Hope lovers - I have a question

[rico]

I've never really understood what a 'floating' disc means. Could someone explain how using a floating rotor helps the braking? It sounds like the disc moves? But that sounds a bit dodgy?

of Bucks

eg - http://cgi.ebay.co.uk/Hope-Floating-D

[Justin S]

The floating rotor is just like a motorbike disc.The disc is riveted onto the spider and moves sideways slightly.This means you can have a slightly lighter rotor as the centre is alloy.As for helping braking,not so sure.But they do look funky,although i decided to go for standard discs.

[beyond rational]

Greater cooling for one thing as the thermal mass is comparatively less and the surface area greater. Not to mention reducing unsprung wieght and momentum.

Do not confuse this with a floating caliper though!

[catso]

Virtually all Motorcycles have semi-floating (move slightly under pressure) or full-floating (rattle like a tamborine - usually on higher performance/race bikes) front Discs rather than one piece as the design allows heat expansion of the disc without the carrier meaning warping is less likely, also because the Disc 'floats' it will run more 'true' through the caliper (there is always some drag) this means that there is less friction so the wheel runs more freely, because of the reduced drag/friction the disc will get less hot so braking/cooling is improved, as mentioned above it also allows a lighter Alloy carrier to be used so reducing unsprung weight.

The benefits, presumably, are not as great on a pedal-powered machine where, I would imagine the greatest advantages would be weight saving (alloy carrier/steel disc) and freer running. I wouldn't think disc warping would be such a problem as, for example, on Racing Motorbikes which weigh significantly more and travel at significantly higher speeds.

[rico]

Thanks guys. Bit confusing eh?

[LRdriver II]

Downhill and freeride boys generate alot of heat so is of use to them.

Never the less I specced my Orange 5 with the Hope pro-package and get an upgrade to floating rotors..soooo preetty..bling bling..

[KUB3]

Basically the floating alloy centres looks very trick in gloss black, so I went for them. Bargain

[rlk500]

I think one advantage is that warpage is a potential problem that floating disks can eliminate, even for general off road use. Imagine the scenario you descend off a fairly steep hill that requires a fair amount of brake use. The disks will be hot, easily hot enough to burn you if you touched them. At the bottom of the descent is a big puddle, you go straight through it, your disks having been red hot are now doused in cold water, the subsequent sudden cooling is what will often cause warping. The floating arrangement will reduce the possibility of warping in what must be a fairly common occurrence for MTB riding.

[mat205125]

KUB3 said:

Basically the floating alloy centres looks very trick in gloss black, so I went for them. Bargain

Hat's off to your honesty

[beyond rational]

rlk500 said:

I think one advantage is that warpage is a potential problem that floating disks can eliminate, even for general off road use. Imagine the scenario you descend off a fairly steep hill that requires a fair amount of brake use. The disks will be hot, easily hot enough to burn you if you touched them. At the bottom of the descent is a big puddle, you go straight through it, your disks having been red hot are now doused in cold water, the subsequent sudden cooling is what will often cause warping. The floating arrangement will reduce the possibility of warping in what must be a fairly common occurrence for MTB riding.

I can't say I've heard of anyone getting warpage by that scenario, infact most manufactuers recommend getting the brakes hot and then dousing with water in order to bed them in. Personaally I've never seen a disc where warpage could be attributed to heat alone, I imagine it could happen if the rotor was thin enough, the rider heavy enough and the hill long enough but most of the time discs are distorted from impact.

Edited by beyond rational on Tuesday 23 January 16:22