Adding a front disc to a road bike !! And Now Hydro!

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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby MichaelB » Fri May 31, 2013 10:50 am

cobba wrote:
rkelsen wrote:And with weight being such an issue in racing, I don't think we'll see through axles on road bikes any time soon. Of course, I might be wrong in this respect, and to be honest I hope I am.


375 gm 15mm QR road fork: http://whiskyparts.co/catalog/forks
$660: http://www.bikeman.com/FK5201.html


I wouldn't quite call it a road fork if it can take a 45mm wide tyre.

Also, A2C distance is 397mm which is a CX level distance. Road forks are closer to 365/370mm. Bit exxy too, costs even more than the 3T ones, and they aren't cheap
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by BNA » Fri May 31, 2013 11:45 am

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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby barefoot » Fri May 31, 2013 11:45 am

MichaelB wrote:I wouldn't quite call it a road fork if it can take a 45mm wide tyre.


...and I wouldn't call it a road fork if it can't! :twisted:

tim
who has ridden up and down the driveway on his "road" bike with 26x2.1" tyres fitted :mrgreen:
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby cobba » Fri May 31, 2013 5:36 pm

MichaelB wrote:
cobba wrote:
rkelsen wrote:And with weight being such an issue in racing, I don't think we'll see through axles on road bikes any time soon. Of course, I might be wrong in this respect, and to be honest I hope I am.


375 gm 15mm QR road fork: http://whiskyparts.co/catalog/forks
$660: http://www.bikeman.com/FK5201.html


I wouldn't quite call it a road fork if it can take a 45mm wide tyre.

Also, A2C distance is 397mm which is a CX level distance. Road forks are closer to 365/370mm. Bit exxy too, costs even more than the 3T ones, and they aren't cheap

Looks like someone didn't scroll down the page to the road fork.

Road Fork:
367mm A to C
42mm width between fork legs - 28c tire on 23mm rim

Cyclocross Fork:
397mm A to C
65mm width between fork legs - 45c tire on 25mm rim
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby jasonc » Fri May 31, 2013 5:49 pm

keeping my eye on this:

Image

EDIT:

FLX-FR-320 Full Carbon 3k Glossy Di2 Disc Road Bike Frame BSA (Full Internal cable) + Fork + headset

Full Carbon 3k Glossy Di2 Disc Road Bike Frame(Full Internal cable) + Fork + headset
Wheel Size : 700C
Fit Disc brake
SIZE: 50cm, 52cm, 54cm, 56cm, 58cm
BB Type : BSA English Thread
Headset size : 1 1 /2" Head Tube Reduced to 1-1/8" Fork Tube Threadless Headset
Weight: 900g (50cm)
Fork: 390g
headset : 120g

$490US delivered
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby MichaelB » Fri May 31, 2013 6:19 pm

cobba wrote: ...
Looks like someone didn't scroll down the page to the road fork.

Road Fork:
367mm A to C
42mm width between fork legs - 28c tire on 23mm rim

Cyclocross Fork:
397mm A to C
65mm width between fork legs - 45c tire on 25mm rim


:oops: Still bloody expensive


(AT) jasonc - got a link ? Similar to the FM-166 ?

The rear disc mount looks very similar to the Stradalli R7 posted on the last page
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby jasonc » Fri May 31, 2013 6:43 pm

MichaelB wrote:(AT) jasonc - got a link ? Similar to the FM-166 ?

The rear disc mount looks very similar to the Stradalli R7 posted on the last page


it's an aliexpress link so it comes up as spammer
google the model number
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby MichaelB » Wed Jun 12, 2013 6:25 am

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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby singlespeedscott » Wed Jun 12, 2013 9:31 am

Nice. Hydraulic is certainly on its way.

However Ill be holding out for whenever Campagnolo does a Record EPS with hydraulic discs. Should only be 10 years or so :lol: By then all the issues and hub spacing a should be standardized.
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby MichaelB » Wed Jun 12, 2013 9:59 am

I think the hub spacing issue is pretty well sorted for discs at 100/135, but I think that the through axle may be the next standard to be tested.

