Best use of road disc brakes

[GSmith]

http://digg.com/video/this-is-the-gr...eo-of-all-time

[Too Tall]

Good grief. I've seen this before but can't stop watching it In my dreams I can do about 1% of that ;)

[Bobonli]

Mad skills! Somewhere on the Youtube there is a behind the scenes video and they were using another bike with traditional brakes, IIRC.

Road discs are a passing fad, according to the 14 people I rode with today.

[GSmith]

Pooch sent me a note and said that one of the riders in the video suffered a severe spinal and is now paralyzed... playing roulette with the law of averages I suppose as the pressure mounts to do bigger and more risky things with each new video.

The scene on the bridge made me cringe.

[Bobonli]

I didn't know that (^^) but it's not surprising. I've been showing the video to all my non-bike colleagues and they've all commented how risky some of the stunts seem; in particular, the scene on top of the train cars where if you fall you are certainly breaking a rib or vertebrae. Some of the stunts might involve camera trickery to make them seem "higher" than reality but a few (the trains and the bridge) are scary because we know the scale of things.

I'm sad to think someone was permanently injured making that video.

[edoz]

Martyn Ashton had that accident back in September.

[Matthew Strongin]

I didn't know that (^^) but it's not surprising. I've been showing the video to all my non-bike colleagues and they've all commented how risky some of the stunts seem; in particular, the scene on top of the train cars where if you fall you are certainly breaking a rib or vertebrae. Some of the stunts might involve camera trickery to make them seem "higher" than reality but a few (the trains and the bridge) are scary because we know the scale of things.

I'm sad to think someone was permanently injured making that video.

He wasn't injured making the video. It was during a demo at a Moto GP event. Trials superstar Martyn Ashton has sustained a life changing spinal injury | Dirt

Absolutely sucks for anyone to sustain such an injury. And whether it's making videos or during other events, these folks keep pushing the limits and injuries this severe will become more common. I find myself watching this stuff less and less, especially live. I just don't want to be watching the day something really bad happens.

[Bobonli]

I misunderstood Gary's post to mean he was hurt making Bike Party. Either way it sucks.

There have been a couple of good articles lately (last month in Outside Magazine) about how protective gear, namely helmets, have their limits as we push the envelope doing stuff like this.

[Saab2000]

Here's a clip on the bike itself.

It really sucks that Martyn Ashton has suffered such a terrible injury but the video is interesting for cycling tech junkies.

[KittenMeat]

I find it kind of funny that they had to go with custom units from formula to get road discs that actually worked well enough to trust doing these stunts.

this just shows how badly we need a real contender in the hydraulic disc market (Shimano, but mechanical shifting please in my dreams...)

[Jocko Homo]

I think discs are the future.

[Paul]

Martyn in his stunt wheelchair!

image.jpg

https://twitter.com/martynashton/sta...41826506174466

[Tristan]

I find it kind of funny that they had to go with custom units from formula to get road discs that actually worked well enough to trust doing these stunts.

It's not quite as simple as that because of the unique needs of trials brakes.

I've used hydraulic disc brakes on trials bikes and it's a different set of expectations to a 'normal' bike. A normal mountain bike brake has to have plenty of grunt to slow the bike down, but once the brake is locked very little power is required. On a trials bike it's the opposite...locking the brake is critical and the torque created by landing a pedal-kick is massive and overpowered the Shimano and Magura hydro discs I tried. This sort of torque cannot be applied by a mountain bike or road bike. This is why Hope make trials-specific hydro brake....no modulation, no need for heat dissipation, but a shitton of torque at lockup.

Mechanical brakes like the BB7 work really well on a trials bike because you can play with the leverage ratios to get that zero-modulation, high lockup force that is required. To ride brakes set like this on a road or mountain bike would be downright frightening though.

I haven't tried doing any trials on my road disc bike but I assume the R785s would be similar in this regard. Plus that video was shot before the R785 was released.

[Colinmclelland]

It's not quite as simple as that because of the unique needs of trials brakes.

I've used hydraulic disc brakes on trials bikes and it's a different set of expectations to a 'normal' bike. A normal mountain bike brake has to have plenty of grunt to slow the bike down, but once the brake is locked very little power is required. On a trials bike it's the opposite...locking the brake is critical and the torque created by landing a pedal-kick is massive and overpowered the Shimano and Magura hydro discs I tried. This sort of torque cannot be applied by a mountain bike or road bike. This is why Hope make trials-specific hydro brake....no modulation, no need for heat dissipation, but a shitton of torque at lockup.

Mechanical brakes like the BB7 work really well on a trials bike because you can play with the leverage ratios to get that zero-modulation, high lockup force that is required. To ride brakes set like this on a road or mountain bike would be downright frightening though.

I haven't tried doing any trials on my road disc bike but I assume the R785s would be similar in this regard. Plus that video was shot before the R785 was released.

REALLY late to this...but...i find my front wheel based wheelies going backwards downhill aren't quite as reliably good as that. But really are we saying they did that using brakes with a shit tonne of torque but no modulation, because I would be wanting modulation to pull that off? It's impressive whatever, but if they've got on/off type brakes is makes it more impressiver to me

[Tristan]

REALLY late to this...but...i find my front wheel based wheelies going backwards downhill aren't quite as reliably good as that. But really are we saying they did that using brakes with a shit tonne of torque but no modulation, because I would be wanting modulation to pull that off? It's impressive whatever, but if they've got on/off type brakes is makes it more impressiver to me

My trials skills are amateur at best and very rusty but...

Front and rear brakes on a trials bikes perform very different tasks. The front brake needs far more modulation as you quite often land on the front wheel and use the brakes stopping force to keep the rear wheel off the ground. The front also does the bulk of the controlled slowing. A "normal" front brake would be ok on a trials bike but biasing the brake away from modulation and towards lock-up would be better. Those front-wheel manuals are usually done using the front brake for resistance (which is why the rider doesn't accelerate down the hill) and a front brake which modulates would make them easier.

[Colinmclelland]

....would make them easier.

Easier, but not easy? Looks easy. I'm almost certain it would be. I've just never tried it!

Thanks Tristan.