MTB brakes

Mike_H

autos are better - WRWD508
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Time to do some maintenance to my main bike (a Niner ROS9 I built about 3 years ago). Noticed on a ride yesterday that I was getting some weird motion out of my 2-piece brake rotor in the rear. When I hold the brake and rock the bike fore and aft, there is motion in the rivets where the braking surface joins with the hub. My current setup is I have magura MT trail brakes with the two piece rotors. I have a 4 pot front caliper and 2 pot rear. Stopping power is good, but I can't lock up the rear. I'm running 4 pot front and 2 pot rear brakes, 180mm discs. I will be honest and say I "experimented' with some knock-off Hopes and I am probably paying the price. Curious if it might have something to do with the rotors?

Are the Hope rotors worth 70 bucks? Should I be running a one piece rotor? Is the little bit of "rock" that happens on the rivets of a two piece rotor normal? I've never noticed it before...so I think the rotor is ready to be replaced, but maybe not?

What is your favorite rotor and why?


@JMT @gasiorv @techjeeper @Woodrow @KJT
 
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I personally don't do a lot of long downhill runs, I am more of a XC and trail rider so take what I say with a grain of salt.

You should be able to lock up that rear wheel with ease, even with the 2 piston. Possibly you need a better bleed. I run a 160mm with XTR 2 piston brakes rear and can lock up my rear in a heartbeat. I am running the same 2 piston XTR on the front with 200mm rotor and that combo has me comfortable in every downhill situation I have ever been (which includes some long 3.5-4 mile steady downhill runs). I think the major benefit of the 2 piece rotor is heat "resistance" and the heat won't transmit as fast through the inner material. However, other than that, I don't know much about them and never seen one in person. As far as rotors, I typically just buy the cheapest shimano brand available from Jensonusa when I go to order and I do run the finned brake pads for better heat dissipation.

Sorry, I am not much help when it comes to the Hopes, Saints, and such.
 
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Time to do some maintenance to my main bike (a Niner ROS9 I built about 3 years ago). Noticed on a ride yesterday that I was getting some weird motion out of my 2-piece brake rotor in the rear. When I hold the brake and rock the bike fore and aft, there is motion in the rivets where the braking surface joins with the hub. My current setup is I have magura MT trail brakes with the two piece rotors. I have a 4 pot front caliper and 2 pot rear. Stopping power is good, but I can't lock up the rear. I'm running 4 pot front and 2 pot rear brakes, 180mm discs. I will be honest and say I "experimented' with some knock-off Hopes and I am probably paying the price. Curious if it might have something to do with the rotors?

Are the Hope rotors worth 70 bucks? Should I be running a one piece rotor? Is the little bit of "rock" that happens on the rivets of a two piece rotor normal? I've never noticed it before...so I think the rotor is ready to be replaced, but maybe not?

What is your favorite rotor and why?


@JMT @gasiorv @techjeeper @Woodrow @KJT

I’m relying on @KJT because he works at the best bike shop in town and is a Jedi.
 
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I personally don't do a lot of long downhill runs, I am more of a XC and trail rider so take what I say with a grain of salt.

You should be able to lock up that rear wheel with ease, even with the 2 piston. Possibly you need a better bleed. I run a 160mm with XTR 2 piston brakes rear and can lock up my rear in a heartbeat. I am running the same 2 piston XTR on the front with 220mm rotor and that combo has me comfortable in every downhill situation I have ever been (which includes some long 3.5-4 mile steady downhill runs). I think the major benefit of the 2 piece rotor is heat "resistance" and the heat won't transmit as fast through the inner material. However, other than that, I don't know much about them and never seen one in person. As far as rotors, I typically just buy the cheapest shimano brand available from Jensonusa when I go to order and I do run the finned brake pads for better heat dissipation.

Sorry, I am not much help when it comes to the Hopes, Saints, and such.

I suspect I should be able to lock up the tires, and have done many bleeds. Not sure why mtb brake are such a pain in the ass to bleed, but I struggle.

