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Best Heavy Duty Rotors? (e-bike related)

gemini2k

Turbo Monkey
Jul 31, 2005
3,526
115
San Francisco
What the verdict on the best heavy duty rotors these days? I don't really care about weight, since this would be going on my e-bike. As it turns out, constantly pinning it up and down SF hills and stopping from 25+ mph on flats while me being 200+ pounds on a 50+ pound bike is overwhelming the stock 7inch rotors a bit more than I'd like. The fork/bike (Specialized Vado) are only rated for 7inch, so I'm hesitant to throw 8inch rotors on there. I figure if I can find something thicker/more solid that might help with cooling and warping.

Thoughts?
 

commencaldh

Jeremy Hottinger
Apr 26, 2015
137
17
my hope rotors seem to be doing well with the abuse i put them through, but maybe mod the e-bike with some moto rotors and brakes.
 

buckoW

Turbo Monkey
Mar 1, 2007
1,533
193
Champery, Switzerland
My understanding is that the new thicker rotors designed for Ebikes need a wider caliper to go with them. TRP makes an ebike caliper and thicker rotor, btw.
I have Hope rotors on mine and they hold up well. We put 225mm Hope rotors on my 68yr old Mom’s eMTB with great success. (I no longer hear complaints about brakes every other day.).
 

HardtailHack

used an iron once
Jan 20, 2009
2,259
163
Phwoar, a road E-Bike post in the DH section, awesome!

Hope only make a ventilated 8" rotor and you need their Tech V2,3,4,5 calipers, maybe the newer ones work in the wet but my old ones didn't.
Things have no doubt changed, even Magura make brakes that work now.
 
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Toshi

Harbinger of Doom
Oct 23, 2001
25,813
1,636
I've got 4-piston XTs with Ice Tech rotors on my Pivot Shuttle and they hold up fine.
 

Jm_

Turbo Monkey
Jan 14, 2002
9,028
1,450
AK
Are they the experimental Shimano dual discs from the early 2000s? The ones where pros were soaking them in oil prior to race runs as they were too powerful?
Yep. I have to wonder how those would fare today...
 

HardtailHack

used an iron once
Jan 20, 2009
2,259
163
Are they the experimental Shimano dual discs from the early 2000s? The ones where pros were soaking them in oil prior to race runs as they were too powerful?
Guessing they are Hopes, look near identical to my Motos from 2009, I still have a ventilated rotor in the garage. Still have multiple types/brands of pads too, tried any type I could find to hopefully make them work in the wet. Everybody commented on how awesome they looked and I guess that was a pretty big part of DH, the banter at the top of the hill.
 

Jm_

Turbo Monkey
Jan 14, 2002
9,028
1,450
AK
Guessing they are Hopes,
They are not hopes. Shimano used a dual-rotor design that had 3 pads, one sandwiched in between two of the rotors. The had water-cooling and a radiator to boot. Hope ventilated rotors were a different thing.
 

HardtailHack

used an iron once
Jan 20, 2009
2,259
163
They are not hopes. Shimano used a dual-rotor design that had 3 pads, one sandwiched in between two of the rotors. The had water-cooling and a radiator to boot. Hope ventilated rotors were a different thing.
Well I apologize, I was wrong, had no idea that Shimano thing existed, a bike with those brakes and Airlines would be pretty sweet. It does look very British, just add bits until it starts working.

So both the outer rotors floated? I don't see how the centre pad would be of any use otherwise, unless it relied on the discs flexing......?
Crazy voodoo.Brakes seem like one of the simplest parts on a bike but they have taken many years to get performing at a level that everyone except the regulars in the Frankenbrake thread are happy with..
 

Sandwich

Pig my fish!
Staff member
May 23, 2002
15,829
937
01776
Maguras are usually thicker than others. If you're having trouble with overheating, I'd go for a two piece rotor like a hope, or grab a shimano icetech setup. That should help more than 0.1mm.
 

