Frankenbrakes and brake improvement discussion
- Thread starter Udi
- Start date
There is a little screw for that but it seems like it’s already adjusted for the shortest throw. I adjusted it twice to see and it didn’t make things better so I put it back where it was. There is more throw then I would like after the pads are worn but Im used to it now for riding but for manuals I’d prefer less.
They have more power and the levers can be setup very close to the bars. I like these brakes mainly for the light lever pull and huge power which makes me get arm pump later in the run compared to everything else i’ve tried.
Just did a little bit of service to the Tech3 V4s.
They had become a bit squeaky when just slightly moving the bike, just as the wheel starts to move.
Cleaned the pistons using the alcohol soaked string method and cotton buds.
Had 3 sticky pistons, 2 freed up easily, the other took at bit of work.
For anybody interested, I made a cleaning spacer using 3 stacked dimes taped together next to 3 more stacked dimes taped together, both stacks are taped side by side with a small zip tie between to act as a handle The dimes sit nicely against each piston. The total thickness is about 15 thou less than 2 pad backers and rotor, so no worries about popping the pistons out, as long as you tease them out so they are even.
Lubed everything up with some Motul Dot fluid, did a bleed and put it all back together.
Now have silence again, as well as a crisper lever feel.
God I love bleeding Hope brakes, no faffing about with syringes, velcro straps, or chicken sacrifice - nothing but a bottle of fluid, an 8mm wrench, a piece of tubing and a catch-can.
I know Hope recommends Hunters Silicone Lube ( a plumbing supply of all things) but I can't find it over this side of teh pond. I thought about red rubber grease, like when doing car calipers, but in the end just used brake fluid.
What do you guys use for lubing pistons when your done cleaning?
They had become a bit squeaky when just slightly moving the bike, just as the wheel starts to move.
Cleaned the pistons using the alcohol soaked string method and cotton buds.
Had 3 sticky pistons, 2 freed up easily, the other took at bit of work.
For anybody interested, I made a cleaning spacer using 3 stacked dimes taped together next to 3 more stacked dimes taped together, both stacks are taped side by side with a small zip tie between to act as a handle The dimes sit nicely against each piston. The total thickness is about 15 thou less than 2 pad backers and rotor, so no worries about popping the pistons out, as long as you tease them out so they are even.
Lubed everything up with some Motul Dot fluid, did a bleed and put it all back together.
Now have silence again, as well as a crisper lever feel.
God I love bleeding Hope brakes, no faffing about with syringes, velcro straps, or chicken sacrifice - nothing but a bottle of fluid, an 8mm wrench, a piece of tubing and a catch-can.
I know Hope recommends Hunters Silicone Lube ( a plumbing supply of all things) but I can't find it over this side of teh pond. I thought about red rubber grease, like when doing car calipers, but in the end just used brake fluid.
What do you guys use for lubing pistons when your done cleaning?
On my V4s I bought some Finish Line Fluoro grease which is apparently recommended for them. If I'm being lazy, I just spray them with silicone spray and wipe off the excess and that works pretty well.
The grease depends on the fluid. For DOT use fluoro grease and for mineral oil use red rubber grease
RE: Assembly Grease
Answered in detail here:
https://ridemonkey.bikemag.com/threads/frankenbrakes-and-brake-improvement-discussion.274164/page-17#post-4266430
and here:
https://ridemonkey.bikemag.com/threads/brake-piston-maintenance.277711/post-4170624
For DOT brakes the ideal product is PFPAE, and for mineral oil brakes there are likely a few suitable options (anything safe for Nitrile/NBR seals is probably fine). Silicone grease works in a pinch for both to my knowledge. What isn't a great assembly/seal lubricant is the working fluid - i.e. using DOT fluid or mineral oil - because it has no capacity to stay in place and will get wiped and washed away (in that order) in short time. The precise reason PFPAE is superior to silicone grease in a DOT brake (as an example) is its lubrication longevity.
