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Seems like it is only the manufacturers who are pushing this. This is surely change for change sake on road bikes?
http://www.bikeradar.com/gear/article/the-problem-with-disc-brakes-in-road-...
http://www.bikeradar.com/gear/article/the-problem-with-disc-brakes-in-road-...
In reply to woolsack:
I guess many cyclists who have realised how good discs are with MTBs now want the same on the road. Oddly enough I wasn't that keen, being a MTBer who's just bought his first road bike for 25 years, but ended up getting them anyway because the bike I wanted had them. Actually quite impressed so far, but time will tell.
The big thing I know I have to get used to with the road is that you brake differently. Having extra stopping power is all well and good, but you have a much smaller contact patch on the tyres so that becomes the key factor. I've had a couple of occasions where I've misjudged my stopping distance because I'm used to MTBs and big tyres.
Will road-racing change ? Heard Gary Fisher talking about how he persuaded the UCI to allow 29ers in MTB races on safety grounds, but I've got a feeling that discs would be more dangerous, particularly in a big pile up.
I guess many cyclists who have realised how good discs are with MTBs now want the same on the road. Oddly enough I wasn't that keen, being a MTBer who's just bought his first road bike for 25 years, but ended up getting them anyway because the bike I wanted had them. Actually quite impressed so far, but time will tell.
The big thing I know I have to get used to with the road is that you brake differently. Having extra stopping power is all well and good, but you have a much smaller contact patch on the tyres so that becomes the key factor. I've had a couple of occasions where I've misjudged my stopping distance because I'm used to MTBs and big tyres.
Will road-racing change ? Heard Gary Fisher talking about how he persuaded the UCI to allow 29ers in MTB races on safety grounds, but I've got a feeling that discs would be more dangerous, particularly in a big pile up.
In reply to woolsack:
I can see no benefit in terms of braking performance but like the idea of not wearing the rims out on expensive wheels and either having to replace or rebuild them.
It's an interesting challenge designing them though, I had not given it much thought but the forces and temperatures are very different in road biking to mtbing.
Cheers
Toby
I can see no benefit in terms of braking performance but like the idea of not wearing the rims out on expensive wheels and either having to replace or rebuild them.
It's an interesting challenge designing them though, I had not given it much thought but the forces and temperatures are very different in road biking to mtbing.
Cheers
Toby
In reply to Chris the Tall:
It's an industry "solution" to a problem that didn't exist. Well it didn't exist for riders. Manufacturers didn't want the cost of threading and facing the BB shell so they sold pressfit BBs as being "stiffer". It's more likely that the extra frame material round the BB area is the cause of the stiffness not the BBs themselves.
I see that Santa Cruz have stated they won't be using pressfit BBs on their bikes.
It's an industry "solution" to a problem that didn't exist. Well it didn't exist for riders. Manufacturers didn't want the cost of threading and facing the BB shell so they sold pressfit BBs as being "stiffer". It's more likely that the extra frame material round the BB area is the cause of the stiffness not the BBs themselves.
I see that Santa Cruz have stated they won't be using pressfit BBs on their bikes.
In reply to woolsack:
"The whole wheel-change problem; that needs to be sewn up," Christ said.'
Who would have thought that the debate would go so high?
"The whole wheel-change problem; that needs to be sewn up," Christ said.'
Who would have thought that the debate would go so high?
In reply to woolsack:
There are 2 advantages to RDBs:
1 - won't be wearing out expensive rims
2 - can have lighter rims as no need to beef up the braking surfaces, although weight and performance gains there almost certainly cancelled out by increased weight of the bike as a whole.
In practice, for most road riders, it's a pointless as electronic shifting.
Yes, my MTB has hydraulic disk brakes, as there are clear advantages in that application.
There are 2 advantages to RDBs:
1 - won't be wearing out expensive rims
2 - can have lighter rims as no need to beef up the braking surfaces, although weight and performance gains there almost certainly cancelled out by increased weight of the bike as a whole.
In practice, for most road riders, it's a pointless as electronic shifting.
Yes, my MTB has hydraulic disk brakes, as there are clear advantages in that application.
In reply to woolsack:
Having boiled the brakes on my MTB more times than I care to remember when the escape route is to turn into the hill to slow down, I'm stuggling to work out how they could be safe on a roadbike where you only have a defined surface to run on. Yes, you can modify your braking patterns to help, but even on 200mm discs some alpine descents i've done have required stoping multiple times to let the brakes cool off.