UCI have recently approved it for CX , I think I read somewhere ....
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby lock_ » Wed Jun 12, 2013 4:58 pm

Bianchi, Colnago and Pinarello. The last manufacturers I'd expect to see producing roadies with disc brakes, yet here we are...

Still hoping for a Tarmac SL5 disc (the Roubaix is a given) and a SuperSix evo disc, don't think we'll see anything from Giant (apart from the TCX disc).

Oh, and of course Shimano.... Lots of hinting in that road.cc article; they either know something and cant say, or know nothing and want it to seem like they do (so really, we get nothing from it).

Would like to see some long term reviews of Red Disc too, not just the press camp promo pieces.
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby MichaelB » Wed Jun 12, 2013 9:15 pm

lock_ wrote: ....

Would like to see some long term reviews of Red Disc too, not just the press camp promo pieces.


They aren't available till July, so it will be a while till we get something like that.

I'd love to just try it !!!!
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby MattyK » Mon Jun 17, 2013 10:38 am

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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby barefoot » Mon Jun 17, 2013 5:01 pm

So... now that road disc is "here"... where will they go in future?

Essentially, all that has been done to date is to take a MTB disc brake, which has evolved over the last couple of decades to suit the needs of MTB, and stuck it on a road bike. Now I expect we'll start seeing some divergence, with road discs slowly (?) evolving to fit the needs of road.

The two critical factors for road bikes, obviously, are weight and aero. Weight is also a consideration for MTB, but not to the same extent, and aero is really an afterthought.

One thing that amazes me about disc brakes is just how heavy the disc itself is. A 160mm rotor can weigh up to 200g (for a rotor with minimal slotting, which is where I think they should be heading [1]). That's within coo-ee of the weight of a light road rim.

The rubbing track is where all the weight is; the rest of the rotor is mostly holes... and doesn't even need to be steel [2]. But there's no reason why the rubbing track of a disc brake needs to be as wide as the current standard design (with pads ~20mm square). If the rubbing track was narrower, we'd strip a heap of weight out of the rotor.

Say we go from a 160mm rotor with a 20mm wide rubbing track to a 160mm rotor with a 10mm wide track: you've almost halved the mass of the rubbing section of the rotor. And does it even need to be 10mm wide? Could we brake on a 5mm wide brake track?

When calculating brake effectiveness, we usually idealise a disc brake caliper as acting at a single point on the rotor - at the effective radius. Apply a pressure there, and a given friction coefficient will produce a friction force at that point, resulting in a brake torque about the axle. So, this narrow-track brake rotor would just have all the brake force concentrated on the effective radius.

Now, there's nothing wrong with a narrow brake track and a narrow pad to fit. But to get a reasonable contact area and pad volume, you'll need to make it longer. Home mechanics might be familiar with the difference between the pads that fit Falcadores (banana-shaped friction material) compared to a more typical Euro car (a squarer block of friction material). For a variety of reasons Euros tend to use big single piston calipers, Australians tend to use longer twin-piston calipers. And that's what I imagine happening to road bike disc brakes. Longer multi-piston calipers on longer banana-shaped pads.

The biggest aero nightmare I see on MTB-style disc brakes is the hub. The standard 6-bolt disc mounting flange is a disgrace. That will have to change. It's big and lumpy and the front one especially is right out in the free-stream airflow, not even sheltering in the wake of the tyre.I haven't had much to do with the Shimano centre-lock system, but at least that's a bit more aerodynamically compact. I thing we'll see a few iterations here, as the Big S and Small S develop incrementally more aerodynamic disc mount standards.