RE: Clearance / Rubbing
It's a common issue on brakes with lower piston/pad rollback, and while properly cleaning and lubricating the pistons can help, sometimes the seals just need replacing - particularly if the brake has seen a lot of use. The seals on a brake do more than holding hydraulic fluid in, the caliper slave seals are also springs and thus dictate the piston rollback distance. Elastic materials (NBR, EPDM, etc) will change both dimensionally and in durometer over time, and both of these will result in changes to the spring rate and spring travel characteristics. This means rollback and clearance changes as the brake ages, some worse than others, but all eventually need changing (often before actually leaking). If cleaning / lubricating doesn't work, I highly recommend trying a change of caliper seals + pistons (usually not much extra to do both on plastic/resin piston brakes). I've found particularly on Formula that it can improve the piston response and clearance, and parts are reasonably priced. Not the easiest job though, plenty of decent mechanics mess this one up so take your time if DIY, or use someone with experience if not.
RE: Throw
I've said it before - it's easy to make a brake with high peak force but long free throw, it's also easy to make a brake with lower peak force but short throw. If your brake stops hard but needs the reach (i.e. starting point) set far out, so that the engagement (i.e. ending / bite point) isn't right on the grip, or "pretty close to it, because I like it that way", then congratulations you've picked up yet another mediocre brake. If you're happy with it then great, but if we have long throw and/or throw that grows with pad wear, that is absolutely the definition of mediocrity.
In my experience buckoW (along with plenty of others, but I single him out because 1. his gear opinions hold more water than others in my personal opinion due to his riding and riding volume, and 2. I know he can cop this - most fragile egos can't) is great at wanking on about how great a product is immediately when he gets it (if it's decent - i.e. not every product) - but often the truth comes out about the flaws either after a year of using it, or when he switches to the next product. So in my book, just because he likes the Dominions now, doesn't actually mean it's a great brake. I've watched him rave then rant (in that order) about TRPs, Hope V4s, Formula RORs, etc etc before. Give any product a year of hard DH use, then see its true colours.
Answered in detail here:
https://ridemonkey.bikemag.com/threads/frankenbrakes-and-brake-improvement-discussion.274164/page-17#post-4266430
and here:
https://ridemonkey.bikemag.com/threads/brake-piston-maintenance.277711/post-4170624
For DOT brakes the ideal product is PFPAE, and for mineral oil brakes there are likely a few suitable options (anything safe for Nitrile/NBR seals is probably fine). Silicone grease works in a pinch for both to my knowledge. What isn't a great assembly/seal lubricant is the working fluid - i.e. using DOT fluid or mineral oil - because it has no capacity to stay in place and will get wiped and washed away (in that order) in short time. The precise reason PFPAE is superior to silicone grease in a DOT brake (as an example) is its lubrication longevity.
RE: Clearance / Rubbing
It's a common issue on brakes with lower piston/pad rollback, and while properly cleaning and lubricating the pistons can help, sometimes the seals just need replacing - particularly if the brake has seen a lot of use. The seals on a brake do more than holding hydraulic fluid in, the caliper slave seals are also springs and thus dictate the piston rollback distance. Elastic materials (NBR, EPDM, etc) will change both dimensionally and in durometer over time, and both of these will result in changes to the spring rate and spring travel characteristics. This means rollback and clearance changes as the brake ages, some worse than others, but all eventually need changing (often before actually leaking). If cleaning / lubricating doesn't work, I highly recommend trying a change of caliper seals + pistons (usually not much extra to do both on plastic/resin piston brakes). I've found particularly on Formula that it can improve the piston response and clearance, and parts are reasonably priced. Not the easiest job though, plenty of decent mechanics mess this one up so take your time if DIY, or use someone with experience if not.
RE: Throw
I've said it before - it's easy to make a brake with high peak force but long free throw, it's also easy to make a brake with lower peak force but short throw. If your brake stops hard but needs the reach (i.e. starting point) set far out, so that the engagement (i.e. ending / bite point) isn't right on the grip, or "pretty close to it, because I like it that way", then congratulations you've picked up yet another mediocre brake. If you're happy with it then great, but if we have long throw and/or throw that grows with pad wear, that is absolutely the definition of mediocrity.