There is nothing scarier than boiling brakes on a fast descent.
In terms of performance, I can't see any improvement from disc brakes except posibly in the nastiest weather on horribly gritty roads.
Having boiled the brakes on my MTB more times than I care to remember when the escape route is to turn into the hill to slow down, I'm stuggling to work out how they could be safe on a roadbike where you only have a defined surface to run on. Yes, you can modify your braking patterns to help, but even on 200mm discs some alpine descents i've done have required stoping multiple times to let the brakes cool off.
There is nothing scarier than boiling brakes on a fast descent.
In terms of performance, I can't see any improvement from disc brakes except posibly in the nastiest weather on horribly gritty roads.
In reply to LastBoyScout:
I have very little interest in RDBs, but I would have thought additional weight is fairly irrelevant because all the bikes are 'weighted up' to 6.7kg, so less weight on the rims is likely to provide a small advantage.
I have very little interest in RDBs, but I would have thought additional weight is fairly irrelevant because all the bikes are 'weighted up' to 6.7kg, so less weight on the rims is likely to provide a small advantage.
In reply to balmybaldwin:
What would your thoughts be if, as a result of allowing disc brakes in racing, manufacturers improved them so that they didn't boil?
What would your thoughts be if, as a result of allowing disc brakes in racing, manufacturers improved them so that they didn't boil?
In reply to 999thAndy:
You can't buck physics. Keeping weight down, making it aero and achieving the necessary heat dissipation is going to be a tall order indeed
> What would your thoughts be if, as a result of allowing disc brakes in racing, manufacturers improved them so that they didn't boil?
You can't buck physics. Keeping weight down, making it aero and achieving the necessary heat dissipation is going to be a tall order indeed
In reply to 999thAndy:
Or Road BB7 cable discs can be used, and if the have good outer cabling on them ( ie less compressible), they're pretty damn good and they don't boil.
As wheel technology improves (as it always does) rims may/will get lighter by enough of a degree to offset the weight of the discs (and the frame being beefier due to having them) on a bike, i think.
I think eventually wheel weight (and braking) will have got to a point which wouldn't be achievable with rim brakes, and that we're not seeing much of an advantage at the moment, because it's something which is only just being adopted.
> What would your thoughts be if, as a result of allowing disc brakes in racing, manufacturers improved them so that they didn't boil?
Or Road BB7 cable discs can be used, and if the have good outer cabling on them ( ie less compressible), they're pretty damn good and they don't boil.
As wheel technology improves (as it always does) rims may/will get lighter by enough of a degree to offset the weight of the discs (and the frame being beefier due to having them) on a bike, i think.
I think eventually wheel weight (and braking) will have got to a point which wouldn't be achievable with rim brakes, and that we're not seeing much of an advantage at the moment, because it's something which is only just being adopted.
Post edited at 14:15
In reply to woolsack:
Which isn't the same as impossible...
> You can't buck physics. Keeping weight down, making it aero and achieving the necessary heat dissipation is going to be a tall order indeed
Which isn't the same as impossible...
In reply to 999thAndy:
Disc brake boiling is a vastly over exaggerated problem unless you have moisture in your system.
Disc brake boiling is a vastly over exaggerated problem unless you have moisture in your system.
In reply to woolsack:
A while ago people were arguing against discs in cyclocross, saying that nobody had won with discs, and I read recently about somebody winning with discs on their bike.
I'm not saying it's a deciding factor, but looking at what is the case now, isn't always such a good basis on which to say what new products could bring to cycling, or anything at all particularly.
Discs would mean that dragging brakes won't lead to tyre blow outs on alpine descents due to the air in them heating up, which is an aid to safety.
A while ago people were arguing against discs in cyclocross, saying that nobody had won with discs, and I read recently about somebody winning with discs on their bike.
I'm not saying it's a deciding factor, but looking at what is the case now, isn't always such a good basis on which to say what new products could bring to cycling, or anything at all particularly.
Discs would mean that dragging brakes won't lead to tyre blow outs on alpine descents due to the air in them heating up, which is an aid to safety.
Post edited at 14:21
In reply to The New NickB:
I think we'll see the weight limit lowered before we see RDBs - they can already make much lighter bikes, and that's were the trickledown of technology will have big impact.