The caliper itself, I think is aerodynamically better than a rim brake caliper. It's already tucked in behind the leg of the fork. The fork leg creates an aerodynamic wake, and anything that hides in that wake essentially gets a free ride. The caliper just needs a bit of smoothing out - right up to the arbitrary limit of fairing that the UCI will allow - and it may even be able to recover a bit of pressure, reduce the size of the wake behind the fork leg, and improve the aerodynamics of the bike. By a poofteenth, but that's enough to market the hell out of it ;-)

Cables or hydro lines - internal, or clipped on to the back of the fork leg. Hydro will give the benefit that the brake cable no longer needs to travel in a graceful sweeping arc; sharp elbows work just fine, so we could end up with a bit plumbing used to keep the brake lines close to the bike, out of the wind.

Could we see frames and forks with integrated brake lines? For the fork especially - there could be a hollow tube moulded in to the fork steerer and leg to be filled with brake fluid. Connect a brake line from the lever to the stem, and another from the fork tip to the caliper, and the fork contains the fluid in integral internal hydraulic tube in between. Likewise the frame: plug a flexible line from the lever into somewhere at the head tube, and the internal fluid ways will deliver pressure to a short line from the rear dropout area to the caliper.

What other incremental developments do people imagine coming in the future of road bike disc brakes?

tim

[1] My day job is testing automotive disc brakes. I am yet to see slotted or drilled car rotors improve anything other than bling factor. All they do is cause pad wear, as the edges of the slots shave the surface off the pads. We saw in a recently discussed article, disc brakes in CX failing in mud due to excessive pad wear. I reckon this was largely due to abrasive debris (ie mud) getting into the rotor slots, and getting into the brake contact area that way. I'd like to get rid of the slots. On principle, I bought a set of Avid "solid sweep" un-slotted rotors, but haven't fitted them yet... damn they're heavy with all that steel where the slots used to be!
[2] I'm leaving aside the carbon-ceramic friction couple systems for now, although I have no doubt they'll be significant... in time, at the bleeding edge. But metal rotors will always be a big part of the scene.
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby Nobody » Mon Jun 17, 2013 6:38 pm

MattyK wrote:... and road.cc like them.
http://road.cc/content/review/85499-trp ... isc-brakes
Thanks for posting.
road.cc wrote:They're more powerful and controllable than rim brakes and easier to set up and maintain than mechanical discs, and they win over stem-mounted converters in their simplicity with no noticeable loss in performance.
...
They're the best performing brakes I've used with a road lever.
I see what you mean. I'm glad I waited. :D
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby lock_ » Mon Jun 17, 2013 6:55 pm

^Think you've got most of them. Big '+1' on the internal routing, don't really want to see cables/hoses/wires on my bike.

Through axles. Should be able to distribue the load better to the other fork leg, hopefully reducing the amount of reinforcement required (weight). It'd be nice if this was introduced at the same time everyone is buying new disc equipped roadies. Giant have some through-axle equipped models on the UCI approval list (CX). Never heard of a Giant Brava, interesting, although at a guess I'd say it's a female specific CX bike.

ABS. Put this under the 'requires more thought' category. There's the power requirements; powering the ABS solenoids would be a rarity, but signal processing could drain batteries. Also the weight; solenoids, new sensors, more wire. Those points aside I'm not sure the braking characteristics of an ABS are suitable for road bikes, much smaller contact patch/higher tire pressures than motorcycles. I've locked a front wheel while turning in the wet before, and 'things' happened quickly, not sure if a computer could detect and correct in time. Of course I'm just geeking out about flying into a corner too hot, locking both wheels, drifting through the corner and coming out the other side upright and unscathed :lol: . I'll be happy with 'better than rim braking' in the wet and not having to replace wheelsets every 18months.
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby MichaelB » Mon Jun 17, 2013 7:50 pm

Holy dooley, that's a couple of long posts !!!!

Thought I'd add my few cents as well.

Caliper design : Yep, definitely MTB based, and I think that road calipers should be a longer narrower pad, hence why I am experimenting with what I am doing on the Liscio. Stay tuned.

