Quantcast

Frankenbrakes and brake improvement discussion

canadmos

Cake Tease
May 29, 2011
20,774
19,848
Canaderp
When was the last time you bled the brakes? I haven't noticed any big changes in lever throw on mine, with new pads vs worn down ones.
 

Andeh

Customer Title
Mar 3, 2020
1,053
1,024
Hard to keep track, TBH. I'd guess I do it every 6-9 months or so? I know I just replaced pistons on one bike relatively recently (like a month ago) and bled front & rear on that bike at the same time. I usually bleed DOT brakes when they start feeling kinda spongy at the bite point.
 

Gary

"S" is for "neo-luddite"
Aug 27, 2002
7,790
5,702
UK
So what's the actual cause of the excessively stiff lever action?
 

Andeh

Customer Title
Mar 3, 2020
1,053
1,024
Anyone interested in measuring lever force on various brakes like Dale Stone did in his video? I'm planning on checking what it is on my Dominions to satisfy my curiosity. It'd be interesting to get some numbers on MT7s, Saints, TRP DHR Evos, Hope Tech 4s, Code RSCs for comparison. I don't own MT7s or Codes anymore, but I know their force felt like a LOT more than the Dominions. Shimano has always felt light-ish to me, and have never got a chance to try Hopes or TRPs.
 

Westy

the teste
Nov 22, 2002
54,629
20,444
Sleazattle
So what's the actual cause of the excessively stiff lever action?
I would assume it is the return spring. Makes sense that large pistons could have more friction and volume that could require a stronger spring to make the brakes responsive.

Or perhaps they don't want to repeat their parking brake functionality from a few years back.
 
Last edited:

Sandwich

Pig my fish!
Staff member
May 23, 2002
21,158
6,124
borcester rhymes
Anyone interested in measuring lever force on various brakes like Dale Stone did in his video? I'm planning on checking what it is on my Dominions to satisfy my curiosity. It'd be interesting to get some numbers on MT7s, Saints, TRP DHR Evos, Hope Tech 4s, Code RSCs for comparison. I don't own MT7s or Codes anymore, but I know their force felt like a LOT more than the Dominions. Shimano has always felt light-ish to me, and have never got a chance to try Hopes or TRPs.
I can participate with an MT5 2 finger lever setup. I have an accurate scale at work that should be able to measure such a weight. I can confirm with XTs and the tektros on my commuters to give a comparison if that's helpful.

I would assume it is the return spring. Makes sense that large pistons could have more friction and volume that could require a stronger spring to make the brakes responsive.

Or perhaps they don't want to repeat their parking brake functionality from a few years back.
because it's SRAM, and the customer is the beta tester. In two years, they will fix it, not tell anybody, and act strangely when anybody asks why they changed it but didn't say anything.

I love that the dude showed the low compatibility brake pad and brake lever- up yours, customer!
 

Andeh

Customer Title
Mar 3, 2020
1,053
1,024
I can participate with an MT5 2 finger lever setup. I have an accurate scale at work that should be able to measure such a weight. I can confirm with XTs and the tektros on my commuters to give a comparison if that's helpful.
So trying to do the test myself, there's a lot to it that I can see variability. I set it up, started adding water to the hanging bottle, looking at immediately noticed that (of course) my caliper wasn't 100% centered perfectly over the rotor, so one pad contacts before the other.

Anyways, it took 315-360g (depending on slight variations of my rotor true-ness) of weight to get one pad to just barely touch the rotor. By 590g of weight, the rear wheel would no longer spin in the stand. I'm sure at that point actually riding the wheel would still spin, but you're definitely into the engagement zone by that point.
 

canadmos

Cake Tease
May 29, 2011
20,774
19,848
Canaderp
The Sram Level brakes that came on my new bike work, but the levers absolutely suck.

For one, it feels like I have to pull the levers an inch before the brake pads do anything.

Second, the ergonomics of them forces me to run them quite far in and away from the grips - for my index finger to rest on them where I like. But when the levers are pulled in, they feel like they "grow" way too long.
 

Nick

My name is Nick
Sep 21, 2001
24,150
14,866
where the trails are
So I did a thing ... Radic KAHA brakes.
View attachment 205657

I'm going to run these with my existing 203mm / 2.3 TRP rotors.

Initial thoughts:
machining quality is excellent​
lever feel is smooth, throw has to be only a few mm with bleed block installed​
lever shape feels good, no sharp edges that I can feel, initially reminds of Formula levers​
LIGHT, will weigh with pads but yea, light​
Snow and mud around here but will get them mounted up and tested as soon as I can.
Trail ride yesterday with some speed. These are incredible. Pads are bedded in and levers/bite adjusted to taste. Just an immense amount of power and easy controlled with a great feeling lever. It would be nice if the lever reach was tool-less but whatever. Very impressed so far!
 

Sandwich

Pig my fish!
Staff member
May 23, 2002
21,158
6,124
borcester rhymes
Question, are people still combining brake pad formulas? I need a little more power out of my MT5s and I have race flavor pads in the bin. I set them up with performance/race pad combinations just for fun as hopefully a little more power but still quiet. I remember people used to do this with shimanos to keep them quiet.
 

lobbster

Chimp
Apr 14, 2024
1
5
I've signed up to the forum just to add to this discussion.

I havent found anyone that has actually tested this combo even though there is a lot of talk.

Shimano m785 lever with julie caliper (low pressure 28mm piston diameter version). I used a shimano bh90 hose with all shimano stuff at the lever end and then a hope m6 banjo bolt with the hope crush washers on the caliper to replace the original barbed fitting.