Maybe more bike manufacturers should run teams - I make it 3 out of 18 at the moment (Cannondale, Trek and Giant)
> I have very little interest in RDBs, but I would have thought additional weight is fairly irrelevant because all the bikes are 'weighted up' to 6.7kg, so less weight on the rims is likely to provide a small advantage.
I think we'll see the weight limit lowered before we see RDBs - they can already make much lighter bikes, and that's were the trickledown of technology will have big impact.
Maybe more bike manufacturers should run teams - I make it 3 out of 18 at the moment (Cannondale, Trek and Giant)
In reply to neuromancer:
I wasn't so much interested in boiling fluid as to disc and pad temperatures on long descents. A puny steel disc has a limited capacity for heat. Cast iron is much better that has it's own issues and I wouldn't want that glowing red hot anywhere near my bare legs. Mind you, it'll get the hairs off!
I wasn't so much interested in boiling fluid as to disc and pad temperatures on long descents. A puny steel disc has a limited capacity for heat. Cast iron is much better that has it's own issues and I wouldn't want that glowing red hot anywhere near my bare legs. Mind you, it'll get the hairs off!
In reply to woolsack:
I think the main advantage of disks is when it is wet, you don't get that lag as the brake blocks dry the rim before they grip. So in a few circumstances they could be safer. The rest of the time they might offer a little better feel but I doubt any extra power and with the negatives of being less aero and heavier.
So maybe disks if it is rain affected race otherwise rim brakes?
I think the main advantage of disks is when it is wet, you don't get that lag as the brake blocks dry the rim before they grip. So in a few circumstances they could be safer. The rest of the time they might offer a little better feel but I doubt any extra power and with the negatives of being less aero and heavier.
So maybe disks if it is rain affected race otherwise rim brakes?
In reply to woolsack:
Cars have used carbon discs to good effect, I don't suppose they're too heavy. Don't know about the aero bit.
> You can't buck physics. Keeping weight down, making it aero and achieving the necessary heat dissipation is going to be a tall order indeed
Cars have used carbon discs to good effect, I don't suppose they're too heavy. Don't know about the aero bit.
In reply to 999thAndy:
Well the solution is easy and obvious - much larger fluid resevoirs (more need to heat it up) bigger heat sinks etc - this all makes it heavy...
If they can do it in a nice lightweight package, then great - just don't look at me to be the guinea pig
Well the solution is easy and obvious - much larger fluid resevoirs (more need to heat it up) bigger heat sinks etc - this all makes it heavy...
If they can do it in a nice lightweight package, then great - just don't look at me to be the guinea pig
In reply to neuromancer:
In this country maybe but then you rarely find downhills more than a mile in length, on long alpine descents it is a different story
In this country maybe but then you rarely find downhills more than a mile in length, on long alpine descents it is a different story
In reply to 999thAndy:
What have we got that is carbon already there? Oh, the rim
Carbon discs have very low cold friction level so they need to run at a steady bulk temperature which in cycling won't be happening. Carbon does have great heat capacity though
> Cars have used carbon discs to good effect, I don't suppose they're too heavy. Don't know about the aero bit.
What have we got that is carbon already there? Oh, the rim
Carbon discs have very low cold friction level so they need to run at a steady bulk temperature which in cycling won't be happening. Carbon does have great heat capacity though
In reply to Timmd:
In a few UCI World Cup races Lars van der Har was pretty much the only top rider using discs, and they were considered a critical factor in him dominating on some courses. However on other courses they didn't have the same effect and the races were more even.
It did show that in the right conditions than can help, but away from those conditions the impact is less pronounced. I'll have a look to see if I can dig out details of the courses they worked on.
> A while ago people were arguing against discs in cyclocross, saying that nobody had won with discs, and I read recently about somebody winning with discs on their bike.
In a few UCI World Cup races Lars van der Har was pretty much the only top rider using discs, and they were considered a critical factor in him dominating on some courses. However on other courses they didn't have the same effect and the races were more even.
It did show that in the right conditions than can help, but away from those conditions the impact is less pronounced. I'll have a look to see if I can dig out details of the courses they worked on.
In reply to woolsack:
I think thats a bit narrow minded. How popular do you think the Tour de France would be if bike technology was limited to that available in 1965?
