UCI are going to allow discs in cyclocross

[Palinurus]

What are discs like when they are covered in a melon-sized glob of chewy November mud? I've no experience with them at all. Or do they not tend to collect the stuff? (with cantis it's incredible how much stuff gets attached to them in a muddy race, not like I've got a spare bike and an assistant with bucket and sponge)

Not that I'm going to get a new 'cross bike for a while. Still curious though.

[TimO]

... less rim wear ...

Which is one very good driver for me.  Having had a rim explode after only a few thousand miles of commuting this year, disc brakes and much longer rim life seems like a big win to me.  Thankfully it happened to me at relatively low speed on a flat road (just outside South Ken station), but I was due to do the Brighton FNRttC the next day, which could have easily meant a blowout on Reigate Hill, which would not have been fun.

[David Martin]

I got my first disk brakes this year on my Cyclescheme bike.

I am loving them. No rim wear, no pad wear, no readjsutment. I have nearly worn out the tyres (in 7 months - not doing enough miles) and the brakes are still great.

As for road bikes - at the moment no team bikes can take disks. When they are allwoed to then it will not be very long at all before disk compatible frames are made.

They are available for hybrids already, so race frames can't be far off. They are fitted to XC MTBs that weigh less than my carbon road bike so the tech to put them on carbon is there. And you would probably not need disks as wide as 160mm either. Look for a more mininalist design.

..d

[Jacomus]

I don't think the carbon team frames are up to the forces created disc braking either, not for mountain stages anyway.

At descending speeds found on mountain stages you would not be able to use quick release either, too much chance of the braking forces torquing the wheel out of the fork ends.

This problemo can be overcome by putting the caliper on the front of the fork, no the rear, which torqes the QR up into the dropout not down.

On a different note, I can see this bike that I have been drooling over for a couple of years now, hopefully inching towards production.

Canyon | Technology | Project Studies | Project 6.8

[alexb]

I got my first disk brakes this year on my Cyclescheme bike.

I am loving them. No rim wear, no pad wear, no readjsutment. I have nearly worn out the tyres (in 7 months - not doing enough miles) and the brakes are still great.

As for road bikes - at the moment no team bikes can take disks. When they are allwoed to then it will not be very long at all before disk compatible frames are made.

They are available for hybrids already, so race frames can't be far off. They are fitted to XC MTBs that weigh less than my carbon road bike so the tech to put them on carbon is there. And you would probably not need disks as wide as 160mm either. Look for a more mininalist design.

..d

I love my disced up commuter too. It's a lot cleaner too because there's no slime from the brakes to run all over the frame. I thought that the brakes were pretty poor when I got it until I went back to the other bike recently and realised justy how good they are. They just don't feel it!

[Mr Larrington]

At descending speeds found on mountain stages you would not be able to use quick release either, too much chance of the braking forces torquing the wheel out of the fork ends.

Bung the caliper on the front of the right fork blade instead of the rear of the right?

[LittleWheelsandBig]

Do some all mountain riding and you will learn that discs offer much more modulation than rim brakes.

Point a MTB down a 45 degree sloped single track and try getting down it just on rim brakes.

Is all mountain riding anything like MTBing?  I raced the third Australian MTB Championships back in the mid-80s and used to enjoy doing bicycle trials, with cantilever brakes.  Provided I can get the saddle low enough and my arse far enough back, 45 degree downhills are just fine, thanks.

I'll give you the point that muddied rim brakes are less useful (so disc brakes are helpful on MTBs ridden in really wet conditions, not so common when I lived in Oz) but is that really such a problem on a road racer?  bikenerd (who I was replying to) was talking about crits after all!

[bikenerd]

During a wet crit disc brakes will be an advantage - you won't have the "two rotations of the wheel to wipe the wet off" that you get with rim brakes, so you'll be able to brake later.
During a dry crit, they probably won't have any advantage due to the tyre width not wide enough to have enough traction to fully take advantage of the power of the disc brake.  People may start running wider tyres though!

All mountain riding is flinging yourself off a mountain on a bike.  It is an extreme version of mountain biking and riders usually have 6 inch of suspension front and rear, 210mm rotors for their disc brakes, knee and arm pads and maybe even full face helmets.

