Bike porn

My own idea for the 'ultimate' rim brakes is to take the arms of the EE brakes from the main pivots down, build them into the forks and drive them with hydraulics.

If you're going down that route, why not just drive the pads directly with hydraulic pistons, like a Magura HS33? No need for any kind of linkage or pivots to complicate things.

What would be the advantage over a purely cable driven brake?

Because hydraulic rim brakes are superior to traditional brakes. You could use a similar cable operated system to operate a disc too, CX or touring is an application for this where you can't have a lever mounted resivoir.

Ok you will have cable stretch / wear issues, although probably less so than on a normal cable brake as the hyrdaulic system will act as a servo. I admit though, its one of those idea's that I'm sure would be cheap, practical and applicable on all bikes but is going against current trends. Will we see discs on road bikes though?

Loving the chunky stays on the 3rensho, looks like it could take more of a beating than most other NJS frames...

Will we see discs on road bikes though?

Not on road race bikes, I think, because they will always be heavy and road race brakes already work well enough. There is also a slight additional hassle in doing fast wheel changes with disc brakes, so pro road teams won't want them.

Rim wear is a genuine issue for all weather bikes, so discs will become pretty much ubiquitous on utility bikes, which includes touring and commuter bikes with drop bars. Since cyclocross gear already crosses over into the spring classics, it won't be a surprise if somebody uses discs in P-R on their "wet conditions" option bike, assuming the UCI change the rules to allow it. At the moment, only CX bikes under UCI rules can have discs.

If you're going down that route, why not just drive the pads directly with hydraulic pistons, like a Magura HS33? No need for any kind of linkage or pivots to complicate things.

Because i was hesitant about asking the piston to take the shear load from the pads, and hadn't thought of Magura's system which seems to be to take the shear on a simple sliding contact between tabs on the pad holder and claws that project from the cylinder body.

By the way, do you know what keeps the pad holders in the claws?

disc brakes xor radial spokes. That might be a factor.

Not on road race bikes, I think, because they will always be heavy and road race brakes already work well enough. There is also a slight additional hassle in doing fast wheel changes with disc brakes, so pro road teams won't want them.

Dont disc brakes have an issue of heating up, and then stopping working properly when they are hot?

this might perhaps be an issue for braking on long descents. Not sure though.

This seems a little bit daft.

I fucking love the colour on the 3Rensho.

very close to RAL 9018, mostly used as interior color on tanks
and warships. Traditionally "blended" with high octane molybdenum gasoline
giving a satin finish, if you survive the painting procedure...
Also used in bathroom decoration in 50s, probably the main reason
that many people been costive.

The fork bridge on that 3rensho is a piece of art.

very close to RAL 9018, mostly used as interior color on tanks
and warships. Traditionally "blended" with high octane molybdenum gasoline
giving a satin finish, if you survive the painting procedure...
Also used in bathroom decoration in 50s, probably the main reason
that many people been costive.

The fork bridge on that 3rensho is a piece of art.

I'm having my Panasonic done in something very, very similar to that 3rensho.
I have been admiring the whole thing for months now, the fork bridge is similar
to those used by Panasonic.

Why doesn't someone just make a cable actuated hydraulic brake, the resivoir / actuator could be really small and mounted on the brake. You could then use all brakes / shifter combinations. Wow design idea for the day - can I be bothered firing solidworks up???

Hayes made cable actuated hydraulic discs back in the day, but i think they ended up being worse than just cable discs and nowhere near as good as hydraulic. Because the problem with the cable discs unless serviced frequently was the cables dragging, coupling this with a hydraulic system at the other end didn't bode well. all the disadvantages of cables, plus none of the advantages of hydraulics, plus brakes locking up.

could poss work better on the road where it aint as mucky but doubt it.

anyway, do we really need hydraulic brakes on the road? I find stopping easy enough...

