Disc Brakes

[stanley02]

I'm looking to upgrade my disc brakes. I have Magura Julie brakes, 180 in the front and 160 rear. My question if I buy a different brand do I have to use the same size rotors or can I use different sizes? For example I see Hayes has a 178 front, would that work? BTW I have a Lefty fork, which I'm not sure if that would make a difference.

thanks,
Paul

[werace424]

I'm looking to upgrade my disc brakes. I have Magura Julie brakes, 180 in the front and 160 rear. My question if I buy a different brand do I have to use the same size rotors or can I use different sizes? For example I see Hayes has a 178 front, would that work? BTW I have a Lefty fork, which I'm not sure if that would make a difference.

thanks,
Paul

I can't help you with your brake question, but do you get hasseled for being named Paul Stanley? Or does Stanley02 have nothing to do with your name?

[sevenforty]

If you are thinking of Hayes, just shoot them an email and get the best answer. I actually just contacted them the other day about getting bleed instructions for the Strokers. They were pretty quick to respond and answered everything I had for them. Good customer service. Just click on 'contact' on their website and it should give you the hayestech address.

[oldskoolbiker]

I'm looking to upgrade my disc brakes. I have Magura Julie brakes, 180 in the front and 160 rear. My question if I buy a different brand do I have to use the same size rotors or can I use different sizes? For example I see Hayes has a 178 front, would that work? BTW I have a Lefty fork, which I'm not sure if that would make a difference.

thanks,
Paul

If you buy a new set of brakes, they will come with discs, but they won't come with mounting adapters. It might be possible to use your existing Magura adapters, but to be safe just buy the adapters for the brand of brakes you buy. Then you could sell your old brakes as a full set, or move them over to another bike.

I don't think a lefty fork will matter, obviously it will take up to 180mm disc since that is what's on there now.

[g_barr]

If you buy a new set of brakes, they will come with discs...
They SHOULD come with rotors/discs. I'm not sure you want to mix old and new parts or different manufacturers - there are potential reliablity/operational issues with mixing and matching. Even mixing part groups made by the same manufacturer may cause problems since dimensions, specifications... may be different enough to affect performance.

I bet you would instantly void a brake manufacturer's warranty by mixing and matching too.

[TrailVictim]

I'm looking to upgrade my disc brakes. I have Magura Julie brakes, 180 in the front and 160 rear. My question if I buy a different brand do I have to use the same size rotors or can I use different sizes? For example I see Hayes has a 178 front, would that work? BTW I have a Lefty fork, which I'm not sure if that would make a difference.

thanks,
Paul


Is there anyting wrong with the current brakes? If not why upgrade? I've used the Julie in the past and they we're pretty decent hydro brakes.

[punga]

They SHOULD come with rotors/discs. I'm not sure you want to mix old and new parts or different manufacturers - there are potential reliablity/operational issues with mixing and matching. Even mixing part groups made by the same manufacturer may cause problems since dimensions, specifications... may be different enough to affect performance.

I bet you would instantly void a brake manufacturer's warranty by mixing and matching too.
Of things you can mix and match, rotors would be the easiest, assuming dimensions are the same, i.e. a 180mm Avid rotor should work fine with a Hayes 180mm set up (caliper and appropriate adaptor).

[g_barr]

Of things you can mix and match, rotors would be the easiest, assuming dimensions are the same, i.e. a 180mm Avid rotor should work fine with a Hayes 180mm set up (caliper and appropriate adaptor).
How about rotor thickness - that could cause problems if it's too thick, right? Slightly thinner shouldn't be a huge deal since dual hydraulic pistions will center on the rotor.

I guess the only reason to mix and match is if you found the lever, hose and caliper without a rotor on eB, CList...

[jabberwocky]

Disc thickness does not matter. All disc brake systems on the market can adjust to handle pad wear (which can vary several millimeters), so a millimeter of difference at the rotor won't matter.

[punga]

Disc thickness does not matter. All disc brake systems on the market can adjust to handle pad wear (which can vary several millimeters), so a millimeter of difference at the rotor won't matter.
Exactly. And if the rotor were too thick, the caliper can be spread with screwdriver to accommodate it. And there might be times where you mix and match, i.e. you bend a rotor and can't find exact replacement. Or you want a cool set of aftermarket "designer" rotors like these. (http://www.dirtydogmtb.com/rotors.htm)

p!

[nocro]

Disc thickness does not matter. All disc brake systems on the market can adjust to handle pad wear (which can vary several millimeters), so a millimeter of difference at the rotor won't matter.

Um Jab?

http://www.dirtydogmtb.com/images%209-16/skull203.jpg

[smdubovsky]

Disc thickness does not matter.

Jab, I'll have to disagree w/ you again;) I have a rotor (a hayes I think - can't find it right now) that will *NOT* fit into a new set of either juicy 5s or 7s. It can be wedged in w/ force but you wouldn't be going very far on it. I documented it once on mtbr. IIRC, like 0.6mm thicker than an Avid rotor. Once the pads wore some it would be fine, but new pads + thicker rotor = no fit. Clearance is that tight on a new setup.

