Shigura brakes

[Gunder]

Todays project is the Shigura brake conversion.

Since the master cylinder seal went out on my Magura's and replacement parts are a month out, I ordered a set of Shimano XTR levers to replace them with. Plus the Magura levers being made out of plastic, are in my mind the weakest link in that brake system. Not to mention I'm not the biggest fan of how there lever blades feel, but after 800 miles I did get used to them.

This consists of pairing Shimano levers with Magura calipers. The premise here is that the Shimano (4 piston compatible levers) have a longer but smaller diameter master cylinder bore than the Magura levers. This compared with the very large Magura 4 caliper pistons creates a much more favorable hydraulic ratio. In short, it theoretically gives you more power. I this case I am using the new XTR BL-M9120 Levers. In reality any of the XX2X or XX1X series of levers from Shimano will work as they are all 4 piston capable.

Everything on the Magura Caliper end stays the same.



You must use the Shimano hose barbs and olives. L to R is Magura, Sram and Shimano. The Magura barb has the longest head of the 3, Shimano has the thinest. Plus Shimano olives are a full MM shorter than the Sram and Magura offerings. In a pinch you could probably get by with mixing up the Magura / Sram olives (just dont cross contaminate those fluids), but Shimano needs its only barbs and Olives.



Here is a selection of various hose nuts, L to R matura native, Magura that goes into their lever banjo swivel, Shimano external thread, and Sram. The Magrua, Sram and Shimano internal style all use the same threads and are roughly the same length. These are interchangeabe.



These new Shimano levers are I-spec EV so they are close enough of a fit, you can use them with the Sram matchmaker system, no adapter needed. Thats a Sram match maker nut in the Shimano stock lever mount.



With the proper barb and olive on the hose, the brake line gets torqued to 6NM. I then bled the system, using a syringe at the caliper and a Shimano funnel at the lever, I pushed all new fluid threw the system. Pulled suction with lever, then pushed through and repeated a few times. Closed off the caliper bleed port, and then finished bleeding the lever with the funnel.



To compare the two systems, I left the stock Magura system on the font and went for a ride.

All I can say is WOW, the Shigura system has a stupid amount of power over the stock Magura. The stock Maura's never made me wish for more power, as they where plenty strong enough to stop the E-bike on even the steepest terrain here in Bellingham. However the Shigura setup blows it out of the water. The rear brake is now so strong, it makes the Magura front feel like its useless. The rear Shigura system is so strong, it will full stop the bike on its own, and make you want to catapult over the front. So you need to get comfortable with its power. For reference with the E-bike in trail mode, you can still pedal (with a bunch of resistance) against the stock Magura front brake. You can not pedal against the Shigura rear brake.

The modulation feels great. However, the Shigura setup, has that same vague bite point partway not the lever travel that all Shimano's are known for. I've ridden enough Shimano systems, I am used to it. I do prefer the very firm bite point of the Codes tho, but this system is way stronger than the stock codes, stock Magura,s or even the stock Saints. I will be converting the front next.

[frorider]

Followed this concept on ridemonkey yrs back but never had a need to build ‘em. Thx for the pics and info.

[Andeh]

"These new Shimano levers are I-spec EV so they are close enough of a fit, you can use them with the Sram matchmaker system, no adapter needed. Thats a Sram match maker nut in the Shimano stock lever mount."

That's fascinating, never would have thought to try that. I'm happy with my Hayes, but passed that tidbit along to a friend who runs XTR brakes with SRAM shifting. He's tried a few aftermarket adapters and not liked them.

[XXX-er]

I wonder what shimano levers do to the magura piston assmeblies ?

Obviously facking with some kind of leverage/ design parameter in a so far seemingly good way

do keep us apprised as to what happens good or bad

[Gunder]

"These new Shimano levers are I-spec EV so they are close enough of a fit, you can use them with the Sram matchmaker system, no adapter needed. Thats a Sram match maker nut in the Shimano stock lever mount."