In my experience buckoW (along with plenty of others, but I single him out because 1. his gear opinions hold more water than others in my personal opinion due to his riding and riding volume, and 2. I know he can cop this - most fragile egos can't) is great at wanking on about how great a product is immediately when he gets it (if it's decent - i.e. not every product) - but often the truth comes out about the flaws either after a year of using it, or when he switches to the next product. So in my book, just because he likes the Dominions now, doesn't actually mean it's a great brake. I've watched him rave then rant (in that order) about TRPs, Hope V4s, Formula RORs, etc etc before. Give any product a year of hard DH use, then see its true colours.
But I noticed an uneven wear at least on the rear. The ingoing side wears a lot faster. This forces the pistons to move in an unparallel way leading to them sticking more than designed and desired. I think/feel this leads to rubbing rotors and a mushy feel at the lever. I had a perfect bleed and also freshly Finish Line Fluoro greased pistons prior.
The Trickstuff Power pads also tend to stick-slip on very steep slow stuff a bit. I'm wondering if that adds to the uneven wear of the rear pads.
Thoughts?
Alright, I've been following this thread for awhile and finally joined the forum. Tech question for the "Shigura" crowd... has anyone used a Shimano barb in the Magura hose, or must you use the Magura barb? I mic'd the barbs and there is a .002" difference. (Magura .097"/Shimano .095") Thanks for any input.
I've had better success with Magura Olive and Barb.
If you don't have a leak, don't worry about it.
I would probably attempt to use whatever the levers are supposed to have, as the interface is compressed to make a leakless seal. I think Udi has even said they are interchangeable.
Question about Magura pads: I fucked the pads of my new MT5s during the install and I need new pads.
1. Are the four-piece ones OK, or do I need the one-piece pads? And if the four pieces are fine, do you need the pins to hold them in place?
2. I am also going to buy a Magura disc. Can I use sintered pads on the Magura discs?
So I installed my MT5s yesterday. It was the first time I've ever cut a brake line. I also had a hard time pulling the pads out, and thought fuck it, I'll just leave them in... oops. got oil all over the pads. luckily I have the pads from the other brake, so I cannibalized those. I discovered (I hope this is right), it just takes a little forceful wiggling to get them out. I guess they will get easier to pull out as the pads wear out.
any info on pads and discs is much appreciated. thanks
1. Are the four-piece ones OK, or do I need the one-piece pads? And if the four pieces are fine, do you need the pins to hold them in place?
2. I am also going to buy a Magura disc. Can I use sintered pads on the Magura discs?
So I installed my MT5s yesterday. It was the first time I've ever cut a brake line. I also had a hard time pulling the pads out, and thought fuck it, I'll just leave them in... oops. got oil all over the pads. luckily I have the pads from the other brake, so I cannibalized those. I discovered (I hope this is right), it just takes a little forceful wiggling to get them out. I guess they will get easier to pull out as the pads wear out.
any info on pads and discs is much appreciated. thanks
1) Four piece ones are argued to be better by magura, as you get four leading edges (bite) rather than two. The high end pads come in four piece formats. I bought a set of their Race pads in order to get the pins as well as pads. All aftermarket ones come without pins (swisstop). Yes, you do need pins. I believe they are magnetic, but they aren't like the two piece ones that have clips.
2. No idea, but you should be able to even better then others as the maggies are thicker. I am running formula rotors with maggie race pads and they seem fine so far.
I honestly haven't gone DHing since upgrading the pads, but they feel much more "bitey" around the house. To get them out, you need to push them towards the opposite side, then pull out from the bottom. The upper clips keep them from falling out, and fuckin' magnets keep them stuck.
2. No idea, but you should be able to even better then others as the maggies are thicker. I am running formula rotors with maggie race pads and they seem fine so far.
I honestly haven't gone DHing since upgrading the pads, but they feel much more "bitey" around the house. To get them out, you need to push them towards the opposite side, then pull out from the bottom. The upper clips keep them from falling out, and fuckin' magnets keep them stuck.
I found the Magura house on mt4s thinner than Shimano, making it very hard for a Shimano olive to make a seal in the lever. Magura olives never let me down, otoh.