I’m more XC too, this bike is a hard tail with a 120mm fork…plus, Michigan. A “good” trail will get us 100 feet of elevation per mile, so big, long downhills aren’t really a thing (unless you’re in copper harbor). I’ve never felt my brakes were unsafe, just that there is more performance than I’m getting.
 
Never rode in Copper Harbor but I have ridden in upstate Michigan. I was amazed at how sandy the trails were.
 
I really like Shimano SM-RT86 Rotors, they work with resin and metallic pads well. They were really on sale for a while, I bought enough sets to put them on all my bikes.

You might also make sure your pads aren’t glazed. That can really take the bite out of them.
 
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Time to do some maintenance to my main bike (a Niner ROS9 I built about 3 years ago). Noticed on a ride yesterday that I was getting some weird motion out of my 2-piece brake rotor in the rear. When I hold the brake and rock the bike fore and aft, there is motion in the rivets where the braking surface joins with the hub. My current setup is I have magura MT trail brakes with the two piece rotors. I have a 4 pot front caliper and 2 pot rear. Stopping power is good, but I can't lock up the rear. I'm running 4 pot front and 2 pot rear brakes, 180mm discs. I will be honest and say I "experimented' with some knock-off Hopes and I am probably paying the price. Curious if it might have something to do with the rotors?

Are the Hope rotors worth 70 bucks? Should I be running a one piece rotor? Is the little bit of "rock" that happens on the rivets of a two piece rotor normal? I've never noticed it before...so I think the rotor is ready to be replaced, but maybe not?

What is your favorite rotor and why?


@JMT @gasiorv @techjeeper @Woodrow @KJT

Sounds like you've got center locking brake rotors? Thats the only two peace system I can think of, make sure your locking ring or bolts are tight. Always go with a single piece rotor if you can. There should be no motion in any of the brake calipers, however, some rocking motion from the pads is normal. That said, I don't really care for Magura brakes in general, in my experience there not super powerful and they are hard to service. You should easily be able to lock up your braking system with that set up though. Here are some things I would check:

1. Make sure you can put your bike upside down for 10 minutes and you can still pull the lever without touching the bar.
2. Check that all of your pistons are moving freely and equal distances until contacting the rotor.
3. Take out your pads and inspect the area for any kinds of contamination/leaking oil.
4. Sand and then clean the pads and rotors with some 200-400 grit, then clean everything with alcohol (don't forget the caliper).

If any of this fails, I'd say you need to bleed the system, and some new pads and rotors. If your having trouble with the bleed process, let me know and I can give you some tips, however, it's not uncommon to have a faulty leaver which can make it impossible to bleed.

My personal recommendation would be some Shimano, Tektro or sram rotors, my personal favorites are the srams and tektros, they typically run a thicker rotor and handle heat without bending.
Try and stay away from those knock-off brands, they may be cheap, but they tend to fail pretty quickly, Shimano sells some really good budget brakes, I'd recommend some Shimano XTR brakes, but if you want to keep the cost down try some Mt 200s.

Good luck!
 
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Not sure what you mean by a two-piece system. Sounds like you've got center locking brake rotors? Thats the only two peace system I can think of, make sure your locking ring or bolts are tight. Always go with a single piece rotor if you can. There should be no motion in any of the brake calipers, however, some rocking motion from the pads is normal. That said, I don't really care for Magura brakes in general, in my experience there not super powerful and they are hard to service. You should easily be able to lock up your braking system with that set up though. Here are some things I would check:

1. Make sure you can put your bike upside down for 10 minutes and you can still pull the lever without touching the bar.
2. Check that all of your pistons are moving freely and equal distances until contacting the rotor.
3. Take out your pads and inspect the area for any kinds of contamination/leaking oil.
4. Sand and then clean the pads and rotors with some 200-400 grit, then clean everything with alcohol (don't forget the caliper).

If any of this fails, I'd say you need to bleed the system, and some new pads and rotors. If your having trouble with the bleed process, let me know and I can give you some tips, however, it's not uncommon to have a faulty leaver which can make it impossible to bleed.

