,

Now disc brakes are allowed in the pro-peloton, have there been any good examples of where a disc-braked rider has managed to out brake his closest competitors on rim-brakes and create a decent lead for themselves?

Just wondering, as I was expecting to see some being boasted about, or shown on TV, but havent seen anything.

Topic

[fukawitribe]

There are some cases already

There are some cases already where disc equipped bikes appear more aero than rim, e.g.

https://www.slowtwitch.com/Tech/Disc_and_Rim_Brake_Aero_Drag_6073.html

(disc better over most of the yaw range they tried, rim brakes more slippery at high yaw towards NDS, head-on is never going to be much different) but what i’m looking to see is what folk can come up with now that aero/deep-section wheels are increasingly being properly designed without needing to consider a brake track, as Canyon48 alluded to.

[Canyon48]

Anthony.C wrote:

Canyon48 wrote:

The aero advantages are significant of disc brakes over rim brakes. Removing the brake surface as well as moving the calliper away from the rim gives vastly improved airflow over the tyre and rim.

I don’t know where you get that from, disc brakes are always said to be less aero.

The key there is “said to be”. The first disc brake road bikes were less aero (those bikes which were essentially unchanged from their rim brake counterparts, just with added discs).

But the latest disc brake bikes, designed from the ground up as disc brake bikes, are in fact more aero. Or, at the very least, not less aero 😛

I also have 1500 hours of CFD simulations and a few hours of wind tunnel data comparing the two, the disc brake version (modelled using some of the neat tricks the Scott Foil Disc uses around the calliper) was massively better than the rim brake version.

But again, not to say that all disc brake bikes are faster, though the latest disc brake bikes that have exploited the advantages really are faster.

[Kapelmuur]

I’m sure I remember drum

I’m sure I remember drum brakes when I was a nipper, I used to covet them as the rod operated rim brakes on my Hercules were useless and stopping was more effective by dragging my feet on the road.

[don simon fbpe]

http://road.cc/content/news

http://road.cc/content/news/138535-disc-v-rim-brakes-which-more-aero

[Anthony.C]

Canyon48 wrote:

The aero advantages are significant of disc brakes over rim brakes. Removing the brake surface as well as moving the calliper away from the rim gives vastly improved airflow over the tyre and rim.

I don’t know where you get that from, disc brakes are always said to be less aero.

[Canyon48]

The aero advantages are

The aero advantages are significant of disc brakes over rim brakes. Removing the brake surface as well as moving the calliper away from the rim gives vastly improved airflow over the tyre and rim.

[beigemaster]

I was having a think about

I was having a think about this myself. I would imagine where you would gain the most advantage by way of actual time gaps would be presumably on a very long Alpine descent with multiple hairpins (especially in the wet). However, at the moment the only riders who are really using the discs seem to be the sprinters and the larger guys on aero style frames- who are almost never going to be at the front of the peleton on that type of descent/stage bar perhaps Sagan who could probably walk on water if he gave it a crack. 

 

There is a forecast for storms this week as Le Tour enters the mountains, so watch this space. 

 

Other and perhaps more subtle difference, it seems that manufacturers are able to get aero gains from losing the callipers as there’s greater clearance for wider tyres and rim combos, so again that might offer a marginal gain but pretty hard to quantify- I’m sure it’s been noted that John Degenkolb won on the pave on stage 9 on a disc brake bike.  

 

[wycombewheeler]

dottigirl wrote:

dottigirl wrote:

Dan Martin expressed concern today that the relative increase in incidents was down to the disparity in braking between discs and rims. 

At least, there is still some concern in the pro peloton about this, though it doesn’t really affect us plebs.

 

Right…because when you are riding at 30mph 6 inches behind another bike the key factor is how hard brakes can be applied and reaction time doesn’t factor at all.

It’s quite clear that if rider a is travelling behind rider b and b brakes hard there will be an incident no matter what brakes are used.

The ludites claim there is no inherent benefit and disc brakes as rim brakes provide all the braking the tyres can deal with and now they also claim braking differences are problematic.

[dottigirl]

Dan Martin expressed concern

Dan Martin expressed concern today that the relative increase in incidents was down to the disparity in braking between discs and rims. 

At least, there is still some concern in the pro peloton about this, though it doesn’t really affect us plebs.

 

[madcarew]

BehindTheBikesheds wrote:

Mungecrundle wrote:

BehindTheBikesheds wrote:

future? what benefits does it bring aside from wear, something that isn’t an issue at pro level?

crack on

Why not give them a go yourself, maybe over this winter? Then you would have an informed opinion which would actually be worth reading. I wonder if road.cc might have a spare test bike? You have contributed enough interesting and thought provoking if sometimes controversial material over the years that keeps their website fresh.

What advvantages in pro racing do discs have over rim brakes, I’m still waiting.

Greater control, better stopping. But you’re not really listening to the answer. 

[Mungecrundle]

What are you expecting?
What are you expecting?

[Anonymous]

Mungecrundle wrote:

Mungecrundle wrote:

BehindTheBikesheds wrote:

future? what benefits does it bring aside from wear, something that isn’t an issue at pro level?

crack on

Why not give them a go yourself, maybe over this winter? Then you would have an informed opinion which would actually be worth reading. I wonder if road.cc might have a spare test bike? You have contributed enough interesting and thought provoking if sometimes controversial material over the years that keeps their website fresh.

What advvantages in pro racing do discs have over rim brakes, I’m still waiting.

[Rapha Nadal]

Mungecrundle wrote:

Mungecrundle wrote:

BehindTheBikesheds wrote:

future? what benefits does it bring aside from wear, something that isn’t an issue at pro level?

crack on

Why not give them a go yourself, maybe over this winter? Then you would have an informed opinion which would actually be worth reading. I wonder if road.cc might have a spare test bike? You have contributed enough interesting and thought provoking if sometimes controversial material over the years that keeps their website fresh.

And there we have it.  The impression I get is that those who are dead against discs are those who’ve not actually used them.

I honestly cannot recall anybody I know who uses discs to say that they’re going back to calipers because this progression of technology is utter shite!

[Mungecrundle]

BehindTheBikesheds wrote:

BehindTheBikesheds wrote:

future? what benefits does it bring aside from wear, something that isn’t an issue at pro level?

crack on

Why not give them a go yourself, maybe over this winter? Then you would have an informed opinion which would actually be worth reading.

I wonder if road.cc might have a spare test bike? You have contributed enough interesting and thought provoking if sometimes controversial material over the years that keeps their website fresh.

[Anonymous]

future? what benefits does it

future? what benefits does it bring aside from wear, something that isn’t an issue at pro level?

crack on

[Author]

Replies