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

[jasonc]

Try stopping a car rolling down a hill in neutral with the engine turned off... You lose a huge amount of braking force.

that's a sensational analogy.

[Crittski]

lol

http://www.wiggle.co.uk/hope-vented-203mm-rotor/

[Hotdog]

Seriously considering doing a front disc conversion on one of my (dual 700c wheel) recumbents, the one that doesn't already have discs. My steel framed tourer/commuter with BB7's sold me on disc brakes long ago and I'd really like one on the carbon lovely too

Of the currently available forks the Evo A647 fork looks like the go and as I can fit MTB levers I can pick from all available disc brakes including the full range of hydraulics. I don't know a lot about these things but the 2012 Shimano XT hydros look good to me right now, not the lightest or prettiest option out there but they get good reviews from the MTB'ers and those cooling fins attached to the brake pads look like a very good idea for dissipating heat on those long descents. Anyway, the real question is which hubs? Ideally I'd like to minimise the 'bike mullet' effect (front-rear asymmetry) by re-using the current front rim in building a disc-compatible wheel, which would mean I need to stick to the current number of spokes (24, laced 2 cross I don't think that's necessarily too flimsy for a road disc wheel). The only disc compatible 24H hubs I've been able to find are the Novatec ones though, are they any good and are there any other options that I've missed?

Alternatively I could just wait a few months and end up with a bunch more off the shelf options for forks and wheels. I did tweet HED to ask what happened to the disc-compatible Ardennes and Stinger wheels that were shown at last year's Interbike, they responded saying that they're still tweaking them a bit but hope to have them out by the end of the (northern hemisphere) summer. The disc compatible Ardennes wheels would be almost ideal for me as my current wheels are HED Kermesse's, essentially the same as the current Ardennes CL.

[Nobody]

That might catch on like in the auto industry. It wasn't too many years ago that base Corollas and Pulsars etc ran solid front discs (I remember upgrading a Corolla to ventilated on the front). Now they all seem to have ventilated.

Maybe running smaller ventilated discs will provide an aero advantage in the future.

[MichaelB]

.... Anyway, the real question is which hubs? Ideally I'd like to minimise the 'bike mullet' effect (front-rear asymmetry) by re-using the current front rim in building a disc-compatible wheel, which would mean I need to stick to the current number of spokes (24, laced 2 cross I don't think that's necessarily too flimsy for a road disc wheel). The only disc compatible 24H hubs I've been able to find are the Novatec ones though, are they any good and are there any other options that I've missed?

.....

The Novatech are widely used, but another option is Circus Monkey They have plenty of 24 H front disc hubs, and are well priced and light to boot.

They have a good following on WW forums. There are plenty available via ebay too.

[MichaelB]

lol

http://www.wiggle.co.uk/hope-vented-203mm-rotor/

Only fits the Hope V2 brakes though

Mind you, have put caliper spacers on Nissan 4 pot calipers on a road car before .......

Wonder what the width difference is to a std spec rotor ....

[Hotdog]

The Novatech are widely used, but another option is Circus Monkey They have plenty of 24 H front disc hubs, and are well priced and light to boot.

They have a good following on WW forums. There are plenty available via ebay too.

Thanks Michael, the Circus Monkey hubs look ideal.

BTW I've exchanged a few more tweets with HED about their disc-compatible wheels, they've basically admitted that they're holding them back until the cyclocross frame builders settle on a single rear dropout spacing for disc equipped bikes. Pretty frustrating for those of us only interested in the front wheel anyway!

Sent from my GT-P6800 using Tapatalk 2

[jasonc]

The Novatech are widely used, but another option is Circus Monkey They have plenty of 24 H front disc hubs, and are well priced and light to boot.

They have a good following on WW forums. There are plenty available via ebay too.

Thanks Michael, the Circus Monkey hubs look ideal.

BTW I've exchanged a few more tweets with HED about their disc-compatible wheels, they've basically admitted that they're holding them back until the cyclocross frame builders settle on a single rear dropout spacing for disc equipped bikes. Pretty frustrating for those of us only interested in the front wheel anyway!

has front spacing been decided?

[cobba]

lol

http://www.wiggle.co.uk/hope-vented-203mm-rotor/

Only fits the Hope V2 brakes though

Mind you, have put caliper spacers on Nissan 4 pot calipers on a road car before .......

Wonder what the width difference is to a std spec rotor ....

Vented V2 = 3.25mm
Non-vented V2 = 1.85mm

[MichaelB]

.... has front spacing been decided?

Currently, all hubs are 100mm OLN as far as I am aware, and seems to be no move away from that.

It's just the 135 vs 130 atm for the rears

[twizzle]

Try stopping a car rolling down a hill in neutral with the engine turned off... You lose a huge amount of braking force.

Vacuum boosters were required due to the shifting from self-energising drum brakes to disc brakes. And the booster simply increases pedal force, it could just have easily been used with cable brakes.

[toolonglegs]

Vacuum boosters have been around since early 30's... 20 years before discs where started to be fitted to production cars.yes just a simple way to increase braking force in hydraulic systems... Drum or disc. Not sure how you could vacuum assist a full mechanical system?.

[Ross]

Disc brakes on bike seem to be getting like the lights arms race, maybe this is the next generation disc setup for bikes

[Nobody]

Disc brakes on bike seem to be getting like the lights arms race, maybe this is the next generation disc setup for bikes

I believe the biggest arms race is still who can have the lightest carbon road bike. Bonus points for lots of bling.