My personal recommendation would be some Shimano, Tektro or sram rotors, my personal favorites are the srams and tektros, they typically run a thicker rotor and handle heat without bending.
Try and stay away from those knock-off brands, they may be cheap, but they tend to fail pretty quickly, Shimano sells some really good budget brakes, I'd recommend some Shimano XTR brakes, but if you want to keep the cost down try some Mt 200s.

Good luck!
 
Time to do some maintenance to my main bike (a Niner ROS9 I built about 3 years ago). Noticed on a ride yesterday that I was getting some weird motion out of my 2-piece brake rotor in the rear. When I hold the brake and rock the bike fore and aft, there is motion in the rivets where the braking surface joins with the hub. My current setup is I have magura MT trail brakes with the two piece rotors. I have a 4 pot front caliper and 2 pot rear. Stopping power is good, but I can't lock up the rear. I'm running 4 pot front and 2 pot rear brakes, 180mm discs. I will be honest and say I "experimented' with some knock-off Hopes and I am probably paying the price. Curious if it might have something to do with the rotors?

Are the Hope rotors worth 70 bucks? Should I be running a one piece rotor? Is the little bit of "rock" that happens on the rivets of a two piece rotor normal? I've never noticed it before...so I think the rotor is ready to be replaced, but maybe not?

What is your favorite rotor and why?


@JMT @gasiorv @techjeeper @Woodrow @KJT
I love good brakes and I’ve tried a bunch on different bikes over the years. Quality brakes are worth extra money to me.

Out west, we have some great long, technical and steep descents. Here, brakes with good power, modulation and minimal fade can save your bacon.

I actually still have some 2 piece Hope rotors (180/160) on my ssXC bike with some stylish but old Formula 2 piston brakes. They are fine for that bike. They look cool but the rivets can have clearance problems depending on your set up and they aren’t the quietest or strongest that I’ve tried.

I prefer one piece rotors, one size bigger in front (180/160 XC, 200/180 trail and 220/200 all mountain/DH work for me). In Michigan, going down a rotor size from those recs is probably fine, especially if weight is a big concern. The higher end SRAM and Shimano rotors both work well. I favor metallic pads for their power over the the quieter organics. 4 piston calipers front and rear are my recommendation on anything but an XC bike. SRAM’s excellent modulation beats Shimano’s more on/off feel to me. I’ve tried other more boutique brand brakes but I like the 4 piston SRAMs a lot and pads and parts are readily available.

For my trail bike, SRAM G2 ultimates with 200/180 centerline rotors work well. That set up may be a good replacement for you current brakes. Right now, for really big power on my 2 more downhill oriented 29ers, I’m running SRAM code ultimate calipers and Galfer wave rotors and pads (223mm front 203mm rear). The Galfers are the most powerful rotors and pads I’ve used but they are a small company and I can’t really recommend their customer service (think Savvy). SRAM also has a new more powerful brake (the Maven) which is probably overkill, but then I said that about 200mm plus droppers as well and was proven wrong.
 
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Sounds like you've got center locking brake rotors? Thats the only two peace system I can think of, make sure your locking ring or bolts are tight. Always go with a single piece rotor if you can. There should be no motion in any of the brake calipers, however, some rocking motion from the pads is normal. That said, I don't really care for Magura brakes in general, in my experience there not super powerful and they are hard to service. You should easily be able to lock up your braking system with that set up though. Here are some things I would check:

1. Make sure you can put your bike upside down for 10 minutes and you can still pull the lever without touching the bar.
2. Check that all of your pistons are moving freely and equal distances until contacting the rotor.
3. Take out your pads and inspect the area for any kinds of contamination/leaking oil.
4. Sand and then clean the pads and rotors with some 200-400 grit, then clean everything with alcohol (don't forget the caliper).

If any of this fails, I'd say you need to bleed the system, and some new pads and rotors. If your having trouble with the bleed process, let me know and I can give you some tips, however, it's not uncommon to have a faulty leaver which can make it impossible to bleed.

