Hello Vital MTB Visitor,
We’re conducting a survey and would appreciate your input. Your answers will help Vital and the MTB industry better understand what riders like you want. Survey results will be used to recognize top brands. Make your voice heard!
Five lucky people will be selected at random to win a Vital MTB t-shirt.
Thanks in advance,
The Vital MTB Crew
You've probably already seen them, but there are a lot of very inexpensive vacuum bleeders available for automotive work that might be good for any experimentation you wanted to do with mechanizing this a bit more. They don't all have gauges but here is one with a gauge for under $30: https://www.harborfreight.com/brake-bleeder-and-vacuum-pump-kit-63391.html
I'd used one without a gauge many years ago, to bleed some Hope brakes, back when no one in the bike world was offering anything like the nice "Pro" bleed kits that exist now. Compared to the crap syringes that we were working with at the time, it was a step up, but we didn't really have it dialed in terms of getting a good enough seal at the fittings, so air leakage could be a problem. That really isn't any different than pulling a vacuum on syringes though, so if you already have good airtight fittings to use with your brake system now, then splicing them into the vacuum bleeder shouldn't be a big deal. The neat thing about these devices vs. a syringe is, even without a power source, they can maintain a vacuum and leave your hands free to do other work, and they also have a large catch can, you don't run out of capacity if you are needing to move a lot of fluid.
Sram just changed the name, it's the same product.
https://www.sram.com/en/service/articles/Hydraulic-Brake-Grease-Formerly-DOT-Grease
Bs. Shigura is best bang for the buck if you know how to set it up with plutonline and like the hard bite point.
i can argue in the long run Hope is the best bang for buchk, shigura is dogshit, if the master leaks it goes in the bin, levers are made of cheese so every couple crashes you need a new one, if something happens to the caliper side you can't service that one either, so no, definitely not good value
does anyone have any hint of media release date for the new shimano brakes?
In november I was told End of Feb but not sure if still the case?
Are you talking about Magura or Shigura?
Shifura, but it’s the same on both, on Magura you get the 5 year leak proof, on shimano you get the normal warranty and no parts to fix/service the brakes
I would pretty much just use a shock vacuum bleeder - only smaller and with seals made for DOT fluid (and a separate machine for mineral oil, or even the same one used on dampers). Maybe have a split hose to tap in to both ends but the machine itself wouldn't need much changed. I don't pressurise the fluid at the end, other than to make sure there is a bubble of fluid in the bleed port and air doesn't get sucked back in. The bladder compensates for extra volume anyway, and any firmer lever feel will disappear once the pads have worn slightly. If you wanted something like that I would rather use a product like the @CascadeComponents brake adjuster
Also if anyone is interested, you can get push-loc and threaded fittings off ali express dirt cheap, along with syringes and luer adapters if you want to play with bleeding techniques (or rebuilding 4 ohlins TTX25 shocks at once....)
https://www.aliexpress.com/item/1005002817631533.html?spm=a2g0o.store_pc_home.promoteWysiwyg_6000894952908.1005002817631533 (just an example)
But Shimano levers are not cheese to the level Magura are...
Feels a bit like ranting for the sake of ranting...
FWIW, based on a tightness testing fixture we have at work (measuring pressure drop at 50 mbar pressure levels and the like), I'd use compression fittings instead of push in fittings. Somewhat stiff hoses so they don't buckle and close off under vacuum is a good choice too.
As for luerlock fittings off Aliexpress, I don't have the best experience... I've had to crank down on them with pliers to make them seal at least somewhat reliably...
EDIT: as for separate machines, what about using the machine just to apply vaccum and pressure and using external fluid tanks? That way you can have separate tanks for mineral or dot fluid. There is still the chance of vapour getting pulled further into the system and mixing with the other fluid though...
the blades on Shimano are as strong as the lip on a can of beer, crash once and they're fatigued, crash twice and you need a new one, on magura the sort of carbotecture master is more of an issue, it not ranting, it makes sense, both options, especially when paired together are a worse combo bang for buck in the long run than say Hope as you miss both companies warranties and get both levers and calipers that are officially un serviceable
Servicability wise Sram is probably the best option.
i'd say so, but if you take performance and value for money then it's quite horrible as well
Formula offers every single part needed even for brakes that are 20years old 😉
you have made your opinion on Shimano known, repeating it every time someone talks about it won’t change anything
I want more digital photo forensics instead please
Yes.
I think you've just encountered the concept of a "mechanical fuse".
Shimano seems to always be in a weird spot. I've friends who've had no issues to report and others who quit the brakes due to too many issues, myself included. When they were new they were damn good, but they didn't age well. Every brake is easy to set up as they're all just a variation on a theme, you just have to find their note differences to interpret their take right. Where I think Shimano gets things right is their fluid paths. Every unit I've worked on has had air in the reservoir, whether that was new on a bike or from a box. When mounted, you would never notice it til you came to near the end of the pad life or flipped the bike upside down. Their fluid paths guide the air up out of the active part of the system really well. I've bemoaned the issues I've had with em here and elsewhere so I'll just say where they're wrong is service parts availability, and arguably that some brakes are strictly designed not to be serviced at all due to permanent fasteners (lookin' at you, non series Deore).