The one-piece are the way to go. Four-pieces defeats the point of having four pots, it's more like having 2 calipers
Think I'm going to give the Shigura thing a try as well. Does it matter which Shimano lever I use? Currently running a Deore brakeset, can I reuse the levers? Also curious if the existing Shimano brake adapters and rotors will play nicely with the MT5/MT7 calipers.
I just looked up some trickstuff brakes to see what they cost.
They don't seem to have a lot of faith in their product.
They don't seem to have a lot of faith in their product.
After switching my curas over to cura levers I think I'm hooked on the shimano lever/cura caliber match. Turned me into a crack head.
Stronger than either brake in their native form. Everything else feels like shit now. It's udi's holy grail of short throw and stupid power. I might just rotate levers every year. It's kinda worth it.
Stronger than either brake in their native form. Everything else feels like shit now. It's udi's holy grail of short throw and stupid power. I might just rotate levers every year. It's kinda worth it.
Cura 2 caliper?
Yep. That setup with metal pads is the shit. On my dh bike they would heat up a little though on ass dragger descents.
I'm about to throw some xt levers on the 4 piston ones I just put on my dh bike.
They never went full retard on me but the saint/2 piston combo I had on my dh bike started to vary the bite point a little at inopportune moments (aka 'the shimano problem') on season 2. So it was starting.
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I'm using XT (M8000) on one bike and SLX (M7000) on another. In my research I've concluded that Deore on up is good, Zee being the only exception, as it has a different MC volume. Might want to check me on that. I use SRAM speedline rotors on ALL of my bikes... I have found them to be the most consistent and friendliest on pads. Adapters are pretty universal across the board.I have Shimano on Magura, vice versa, and plenty of no-name bo-bo brands as well.
@kidwoo is the MC diameter of the Cura lever specified in the spreadsheet found in the first post of this megathread?
I cannot access it from my phone for whatever strange reason...
From your experience, the MC on the Shimano lever should be smaller than the Formula one. Do you have a longer throw too?
Shimano levers have in my opinion better ergonomy than Formulas mainly because the bit point can be set closer to the bar but reliability is not their strongest asset, nor the availability of spare parts. As you mentioned, the dead throw will get longer as the servo wave mechanism wears and the bit point might wander randomly. Personally I did not have issues with the later on my Shiguras after around 3000km of trails. YMMV
I cannot access it from my phone for whatever strange reason...
From your experience, the MC on the Shimano lever should be smaller than the Formula one. Do you have a longer throw too?
Shimano levers have in my opinion better ergonomy than Formulas mainly because the bit point can be set closer to the bar but reliability is not their strongest asset, nor the availability of spare parts. As you mentioned, the dead throw will get longer as the servo wave mechanism wears and the bit point might wander randomly. Personally I did not have issues with the later on my Shiguras after around 3000km of trails. YMMV
Thanx!
10 mm for the Shimano means indeed moar power
I just looked back at udi's spreadsheet.
We need to talk about these hope trialzone things.
I went to go add the shimano/cura numbers but it's locked. Far more important however is what to call them:
shormula
formano
curano
shimura
That's way more interesting that moving numbers down a spreadsheet.
We need to talk about these hope trialzone things.
I went to go add the shimano/cura numbers but it's locked. Far more important however is what to call them:
shormula
formano
curano
shimura
That's way more interesting that moving numbers down a spreadsheet.
It says here a Shimura variety is a higher-dimensional analogue of a modular curve that arises as a quotient variety of a Hermitian symmetric space by a congruence subgroup of a reductive algebraic group defined over Q, which is why they're more powerful than either of the Shimano or Formula varieties.
I gained so much from that presentation. Ready for another day now that I am educated.
Trimulas sounds an entry in the urban dictionary I should not look up at work.
fun fact: this weekend I played "Cards Against Humanity" for the first time. My wife was also there. I made an amateur mistake: I didn't pretend not to know what "pixelated bukkake" was. I declined to offer the explanation out loud, to which my wife asked "how do you even know what that is". Shoulda proclaimed my ignorance, and looked it up on the urban dictionary. that would have been wiser. luckily the conversation did not go further than that.
Can one buy DRT levers alone?