LWAB: have you tried disc brakes?  You might be surprised how much you like them.

[LittleWheelsandBig]

LWAB: have you tried disc brakes?  You might be surprised how much you like them.

I didn't like walking a tandem MTB several kilometres out of the bush because we overheated a disc and warped it.  Just let me know when the plastic bits on hydraulic discs stop melting on tandems and I'll try them again.

[bikenerd]

LWAB: have you tried disc brakes?  You might be surprised how much you like them.

I didn't like walking a tandem MTB several kilometres out of the bush because we overheated a disc and warped it.  Just let me know when the plastic bits on hydraulic discs stop melting on tandems and I'll try them again.

That doesn't sound like fun!  How long ago was this?  Also, do you think that if you had had rim brakes on you wouldn't have blown the tyre of the rim?

[LittleWheelsandBig]

About seven years ago now.  I've never overheated the tyres of a fat-tyred tandem, I think there is enough tyre volume for it to not be a problem.  I've only ever blown the front tyre off one road tandem, not repeated following a change of tyre.

I think (with well-fitting tyres and rims) blowing tyres off is very difficult.  Quite a few years ago, Rodriguez in the USA did some tests with pedalling down very long 10% grades on a tandem dragging a brake in an attempt to find how hot rims became.  He put temperature-sensitive paint (various change points) on the rims and (from memory) found that the temperature variation only added another 20 psi or so, no matter what he did.

[Zoidburg]

During a wet crit disc brakes will be an advantage - you won't have the "two rotations of the wheel to wipe the wet off" that you get with rim brakes, so you'll be able to brake later.
During a dry crit, they probably won't have any advantage due to the tyre width not wide enough to have enough traction to fully take advantage of the power of the disc brake.  People may start running wider tyres though!

All mountain riding is flinging yourself off a mountain on a bike.  It is an extreme version of mountain biking and riders usually have 6 inch of suspension front and rear, 210mm rotors for their disc brakes, knee and arm pads and maybe even full face helmets.

LWAB: have you tried disc brakes?  You might be surprised how much you like them.

No thats free riding or even DH, all mountain is just XC but with some more difficult/technical bits thrown in, stuff the pootlers leave alone and well beyond what you would find on a usual XC race circuit.

MTB Cantilevers and V's were designed around the US market - the test bed being warm dry dusty California, they have never really been any great shakes in real UK riding conditions, this is true of a lot of kit that was designed with the US market in mind, stuff like fork boots that trap water, the lack of crud catcher bosses, rearward facing seat tube slots that collect mud, tyre design etc etc.

[Charlotte]

Just let me know when the plastic bits on hydraulic discs stop melting on tandems and I'll try them again.

The dinner-plate sized rear disc on our Santana has taken some serious abuse in the couple of years we're had it.  You don't need hydraulics - a cable disc is easily good enough.  It's that fabulous a stopper that a disc on the front isn't necessary either (as you know, disc brakes on the front of tandems are a bone of contention amongst manufacturers).  Hell, you hardly ever even need the front rim brake with that baby.

We bought a spare set of pads when we picked it up from the shop.  Despite a variety of stupid and hilly escapades, it's neither melted any plastic parts, nor needed the spare pads yet.  You might be pleasantly surprised by how things have moved on.

[LittleWheelsandBig]

You don't need hydraulics - a cable disc is easily good enough.
SNIP
Despite a variety of stupid and hilly escapades, it's neither melted any plastic parts, nor needed the spare pads yet.  You might be pleasantly surprised by how things have moved on.

So all those people going on about hydraulic discs being so much better than cable discs are wrong?  Make up your minds, people 

Melting plastic parts on a tandem's hydraulic disc isn't that rare.  I thought that Santana specified all-metal components on their disc brake to avoid heat damage of plastic components.  The UK Tandem Club discussion board has something about an overheated BB7 recently and links to http://www.westyorkshiretandemclub.co.uk/technical.htm 

[bikenerd]

Hydraulic discs avoid contamination, which cable discs on a MTB going through a typical British winter are prone to.  In theory, they should have greater stopping power as well, as the fluid in the system is incompressible and subject to a lot less friction than a Bowden cable.