Its hard not to see the similarities between Formula 1 and its engines with cycling and its brakes.
Nobody likes change but I can't see there being any issues either technical, safety or fairness that couldn't be resolved if the right people got to sit down with the intention of finding a solution.
> Seems like it is only the manufacturers who are pushing this. This is surely change for change sake on road bikes?
I think thats a bit narrow minded. How popular do you think the Tour de France would be if bike technology was limited to that available in 1965?
Its hard not to see the similarities between Formula 1 and its engines with cycling and its brakes.
Nobody likes change but I can't see there being any issues either technical, safety or fairness that couldn't be resolved if the right people got to sit down with the intention of finding a solution.
In reply to Antigua:
Japanese keirin is hugely popular and that is a formula that is completely locked down technologically
There isn't a problem with road racing brakes though. Is there?
> I think thats a bit narrow minded. How popular do you think the Tour de France would be if bike technology was limited to that available in 1965?
Japanese keirin is hugely popular and that is a formula that is completely locked down technologically
> Its hard not to see the similarities between Formula 1 and its engines with cycling and its brakes.
There isn't a problem with road racing brakes though. Is there?
In reply to Toby_W:
Even more relevant on a crosser and the main reason why I've gone for discs on my new one.
> (In reply to woolsack)
>
> I can see no benefit in terms of braking performance but like the idea of not wearing the rims out on expensive wheels and either having to replace or rebuild them.
>
> I can see no benefit in terms of braking performance but like the idea of not wearing the rims out on expensive wheels and either having to replace or rebuild them.
Even more relevant on a crosser and the main reason why I've gone for discs on my new one.
In reply to woolsack:
No, but possibly it could be greener to have discs, if you think about how much longer wheels could last, and there's arguably some benefits to be had in terms of wheels getting lighter where it matters, and people not having tyre blow outs in the alps.
There isn't a problem but there could be benefits.
> Japanese keirin is hugely popular and that is a formula that is completely locked down technologically
> There isn't a problem with road racing brakes though. Is there?
No, but possibly it could be greener to have discs, if you think about how much longer wheels could last, and there's arguably some benefits to be had in terms of wheels getting lighter where it matters, and people not having tyre blow outs in the alps.
There isn't a problem but there could be benefits.
In reply to Timmd:
Top end race wheels are pretty light as they are, especially tubular rims. You have to have a rim whatever brakes are on the bike.
I just think the manufacturers are busily trying to persuade us we need a change for no real benefit aside from feathering their own nests
Top end race wheels are pretty light as they are, especially tubular rims. You have to have a rim whatever brakes are on the bike.
I just think the manufacturers are busily trying to persuade us we need a change for no real benefit aside from feathering their own nests
In reply to woolsack:
You do, but the rim has to have a braking surface too. Lightweight mountain biking XC rims seem to have qot lighter by around a quarter or a fifth (from my random observations on rim weight) now a braking surface isn't needed.
I don't doubt there are companies rubbing their hands together at the idea of developing and selling new products, though.
Most of us probably wouldn't need discs, but I can see small gains in wheel rim design happening on bikes with disc brakes fitted.
You do, but the rim has to have a braking surface too. Lightweight mountain biking XC rims seem to have qot lighter by around a quarter or a fifth (from my random observations on rim weight) now a braking surface isn't needed.
I don't doubt there are companies rubbing their hands together at the idea of developing and selling new products, though.
Most of us probably wouldn't need discs, but I can see small gains in wheel rim design happening on bikes with disc brakes fitted.
Post edited at 01:33
In reply to woolsack:
I believe it's popularity has more to do with it unpredictability, which makes it good for betting. There was speculation that it's inclusion in the Olympics at the expense of the 1k pursuit was down to lots of brown envelopes.
Gary fisher reckons it takes 10 years to perfect an innovation. Do we really want the manufacturers to abandon their R and D departments ?
> Japanese keirin is hugely popular and that is a formula that is completely locked down technologically
I believe it's popularity has more to do with it unpredictability, which makes it good for betting. There was speculation that it's inclusion in the Olympics at the expense of the 1k pursuit was down to lots of brown envelopes.
Gary fisher reckons it takes 10 years to perfect an innovation. Do we really want the manufacturers to abandon their R and D departments ?
