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As much as I resent it, I've been trying the piston massage on all the Sram brakes I've worked on, and even worse, it improves the lever feel of all of them. What I do is a full bleed to flush out the fluid (I'm using motorex dot 5.1, great fluid) locking off the syringe at the lever and then doing the piston massage until all the pistons are moving as evenly and freely as possible. Then I'll open up the lever syringe again and do a lever bleed / vacuum to get the last bit of air out. Takes some time to do but it's been making the brakes have a lot better lever feel, way less mush, even with the g2s. Pisses me off every time I do it though haha.
of course it's annoying to do, it's easy to push the pistons out but takes ages to put them back in, i'm still unsure what makes them so hard to push back, i mean the maguras use the same kind of pistons and they move like nothing
Tolerances...
Is the piston massage described in the Maven bleed procedure?
EDIT: found it:
https://www.youtube.com/watch?v=HaNINyOcmJI
Yup, now they have a tool rather than the dual rotor
I just wish it was that easy to push them back
On the Hopes you blow on them and they move back
you have to push them in straight by applying the pressure in the middle of the piston. Bit off to the side you tilt the pistons which makes them go in a lot harder. If you do tilt them push on the other side to straighten them in the seals again, you'll feel once you hit the sweet spot, they slide very easily.
I think very easily it’s something else, Hope, Magura even I just do it with my fingers
Sram of all kinds require force, and I’m aware the more centered the better or they go all wonky
I don’t understand how much more it can cost to make them slide nicely with better tolerances
Even Trp got that sorted nicely
Could be the bores, the pistons or the seals.
Have you tried this hub, rotor and caliper combo on another frame? Have you tried a different wheel and/or rotor on this frame? A different brake?
What I'm asking is this a Hope V4 caliper issue, a frame issue (frame model or specific frame even maybe) or a combination issue.
I found the hopes and other big rotor(thick) calipers need the rotors perfectly in the centre or they will always unbalance themselves and often rub.
After going back and fourth for the last month I decided to pull the trigger on some T4V4’s to replace the Radic Kaha’s that I’ve been running for the last year. I figured my purchase should trigger some event that causes hope to release the new gravity brake causing me to have buyers remorse over the purchase for not waiting, but giving anyone else the opportunity to grab some discounted T4V4’s or the new brake… your welcome 😂.
Some initial impressions:
Last time I worked on a set of hope brakes was at least 15 years ago, and they always seemed to be shelf queens imo. I know that has changed but I’m happy to see/feel it in person. Pad retraction is pretty damn good, having struggled with mt7 for longer than I should have and coming from Kaha’s that are intolerant of any runout in rotors I’m pretty happy that these have a decent amount while still having short throw. Coming to that, the dead stroke is much much better than I was expecting, not sure if it’s exaggerated or what but with the contact point adjuster wound in for the least free/dead stroke I am measuring 14mm until the lever firms up. That’s actually very close to where I have the free stroke set on my Kaha’s, also adjustable, to maintain reliability. I will say, they have a heavier lever pull than both the Kaha’s and the Dominions, by a fair amount to the latter.
I pulled my Trickstuff pads from my Kaha’s to have a better idea of how they stop, with everything else being equal, tbh I feel like there is no difference in power other than I builds slower, more modulation, but required more lever throw to get there.
I was able to get the calipers centered on the rotors and have nearly equal piston extension front and rear. The bleed process brought back memories but I used a miniature hose clamp to secure the hose to the barb at the caliper which made it a lot easier to pull a vacuum and dislodge any bubbles in the caliper before I pulled the diaphragm and performed a push bleed from the caliper. The front brake was pretty poorly bled from the factory, the rear was perfect (based on lever feel prior to cutting the hoses) can’t wait to put some laps on them and hoping, pun intended, they solve my weird reliability issue that comes and goes with the Kaha’s…
Im curious to know how you like them with the power pads, they’ve been my favourite pads on every other brake I’ve used.