Jm_

Turbo Monkey
Jan 14, 2002
9,028
1,450
AK
I definitely noticed a big improvement moving to the icetech rotors on my two summer bikes. On the RFX, got me out of glazing the pads and holding on for dear life on the 45° grades, on the XC bike with only 6" rotors they never overheated during multi-thousand foot descents, power was never huge at 6", but it was adequate for XC race and the fact that I could use them so heavily and not overheat was impressive. The downside is like any rotor they will wear and at some point you should replace em (measure the thickness). It's a steel-aluminum sandwich so you don't want to get let it go too far, but I don't now of anyone that has.
 

mykel

Turbo Monkey
Apr 19, 2013
1,898
538
sw ontario canada
I have a couple of sets of old Magura Venti rotors from the Louise BAT days.


(not mine, pic from teh 'netz)

I fucking love them. They get / got ported all over the place.
All of them are pretty much at their limit at about 1.75 according to Magura.
Thing is, now they are the size of some new rotors....
Currently being used with Hope Tech3V4 and Avid XO Trails.

They still stop my fat ass, they run true and don't gobble...

Are they really done??
 
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'size

Turbo Monkey
May 30, 2007
1,917
249
AZ
my OG galfer rotors are thicker than any other brand i've used before or since. not sure if they're still that way.
 

Udi

RM Chief Ornithologist: “I Brake for Birds”
Mar 14, 2005
4,717
796
Plenty of good suggestions here but I wouldn't use ice tech on an e-bike.
They do have a significantly shorter wear life than regular rotors even under non-electric chairlift usage, and heavy guy + e-bike + ice tech is a recipe for disaster if you don't closely monitor wear. I do think they're good rotors (lightweight, great heat dissipation) but just not the right one for this particular case.

I would just spring for 8" rotors (at least) though, if the frame/fork can't handle that then you really shouldn't be on it anyway. If you think about it, a brake with very high peak force on a 7" rotor could easily put more force through the frame/fork anyway, and going up a rotor size will work wonders for heat dissipation - because the extra leverage (thus extra peak force at contact patch) will mean you'll likely drag them less too, in addition to the larger dissipation area. If the bike spontaneously combusts from the bigger rotors then it probably would have happened eventually anyway, just put the 7" back on when you get it warrantied and say the other burns were from an unrelated house fire.
 

Udi

RM Chief Ornithologist: “I Brake for Birds”
Mar 14, 2005
4,717
796
I was trying to figure out why on earth you bought it, but leisure cycling while looking stylish are all the important things.
"Perfect for urban commuting and leisure cycling, the Specialized Turbo Vado is a stylish, yet practical electric bike that offers a powerful boost to your natural pedalling power."
 
Plenty of good suggestions here but I wouldn't use ice tech on an e-bike.
They do have a significantly shorter wear life than regular rotors even under non-electric chairlift usage, and heavy guy + e-bike + ice tech is a recipe for disaster if you don't closely monitor wear. I do think they're good rotors (lightweight, great heat dissipation) but just not the right one for this particular case.

I would just spring for 8" rotors (at least) though, if the frame/fork can't handle that then you really shouldn't be on it anyway. If you think about it, a brake with very high peak force on a 7" rotor could easily put more force through the frame/fork anyway, and going up a rotor size will work wonders for heat dissipation - because the extra leverage (thus extra peak force at contact patch) will mean you'll likely drag them less too, in addition to the larger dissipation area. If the bike spontaneously combusts from the bigger rotors then it probably would have happened eventually anyway, just put the 7" back on when you get it warrantied and say the other burns were from an unrelated house fire.
@Udi, Why do Ice Tech have a shorter wear life?
 

toodles

Turbo Monkey
Aug 24, 2004
2,596
758
Australia
@Udi, Why do Ice Tech have a shorter wear life?
Rotors.jpg


Yes I'm aware I'm a brake dragging squid. No need to point that out.