In reply to Chris the Tall:
With 'normal' brakes, you can generally fix issues with minimal and regular tools. With hydraulic disks, it's a little bit more complicated. Especially when on the side of the road...
With 'normal' brakes, you can generally fix issues with minimal and regular tools. With hydraulic disks, it's a little bit more complicated. Especially when on the side of the road...
In reply to Chris the Tall:
But the point is that the Tour is interesting because it is largely a level playing field as far as the technology goes and it is all about who is the best rider, has best tactics and best blood doping
But the point is that the Tour is interesting because it is largely a level playing field as far as the technology goes and it is all about who is the best rider, has best tactics and best blood doping
In reply to balmybaldwin:
I've done 2k+ descents (that's vertical metres, not distance travelled) in the alps and yes, whilst my brakes got hot (I camelbak'd them occasionally), they never faded because they were well filled and bled.
In reply to woolsack:
The speeds that the tour are travelling will significantly increase the air cooling that the brakes receive over mtb discs. Moreover, have you tried ice techs and/or finned pads?
As to the point of hot rotors giving people a few burns - when people bail on the downhill stages of the tour (it's not like you're suddenly going to hit 150 degree rotors on your sunday sportive) the impact of hitting road and twisted metal at 50mph is not going to be made significantly worse by a few bits of it being hot enough to maybe at best give you a small localised second degree burn.
To the implication that disc rotors are all sharpened blades a-la-"ben hur". I've never heard nor seen anyone get sliced open by a disc brake. I mean shit, you could machine a perfectly rounded edge to the disc and it wouldn't affect braking. This is a non-argument.
And finally to the suggestion that once you have disc brakes braking suddenly becomes dangerous as they are too powerful for road contact patches I have two points. Road contact patches are smaller, but more effective as the surface is less undulating. Therefore they need a smaller area to get the same modulus of friction as a mountain bike. It does not mean they cannot withstand lateral sliding friction forces at a tenth of the ability. Secondly, if you have ridden on good disc brakes you will understand that one of their best qualities is what is (weirdly) called "Modularity". That is, it is so easy to feather them and get the exact amount of braking you want. They are not sticky or "all-or-nothing" like rim brakes.
I've done 2k+ descents (that's vertical metres, not distance travelled) in the alps and yes, whilst my brakes got hot (I camelbak'd them occasionally), they never faded because they were well filled and bled.
In reply to woolsack:
The speeds that the tour are travelling will significantly increase the air cooling that the brakes receive over mtb discs. Moreover, have you tried ice techs and/or finned pads?
As to the point of hot rotors giving people a few burns - when people bail on the downhill stages of the tour (it's not like you're suddenly going to hit 150 degree rotors on your sunday sportive) the impact of hitting road and twisted metal at 50mph is not going to be made significantly worse by a few bits of it being hot enough to maybe at best give you a small localised second degree burn.
To the implication that disc rotors are all sharpened blades a-la-"ben hur". I've never heard nor seen anyone get sliced open by a disc brake. I mean shit, you could machine a perfectly rounded edge to the disc and it wouldn't affect braking. This is a non-argument.
And finally to the suggestion that once you have disc brakes braking suddenly becomes dangerous as they are too powerful for road contact patches I have two points. Road contact patches are smaller, but more effective as the surface is less undulating. Therefore they need a smaller area to get the same modulus of friction as a mountain bike. It does not mean they cannot withstand lateral sliding friction forces at a tenth of the ability. Secondly, if you have ridden on good disc brakes you will understand that one of their best qualities is what is (weirdly) called "Modularity". That is, it is so easy to feather them and get the exact amount of braking you want. They are not sticky or "all-or-nothing" like rim brakes.
In reply to neuromancer:
A 140/160/180mm diameter steel disc @200-300c pressed against your leg will give you more than a small localised burn. That is a very realistic temperature on a long descent.
How much heavier do the forks now need to be to be strong enough for the brake caliper loading? How much heavier does the hub need to be to mount the disc.
Don't get me wrong, discs are a great idea for MTB or CX but the rim brake is perfectly adequate for it's intended use on the road. It's a manufacturer driven proposition
> is not going to be made significantly worse by a few bits of it being hot enough to maybe at best give you a small localised second degree burn.
A 140/160/180mm diameter steel disc @200-300c pressed against your leg will give you more than a small localised burn. That is a very realistic temperature on a long descent.