[twizzle]

Vacuum boosters have been around since early 30's... 20 years before discs where started to be fitted to production cars.yes just a simple way to increase braking force in hydraulic systems... Drum or disc. Not sure how you could vacuum assist a full mechanical system?.

That was just for lazy people and/or bad brake design (ie. brake systems using leading/trailing shoes instead of running two or more leading shoes with multiple slave cylinders) . And the vac booster isn't in the hydraulics (although some cars used a hydraulic slave cylinder through a vac booster to a second master cylinder, ie. "remote booster"), it's in the mech side and boosts the pressure applied to the master cyliner, but could just have easily boosted effort to a full mech system.

[toolonglegs]

Show me a car with cable operated mechanical brakes please... apart from drum activated hand brakes.

[Nobody]

Show me a car with cable operated mechanical brakes please... apart from drum activated hand brakes.

I think that was the original point. They don't exist because cable is inferior for whatever reason.

[toolonglegs]

Show me a car with cable operated mechanical brakes please... apart from drum activated hand brakes.

I think that was the original point. They don't exist because cable is inferior.

They exist, but they are pretty rare I would think... but I still cannot see how you could vacuum assist a full mechanical system ie: cable operated cam system ... but anyway totally OT now.

[baabaa]

Ideally I'd like to minimise the 'bike mullet' effect (front-rear asymmetry) by re-using the current front rim in building a disc-compatible wheel, which would mean I need to stick to the current number of spokes (24, laced 2 cross I don't think that's necessarily too flimsy for a road disc wheel). The only disc compatible 24H hubs I've been able to find are the Novatec ones though, are they any good and are there any other options that I've missed?

Umm maybe just me but 24H seems too low in spokeage to me and you may/could/would have constant rotor rub. This would turn me into a loon as I hate any bike rub, rattle or squeaks so tend to ride ss most of the time.
Why not send an email to some of the o/s wheel building gurus like peter white, pro wheel builder or handspun before you start the build.
I would also say Peter Bundy would also be able and happy to help.

[Hotdog]

Umm maybe just me but 24H seems too low in spokeage to me and you may/could/would have constant rotor rub. This would turn me into a loon as I hate any bike rub, rattle or squeaks so tend to ride ss most of the time.
Why not send an email to some of the o/s wheel building gurus like peter white, pro wheel builder or handspun before you start the build.
I would also say Peter Bundy would also be able and happy to help.

24 spokes were used on the Mavic Speedcity and similar wheels during that period a few years ago when a number of disc-equipped flat-bar roadies appeared on the market. There are also a few 24 spoke 29er wheels currently available, and Mavic are apparently releasing a 20 spoke front wheel in the 2013 Crossmax SLR wheelset (now that probably is a bit silly ). Furthermore the disc-compatible Ardennes CL cyclocross wheels that HED showed at Interbike last year use exactly the same rim (24 hole HED Belgium C2) that I'm taking about re-using. I think that as long as I keep away from skinny ultra-light spokes (e.g. go for DT aero comps instead of aerolites) then I should end up with a wheel that's strong enough for strictly on road use. If I'm wrong then the likely outcome is breaking spokes, if it happens regularly then lesson learned, I'll build a stronger wheel.

I can't see how the number of spokes could cause rotor rub though. The rotor is attached directly to the hub and the brake calliper is attached to the fork, no amount of flexing of the spokes and rim are going to make them move relative to each other.

[AndrewBurns]

Just ordered some carbon 29er disc wheels from Farsports for my CX commuter bike. 23mm carbon rims with 28 CX-ray spokes front and back and Novatec hubs, apparently around 1450 grams a pair.

[Mulger bill]

Disc brakes on bike seem to be getting like the lights arms race, maybe this is the next generation disc setup for bikes

Six pot callipers have been tried before and now that Hope have ventilated floating rotors, I'd say we're there already...

[Hotdog]

Just ordered some carbon 29er disc wheels from Farsports for my CX commuter bike. 23mm carbon rims with 28 CX-ray spokes front and back and Novatec hubs, apparently around 1450 grams a pair.

The FSC29-C's? Looks like a nice set of wheels, let us know what you think once they arrive. Do you mind telling us how much they cost you?

[AndrewBurns]

The FSC29-C's? Looks like a nice set of wheels, let us know what you think once they arrive. Do you mind telling us how much they cost you?

Yep that's them. All up including shipping and paypal fee was $681USD, they say shipping time will be between 20-25 days, I'll post some pics and weights when they come in.

[MichaelB]

Just ordered some carbon 29er disc wheels from Farsports for my CX commuter bike. 23mm carbon rims with 28 CX-ray spokes front and back and Novatec hubs, apparently around 1450 grams a pair.

The FSC29-C's? Looks like a nice set of wheels, let us know what you think once they arrive. Do you mind telling us how much they cost you?

I'm looking at using a set of these rims to build a set around some Circus Monkey hubs that are on their way. The rear hub is their new CX one that is 130mm OLN.

If things work out right, they'll be as close as %^&* is to swearing at 1,400g.

The rims themselves are USD $384 shipped per pair. It's either those MTB rims or some 38mm deep carbon clinchers that come in at 60g per rim more.