They use Hope pads, though you might need to do a tiny bit of dremeling.
Seems like the barb/olive interface is reusable.
in one of the vids he was putting ends on the cable - looked very easy, maybe tool free. I want to go back and look closer
that other video lied
this video shows the thing but I canāt see that they sell the parts
Hmm I thought that the $300 brake was the same as the $500 brake aside from titanium bits and an extra adjust. But the $300 also has one smaller piston per caliper, like Codes and other brakes do. and slightly smaller brake pads (Hope E4 vs V4 for the big brake). Iām wondering how big the difference is in reality.
big
Iāve gone off the deep end now but looking at piston and pad size is finally making brakes make sense to me. Iāve read a lot of qualitative reviews and seen performance testing that seems largely meaningless (some Germans measuring decel tests from 30-15 or 30-0 km/h where all the results are within 1.5 secondsālike who cares).
But goddamn, pad and piston size correlates to the above vibes really well:
| Brake | Pistons mm2 | Pad mm2 | Brake fluid | Master Cylinder mm2 |
|---|---|---|---|---|
| Code | 762 | 1168.5 | DOT | ??? |
| Lewis LH4 | 756 | 1073 | Mineral Oil | ??? |
| Hope 4 V4 | 908 | 1020 | DOT | ??? |
| Hope 4 E4 | 804 | 1073 | DOT | ??? |
| Hayes Dominion | 908 | 1330.56 | DOT | ??? |
| Lewis LHT | 908 | 1020 | Mineral Oil | ??? |
| Magura MT7 | 908 | 1121 | Mineral Oil | ??? |
| XTR 9120 | 908 | 920 | Mineral Oil | ??? |
| SLX 7120 | 808 | 920 | Mineral Oil | ??? |
| Saint M820 | 808 | 920 | Mineral Oil | ??? |
Got to find and add master cylinder size and perhaps DOT vs mineral and Iām getting somewhere lol. (edit: added some more)
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I think youād ideally want āfluid volume moved per lever throwā
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Yeah Iāve seen some folks touch on something similar for specific brake sets as it is obviously what the system does lol. I think the ratio of master cylinder volume to slave cylinder volume is the key stat. Liquid leverage brooooo.
I was just surprised that the piston and pad numbers alone corroborated the qualitative stuff Iāve read and some of the testing people have done on these brakes.
One stat of note is 454 mm2 for several of these brakes, though they use different sized piston combos to get to this number. Very out of context but seems like a sweet spot of sorts to me.
Honestly looking at these numbers makes me want to just get XTRs, and theyāre on sale at a few places right now. The promise that the Lewis brakes hold is that bleeding them sounds easy, the olive/barb mechanism seems good and novel, and the TAF looks. But Iād probably opt for the bigger ones because I kinda donāt want a lateral move off Codes if Iām going to spend a bunch of money.
How do the OG Saints stack up with the others?
What model number are those? Edit: M820 look to be identical to SLX.
after I get the rear XTR M9120 caliper off my bike and swapped for TRP Slate, Iām gonna replace the shimano ceramic pistons with phenolic and reuse them on a different build
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This and lever travel to master cylinder travel
What piston sizes are you seeing for the XTR M9120? wasnāt aware they were any different than any of the other Shimano 4-pot calipers (15/17mm pistons)
I think you are correct. No idea where I got my numbers. I think the first thing that I saw was like an alibaba site with replacement pistons lol.
Also please be comparing XTR to the TRP for me! Why are you switching?
ok third post in a row sorry but lolling that (I read but havenāt been able to corroborate that) the Trickstuff guy did my chart but way better* (and Lewis stole it and put it on their site):
https://www.lewisbike.lastregabike.de/assets/files/Brake-DatabaseLaStrega.xlsx
Which looks like it provides exactly the info Fred described above (a relationship between fluid moved and lever throwāmaster cylinder area is all pretty close). I think I get the whole system now.
*I only now realized that I was only counting the area for a pair of pistons and not 4 per caliper 
edit: even bigger spreadsheet:
didnāt trickstuff used to have all sorts of stuff thtat wasnāt brakes?
the front XTR caliper had the ceramic pistons crack, in a way that would completely foul the rotor with oil but only when you got it real hot
I finally figured it out on the Xanadu trail which made the long rock roll there incredibly inconvenient https://youtu.be/ELZSyeyfNrU?si=uTt3lKqagjImaUHK&t=590
I switched it ātemporarilyā for an older M780 single piston that fit
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Haha that looks like a terrible place to have bad brakes. I had to come off my little mountain here with a bad front brake in May. I was using hillsides and banks as a way to stop at times. Eventually got to some steep rolls that were impossible and had to do the awkward climb down.
Anyway, my brake obsession is currently pointing me at formula cura 4 with the adjustable levers.