Far as I know my cakes will play nice with XT or XTR calipers.
Yeah, I think around the time @Andrew_Squirrel was throwing the Hope calipers aside there was lengthy discussion about mtb calipers and road compatibility.
AFAIK every 2-pot Shimano caliper, ever, has used 22mm diameter pistons.
So take your brand new road bike with flat-mount calipers and flatbar convert it with some ancient open-reservoir XTR BL-M975 levers out of your parts bin. Use some old native-IS-mount BR-M965 calipers with your Di2 ST-9070 levers. As long as you can make the hydraulic lines mate up, it’s gonna work just fine. Go nuts.
I’m currently using M8000 calipers with R8000 shakes. Works great.
The four-piston calipers are a different beast. IIRC roughly 17% more piston area than on the 2-piston calipers , so it’ll definitely be different/weird if you tried to use them with road levers. You’d end up with significantly more lever motion but less finger force to achieve the same level of braking.
Hoses for Saint have a different volume. Don’t recall hearing of lever incompatibility.
…hose volume? Shouldn’t matter in a hydraulic system, as long as it’s big enough to push the (very small amount) of fluid through. The only thing that matters is the ratio of master cylinder area to slave cylinder area. That’s the mechanical advantage of the system, so if you swap a caliper for another caliper with the same piston area, it’s going to behave exactly the same.
FWIW: just checked the Shimano tech docs and M820 (Saint) uses the same BH90-series hose as M7000/M8000/M9000/M9100/R7000/R8000/R9000 brakes do.
Also just looked up the M8000/M8020 caliper deets - M8000 is indeed two 22mm pistons, just like all the rest of the Shimano 2-piston calipers - so 760mm^2 of piston area. The M8020 calipers have two 15mm pistons and two 17mm pistons: 807mm^2 of piston area, or ~6% more area. And the M8000 group uses the same levers for both the 2-pot and 4-pot brakes… hmmmm. Might work with road levers too.
Saint/Zee are 16mm and 18mm pistons = 911mm^2 of piston area, so yeah, ~18% more area than the Shimano standard 2-pot caliper. IIRC the Saint/Zee levers might have a larger master cylinder as well?
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Ah, So the new 4-pot XTs are slightly smaller. Makes sense. A bit more braking for trail/enduro, but not full on dh-power.
Some of the santa cruz dh riders use xtr levers and saint calipers (at least Loris Vergier does; Luca Shaw seems to just go full saint).
His brakes are setup moto-style, and check out the XTR / Saint combo; the straight Saint setup is too on/off for Loris’ liking, Roche explained.
Looks like the new 1x12 XTR’s 4-pot calipers are also 15/17, although there’s also two sets of levers and Shimano claims the XC and enduro levers/calipers aren’t cross compatible. (probably bullshit)
Yeah I’ve heard of people who mix XTR levers and Saint calipers - I think the setup is to take the non servo-wave, extra-light XC XTR levers? I don’t know what the difference is between the XTR and Saint master cylinder size is (if any), so I’m not quite sure what the effect would be.
Well, Shimano changed the volume of the channel inside the hoses for some reason.
The 685/785 level stuff used a BH59. When I was looking into the difference between BH59 and BH90 it seemed like bigger calipers used the 90, but now that I think about it I think I was looking at new Saint vs my old 685 levers. And I think the 90 is actually narrower inside.
PS while I’m talking about that I have to say I don’t like the way the 90 hose feels and prefer the modulation of the 59. If some people I know are any indication Shimano made the hose change because roadies were bitching that their brakes felt soft.
I know that to upgrade to the 4-pot xt, you needed new/different hoses, too.
Wasn’t sure if connection was different or they they changed said hose. For most people at that point, you just buy the complete brakeset and sell your old one.
Pretty sure hose volume on saint has something to due with helping prevent brake fade from hot brake fluid, since it would take longer to heat up the higher volume of fluid… No idea for real, but it makes sense in my brain.
Hooray unfathomable Shimano.
I’ve never measured the ID of the hoses, but it wouldn’t surprise me if the BH90 was smaller than BH59 inside. The main point of BH90 is it flexes/expands less under pressure, leading to a firmer brake lever.
They’re both BH90 series hose. They use a different banjo bolt, and the banjo itself is a little different for some reason only known to Shimano engineers. But note that the O-rings to seal the bolt to the banjo are the same P/N on both, so I suspect that the hoses themselves are interchangeable; it’s only the bolt that matters.
This would be plausible _if_Saint actually had a larger diameter hose.
yeah I hate this so much
I hate this so much.
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Putting this here:
Alt handlebar comparison tool
http://cmartens.ca/projects/bar-charts/v2/
I added it to the fredsheet along with all the calculator tools I keep forgetting the names of.
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That’s awesome. Needs origin8 spacebar.