Dont disc brakes have an issue of heating up, and then stopping working properly when they are hot?

this might perhaps be an issue for braking on long descents. Not sure though.

any issue with disc brakes heating up is incomparable with a rubber block rubbing against your rim - rim brakes deteriorate, become grabbier as they heat up, then your blocks wear down real quick. I've never really had any trouble with disc performance, they do heat up but have never failed me. Lever feel changes a little but thats it, and that's mountain biking too, i don't know about you but I'm alot lighter with the brakes on tarmac.

http://velospace.org/files/vkhvkvhvfycdcdtdxxxesse.jpg

http://velospace.org/files/vkhvkvhvfycdcdtdxxxesse.jpg

No.

Double rainbow, all the way.

I love this frame. I'd like to buy one, strip it and give a rad paintjob.

Hayes made cable actuated hydraulic discs back in the day, but i think they ended up being worse than just cable discs and nowhere near as good as hydraulic. Because the problem with the cable discs unless serviced frequently was the cables dragging, coupling this with a hydraulic system at the other end didn't bode well. all the disadvantages of cables, plus none of the advantages of hydraulics, plus brakes locking up.

could poss work better on the road where it aint as mucky but doubt it.

anyway, do we really need hydraulic brakes on the road? I find stopping easy enough...

Yeh, admittedly I think the brake on my bike is great, shit tektro caliper with aztec pads. although on a tour across the highlands last year I went through a set of pads in 4 days and i've worn past the line on a rim in a year and a bit. If you've tried magura's, they are impressive. Even cable discs are good now. The small contact patch road tyres have is a factor in just how powerful road brakes can be - especially in the wet.

That 3rensho's a treat

it is a nice colour. The owner doesn't appreciate it though looking at the colour of bar tape they have chosen!

looks like it matches the colour used in the logo, which you can just about see from the side on shot. either way, that bike is lovely.

YouTube- LOOK 695 Official Launch Video!

Because hydraulic rim brakes are superior to traditional brakes.
Isn't this just because of better modulation (caused by a better transmission of power i.e.no cable stretch)?
Hydraulic brakes are not inherently more powerful as they work on the same brake pads as a cable system (pad grip on rim being a limiting factor).
The other factor is the power which can be applied (by any transmission system cable/hydro/chaindrive) to the brake pads, this is limited by your hand strength.

Running a cable to a cylinder and piston at the brake has all the stretch of a pure cable system it just moves the pads around indirectly.

I just remember magura's being way more powerful than v-brakes back in the day (rim crushing?), they didn't have the same modulation though - they were pretty much on or off.

I reckon it was efficient hydraulic transmission then-> same power goes in at brakelever- some is lost on the way- brakes close onto rim.

Could also be something to do with gearing. i.e. there is a tradeoff between brake travel and pad pressure

The small contact patch road tyres have is a factor in just how powerful road brakes can be - especially in the wet.

That's more the issue with brakes, for me - to get a set-up where the braking force I can exert is a reasonable match for the grip the tyres have on the road - once you start to skid you lose most of your stopping power. So for a skinny-tyred road bike, I like something that doesn't grip too hard, but is nicely progressive in its action. I have to say that the brakes that have felt the best to me on skinny-tyred road bike are the Shimano twin-pivot 105 sidepulls.
On the other hand, with a big fat knobbly tyre, offroad, the harder the braking action the better, within reason - I remember the original XT V-brakes as being a revelation, compared to ordinary cantilevers. They were the ones with the parallelogram geometry and the special levers with the little plastic chips in to tweak the progressiveness of the braking action.
I would have though that disc brakes were inherently disadvantaged in one way, in that the leverage you can exert is much smaller because the disc is so much smaller in diameter than the wheel; on the other hand, it's up out of the mud and wetness a bit, and it's cheaper to replace a disc when you wear it out than a rim, so inherently advantaged in that way.

I would have though that disc brakes were inherently disadvantaged in one way, in that the leverage you can exert is much smaller because the disc is so much smaller in diameter than the wheel

you think wrong. they are more efficient even in the cable variety. that's why road/cross disks are tiny compared to mtb disks it's easy to overcome the grip of a 23c tyre with a 140mm disk. the hard part is ensuring good modulation.

Also, the discs are made out of a much harder metal than the rims, as it doesn't have to perform two jobs. The brake pads are harder too, so you get better braking without wearing down the rim.

although leverage obviously stills applies, i.e larger the rotor the higher the braking.

For a 23c I would think a 100mm rotor would do!