It's not quite the monster I expected. The bite point is similar to the original m785 brakes due to very little piston retraction in the caliper. However the lever feel is more soft than I would like. Its usable and has lots of power but the main issue is you hit the bars before you can really ramp it up. With the shimano brake, you have a very firm bite point and can modulate power with finger pressure. This julie caliper works more like a sram brake where you modulate the power with lever throw rather than pressure.

Pads could definitely do with more bedding in to get full power but I believe this is too far past optimum for caliper piston area and therefore lever spongeyness. I have also tried an mt7 caliper with this lever and find that's about the limit of piston area that I like the feel of. I honestly prefer the completely standard m785 2 piston with sintered ice tech pads over any other combination of brake ive ever tried
 

Attachments

Boozzz

Chimp
Sep 12, 2019
81
85
Amsterdayummm
So, anyone guinea pigged these yet? Br4ve MTB brakes (ride-beringer.com) Seem cheap enough for only € 999. Dual bearings on the lever, anodised MC piston, funky proprietary pad design, DOT fluid, 285 grams.

No real tech info besides fancy colours on their site, so contacted them for some info in the spirit of the spreadsheet:
  • Mechanical leverage is quite linear, at 7.5.
  • Hydraulic leverage 6.2 (or if I do some free interpreting of the exploded view doc on their site, 6.29 actually, with 2 x 18 mm caliper pistons and 10.15 mm MC piston diameter).
  • Makes for roughly 46.5 total leverage, second only to the Maxima.
They're saying they'll come out with a more progressive cam and lever this year too.

 

Nick

My name is Nick
Sep 21, 2001
24,150
14,866
where the trails are
Trail ride yesterday with some speed. These are incredible. Pads are bedded in and levers/bite adjusted to taste. Just an immense amount of power and easy controlled with a great feeling lever. It would be nice if the lever reach was tool-less but whatever. Very impressed so far!
back on the Radic topic.
Another ride and moar adjusting. These can be set up to be very on/off, or offer tons of modulation. I'm settling in on what I prefer for where I ride. Last descent I had them quite on/off and can see how I quickly that could go bad. Again, just gobs and gobs of stopping power, but now tweaked to right where I want them.

Still a big fan.
 

rideit

Bob the Builder
Aug 24, 2004
23,477
11,641
In the cleavage of the Tetons
This is almost MTBR worthy, but have any of you had real success baking off/torching off mildly contaminated brake pads?
I certainly have tried it over the years, but I never really felt like it was worth the time.
 

jonKranked

Detective Dookie
Nov 10, 2005
86,235
24,737
media blackout
This is almost MTBR worthy, but have any of you had real success baking off/torching off mildly contaminated brake pads?
I certainly have tried it over the years, but I never really felt like it was worth the time.
i've had better luck with sandpaper, but it's really just a temporary fix.
 

Jm_

sled dog's bollocks
Jan 14, 2002
19,095
9,755
AK
This is almost MTBR worthy, but have any of you had real success baking off/torching off mildly contaminated brake pads?
I certainly have tried it over the years, but I never really felt like it was worth the time.
I just throw em in the oven at 400F for 15-20 min, that will evaporate any oil. Be sure to clean the rotors too. It's a permanent fix, until I get more oil on em, such as Shimano brakes that weep when stored. I just bled my XC brakes yesterday and out riding, yep they are weak due to contamination. Not so much that I have to burn it off, mainly because I was riding said bike about 3 weeks ago and it hasn't had enough time to get bad again.

The sandpaper idea is...strange, that won't remove oil.
 

toodles

ridiculously corgi proportioned
Aug 24, 2004
5,578
4,865
Australia

Happymtb.fr

Turbo Monkey
Feb 9, 2016
1,930
1,288
SWE
Those Sinter green pads look like a solid improvement over stock hey. I've never heard of them before.
Enduro-mtb used Sinter's lab to test the brakes. They are new to me too.

Why don't you give their green pads a try and tell us more about them! :brows: Sinter mentions the softness of the compound and skips mentioning long pad life...
 

canadmos

Cake Tease
May 29, 2011
20,774
19,848
Canaderp
Has anyone with Hayes Dominions swapped out the lever clamp bolts with something else?

Those bolts seem to be very poorly made and are quite the eye sore, compared to the rest.
 

troy

Turbo Monkey
Dec 3, 2008
1,018
759
do tell more
They feel super fine in the parking lot. Silky smooth, tons of adjustability, very functional pad contact adjustment, easy to feel the bite point. Once I get some speed, i have no fuckin idea if I am already breaking, dragging the brakes or what the fuck is going on between the pads and the rotor. I have no clue if I have any more power left, or is it all they've got. Tried different pads and rotors, bleed them to death with every fuckin technique I know and bee_kay77's tips. On the bike stand, they are the best fuckin brakes I know. On the trail they felt like crap to me. Or maybe I'm way to used to shimano brutal bite point, and modulating with my fingers...

I wanna try mixing those levers with shimano calipers or maguras, or lewis calipers with shimano levers. Still g2 try shiguras.
 

Happymtb.fr

Turbo Monkey
Feb 9, 2016
1,930
1,288
SWE
I need some advice.
I just rebuild my Dominion levers, the stroke was really long and I also experienced wandering bite point where the stroke could suddenly get shorter on the front brake.
I wonder what kind kind of grease or oil you would use on the ball joint and on the pivot marked on the picture below. I saw some wear marks on both places.
Screenshot_20240509_230551_Samsung Notes.jpg
 
Last edited:

Andeh

Customer Title
Mar 3, 2020
1,053
1,024
I used SRAM DOT grease on the piston seals when 1 lever got sticky. The left blue circle area is outside of the actual hydraulic system, so I'd guess clean it well then use a light oil.