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Frankenbrakes and brake improvement discussion

mykel

closer to Periwinkle
Apr 19, 2013
5,067
3,778
sw ontario canada
kidwoo bent his

And then put shimano levers on anyway.

After they've done a few sketchy pump ups I'll probably put the formula levers back on. It's snowing like a bitch right now so I don't give a flying fuck about bikes at the moment.
How did you bend them? Vice and hammer or something a bit more elegant?
 

Udi

RM Chief Ornithologist
Mar 14, 2005
4,915
1,200
Has anyone tried an alternative lever with them? Modified the existing lever blade?
There's a little trick I used on the T1 previously to get the initial reach setting closer - I drilled out the first 1/3 or so of the threads in the cam so that the threaded adjuster can travel deeper into the cam and increase the range of adjustment. Obviously a stopper spacer on the drill is wise, and you need to be careful to not remove too many threads otherwise it won't support full axial load. If you have lathe access you could do an even neater job by removing material from the threaded rod rather than the cam itself.

This is a much neater way of doing things than bending the lever blades. They're usually forged and thus expensive parts, I'm not on board with bending them. The cam on the other hand can usually be purchased as a separate (cheap) part from Formula, if there were a desire to be able to return the brake to stock. Rod may be a similar case.

I haven't tried this on the Cura4 but I'd look into it before bending levers on a new brake.

That is what I'm worrying about with the Cura4.
I run my levers very close to the bar, like full engagement / lockup just off or barely touching the grip.
I'd test an set of actual Cura4 before making this judgement - not saying you're wrong - but the C4 inherently has longer throw than the regular Cura (if that's what you're judging on), and the minimum reach setting isn't as bad as the old style RO (pre-Racing) for example.

I think given you're happy with them, another set of T3V4 (provided they are within budget) is a good choice too though. Did you not find a solution to the larger rotor issue? I have a Hope 225 here, I think it's quite nice.

I can get Hope / Hayes / Formula / Magura for about 450 Cdn, DRT's - over a G note. The difference pays for my Avy tuning or plastic cranks or Onyx hubs, etc.... Being medically retired, I just don't have it.
You can't fund the brakes which are a safety concern, but you can instead fund a whole bunch of other stuff you don't need? :)
 

jstuhlman

bagpipe wanker
Dec 3, 2009
16,622
12,912
Cackalacka du Nord
my curas were a safety concern for a while after switching from xt. i was used to grabbing hard since the xt’s have little modulation-now with power distributed more evenly across the pull i’ve almost otb’d or skidded out coming into corners a few times trying to grab like i used to with the xts! :D
 

shmity

Chimp
Oct 6, 2004
41
5
There's a little trick I used on the T1 previously to get the initial reach setting closer - I drilled out the first 1/3 or so of the threads in the cam so that the threaded adjuster can travel deeper into the cam and increase the range of adjustment. Obviously a stopper spacer on the drill is wise, and you need to be careful to not remove too many threads otherwise it won't support full axial load. If you have lathe access you could do an even neater job by removing material from the threaded rod rather than the cam itself.

This is a much neater way of doing things than bending the lever blades. They're usually forged and thus expensive parts, I'm not on board with bending them. The cam on the other hand can usually be purchased as a separate (cheap) part from Formula, if there were a desire to be able to return the brake to stock. Rod may be a similar case.

I haven't tried this on the Cura4 but I'd look into it before bending levers on a new brake.
Modifying the cam is an option for sure, im not sure how much material ill have to remove to get them to where i want them though. I've already ordered two new lever blades to play with so Ill start there and work back, cost on the cam kit (which has vs the levers is identical at 24 aud each (nearly half the price of a pair of brake pads WTF?!)

There is a chance ill go full retard and get some levers cnc'd if i can twist the arm of one of my work suppliers enough
 

KAZHA

Chimp
Feb 20, 2015
34
6
Flat AF
Does Cura4 have the same bleed fittings as older Formula brakes?
Need to source a cheap bleed kit for them.
Also what about mineral oil - do I really need Formula stuff? It is hard to source in my area and I have used other manufacturer oil for my Shimano brakes. Obviously don't mix'n'match but purge the whole system
:confused:
 

Flo33

Turbo Monkey
Mar 3, 2015
2,057
1,298
Styria
There is a specific mineral oil bleed kit from Formula. The fittings are the same as with R0R, but the seals are different.