How much heavier do the forks now need to be to be strong enough for the brake caliper loading? How much heavier does the hub need to be to mount the disc.
Don't get me wrong, discs are a great idea for MTB or CX but the rim brake is perfectly adequate for it's intended use on the road. It's a manufacturer driven proposition
In reply to woolsack: Calm down dear, nobody is going to make you buy discs or take away your rim brakes.
In reply to woolsack:
>rim brake is perfectly adequate for its intended use on the road
In the dry, I mostly agree with you - the benefit is probably outweighed by the faff.
>rim brake is perfectly adequate for its intended use on the road
In the dry, I mostly agree with you - the benefit is probably outweighed by the faff.
In reply to woolsack:
I'd be worried about getting rear ended, using discs in the wet amongst other riders who weren't similarly equiped
I'd be worried about getting rear ended, using discs in the wet amongst other riders who weren't similarly equiped
In reply to blurty:
Others above have commented on the ease of modulation. Being rear-ended is more to do with the way in which you and those around you ride than anything to do with unequal braking power.
> I'd be worried about getting rear ended, using discs in the wet amongst other riders who weren't similarly equiped
Others above have commented on the ease of modulation. Being rear-ended is more to do with the way in which you and those around you ride than anything to do with unequal braking power.
I was struck by how quickly discs have emerged in cross in the last season or two, be interesting to see what happens on the road. I've never really felt underbraked on the road ...let's just not speak about the cantis on my cross bike
In reply to neuromancer:
In the wet the front wheel skids with rim brakes so no need for better brakes - maybe a better tyre? I'm commuting on something heavy, "puncture proof" and slick.
In the wet the front wheel skids with rim brakes so no need for better brakes - maybe a better tyre? I'm commuting on something heavy, "puncture proof" and slick.
In reply to woolsack:
I'd love discs on my tourer, on my commuter road bike perhaps but on my actual race bike? The brakes provide far more braking power than I need even in the wet with the right pads and they are simple.
Ultimately though if they can make them beautiful then maybe.
cheers
Toby
I'd love discs on my tourer, on my commuter road bike perhaps but on my actual race bike? The brakes provide far more braking power than I need even in the wet with the right pads and they are simple.
Ultimately though if they can make them beautiful then maybe.
cheers
Toby
In reply to balmybaldwin:
Did you really boil the brakes or are you describing brake fade due to the disc being too hot? That would be more common and can be fixed with different compound pads (and different discs if needs be).
I'm not having a go, I'm just interested. I've had a bit of brake fade on my MTB but always manageable.
Did you really boil the brakes or are you describing brake fade due to the disc being too hot? That would be more common and can be fixed with different compound pads (and different discs if needs be).
I'm not having a go, I'm just interested. I've had a bit of brake fade on my MTB but always manageable.
In reply to woolsack:
MTB XC rims have gone from circa 400/375 grams to around 100 grams less than that from what I've seen, even if discs do add weight to a bike, a similar reduction in road rims could be noticeable on the climbs.
Even if you don't think it's needed, it will bring advances.
www.justridingalong.com/parts/wheel-parts/rims/stans-notubes-ztr-podium-mmx-26quot-32h.html
These rims weigh 290 grams...
> A 140/160/180mm diameter steel disc @200-300c pressed against your leg will give you more than a small localised burn. That is a very realistic temperature on a long descent.
> How much heavier do the forks now need to be to be strong enough for the brake caliper loading? How much heavier does the hub need to be to mount the disc.
MTB XC rims have gone from circa 400/375 grams to around 100 grams less than that from what I've seen, even if discs do add weight to a bike, a similar reduction in road rims could be noticeable on the climbs.
Even if you don't think it's needed, it will bring advances.
www.justridingalong.com/parts/wheel-parts/rims/stans-notubes-ztr-podium-mmx-26quot-32h.html
These rims weigh 290 grams...
Post edited at 14:10
In reply to elsewhere:
That's because rim brakes have poor modulation. Hydraulic discs are much more precise - you can find that point of maximum braking before loss of traction much easier.
That's because rim brakes have poor modulation. Hydraulic discs are much more precise - you can find that point of maximum braking before loss of traction much easier.