That's fascinating, never would have thought to try that. I'm happy with my Hayes, but passed that tidbit along to a friend who runs XTR brakes with SRAM shifting. He's tried a few aftermarket adapters and not liked them.

They are not a perfect fit, but close enough to not need to spend $30 on an aftermarket adapter.

Here is a backlit shot to highlight the differences, you can see a slight difference in the radius of the Shimano clamp and the Sram matchmaker. Taking a file to the matchmaker portion would make quick work of making it perfect. I'll probably measure both an then machine the match maker to be a perfect fit at some point.

I wonder what shimano levers do to the magura piston assmeblies ?

Obviously facking with some kind of leverage/ design parameter in a so far seemingly good way

do keep us apprised as to what happens good or bad

There is nothing to mess with on the Magura calipers, they are cast as a one piece housing. It's just the 4 cylinder pistons and there seals. Since both systems are mineral oil, no issues. I've put 20 miles on them this evening, and I am extremely happy. It worked way better than I had expected.

[John_B]

Hey Gunder aren't you supposed to use crows foot style wrenchs at 90 degrees to the handle of the torque wrench? Otherwise that turns your torque values a little funky.


I'm just desperately trying to validate my lack of expertise by talking shit when I can. That's an awesome brake mode and it sounds like it's working quite well!

[Gunder]

Hey Gunder aren't you supposed to use crows foot style wrenchs at 90 degrees to the handle of the torque wrench? Otherwise that turns your torque values a little funky.

Technically yes you are, but I this situation it doesn't make a signifiant difference.

T1 X (L/L+C) = Torque wrench setting.

T1 is torque spec for the fastener.
L is length of torque wrench from center of head to center of handle.
C is the distance from center of fastener to center of torque wrench head.

So in this case, setting the wrench for 6NM creates an actual value closer to 5.76NM. The torque spec for the compression nut is 5~7NM so well within the range. Thats what 4% ?

It becomes more critical as you start to use larger crowfeet in relation to the length of the torque wrench.

The kicker here is the ANSI standard for torque wrenches is 4% error. All of my Snapon / CDI ones where in the .5~1.5% range. Park for example specs there at 4% Wera specs theres at 3%. Remember too, I'm order to maintain that, you need to always store them fully backed off as well.

Back to this case. With these brake compression nuts all you are actually doing is slightly crushing / deforming the olive to create a seal. That’s why you should never reuse the olives on brake lines or any compression fitting. The barb and nuts are generally fine to reuse if needed.

[XXX-er]

There is nothing to mess with on the Magura calipers, they are cast as a one piece housing. It's just the 4 cylinder pistons and there seals. Since both systems are mineral oil, no issues. I've put 20 miles on them this evening, and I am extremely happy. It worked way better than I had expected.

what i mean is something in the fluid dynamics obviously got altered, size of piston in the lever ? Whatever was altered glad its working well

[stuckathuntermtn]

Thread hijak: does which fluid you use matter? Magura/Shimano/something better?
My Maguras seem good with Royal Blood.
My SLX single pots are old. From the gen that is hard to get to hold a good bleed. Old enough that could probably use a full purge (maybe next year). Bike shop next door is now gonna be some gravel racing boutique dealio. Not sure what kind of support to expect from them. Maybe I'll be pleasantly surprised.

[Gunder]

Thread hijak: does which fluid you use matter? Magura/Shimano/something better?
My Maguras seem good with Royal Blood.
My SLX single pots are old. From the gen that is hard to get to hold a good bleed. Old enough that could probably use a full purge (maybe next year). Bike shop next door is now gonna be some gravel racing boutique dealio. Not sure what kind of support to expect from them. Maybe I'll be pleasantly surprised.

I just use the Shimano fluid in all brakes that use mineral oil. The color / brand does not matter. SLX brakes are generally quite good. If you are having trouble getting a good bleed first thing I’d do is replace the o-rings for the bleed ports and on your bleed devices. That usually fixes it 99% of the time unless you have a major leak some place.