[jabberwocky]

Let some fluid out of the system and the pads will retract further.

[tuba_transport]

Jab, I'll have to disagree w/ you again;) I have a rotor (a hayes I think - can't find it right now) that will *NOT* fit into a new set of either juicy 5s or 7s. It can be wedged in w/ force but you wouldn't be going very far on it. I documented it once on mtbr. IIRC, like 0.6mm thicker than an Avid rotor. Once the pads wore some it would be fine, but new pads + thicker rotor = no fit. Clearance is that tight on a new setup.

A couple of days ago I swapped Hope brakes for Avid Juicy 7's between two bikes of mine. The Avid rotors are .1in narrower than my Hope rotors. I tried to save the hassle of swapping rotors and was getting drag with the Hope rotors paired with the Avid calipers. I swapped the rotors to match manufacturers and all is well now.

ps. I am sooooooo much happier with the Avid Juicy 7's over the Hopes on my Moment.

[rciracing]

Let some fluid out of the system and the pads will retract further.

Letting fluid out? Won't that be replaced by air in the line which will cause trouble?

[tuba_transport]

Letting fluid out? Won't that be replaced by air in the line which will cause trouble?

No. It will allow the pistons to retract a bit more. I have had to do this before also and it works fine. I just leveled my fluid reservoir and loosened the cap screws. I little bit of fluid leaked out because it was overfilled and had expanded so was under pressure. Then I wiped it off and tightened the cap screws back up. Pistons retracted better and all was well.

[jabberwocky]

Letting fluid out? Won't that be replaced by air in the line which will cause trouble?Not if done correctly. All hydraulic systems have a variable volume of fluid (which is how they self adjust for pad wear). If the pads wont retract far enough to allow a rotor between them, there is probably too much fluid in the system. I would open the bleed port on the caliper and gently push the pads a little further into the caliper with a screwdriver (fluid will come out of the open bleed port when you do this). Then cap the caliper bleed port.

If you are careful, you shouldn't even need to bleed the brakes. Mount it up with the thicker rotor and pump the lever several times and it should work.

[stanley02]

I guess my real question is if I have 160mm in the rear now, do I need to replace that with a new 160mm or can I use a different sizer such as 180mm?
The main reason I need to replace them is I bought a new set of rims and had to replace the rotors, because the old rotor where the Coda 4 bolt and the new rims are the 6 bolt. The new rotors where rubbing the brake pad and I had to add a few spacers in the back to stop it from rubbing. While making the adjustment I noticed the threads on the caliper started the strip out not allowing me to tighten the caliper to the frame. Braking sometimes is a good thing.:D

[stanley02]

I can't help you with your brake question, but do you get hasseled for being named Paul Stanley? Or does Stanley02 have nothing to do with your name?

Yes, it always made for a good Halloween costume while growing up.

[DKEG]

I guess my real question is if I have 160mm in the rear now, do I need to replace that with a new 160mm or can I use a different sizer such as 180mm?

If you put a 180mm on, then you need an adapter for the caliper to space it out further from the frame.

[jabberwocky]

I guess my real question is if I have 160mm in the rear now, do I need to replace that with a new 160mm or can I use a different sizer such as 180mm?It depends on the brake, but all brakes will require at least a new adapter. Avid Juicys, for example, all use the same caliper-lever assembly but have different mounting brackets for different rotor sizes. So you can upgrade a 160mm brake to a 180mm brake by buying a new mounting bracket and rotor. Some brakes (mostly older ones) have no bracket, the different sizes used different calipers. Those would be harder to upgrade.

If you are buying a new brake entirely it won't matter. The new brake should come with a new rotor and mounting hardware for its size.

[TiRyder]

I guess my real question is if I have 160mm in the rear now, do I need to replace that with a new 160mm or can I use a different sizer such as 180mm?
The main reason I need to replace them is I bought a new set of rims and had to replace the rotors, because the old rotor where the Coda 4 bolt and the new rims are the 6 bolt. The new rotors where rubbing the brake pad and I had to add a few spacers in the back to stop it from rubbing. While making the adjustment I noticed the threads on the caliper started the strip out not allowing me to tighten the caliper to the frame. Braking sometimes is a good thing.:D

You can use a 180 rotor on the back, but will need to either order a 180 specific caliper or th manufacturers adapter.Are these for DH or XC?

What type of riding do you do? and what are your goals with the upgrade? I have a nearly new set of Magura Marta SL's I was going to list on ebay soon. They are red, but I dont have rotors for them. As you already have the rotors, this might be a match made in heaven.

Linky: http://magura.com/english/frameset/frameset.html

[tuba_transport]

I guess my real question is if I have 160mm in the rear now, do I need to replace that with a new 160mm or can I use a different sizer such as 180mm?

2 things

160mm rotor rear brake is most likely more brake than you need. The front brake is where the vast majority of the braking power comes from.

Most frames are designed to accept up to 160mm rear rotors. Might want to check with Cannondale or whoever the manufacturer is before you buy the adapter and new 180mm rotor.