Yep, I'd much rather a replaceable part fail in a game of lawn darts rather than the MC body.
Hello brake nerds! I have a very annoying issue with my Dominon A4s that has me scratching my head. I bought the set for my fat bike and have been using it a lot this year. When it is freshly bled, the lever free throw is a decent 10-15mm and bite point is crisp. Over the course of a month the free throw grows to a whopping 35+mm where they are nearly touching the bar. The bite is still pretty crisp. I adjust the lever reach as a bandaid fix but eventually the bite keeps going closer and close to the bar. It can't be air trapped in the system otherwise the bite would be spongey right? Could there be a leak somewhere in the system? I noticed two drops of DOT fluid escape the reservoir cap when I was pressurizing them during the last bleed. What the heck is going on with these? It happens to both front and rear at different rates. I am using the SRAM pro bleed kit and the fittings don't leak either.
Heya, let's dig in. Set the lever up so the reservoir is at 12 o'clock on the handlebar. ideally so the reservoir cover screws are perpendicular to the floor. Pump the brake lever a number of times and see if it firms up (a little or a lot). If so, culprit is air in the MC. Culprit could be bleed issue or it could be that the drops of brake fluid you're seeing by the reservoir are indicating a res leak, likely from the bladder. I'd remove the cover and inspect the bladder. It should be free from tears. Dependiong on how heavy handed you were pushing n pulling on your syringes, you may have popped the bladder from its grooves or tore it. Haven't seen that with the Doms(yet) but have seen it with other makes/models.
From your description, it was unclear if the lever throw grows simply when the bike sits for a while, or if it is only through hours of use that it grows. If it is directly related to hours of use, is it possible that you have sticky caliper pistons which aren't advancing through the seals to compensate for pad wear?
The different rate at which the throw increases on front and rear would fit with that, especially if the rear increases faster than the front, as people typically use the rear brake more and go through pads faster.
Checking to see if the pad/rotor gap is staying consistent or, as the pads wear, is it growing in relation to the lever throw would be another way to verify this. If they do seem sticky, then cleaning and lubing the pistons should be an easy fix.
If the pad gap is staying consistent though, that should indicate the pistons are advancing as they should, and, as HexonJuan pointed out, there may be insufficient fluid supply to continue activating them as more and more of the reservoir fluid is called in to fill the increased volume as the pistons advance. I would think the feel would get mushy in that instance though, whereas it sounded like you still get a firm bite point, but it just moves over time.
Thanks, I just did that pump up test and there was no noticeable firm up. The bite point gets a tiny little sharper after a few pulls but that's pretty normal. There is about a month of fat biking left so I will open up the MC after that OR if the lever runs out of adjustment. I am a bit of a gorilla when it comes to pushing and pulling so I might have ruptured the bladder like I did on my Maximas. Really need to curb that habit I built bleeding SRAM brakes.
I ride pretty regularly and have high volume so the bike doesn't sit around for too long. Regardless, I just did a piston advance/lube procedure yesterday and it hasn't helped. As for pad/rotor wear I just installed new Sinter Green pads a few rides ago on a rotor that is pretty fresh so it can't be that. Funny enough the "growth" is pretty random. Sometimes it is the front that gives out faster and sometimes it is the rear. These observations were after around 800 km/ 40,000M+ vert of fat biking in the last 5 months.
Wow, that is mysterious! I look forward to hearing what the culprit was when you finally figure it out. It certainly sounds like you're doing a good and thorough job with the troubleshooting.👍
When I had Dominions, I noticed there was a pretty big change after the first couple rides on free stroke, following new pads. With fresh pads, the free stroke is really short, but it pretty rapidly grows to whatever the nominal rollback is. It was more pronounced running aftermarket pads (like Galfer) instead of the Hayes ones, as the Galfer total backer+pad thickness is greater. I'd always end up with different feeling front/rear since the pads wore at different rates.
Yup this sounds like something related to roll-back, as in the seals are able to pull the pistons back along way. One thing you can do is lubricate the pistons with proper brake grease as that reduces how much the sqaure seal can grip the piston. So they will be able to advance closer to the piston, as that design relies on the surface finish and friction between the seal and piston
Got these in the mail the other day from the UK. Heard some rumblings about the looks on here, they do look decidedly old school but I’m excited to see another player in the game. Will report back once I finally get them mounted.
I have been through 3 sets of pads (OEM organic, OEM metallic and now Sinter) and you are right about the changing feel between them. I ended up bleeding the brakes every time I changed the pads which is pretty annoying.
If they perform most people tend to change their mind on the looks very quickly. Personally I'm just glad to see something new, and hope they got something to offer in the performance department.
Post a reply to: Nerding out on Brakes shall we? Not another tech deraliment