The nerd in me would really love to match a Kahas lever to the v4 calipers to have an even better feel with even lighter pull 🤔 and that would also increase the power even further
Same here, but the levers have been the pain point for me, the seals have started to drag so much that the MC piston spring wont return the mc piston and lever all the way. Granted it only happens after the bike has sat for a few hours and you can pump them quickly to get the seal to soften up and start moving again but its a pain in the a$$. If I can get them to replace the seals under warranty and fix the issue, id be happy to try it out! Until then they will be collecting dust on the bench.
that issue of slow return mc piston is why i'm getting mc seals and pistons from hope as a warranty 😅
from val di sole pits, spotted on jackson's bike
That's a chonky caliper just like the Mavens. Saints are well regarded here in the mountains so I bet these will sell pretty well. They will probably use LV fluid since the XTR levers are being used. Those two openings on top should be easy to cover so mud doesn't get in.
That orange warning sticker is definitely worth 0.001s of drag during a 3 minute course.
Anyone have hose expansion/burst data?
Hayes hose seems like an outlier—-wondering if any anecdotal experiences regarding it and firmness vs standard bh90/goodridge 5mm braided, etc
Trickstuff on their website have pressure ratings for their Goodrige braided hose and for their Beta Kevlar hose
Quite significant difference
Then you’ve got Hope claiming nothing changes and I believe is bullshit
It might make a difference when you’re applying like 80-100% brake.
It won’t make any difference when you’re lightly applying the brake, like 0-10%. You have to expand the hose before the braid can apply any force to it. It’s not like it’s pretensioned around the inner hose.
I do believe it makes brake feel different, sharper more defined bite.
That’s why pros use stiffer hoses on trp, stock ones are soft, you can feel them and see them moving while just using the lever.
So what hoses are the pros using?
Neko and Dak were using Saint hoses a couple years ago. I made that change on mine. Agree it feels more direct.
I’ve seen many using the shimano bh59 hose
If I’m not mistaken they mentioned it on a MoiMoiTV video as well at some stage
If you go through all the tech ransoms on the red site you’ll see some from ages ago
those are just bh90 hoses
bh59 is worse for sure
Does anyone have tips on how to measure the brake caliper vertical alignment so that the brake pads are centered on the friction ring? One method I was thinking was to use a marker on the disc and then observe where the pads make contact.
I’m using Shimano Saint brakes with TRP RS01E 223mm discs. The rear has an IS-PM adapter and the caliper fits very tightly, so it might require some creative thinking. I have couple of Magura shims to align caliper.
I think the question is more along the lines of the diameter ring where the pads contact, not where the pad makes contact with the rotor on the surface area of the pad itself vs. where it does not (that would cover checking if it moves parallel to the rotor or rotates inwards).
For the 'wear ring' method, sharpieing the rotor makes sense.
Just bought the trinity a few weeks ago, didn't have the chance to go on a trail yet but went around town trying to bed in the brakes.
The modulation is amazing, but I still feel there is power left there on a 1 finger pull. Still can't fully lock the front wheel on a fast hard 1 finger pull (unless I use 2, which I never do). Don't need to lock the wheel when I go blasting through a trail, but I want to know I have all that range on 1 finger.
Is this something that shows I still need to bed in the pads more? Using 220 rotors front and rear, 2.3mm monolithic forumlas, 94-96kg average kitted, 16.7kg bike
Thanks!
I weigh more than you and ran these on a bike similarly weighed, you shouldn't have problems locking either front or rear wheels. I would suggest trying to bed them better and re-do your bleed to be certain, getting all the air out can be a bit of a chore the first time. I'd say something is off though b/c locking either front or rear shouldn't take much effort at all.
How many rides have you done on brakes? Mine didn’t take too long to bed in.
You may also want to re-visit your bleed, I had to bleed a few times to get all the air out and now my brakes are solid. There was a good reply to me about this a few pages back.
I can lock the front wheel pretty easily on my setup with 203 2.3mm rotors but Im also only at 75kg rider.
Locking the front wheel on asphalt with grippy front tire and long travel fork requires crazy stopping power.
Post a reply to: Nerding out on Brakes shall we? Not another tech deraliment