I think the problem with discs and tandems is probably people dragging the brake.  Disc brakes prefer to be applied in bursts rather than dragged.  If you drag a hydraulic disc brake you could cook the fluid, which leads to brake fade.  Or over heat the rotor or caliper which is what sounds to be happening on a certain tandems.

For the specific application MTB disc brakes are designed for they are brilliant and far superior to a rim brake in wet, muddy conditions.  For a tandem - especially a road going tandem - that might not be the case.

[LittleWheelsandBig]

For the specific application MTB disc brakes are designed for they are brilliant and far superior to a rim brake in wet, muddy conditions.  For a tandem - especially a road going tandem - that might not be the case.

Or for a criterium on a solo...

[bikenerd]

For the specific application MTB disc brakes are designed for they are brilliant and far superior to a rim brake in wet, muddy conditions.  For a tandem - especially a road going tandem - that might not be the case.

Or for a criterium on a solo...

I still think the late braking into a corner would be an advantage.  You wouldn't be dragging the brake either so wouldn't run into any overheating problems.  The brake / sprint nature of a crit would suit the discs liking being applied in bursts.

[LittleWheelsandBig]

I still think the late braking into a corner would be an advantage. 

Believe what you like, I think you are wrong on this point.

[bikenerd]

I still think the late braking into a corner would be an advantage. 

Believe what you like, I think you are wrong on this point.

Likewise.  We shall have to agree to disagree.

[Mr Larrington]

You don't need hydraulics - a cable disc is easily good enough.
SNIP
Despite a variety of stupid and hilly escapades, it's neither melted any plastic parts, nor needed the spare pads yet.  You might be pleasantly surprised by how things have moved on.

So all those people going on about hydraulic discs being so much better than cable discs are wrong?  Make up your minds, people 

Melting plastic parts on a tandem's hydraulic disc isn't that rare.  I thought that Santana specified all-metal components on their disc brake to avoid heat damage of plastic components.  The UK Tandem Club discussion board has something about an overheated BB7 recently and links to http://www.westyorkshiretandemclub.co.uk/technical.htm 

A mate of mine once melted the plastic brake lines on a pair of Magura hydraulic rim brakes, but he was in a fully-faired recumbent and trying to keep the speed below 65 mph.  California has some long descents.

[Jacomus]

You don't need hydraulics - a cable disc is easily good enough.
SNIP
Despite a variety of stupid and hilly escapades, it's neither melted any plastic parts, nor needed the spare pads yet.  You might be pleasantly surprised by how things have moved on.

So all those people going on about hydraulic discs being so much better than cable discs are wrong?  Make up your minds, people 

Melting plastic parts on a tandem's hydraulic disc isn't that rare.  I thought that Santana specified all-metal components on their disc brake to avoid heat damage of plastic components.  The UK Tandem Club discussion board has something about an overheated BB7 recently and links to http://www.westyorkshiretandemclub.co.uk/technical.htm 

Why on earth would someone spec a 180mm disk on the rear of a tandem

[PaulF]

Well this is Armstrong's Tweet on discs:

lancearmstrong UCI approves disk brakes for cyclo-cross. Great news. I look fwd to the day they're approved for road racing.

[giropaul]

Well this is Armstrong's Tweet on discs:

lancearmstrong UCI approves disk brakes for cyclo-cross. Great news. I look fwd to the day they're approved for road racing.

That definitely makes me against them then!

Seriously, every small "advance?" moves the sport towards the technological/expensive. I really don't want cycling to become a sport where rich kids with rich daddies have an advantage, although it keeps moving that way. There was a lot to be said for the ancient "everyone uses the same bikes" Tour de France idea.

[TimO]

If no allowances were made for technological development, we'd still be using hobby horses or Ordinaries to race with.

You have to allow some innovation, otherwise things will never shift.  I guess it's a fine line between what is reasonable and useful compared to what's too expensive and won't help cycling as a whole.

I don't think disc brakes are too unreasonable, they're a mature technology on some categories of bikes, so I don't think their use on road bikes would make current bikes significantly more expensive.

[Mr Larrington]

If no allowances were made for technological development, we'd still be using hobby horses or Ordinaries to race with.

Ordinaries are specifically banned by the UCI - a "bicycle" has to be RWD and have both wheels the same size.