Shimano oil works fine. Look at the first post in this thread, Udi has set up a spreadsheet with brake fluid facts.
 

KAZHA

Chimp
Feb 20, 2015
34
6
Flat AF
There is a specific mineral oil bleed kit from Formula. The fittings are the same as with R0R, but the seals are different.
Thanks.
I was more concerned about the thread of the fittings,cause mainly Formula bleed kits are labeled for R0R,One brakes and DOT.
 

englertracing

you owe me a sandwich
Mar 5, 2012
1,573
1,069
La Verne
Got some a cura 4 set.
225mm hope rotors front and rear.
They came with organic pads, that was a bummer.
But they are pretty powerful that way.
I really wanted the speed lock fitting, I was pumped about that because internal routing is pretty wack
They showed up with out the speed lock fitting :(
I Was pissed....
I bled the shit out of them.
The caliper has a bit of visible flex.
The lines are soft.
The lever lever body has flex.
Lots of travel
Not as stiff as I wanted once pads were on rotor

You know im overall mostly bummed by shit thats being made these days.
Maybe im foolish for hoping it was going to be something solid like my non radial t1 brakes.
 

Loki87

Monkey
Aug 24, 2008
181
146
Salzburg, Austria
Finally decided to buy the Magura HC1 one finger levers for my MT7 after running them for 4 years with the standard levers.
Yeah, i don´t know what i was thinking waiting so long to do that.
They´re basically Shiguras now, but without sucking in air. Lever feels like a beefier Saint lever, bite point is spot on and they have Magura modulation.
Well worth the money and completely transformed the brake.
So if anyone is thinking about going Shigura, maybe give the HC1 levers a thought. They´re awesome.
 

chris_f

Monkey
Jun 20, 2007
390
409
Not strictly frankenbrake, but I picked up a set of Trickstuff's new pads for the Magura MT7. The importer had decided to stock just those and not the OEM Magura pads, which was interesting.
 

mykel

closer to Periwinkle
Apr 19, 2013
5,067
3,778
sw ontario canada
Not strictly frankenbrake, but I picked up a set of Trickstuff's new pads for the Magura MT7. The importer had decided to stock just those and not the OEM Magura pads, which was interesting.

Let us know how they work out.
I have two pair for the Hope T3V4 sitting in the basket at R2-Bike.
I don't "need" brakepads as I do have a couple pair, but if the Trickstuff are as good as reported they may just give me the extra bite I need over stock.
 

Flo33

Turbo Monkey
Mar 3, 2015
2,057
1,298
Styria
I have only relatively short descents on my Reign on them so far, no lift assisted real dh stuff and I'm at 150 lbs fully ride ready.
They are better than the IceTech sintered pads they replaced in terms of power. They sure will wear down faster though and it has only been dry riding so far. Lever feel on the R0Rs also improved, don't know why yet but guess they simply fit better which is no surprise.
 

Happymtb.fr

Turbo Monkey
Feb 9, 2016
1,907
1,252
SWE
I have som Trickstuff pads for my MT7 caliper about to be installed.
They will replace pads from the Magura performance serie.
 

Udi

RM Chief Ornithologist
Mar 14, 2005
4,915
1,200
I already put a season on the Trickstuff pads as they came with the DRT. I presume the aftermarket ones are the same or pretty similar.

They are excellent pads. Consistency of bite over pad life is significantly better than sintered pads (non-heatsink), right down to the pad backing. They wear fast, but most pads that function under lift-assisted riding do in my experience. I agree with Flo, they do have better bite than the icetech sintered pads (I've got a set of each in one bike right now), but in fairness a) the ROR pads are tiny especially since the fitting icetechs are slightly smaller than stock, Saint sized ones do much better, and b) icetechs are the only good sintered pad in existence that won't glaze to nothing after a couple days of hard lift riding. I still approve of icetech pads for those who need pads that actually last AND also continue to bite after one day of DH runs. With every other pad you'll choose from one or the other.