In reply to M0nkey:
Yes, sorry its an expression - brake fade. Manageable, but only by stopping for a minute or 2 to let the discs cool. Running Sintered pads and 203/180 floating rotors (also happened earlier in the week on Organic pads). The worst I had it was a very long sustained technical descent (2500m vertical) only the steepest bits were a problem as you had to be on the brakes most of the time. Probably just a case of too being a bit too much for the brake system... all 4 of us (including our guide) were experiencing the same with a range of different set-ups (but no on e with "DownHill" Brakes
Yes, sorry its an expression - brake fade. Manageable, but only by stopping for a minute or 2 to let the discs cool. Running Sintered pads and 203/180 floating rotors (also happened earlier in the week on Organic pads). The worst I had it was a very long sustained technical descent (2500m vertical) only the steepest bits were a problem as you had to be on the brakes most of the time. Probably just a case of too being a bit too much for the brake system... all 4 of us (including our guide) were experiencing the same with a range of different set-ups (but no on e with "DownHill" Brakes
In reply to neuromancer:
I think the point is that rim brake torque already exceeds tyre adhesion in the wet. Wet rim brakes pretty much self modulate
> That's because rim brakes have poor modulation. Hydraulic discs are much more precise - you can find that point of maximum braking before loss of traction much easier.
I think the point is that rim brake torque already exceeds tyre adhesion in the wet. Wet rim brakes pretty much self modulate
In reply to woolsack:
So out of all the people replying it would be useful to know who has ridden/owned what. I currently have a rim road bike and 2 disc cx bikes( one which i use on road a fair bit)
my opinion- Discs(cable bb7) are much better in winter,wet crappy conditions, can definitely stop faster in a more controlled manner,maintenance is easier no toe in faff.No rub if you ding a wheel,easier to swap a wheel out.
The only time that rim are equal is in summer in perfect conditions
I have only done uk length descents on them and not used road hydraulic only cable bb7's.
For me discs are the preferred option and my next pure road bike will have them having used road rim and road disc(not sure about hydraulic yet)
Interesting that those worried about a crash in a peloton are more worried about a hot disc and not hitting the tarmac/barriers/cars/whatever at high speed
So out of all the people replying it would be useful to know who has ridden/owned what. I currently have a rim road bike and 2 disc cx bikes( one which i use on road a fair bit)
my opinion- Discs(cable bb7) are much better in winter,wet crappy conditions, can definitely stop faster in a more controlled manner,maintenance is easier no toe in faff.No rub if you ding a wheel,easier to swap a wheel out.
The only time that rim are equal is in summer in perfect conditions
I have only done uk length descents on them and not used road hydraulic only cable bb7's.
For me discs are the preferred option and my next pure road bike will have them having used road rim and road disc(not sure about hydraulic yet)
Interesting that those worried about a crash in a peloton are more worried about a hot disc and not hitting the tarmac/barriers/cars/whatever at high speed
In reply to tjin:
...or even for the mechanic hanging out of the side of the team car with the 'magic spanner'
> With 'normal' brakes, you can generally fix issues with minimal and regular tools. With hydraulic disks, it's a little bit more complicated. Especially when on the side of the road...
...or even for the mechanic hanging out of the side of the team car with the 'magic spanner'
In reply to woolsack:
In terms of braking most modern short reach 'rim' brakes are nowhere near as efficient as the good old fashioned MAFAC centre pulls of the 1960's.
In terms of braking most modern short reach 'rim' brakes are nowhere near as efficient as the good old fashioned MAFAC centre pulls of the 1960's.
In reply to Radioactiveman:
I have a hardtail mountain bike (hydraulic discs), a bike I use for touring (MTB frame, city tyres, cable discs), and a road bike (ultegra rim brakes, on mavic aksiums).
Personally, I think all the bikes I have have exactly the right types of brakes for their applications. I grew up with a mountain bike with V-brakes, which were good at the time, but I'd never go back after the hydraulic discs.
If I have difficulty stopping on the road bike, its inevitably an issue with my technique (if on the front brake at high speed, it's a question of stability), or of tyre traction (with the rear wheel). I can't imagine that any racer would seriously want disc brakes on the rear, under hard braking it's too easy to lock it up even with rim brakes.
In the wet, disc brakes have the advantage that they work very similarly to in the dry (so nice and predictable), but I don't think the extra power is necessary when the road surface means you're more prone to slipping anyway.
