eddy Posted December 20, 2016 Share so we agree disc brakes brake better, like in an emergency. GNo. Brakes slow the rotation of the wheel but it is the friction of the tyre on the tar that stops the bike and is the limiting factor. Maximum stopping power is just before the wheel stops turning. As i CAN lock up a wheel with rim brakes, disks won't stop me faster in an emergency. In fact grabbing a hand full of disk may lead to lock up and loss of control. I agree that a wet disk slows rotation better than a wet rim. Link to comment Share on other sites More sharing options...
V12man Posted December 20, 2016 Share I like your reasoning???? Another thought, how easy can a disc bend for example by accidentally knocking it against a bike rack, towbar or in a crash? I don't know as I don't have enough experience with discs. I like the simplicity of calipers though.....Not easily- it's not so much about more stopping power as about better brake modulation - they really only have marginally more stopping power - but the modulation is greatly improved - in all weather conditions too - also if you break a spoke for instance the brakes will still work perfectly- and ultimately not having a brake track will lead to better, stronger and more aero and more durable rim designs - especially in carbon. Link to comment Share on other sites More sharing options...
eddy Posted December 20, 2016 Share Unfortunately, our world is dictated in a large way by what the "Pro's" do. manufacturers manufacture what the Pro's ride, and then use trickle down technology to make it affordable for us ...I agree with some of your arguments but here you have the cart and horse the wrong way round. The Pros ride what the manufacturers dictate. There is some conflict at the moment because manufacturors would love all pros on disks, but they are resisting. Link to comment Share on other sites More sharing options...
eddy Posted December 20, 2016 Share Loaded bike on a tour? I think there are merits there.Agreed. Ironically, on a loaded bike on the descent in the beg last weekend on a fully laden bike with disks, I was concered about my brake fuid boiling up. Silly, but as it is a new bike and new brakes that I had not tested yet, it created a little niggle. Link to comment Share on other sites More sharing options...
V12man Posted December 20, 2016 Share No. Brakes slow the rotation of the wheel but it is the friction of the tyre on the tar that stops the bike and is the limiting factor. Maximum stopping power is just before the wheel stops turning. As i CAN lock up a wheel with rim brakes, disks won't stop me faster in an emergency. In fact grabbing a hand full of disk may lead to lock up and loss of control. I agree that a wet disk slows rotation better than a wet rim.Max stopping power is at full lock - but there is more to it than just max stopping power - the tire has a limit on traction in total - both for stopping and direction changing... so if you use 50% for stopping you only have 50% available for turning - so 75% stopping 25% turn... 100% stop means 0 traction for turning... this is why brake modulation is important - a good example of this is to try left foot braking in your car - given that most people have little or no ability to modulate their left foot properly when driving without a lot of practice - try it in the absence of other traffic... Link to comment Share on other sites More sharing options...
Jewbacca Posted December 20, 2016 Share everyone still banging on about stopping power... shame. Last comment before I leave the battered foreheads and bloody walls here.... the real benefit is in not having to manufacture rims with brake surfaces. There is no heat transfer onto the rim. Wider rims help the tires behave better etc... The end.. Stopping power is not the real benefit. Stop arguing it. Link to comment Share on other sites More sharing options...
jcza Posted December 20, 2016 Share everyone still banging on about stopping power... shame. Last comment before I leave the battered foreheads and bloody walls here.... the real benefit is in not having to manufacture rims with brake surfaces. There is no heat transfer onto the rim. Wider rims help the tires behave better etc... The end.. Stopping power is not the real benefit. Stop arguing it. Spoilsport Link to comment Share on other sites More sharing options...
lechatnoir Posted December 20, 2016 Share well, it's not as if there's no choice in the matter, so in that regard, ride what you want and have fun. My reason for riding discs is that to me, my bike looks nicer. And the nicer it looks, the more I want to ride. And frankly, that beats any science-y nonsense about better braking, stronger wheels etc etc. And as soon as SRAM decide to sell eTap hydros, they're gonna me MINE... Because they look nice and I like the colour! Link to comment Share on other sites More sharing options...
V12man Posted December 20, 2016 Share [*]Rim brakes on aluminium rims have better heat dissipation, since the rim is basically a 622mm disc. This means they're better for long, fast descents. Road bikes will do >100 km/h on mountain descents, and the energy required to stop goes up with the square of the speed [*]Rim brakes are much easier to service.. These 2 point are contentious - the first point excludes the choice of pad material - disk brakes pads are less prone to contamination and better suited to brake use - they don't have to be concerned with rim longevity at all as rim brake pads do - further - super heated rims and pads perform very poorly braking wise and the tire pressure gets a lot higher - that's not a good thing for handling and taken to extremes can lead to a blowout at high speed The second point - disk brakes are easy to maintain in normal use - on a road bike almost nothing needs be done except pad changes - at most a 2 minute excercise much easier than road bike pad changes - even for the uninitiated. Road bikes brakes are finnicky compared to disc brakes - they work well when well set up- they are pathetic when not well set up. Disc brake setup is much more forgiving to less than perfect setups. Link to comment Share on other sites More sharing options...
Barend de Arend Posted December 20, 2016 Share Max stopping power is at full lock - but there is more to it than just max stopping power - the tire has a limit on traction in total - both for stopping and direction changing... so if you use 50% for stopping you only have 50% available for turning - so 75% stopping 25% turn... 100% stop means 0 traction for turning... this is why brake modulation is important - a good example of this is to try left foot braking in your car - given that most people have little or no ability to modulate their left foot properly when driving without a lot of practice - try it in the absence of other traffic... Max stopping power is just before full lock, unless you're riding in snow. Modulation is important. The quickest way for me to stop on a rigid fork is to basically do stoppies: lock, pop up the rear, unlock, repeat. Wash brown pants. With a suspension fork, the technique varies a little because the fork will dive. In cycling, unlike cars or motorbikes, bodyweight and body position is significant. The more you can throw your weight back and down, the harder you can pull brakes before popping up the rear. Link to comment Share on other sites More sharing options...
Barend de Arend Posted December 20, 2016 Share The second point - disk brakes are easy to maintain in normal use - on a road bike almost nothing needs be done except pad changes - at most a 2 minute excercise much easier than road bike pad changes - even for the uninitiated. Road bikes brakes are finnicky compared to disc brakes - they work well when well set up- they are pathetic when not well set up. Disc brake setup is much more forgiving to less than perfect setups. I can't agree to that. It's very easy to fix a bad rim brake on the fly with an allen key. It's very hard to do that with a disc brake. Link to comment Share on other sites More sharing options...
Barend de Arend Posted December 20, 2016 Share everyone still banging on about stopping power... shame. Last comment before I leave the battered foreheads and bloody walls here.... the real benefit is in not having to manufacture rims with brake surfaces. There is no heat transfer onto the rim. Wider rims help the tires behave better etc... The end.. Stopping power is not the real benefit. Stop arguing it. Good! Show me the data that shows they modulate better Link to comment Share on other sites More sharing options...
LOOK695 Posted December 20, 2016 Share Does anyone know what the rules are concerning using a disc brake road bike in our local races? Link to comment Share on other sites More sharing options...
Spinnekop Posted December 20, 2016 Share Does anyone know what the rules are concerning using a disc brake road bike in our local races?Not allowed. Had 4 races this year where people were DQ'ed Link to comment Share on other sites More sharing options...
'Dale Posted December 20, 2016 Share Forkin' ugly Link to comment Share on other sites More sharing options...
Mongoose! Posted December 20, 2016 Share Not allowed. Had 4 races this year where people were DQ'ed before , during or after? Link to comment Share on other sites More sharing options...
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