My personal recommendation would be some Shimano, Tektro or sram rotors, my personal favorites are the srams and tektros, they typically run a thicker rotor and handle heat without bending.
Try and stay away from those knock-off brands, they may be cheap, but they tend to fail pretty quickly, Shimano sells some really good budget brakes, I'd recommend some Shimano XTR brakes, but if you want to keep the cost down try some Mt 200s.

Good luck!

Hope two piece rotors…they are 6-hole. Aluminum center section and a SS friction area. I guess technically, I should be calling them floating rotors, because there are far more than 2 pieces in the assembly.

1710499924180.png
 
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FWIW, I made a bit of an impulse purchase last night and I have two new, authentic, hope rotors (@Woodrow 200/180 :) ) on the way. My vanity sometimes gets the best of me, and I like the bling of the two piece. I really think my issues are more related to bleed and contamination after doing a bit more research. So I also paid for the mfg recommended fluid vs the aftermarket stuff I use in everything else (that the lbs recommended). I’ll clean the pads with some sandpaper and alcohol too.

I decided to replace the rotors knowing that I can’t fix the ones I have, and they aren’t going to get better. Would hate to have a full separation on the trail.
 
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We need to get you all to Bentonville AR for some mt biking, leave the TJs at home and just ride some great NWA trails over a long weekend!!
We have been going there every year since 2016 and there is more and better every year and there is plenty of trail for everyone (XC riders, Downhillers, Huckers, etc....). Another one of my favorite trips is Coldwater Mtn in Alabama, it doesn't have the mileage that Northwest Arkansas has but wow, the smiles per mile can't be beat. We typically combine coldwater with Oak Mtn in Birmingham and it makes a great weekend!!
So much to do and so little time and money to do it!!
 
FWIW, I made a bit of an impulse purchase last night and I have two new, authentic, hope rotors (@Woodrow 200/180 :) ) on the way. My vanity sometimes gets the best of me, and I like the bling of the two piece. I really think my issues are more related to bleed and contamination after doing a bit more research. So I also paid for the mfg recommended fluid vs the aftermarket stuff I use in everything else (that the lbs recommended). I’ll clean the pads with some sandpaper and alcohol too.

I decided to replace the rotors knowing that I can’t fix the ones I have, and they aren’t going to get better. Would hate to have a full separation on the trail.

👍You won’t be disappointed. Definitely a win on the bling factor (so many color choices😀). I’ve probably had half a dozen sets of Hope rotors in the past. They are well made and beautiful and you will like the extra power of the larger front.

A forum MTB trip like @gasiorv suggests would be fun. I didn’t expect so many parallels between the MTB and TJ hobbies. Everything from thinking through your build for a specific function, to getting your hands dirty to line choice on the trail…fun stuff.
 
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We need to get you all to Bentonville AR for some mt biking, leave the TJs at home and just ride some great NWA trails over a long weekend!!
We have been going there every year since 2016 and there is more and better every year and there is plenty of trail for everyone (XC riders, Downhillers, Huckers, etc....). Another one of my favorite trips is Coldwater Mtn in Alabama, it doesn't have the mileage that Northwest Arkansas has but wow, the smiles per mile can't be beat. We typically combine coldwater with Oak Mtn in Birmingham and it makes a great weekend!!
So much to do and so little time and money to do it!!

Id be down! I actually have some friends heading to Bentonville this year. I’m spending my vacation time in the Dominican and Florida this year, so I’m out, buts it’s a bucket list MTB destination for me.
 
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I have brakes again! They need to be fully bedded in, but I can already tell they are so much better. I did not have a good bleed in the rear, for sure. That coupled with the extra rotor size means I should not have any further trouble with the woah! It was a good upgrade too, as one of the last times I rode I almost ran over a buddy that went OTB in front of me. Got her stopped, but not quickly enough for my comfort. That’s what kicked this whole thing off.

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Who cares how they work, the bling man, the bling!:love:

Seriously, nice looking bike and you'll love the performance.
 
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