I tow the kids trailer with my road bike. The 105 calipers work well enough if its dry, but discs would be nice. If I can persuade the Mrs to get me a Roadrat on her BTW scheme I'll spec that with disks.
Bike Forum
[closed]
Why dont road bikes have disc brakes????
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Posted 3 years ago #
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I do not accept the argement that discs are too much for roadbike tyres. You can never have too much brake and if you lock wheels / go over the bars its not the brakes fault but your lack of skill.
Posted 3 years ago # -
Can't say I have any issues with braking with normal calipers even when towing. Road calipers do actually work remarkably well - better in general than cantis or even Vs. Meanwhile this mention of road bikes having little grip keeps coming up - strange comment when a road slick on tarmac actually has more grip than a knobbly either on road or on typical off-road.
The reason I have discs on my MTB isn't to do with power, modulation, or even working in the wet (all of which calipers or Vs are fine for), but working in mud and dirt and not wearing my rims out in said conditions.
I don't know about too much braking, TJ, but you can have sufficient, and if you can lock the rear or endo over the front then that is sufficient. A well set up caliper (which isn't that hard to manage) can do either.
Posted 3 years ago # -
aracer - even in the wet and cold? Its a long time since I have ridden with road calipers but I do remember them not working well in the wet and cold. Perhaps this has been improved greatly.
To me the main advantage of discs is not wearing rims out.
Posted 3 years ago # -
It's all down to having the right brake blocks - which have improved a lot in recent years. But even average (ie Shimano) blocks work fine in wet and cold nowadays.
Couldn't agree more with your main advantage of discs - is the principle reason I went that way on the MTB - but not a problem I seem to get on the road (some worn rims, but they are many, many years old). The only major problem I have with this now is on the cx-bike - would certainly go for discs on one of those if buying now.
Posted 3 years ago # -
The first attempt at braking after a long, non-stop ride on a cold/wet day can certainly be interesting. Seems to be much better when things have warmed up.
But I'm talking about both disks and calipers.
Posted 3 years ago # -
LOL! Love some of the tags at the top of this thread!
(Does a little dance, because none of the nay-sayers have come up with a conclusive argument against the use of discs on a roadbike)
Posted 3 years ago # -
Presumably you've missed or ignored all the comments pointing out that the system as a whole would be heavier and more expensive, and given the marginal benefits when riding a racing bike you simply can't justify those disadvantages?
Posted 3 years ago # -
What has expense got to do with anything? There are plenty of road bikes out there, that cost more than most MTBs. Which have suspension and all sorts of other gubbins, that you think would make them far pricier.
Weight? I think any weight penalty would be marginal, with careful design, and with new materials/production techniques coming out all the time, I would say that issue would be swiftly negated.
EG: XTR disc hubs are only marginally heavier than Dura Ace non-disc ones. And there are things like Tune disc hubs, that weigh less than most 'road' hubsets. Caliper/disc/lever sets, in tiny road bike rotor sizes, could be made as light as a set of road calipers, levers and cables, I'm sure. As for extra frame material, this would be offset by lighter rims, and not needing a mounting point for caliper brakes.
No, sorry, still not having it. The only real obstacles seem to be rules, stuffiness, and fashion.
Posted 3 years ago # -
Your weight calcs are out. Sure you can get disc hubs weighing not much more than 100g, but that's still 50g more than a non-disc hub. You can get caliper brakes for <200g a pair, and levers for <100g a pair, so a complete system for ~350g including cables, which is little more than one end of a lightweight hydraulic disc. How much lighter are MTB disc only rims (and how much do you reckon you could save off current <250g rims)? Have you not noticed that the mounting point for a caliper comes for free with a frame - arguably you're adding weight by not drilling the hole!
Main obstacle is still lack of any advantage.
Posted 3 years ago # -
[quote]What has expense got to do with anything?
Well, it tends to feed into cost-effectiveness. If you aren't racing, why would you chase negligible performance benefits at escalating cost? Most recreational riders have a budget.
Let us assume that you are correct that disc brakes could be brought in on the same weight, but let us also assume (as you do) that they would be more expensive.
Therefore, as a recreational rider, for a given budget, I can have a bike with adequate brakes and a very very light frame, or a bike with brakes that are more powerful than is strictly required at the cost of a heavier frame. And, to cap it all, my bike won't be race legal. I know which I am going to go for. Your answer may be different.
I don't care, when road racers have tiny little disc brakes I shall have one with tiny little disc brakes, just as I have a mountain bike with disc brakes these days. But I can understand why it isn't a priority for designers and manufacturers, or, indeed, almost anyone except you.
Posted 3 years ago # -
You constantly go on about lighter rims - but my cx wheels have rims which weigh about 350g and they're nothing special, Reynolds carbon sprint rims weigh about 200g. How much lighter exactly do you envisage making them disc specific would make them?
You do realise that a lot of people now ride 35-50mm deep rims for aero benefits, so how would you make these lighter?
For commuting bikes discs are fine but for fast, lightweight road bikes I still don't think discs are at the right level of technology, weight or useability yet. Maybe in 5 years they will, but not now.Posted 3 years ago # -
No, sorry, still not having it. The only real obstacles seem to be rules, stuffiness, and fashion.
but disks are an answer to a problem that doesn't really exist.
Q: are current road brakes powerful enough to overcome the grip of a 23c tyre and does their use enable the user to accurately modulate available braking power?
A: yes.
Q: are disk brakes needed on road bikes?
A: no.