An advantage I could see would be not heating up your rims so much, thus reducing the chance of a blow out on a long descent, but that doesn't seem to be an issue for the pros - more for scaredy cats like myself. The pros tend to let it roll along the straights, regardless of how fast the go (didn't Thor manage 120kph a couple of years ago in the Tour), only braking for the corners.
As for the issue of sharp hot discs in a crash - I don't think that's really a deal breaker. Crashing is going to hurt anyway, there's lots of metal, carbon, concrete, asphalt and so on flying around. Obviously, I wouldn't want to get burnt by a disc, but in the situations were they're likely to get hot (i.e. a long alpine descent), mass pile ups are pretty rare.
In the end, I'm not sure I'd be stopping any quicker on my road bike with discs, and if that's the case, then the only real advantage can be a weight saving on the rims. The question is then whether lightened rims will make up for the extra weight in discs, strengthened frame and hubs etc. I suspect for "steady" riders, the difference will be minimal, perhaps only a help to sprinters, and those who like to make lots of changes of pace.
I have a hardtail mountain bike (hydraulic discs), a bike I use for touring (MTB frame, city tyres, cable discs), and a road bike (ultegra rim brakes, on mavic aksiums).
Personally, I think all the bikes I have have exactly the right types of brakes for their applications. I grew up with a mountain bike with V-brakes, which were good at the time, but I'd never go back after the hydraulic discs.
If I have difficulty stopping on the road bike, its inevitably an issue with my technique (if on the front brake at high speed, it's a question of stability), or of tyre traction (with the rear wheel). I can't imagine that any racer would seriously want disc brakes on the rear, under hard braking it's too easy to lock it up even with rim brakes.
In the wet, disc brakes have the advantage that they work very similarly to in the dry (so nice and predictable), but I don't think the extra power is necessary when the road surface means you're more prone to slipping anyway.
An advantage I could see would be not heating up your rims so much, thus reducing the chance of a blow out on a long descent, but that doesn't seem to be an issue for the pros - more for scaredy cats like myself. The pros tend to let it roll along the straights, regardless of how fast the go (didn't Thor manage 120kph a couple of years ago in the Tour), only braking for the corners.
As for the issue of sharp hot discs in a crash - I don't think that's really a deal breaker. Crashing is going to hurt anyway, there's lots of metal, carbon, concrete, asphalt and so on flying around. Obviously, I wouldn't want to get burnt by a disc, but in the situations were they're likely to get hot (i.e. a long alpine descent), mass pile ups are pretty rare.
In the end, I'm not sure I'd be stopping any quicker on my road bike with discs, and if that's the case, then the only real advantage can be a weight saving on the rims. The question is then whether lightened rims will make up for the extra weight in discs, strengthened frame and hubs etc. I suspect for "steady" riders, the difference will be minimal, perhaps only a help to sprinters, and those who like to make lots of changes of pace.
In reply to Radioactiveman:
I am almost entirely a road rider, I do quite a few TTs and road races at club level and find the rim brakes perfectly adequate.
The cork pads on the carbon rim surface on my deep section TT wheels could be better in the wet but I wouldn't want to lose the aero efficiency.
I do have a MTB which I rarely use with V brakes, that could really do with discs so that it stops in the mud
> So out of all the people replying it would be useful to know who has ridden/owned what.
I am almost entirely a road rider, I do quite a few TTs and road races at club level and find the rim brakes perfectly adequate.
The cork pads on the carbon rim surface on my deep section TT wheels could be better in the wet but I wouldn't want to lose the aero efficiency.
I do have a MTB which I rarely use with V brakes, that could really do with discs so that it stops in the mud
In reply to woolsack:
Take a look at the big picture and you have to ask the question why would a Shimano or Campagnolo or SRAM invest millions of £/$ inventing a better material to rub against a spinning carbon wheel to help reduce its speed when the world outside of Pro cycling are increasingly turning to disks brakes. Where is the commercial sense in that?
> There isn't a problem with road racing brakes though. Is there?
Take a look at the big picture and you have to ask the question why would a Shimano or Campagnolo or SRAM invest millions of £/$ inventing a better material to rub against a spinning carbon wheel to help reduce its speed when the world outside of Pro cycling are increasingly turning to disks brakes. Where is the commercial sense in that?
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