As @Jm_ pointed out - the steel braking surface eventually gets etched through and aluminium provides fuck all braking. This is usually identifiable by a combination of sudden howling from the brakes and sudden screaming from the rider.
 

Flo33

Turbo Monkey
Mar 3, 2015
1,055
339
Styria
View attachment 132179

Yes I'm aware I'm a brake dragging squid. No need to point that out.

As @Jm_ pointed out - the steel braking surface eventually gets etched through and aluminium provides fuck all braking. This is usually identifiable by a combination of sudden howling from the brakes and sudden screaming from the rider.
One could point at the 7 o'clock section of the lower rotor. :nerd::busted:
 

Jm_

Turbo Monkey
Jan 14, 2002
9,028
1,450
AK
This one, because E bikes.









Interestingly, Hope made an "aggressive" saw-blade one many years ago, but they appear to have wiped the internets of it's existence (no, not the current ones with the rounded edges).
 

Jm_

Turbo Monkey
Jan 14, 2002
9,028
1,450
AK
Didn't the old Hope sawblade discs have a tendency to crack and fail?
Meebee, I thought they also took them off the market because they were actually pretty damn dangerous just because of the saw. It's strange that all pictures and evidence seems to be gone though...
 

mykel

Turbo Monkey
Apr 19, 2013
1,898
538
sw ontario canada
Meebee, I thought they also took them off the market because they were actually pretty damn dangerous just because of the saw. It's strange that all pictures and evidence seems to be gone though...

I remember them, but also could not find a pic.

Seems a bit lizzardy :tinfoil:
 

gemini2k

Turbo Monkey
Jul 31, 2005
3,526
115
San Francisco
Plenty of good suggestions here but I wouldn't use ice tech on an e-bike.
They do have a significantly shorter wear life than regular rotors even under non-electric chairlift usage, and heavy guy + e-bike + ice tech is a recipe for disaster if you don't closely monitor wear. I do think they're good rotors (lightweight, great heat dissipation) but just not the right one for this particular case.
Good to know. I'll probably swap out the front at least to something else.

I would just spring for 8" rotors (at least) though, if the frame/fork can't handle that then you really shouldn't be on it anyway. If you think about it, a brake with very high peak force on a 7" rotor could easily put more force through the frame/fork anyway, and going up a rotor size will work wonders for heat dissipation - because the extra leverage (thus extra peak force at contact patch) will mean you'll likely drag them less too, in addition to the larger dissipation area. If the bike spontaneously combusts from the bigger rotors then it probably would have happened eventually anyway, just put the 7" back on when you get it warrantied and say the other burns were from an unrelated house fire.
That's kinda my thinking. I have a hard time believe that an overheated 7" rotor is safer than a slightly cooler 8 inch rotor.

I was trying to figure out why on earth you bought it, but leisure cycling while looking stylish are all the important things.
Original idea was I wanted to use this for my 40 mile commute to work (ride from SF to Santa Clara, take mass transit from Santa Clara to SF, 2-4 days/week ). On my CX/road bike I can average about 17 mph (with stoplights and such). With the e-bike I can basically hold 28 mph (and with a rack and panniers!), which makes my average moving speed like 25. So it becomes fast enough to do regularly instead of 1 day per week.

But also I've found that the e-bike is f-ing amazing for getting around SF. It's cutting my Uber/Lyft bill in half.

I figure as a tech worker in SF, if I'm not going to buy a Tesla, I at least need to own an e-bike.
 

gemini2k

Turbo Monkey
Jul 31, 2005
3,526
115
San Francisco
I summon @jackalope to this thread, and also someone with the necessary powers, to change the thread title for what it really is: a massive outing campaign for closet e-bike riders.
Unrelated: I did got to an erotically/homosexually themed puppet-based musical last night. I didn't ride my e-bike there though because my foot is all swollen from a stupid rock/moto incident.