Disc weight : I disagree. My 180mm Shimano Ice Tech rotors weigh in at 151g, and the G3 cleansweep (all steel) is the same. I think that the SiCCC rotors that Kettle are developing are the way to go, along with the correct pad material (Carbenix or SiCCC)

Rubbing Track : The rubbing track on the Shimano rotors is actually about 11 - 12mm (as I think most of the rotors to suit hyd calipers), But as i have found out, the effective pad area varies significantly !!!!

Aero issues : I'm all for more aero, but I think that the reality is that the effect of aero on something like the disc & caliper and hub mounting is more marketing than anything else.

It seems that most of the new disc equipped bikes already have the hyd cables full internally routed. The Liscio does, and from what I have seen, so does the canyon, Bianchi, & Colnago. Couldn't tell on the Pinarello. Some of the Chinese frames don't seem to follow this trend though.

For me, the direction of development should be the caliper design (stiffness & pad size) and rotor heat rejection capacity (vented anyone) and the development of Carbon/SiCCC rotors. Better hubs that are designed for road load would be a good idea as well.

From my experience (and no scientific testing done at all) is that the front disc size should be 180mm and rear either 140 or 160mm.


ABS is at the moment an unnecessary complication and cost.
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby lock_ » Mon Jun 17, 2013 9:20 pm

MichaelB wrote:From my experience (and no scientific testing done at all) is that the front disc size should be 180mm and rear either 140 or 160mm.

But that's really only because you're working with existing systems. If you were starting with a clean sheet you could go with a 120mm rotor, then engineer the callipers to provide the necessary higher clamping force and increased heat dissipation requirements. After all, much of the improved modulation comes from the increased clamping force disc brakes must provide and smaller rotors would most likely be 'more aero'.

MichaelB wrote:ABS is at the moment an unnecessary complication and cost.

Yeah, pretty much. Although once the dust settles on discs, manufactures will once again look towards possible innovations. Did look like Wiggin's could do with such a system in the giro though :wink: .
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby Nobody » Mon Jun 17, 2013 9:53 pm

lock_ wrote:
MichaelB wrote:From my experience (and no scientific testing done at all) is that the front disc size should be 180mm and rear either 140 or 160mm.

But that's really only because you're working with existing systems. If you were starting with a clean sheet you could go with a 120mm rotor, then engineer the callipers to provide the necessary higher clamping force and increased heat dissipation requirements. After all, much of the improved modulation comes from the increased clamping force disc brakes must provide and smaller rotors would most likely be 'more aero'.
As you probably know, Canyon did a dual 120mm rotor prototype. I believe you'd need a through axle as the tyre's leverage on the QR with a 120 as the pivot point would probably be too much for the QR to stay put.
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby cooperplace » Mon Jun 17, 2013 11:45 pm

barefoot wrote:So... now that road disc is "here"... where will they go in future?

What other incremental developments do people imagine coming in the future of road bike disc brakes?

tim

.

isn't it all about the levers? I'm waiting for an ergonomic lever that combines gear shifters and hydro brake operation in one. (Maybe that's been described in the previous 30 pages of this thread that I've missed?). But I think that can only work with electronic gear shifting. So that will require Campag and Shimano to combine hydraulic brakes and electronic shifting all in one lever.

I'll check this thread again in 3 months to see it it's happened.
Please be nice to me, I'm not very bright.
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby MichaelB » Tue Jun 18, 2013 8:33 am

lock_ wrote:
MichaelB wrote:From my experience (and no scientific testing done at all) is that the front disc size should be 180mm and rear either 140 or 160mm.

But that's really only because you're working with existing systems. If you were starting with a clean sheet you could go with a 120mm rotor, then engineer the callipers to provide the necessary higher clamping force and increased heat dissipation requirements. After all, much of the improved modulation comes from the increased clamping force disc brakes must provide and smaller rotors would most likely be 'more aero'.

.....


I disagree with going to smaller discs. If you look at all the development with discs on cars/motorbikes, if anything they have been getting bigger. Whilst in cycling, we focus on aero and weight (good marketing), I'd rather have a 100g weight penalty for a bigger disc with better modulation and greater system reserve capacity.