Posted 3 years ago # -
I remember the debate over suspension for MTBs, plenty were convinced that whilst a couple of firms were pushing it it had no real benefits and would not stand the test of time.
There are plenty of punters out there who will buy something because it is different or perceived more "hi-tech". Marketing dudes know this.
Only a fool would say that high-end roadie bikes will NEVER have disc brakes.
Posted 3 years ago # -
Q: Are discs better than rim brakes?
A: Yes
Q: If you could have discs and suffer no weight or cost penalty would you have them?
A:
Posted 3 years ago # -
Q: Can pigs fly?
A: No
Q: If pigs could fly, would that be AWESOME?
A: Hell YES!!!
Posted 3 years ago # -
Thanks for the replies and answers...
Posted 3 years ago # -
TBH MTBs do not need discs either...cantis or vs are perfectly acceptable. More sophistication and technology for us to part with our well earned dosh!
Posted 3 years ago # -
Just been Reading through this thread with much amusement. Why, exactly is a road bike only a racing, and anything else with skinny tyres and drop bars isn't a road bike? Sorry, I'm confused. Druidh's Sutra is a touring bike. It's for riding distances on the road. It has skinny tyres and drop bars. That makes it a road bike. To say otherwise makes you a snob. I also have a Sutra, with one gear, aero bars and bar-end levers with cross-top levers as well. It's a road bike. It's not a tourer, it's not a cx bike, and it's most definitly not a mountain bike. It does, however have discs. And a Brooks Swift Ti saddle. ;0)
Posted 3 years ago # -
Cant be bothered to read all this, but I presume somone has mentiond because there not needed.
Posted 3 years ago # -
Erm, you're comparing top-end, ultra lightweight road bike components, with MTB ones. Hardly fair.
Can't be bothered any more.
Posted 3 years ago # -
Hurray
Posted 3 years ago # -
my road bike has got disc brakes. weighs 18lbs
Posted 3 years ago # -
@steve austin.
Got any pix.
Posted 3 years ago # -
I'll bet all roadies would have disc brakes if they were allowed at the TDF or something.
Posted 3 years ago # -
I'll bet all roadies would have disc brakes if they were allowed at the TDF or something.
No, they wouldn't.
Posted 3 years ago # -
I've been running Avid BB7 discs on my commuting/touring/winter training road bike for the last 5 years. No problems with handling or braking control under normal conditions, in snow, on ice or on fast, long Alpine descents with full camping gear. I usually use 28mm touring tyres, but have run 25mm as well.
I chose to use discs for my utility road bike bike for easier adjustment and maintenance (cf V-brakes or cantilevers) and to avoid the serious rim grinding that occurs with regular winter commuting. I wouldn't go back to rim brakes for this sort of application.
I wouldn't use discs on my road racing bike, because of the performance penalty imposed by a beefier fork and added kit weight. Good quality sidepulls are excellent, and currently the best solution for a fair-weather race bike.
So, to cut a long story short, discs work very well for some road bike applications, but they aren't widely adopted because the range of suitable brakes, frames and forks is currently limited.Posted 3 years ago # -
gingerflash
"make smaller, lighter less powerful ones for the road that give as much stopping power"
Less powerful but with as much stopping power? Eh?
Not well worded perhaps. Gist was, as I suspect most understood, max stopping power is the power needed to lock a wheel. Both brakes have enough. Any more is power won't stop you any quicker so can't really be called stopping power just wasted over-capacity and comes at the expense of weight and feel / modulation.
Posted 3 years ago # -
UCI regulations state that a bike has to be heavier than a certain weight. However, many bikes are sold well under this weight and many of the want to be racers are very happy to get their bikes under this weight. If disk brakes gave such a great advantage to people, then you'd be seeing disk brakes at every sportive across Europe.
I really wonder how these small lightweight disks are going to cope with stopping a bike travelling at high speeds down an alpine descent?
Hybrid bikes travel at very different sort of speeds than race bikes so disks on these are a different question. I still think it's done for image, just as cheap 'mountain bikes' that you get in Tescos have suspension for looks, rather than function.
Posted 3 years ago # -
100 posts of mostly complete rubbish
Posted 3 years ago # -
Trolltastic
101
Posted 3 years ago # -
Road bike brakes are cack - fact. If you are cruising to a halt in the dry, they work. But try a really steep South Wales hill leading directly into a roundabout in the wet, and you will see what I mean. I've got 105 calipers with aftermarket blocks and the idea that anyone could compare them to XTR discs is laughable. The Tektro Vs on my commuter are almost as good as discs and about a million times better than the 105 caliper - wet or dry. Come round my house and try it out if you don't believe me.
Posted 3 years ago # -
molgrips, what do you reckon to little discs, then? Do you think they would be a big improvement?
The number of times I've seen TDF riders go over the edge on tight bends, I can't help thinking better brakes might be an idea. Speshly for bigger riders.
Posted 3 years ago # -
They go over the edge on tight bends because they're attempting to go round them at about 40mph - nothing to do with not having disc brakes.
Posted 3 years ago # -
molgrips: your brakes aren't set up right then. I've got Dura-Ace calipers on my road bike and they're more than enough. In fact when Shimano remodelled Dura-Ace they obviously gave it to the pros for a year before it was available to the general plebs and the feedback was that they were TOO powerful. So Shimano cut out a little bit of the rear caliper to make it flex more and make it LESS powerful.
Introducing yet another bloody "standard" to an industry already awash with God knows how many different "standards" for all sorts of things is the last thing on earth that anyone needs.
Posted 3 years ago #
Topic Closed
This topic has been closed to new replies.
