[Closed] Road bike disc rotor options?

Whichever look nicer? On 160 at about 2x your weight and never struggled with them so 140 should be fine even if your a serial brake dagger.

The 140mm rotors will be lighter, by a few grammes, one swig of water from your bottle will weigh more. Bigger rotors are better at heat dissipation. Depending on what the "natural" rotor size is for your forks and rear mount you might need adaptors to fit the larger rotors, not a big deal but a little extra expense.

Try Ashima rotors if 6 bolt, light and work well on CX bike and MTB.

go 160.

140 isn't worth it. You save a few grams yet the performance isn't as good. Only weenie builders need apply IMO.

You need ones that'll fit your hub - centrelock or 6-bolt

140 isn’t worth it

Would disagree within limits and depending on bike setup, On a 160mm rear rotor with normal 25mm road tyres, at my 65kg on Ultegra brakes I found the back brake WAAAY too difficult to modulate in the damp. Normal Shimano grabbiness meant a lot of inadvertent locking up, which is never good news on a roadie. Downsized to 140mm at the back and it's much more controllable, especially once in thick winter gloves. Given the OP weighs less than a packet of crisps, I'd say she probably should consider a 140 on the back at least!

Also note that Hope floating rotors don't play nicely out the box with Shimano post mount calipers. Nowt that a few stroke of a file won't solve.

Thanks folks - looks like 140 or 160 is a viable option. Although I'm only light, I will be sometimes using it for loaded bike packing and long / steep descents.

I've read some info about shimano's "ice tech" rotors being better - anyone got any advice or experience on this?

Also, rotors seem to range from about £20 - £50 ... do the more expensive options offer greater performance?

Thanks all 😊

If your hubs are centrelock - the rotor mount is splined rather than a flat plate with six bolt holes in it - then consider a centrelock adaptor. This lets you mount either a normal six bolt rotor or centrelock rotor should you need to replace in a hurry.

The more expensive rotors "probably" offer better heat dissipation.

I'd go 160mm front, 140mm rear.

@jonEdwards - is that still the case with Hope/Shimano? I thought Hope had modified their later rotors. Hope rotors don't play nicely with Avid BB7 calipers, well the brake pads, you have to cut the tabs off the pads so they don't foul the bolts on the rotor.

I've got 140mm rotors on my CX / Gravel / Roadmax bike, even descending big Welsh hills at speeds approaching 90kph (on tarmac) I've had no issues with power or modulation and I'm 30kg heavier than the OP.

IMHO if you've got Shimano brakes, fit the rotors they were designed to be used with. I think the best ones for the Ultegra are the Freezer Tech ones.

I’d go 160mm front, 140mm rear cos that's what i've got.

As for what rotor, i've Hope road hubs with centre lock and that meant i had all of three choices.

Hi,

In true single track tradition recommend what youve got. I've been running these on my road disc bike

https://www.bike-discount.de/en/buy/formula-disc-rotor-160mm-6-hole-219758

I'm sure they are available elsewhere but this is where I bought mine from.

They have been great, highly recommended. In my opinion avoid discs with fancy designs as they pulsate through the fork and feel terrible.

I also agree with the above comment I'd you have the budget, buy shimano discs for shimano brakes.

I've got 180/160 RT66 on my mtb, I'm 72kg in the nuddy, with the bike loaded up for bikepacking, I've not felt under-braked or under modulated on big descents in the Lakes and mid Wales.

I'd say 140s would be plenty for you. For the weight of a sip of water (10 grammes?) I might be tempted to stick a 160 on the front.  Some people say it gives a more balanced feel between the levers, but I'm sure this is well within the realms of just getting used what you've got pretty quickly.

RT66 is 2nd cheapest shimano.  more expensive gives you alloy carriers which might look a bit better, might give tiny weight gains, icetech might give you barely discernible benefits for heat dissipation.  floating rotors are another expense which can help keep rotors true under extreme heat by allowing some movement between carrier and braking rotor.  I've never felt the need for any of these.  Cheaper discs eg. clarks etc start showing up some poor reviews for material quality control, warping, grinding tolerances.

Edit: seems RT66 isn't available in 140, point remains that there's a cost/quality/performance sweet spot quite low down the price scale.

My wife weighs 65kg, and uses 160/140 on her road bike with no issues.

I weigh 125kg, i use 160/160 with no issues, even fully loaded with camping gear

Both using cable discs.

i’d say the OP should be fine on 140s, unless her frame is built for 160s, in which case they would be fine too.

I'd use the size which your frame is designed for..

I also use fairly cheap basic Shimano discs as i view them as disposable parts, they do wear out and you can damage them by overheating/contamination.

I'd rather change a £7 basic Shimano disc more often than than a £35 fancy Ice-Tech version.

Can you use both centre lock and 6 bolt with the Shimano brakes? It just depends on your wheel/hub right?

I'm a bit out of date with the tech so just wondered.

Yes, whichever wheel/rotor combination you had is ok with Shimano brakes.

160front and 140mm rear max I’d say

the shimano xt ice tech are great

RT81 CL or RT86 can be had for £22-26 on a good day .

id put in what ever centre lock or 6 bolt your hubs are designed for.

my drophandle came with CL rotors with adaptors

?:0(

so I ended up saving 40 grams an end by putting the Rt86 6 bolt on, selling the adaptors and rotors they only cost me £10-15 to upgrade in total

I dislike the new Freeza rotors as I find they warp badly, switched to Sram Centreline X and found them a lot better, also more quiet under braking, the Shimano's 'gobbled' when they got hot, I suspect as they were no longer true.

Another 160 front, 140 rear user here. Partly because the frame is 140 native so it looks nicer, but as an added benefit I found there was still plenty of power but better feel. That's with 40mm tyres. Would be happy with 140mm front on the road but prefer 160mm off road so both road and off road wheelsets are set up that way.

One set is shimano, one hope floating and there's pretty minimal faff to swap. Calipers are flat mount front, post mount rear.

140/140 airotors at 66 grams each were fine for my 75 kg frame in the alps for two years.

lots of heavy breaking into hairpin bends. Down mount ventox and they didn’t overheat.

I think you can get away with virtually anything you like and not have to worry about overheating.

The weight difference between 140 160 and 180 is totally insignificant. Especially if you have to add an adaptor to accommodate a different size..

I'd sticky with the size that's already on, and use a standard shimano disk.. Don't over think it 🙂

I've been using 160mm Hope floating rotors on the road bikes for over 4 years without any problems.

140/140 airotors at 66 grams each were fine for my 75 kg frame in the alps for two years.

lots of heavy breaking into hairpin bends. Down mount ventox and they didn’t overheat.

I think you can get away with virtually anything you like and not have to worry about overheating.

Yet I 'Blued' up a 160mm Shimano Dura Ace Freeza using resin pads, in the Alps this summer, that def over heated!

another 160 front 140 rear here just because worked best with post mount brakes I had and makes some sense though I'm not a dedicated front is my main brake person. Thought some road frames only take 140 rear? As in not much space Have two sets of wheels 1 have icetech rotors but never noticed any difference then again I avoid dragging brakes .....in European alps in summer on a rental road bike and shop insisted that I remember to bring bike in for pads to be checked after 4 days presumably because people descend with a continuous handful of brake ... not big balls I just kill speed as needed not continously