If you go to smaller discs with greater caliper clamping, modulation will suffer, and all of the system components become more critical (levers, relative sizing between cylinders etc).

Smaller twin discs would be OK to solve some issues, but then weight & aero pop their head up again unneccesarily again.
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby MichaelB » Tue Jun 18, 2013 9:13 am

Seems that the SRAM 22 Road hydraulics are starting to get listed in various sites !!! No stock of course. :roll:

There are others, but here is the links to Universal Cycles ;

SRAM S700 Hyd lever & Rim brakes

SRAM S700 Hyd lever & DISC brakes

Another site lsist some specs of the disc based system ;

http://www.mpgear.com/item/BR4685/SRAM/S700-Right/Rear-Road-Hydraulic-Disc-Brake-and-10-Speed-DoubleTap-Lever/1.html?SSAID=446293


It's interesting that the piston size is listed at 19mm for the front and 18mm for the rear. MUCH smaller than what is typically used for twin piston calipers, with 22mm being most common, but ranging from 21 to 24mm.

Wonder what the m/cyl size is ?
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby Ross » Tue Jun 18, 2013 9:27 am

barefoot wrote:[1] My day job is testing automotive disc brakes. I am yet to see slotted or drilled car rotors improve anything other than bling factor. All they do is cause pad wear, as the edges of the slots shave the surface off the pads. We saw in a recently discussed article, disc brakes in CX failing in mud due to excessive pad wear. I reckon this was largely due to abrasive debris (ie mud) getting into the rotor slots, and getting into the brake contact area that way. I'd like to get rid of the slots. On principle, I bought a set of Avid "solid sweep" un-slotted rotors, but haven't fitted them yet... damn they're heavy with all that steel where the slots used to be!


I changed the disc rotors to slotted (not drilled) on a previous car I had and could notice a big difference in the braking. I can see your point about the brake pads wearing (I didn't have the car long enough or do enough miles to tell) but I guess that's the price you pay for better performance.

Many performance type cars such as V8 Supercars run a slotted rotor, I'm sure they have tested them and compared them to non-slotted rotors. Obviously V8 Supercars have different braking requirements than a road bicycle.
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby rkelsen » Tue Jun 18, 2013 10:15 am

barefoot wrote:[1] My day job is testing automotive disc brakes. I am yet to see slotted or drilled car rotors improve anything other than bling factor. All they do is cause pad wear, as the edges of the slots shave the surface off the pads.

Right. Next you'll tell me that the spoiler on my boot doesn't help me go faster in traffic. :roll:
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Re: Adding a front disc to a road bike !! And Now Hydro!

Postby lock_ » Tue Jun 18, 2013 11:29 am

MichaelB wrote:I disagree with going to smaller discs. If you look at all the development with discs on cars/motorbikes, if anything they have been getting bigger. Whilst in cycling, we focus on aero and weight (good marketing), I'd rather have a 100g weight penalty for a bigger disc with better modulation and greater system reserve capacity.


Probably going to have to agree on disagreeing on this one.

Bicycles don't usually travel 300+ km/h. Even cars and motorcycles would have a theoretical limit to the size of the brake rotor, this may well be larger than the wheel size however... Both cars and even motorcycles have a much more favourable CG and traction levels allowing higher decelerations. Guess I'm saying they can make use of the braking power, whereas any bicycle based disc brake system is capable of providing the maximum braking deceleration possible (or at least that's my assumption).

So that just leaves modulation.

MichaelB wrote:If you go to smaller discs with greater caliper clamping, modulation will suffer, and all of the system components become more critical (levers, relative sizing between cylinders etc).


Take the same braking system and increase the disc size, you'll be able to apply less lever force for the same braking torque (as you've increased the moment arm). But all this does is reduce the range of force you are able to apply to the brake lever, ie; reduce level of modulation (well at least my definition of). I guess what you're saying is that if you reduce the amount of force you need to apply to the brake lever you are better able to control that braking effort; this certainly has value, but you may be able to get the same effect by manipulating master/slave ratios.
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