[NuMexJoe]

Thread hijak: does which fluid you use matter? Magura/Shimano/something better?
My Maguras seem good with Royal Blood.
My SLX single pots are old. From the gen that is hard to get to hold a good bleed. Old enough that could probably use a full purge (maybe next year). Bike shop next door is now gonna be some gravel racing boutique dealio. Not sure what kind of support to expect from them. Maybe I'll be pleasantly surprised.

Stuckie, I've been using Febi Bilstein 6162 fluid in Shimano and Magura brakes for several years now with no ill effects. Much cheaper than what either manufacturer would like you to buy.

Gunder, thanks for the pics! Been reading about Shiguras for a while now, but it still doesn't solve the limited pad rollback on my MT7s, which is why they're on my DH bike now where I don't hear them singing.

[XXX-er]

It might have been the cold but I've heard of drug store mineral oil giving slow lever return on shimano's from back in the day like 20+ yrs ago

[mntlion]

It might have been the cold but I've heard of drug store mineral oil giving slow lever return on shimano's from back in the day like 20+ yrs ago

if its the light min oil, seems to be fine. At least to banff "summer" temps

[XXX-er]

if its the light min oil, seems to be fine. At least to banff "summer" temps

It's just one anecdote/ data point from back in the day out of an xc ski & bike shop in PG, the mineral oil was from london drugs

[Gunder]

Stuckie, I've been using Febi Bilstein 6162 fluid in Shimano and Magura brakes for several years now with no ill effects. Much cheaper than what either manufacturer would like you to buy.

Gunder, thanks for the pics! Been reading about Shiguras for a while now, but it still doesn't solve the limited pad rollback on my MT7s, which is why they're on my DH bike now where I don't hear them singing.

I got a large shop sized jug of the Shimano stuff that I've had for years. Its damn near a lifetime supply!

I've been contemplating, putting a pad screw into the caliper and putting a spring on it between the pads. Seems to me that the lack of a spring and relying solely on magnets, is causing the pads to drag a bit.

[stuckathuntermtn]

I have MT7s but I'm pretty sure I don't have pad drag. You ever lube the pistons? Supposedly that helps.
Can I mix blue Magura and red Shimano fluid so I can make it purple drank? Kidding. Kinda. Like, if I bleed with 1 and the other is in there, will they mix or will they separate like oil and, um, a different density of oil?

[Andeh]

Yes, several times. I've also found for whatever reason, Maguras seem to be more susceptible to sticky pistons, in the same conditons.

[Dee Hubbs]

I have MT7s but I'm pretty sure I don't have pad drag. You ever lube the pistons? Supposedly that helps.
Can I mix blue Magura and red Shimano fluid so I can make it purple drank? Kidding. Kinda. Like, if I bleed with 1 and the other is in there, will they mix or will they separate like oil and, um, a different density of oil?

Some Pro mechanics use both fluids, this way they know all the old Red is completely bleed out, and once Blue starts flowing they know it's been complete refreshed. Then vice versa on the next bleed.

[toast2266]

Maybe I'm way off base here, but this seems like it combines all of the annoying finicky rubbiness of the magura caliper with the annoying wandering bite point and necessity of frequent bleeding of the shimano levers.

[Gunder]

Maybe I'm way off base here, but this seems like it combines all of the annoying finicky rubbiness of the magura caliper with the annoying wandering bite point and necessity of frequent bleeding of the shimano levers.

I've got 100 miles or so on them now, and so far no complaints. I did however do a second bleed after the first ride and the bite point is damn near instantaneous. As good or better than any code's I've run and these are hands down the strongest brakes I've used now. In fact the stopping power is so strong, I dont think I'd put them on anything but an Ebike.

[stuckathuntermtn]

Of course as soon as I say something, I get pad drag. Might just be dirty/warped rotors. They are Centerlines. Not as good with heat as RT86.