I didn't get a lot of wet days on them so can't comment on how they go in properly wet / muddy conditions but maybe Flo or Happy can comment on that. I'm curious, as that's the area where some organic / semi pads struggle.

My only minor complaint was (from memory) they put a huge chamfer on the bottom of the pad material, no one needs that much chamfer.
 

Happymtb.fr

Turbo Monkey
Feb 9, 2016
1,907
1,252
SWE
I have now been running the trickstuff red pads in my mt7 front caliper paired with Shimano lever. My former pads, Magura performance must have been losing some grip / glazing since it took quite some commitment to lock the front wheel. Now with the new Trickstuff pads it has never been so easy to lock the front wheel. Scary easy! Much easier than what I remember from my Shigura with fresh magura pads and even easier than the Saint l had a few years back. I was anticipating the first ride as I saw myself flying over the bar already... but I manage maybe because I was riding on well known tracks? I will report once I get more time with them on more challenging terrain.

How do you guys bed in your pads?
I usually do as follows, but there might be a better way?
I start by wetting the pads with water and rubbing them against each other until they are covered by a kind of slurry. Then I put them in the caliper, spray more water on them and on the rotor before starting riding the bike with some pressure on the lever. I ride until the hawling stops, then put on some more water and ride again. Finally I do some acceleration followed by hard breaking until complete stop. Done!
 

englertracing

you owe me a sandwich
Mar 5, 2012
1,573
1,069
La Verne
I put some silkoline like water in xt8000 brakes.
Seems like the rear lever can return faster, MAYBE.
Was curious to see if it turns ugly grey in 10 rides like the shimano oil does.
 

HAB

Chelsea from Seattle
Apr 28, 2007
11,580
2,005
Seattle
It's not the oil, it's the MC's inner bore wearing out because Shimano doesn't anodize it after machining.
That. You could put unicorn jizz in there and it wouldn't matter, what you're seeing is very finely powdered aluminum from the MC bore wearing.
 

englertracing

you owe me a sandwich
Mar 5, 2012
1,573
1,069
La Verne
It's not the oil, it's the MC's inner bore wearing out because Shimano doesn't anodize it after machining.
Pricks, they should be hard anodizing its tits off then honing it aftet that.
Seems like its always in the caliper though.

That. You could put unicorn jizz in there and it wouldn't matter, what you're seeing is very finely powdered aluminum from the MC bore wearing.
Since you said i could...


Anyone know where to get unicorn jizz?
 

Rockland

Turbo Monkey
Apr 24, 2003
1,870
262
Left hand path
With Shimano brakes it's more than just the finishing of the MC bore. It's a combination of several factors that people have come across. The crazy thing to me is why Shimano won't fix the issue. I have a hard time believing they can't understand the root of the problem with the resources they have. It's gotta be something beyond the engineering: targeting too low a price point - intended disposable - not rebuildable - ect. I've owned every generation of Shimano disc brake, starting with the 4-piston XT M755 derived from a Grimeca design. The usable lifespan of a lever is getting worse not better.

The MC pistons, on the majority of their levers are plastic, and have very small bearing land area. While the tolerance of piston in bore may be adequate with a fresh lever, the nature of the servowave action has a lot of side loading in the initial part of the travel. The plastic piston land wears down, and the bore eventually wears. The U-Cup seals also see more radial movement and begin to wear.

The Shimano fluid may also play a part, as suspected by others. I regularly ride in the winter with temps below 0 def F. The brake action certainly has the feel of a more viscous fluid, though I suspect that some of this is the caliper seals having stiffer movement. I began experimenting with Redline Likewater this past winter. It seemed to be a positive change, but I'd really need to try it in a fresh lever to eliminate some variables.

I'm tempted to experiment with refinishing the bore of a lever, and making new pistons (metal, with a wear band & different U-Cup seals). I've got a lathe, and material, it's more of a question of why bother. I've moved on to Cura 4's with sintered pads & big rotors.