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...
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
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...
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
But Shimano levers are not cheese to the level Magura are...
Feels a bit like ranting for the sake of ranting...
That makes sense to me. Thanks for taking the time to reply.If you could wave a magic wand, would the brake bleeding machine also be able...
That makes sense to me. Thanks for taking the time to reply.
If you could wave a magic wand, would the brake bleeding machine also be able to pressurize the system at a consistent and repeatable pressure - like the trick of pressurizing Codes from the bleeding edge fitting at the caliper before closing it off. Sometimes I do end up letting a touch of fluid out of one or the other. I can definitely see the value of doing that consistently and quickly in a shop setting.
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...
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....)
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...
But Shimano levers are not cheese to the level Magura are...
Feels a bit like ranting for the sake of ranting...
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
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...
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
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
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...
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
I think you've just encountered the concept of a "mechanical fuse".
people missing the part that Brage is scrubbing the speed..... When sponsored... you tend to make do with what you have.Pretty much every single person i've...
people missing the part that Brage is scrubbing the speed..... When sponsored... you tend to make do with what you have.
Pretty much every single person i've spoken to who have changed away from shimano to brands from TRP, SRAM to trickstuff all enjoy how much better they are than shimano. Shimano have the benefit of being easy to setup... perfect for pinkies to say "they are better" because they can lever bleed with a cup.
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).
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...
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
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.
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...
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.
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...
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.
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.
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...
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.
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...
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.
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.
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...
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.👍
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...
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.
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.
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...
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.
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...
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.
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...
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.
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.
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...
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.
Hey, I don't know if you have checke this yet, but take a look at how the olive is sitting on the hose at the lever. When I first got my Hayes, I had a shop set them up for me and who ever did the install got the barb and olive on the hose crooked. That allowed dot fluid to get into the fiberglass insulation in the hose and bassically would drain the master cylinder over time. I cut the old barb and olive off and properly set a new one in and I've never had issues since
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...
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.
Hey, I don't know if you have checke this yet, but take a look at how the olive is sitting on the hose at the lever...
Hey, I don't know if you have checke this yet, but take a look at how the olive is sitting on the hose at the lever. When I first got my Hayes, I had a shop set them up for me and who ever did the install got the barb and olive on the hose crooked. That allowed dot fluid to get into the fiberglass insulation in the hose and bassically would drain the master cylinder over time. I cut the old barb and olive off and properly set a new one in and I've never had issues since
Great point! I have a few spare olives and enough hose so I will install fresh ones on the next bleed. I've experienced that once on SRAM when I kinked my hose.
Hey All, this is borderline brake tech... more of a brake question then anything.
For all the TRP DHR Evo users (The previous generation, not the new Evo X) what are you doing for dropper post remote mounting? I previously had a wt light action remote, with a discrete 22mm clamp that played ok with the dhr evo levers. This last weekend, I went to move a wt remote pro over to the bike with the DHR Evo's and there is virtually no way to get them to play together ergonomically. I emailed WT components and they pointed out that while TRP claims that their levers are I Spec-II compatible, that TRP altered their version of I-spec and not directly compatible with WT (and sounds like most other) ispec clamp designs.
So... what dropper levers are people using with this brakes, and how do you have them mounted?
Orbital sander + 120 grit pad 20-30 seconds on each side x2 using medium pressure. This is how I prep my rotors when changing pad compounds/brands...
Orbital sander + 120 grit pad 20-30 seconds on each side x2 using medium pressure. This is how I prep my rotors when changing pad compounds/brands. I even do this when changing pads to fresh ones. Never let me down.
Going to circle back here. Just got an orbital sander to breath new life into some of the "dead" rotors I've accumulated.
Holy smokes did it work super well, a bit of 150 grit to 220 and they look brand new.
You don't even need to use an orbital sander. I just take a sheet of 150 grit, spin the wheel on the frame and hold the sandpaper against the rotor one side at a time. You don't need much pressure or time - just trying to clean off the surface deposit of pad compound.
Orbital sander + 120 grit pad 20-30 seconds on each side x2 using medium pressure. This is how I prep my rotors when changing pad compounds/brands...
Orbital sander + 120 grit pad 20-30 seconds on each side x2 using medium pressure. This is how I prep my rotors when changing pad compounds/brands. I even do this when changing pads to fresh ones. Never let me down.
You don't even need to use an orbital sander. I just take a sheet of 150 grit, spin the wheel on the frame and hold the...
You don't even need to use an orbital sander. I just take a sheet of 150 grit, spin the wheel on the frame and hold the sandpaper against the rotor one side at a time. You don't need much pressure or time - just trying to clean off the surface deposit of pad compound.
Yeah, but an orbital sander is way easier in my opinion. Granted you might scuff up some of the pant/markings off the brake surface itself, but it was a price I was willing to pay.
I've tried the sandpaper to rotor on the bike for years and never got it to work.
Hey All, this is borderline brake tech... more of a brake question then anything.For all the TRP DHR Evo users (The previous generation, not the new...
Hey All, this is borderline brake tech... more of a brake question then anything.
For all the TRP DHR Evo users (The previous generation, not the new Evo X) what are you doing for dropper post remote mounting? I previously had a wt light action remote, with a discrete 22mm clamp that played ok with the dhr evo levers. This last weekend, I went to move a wt remote pro over to the bike with the DHR Evo's and there is virtually no way to get them to play together ergonomically. I emailed WT components and they pointed out that while TRP claims that their levers are I Spec-II compatible, that TRP altered their version of I-spec and not directly compatible with WT (and sounds like most other) ispec clamp designs.
So... what dropper levers are people using with this brakes, and how do you have them mounted?
Most I-Spec II adapter have a lip at the end, I just cut that lip and it worked well for the time I had my set of DHR Evo and wolftooth dropper / sram shifter.
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.
Hey, I don't know if you have checke this yet, but take a look at how the olive is sitting on the hose at the lever. When I first got my Hayes, I had a shop set them up for me and who ever did the install got the barb and olive on the hose crooked. That allowed dot fluid to get into the fiberglass insulation in the hose and bassically would drain the master cylinder over time. I cut the old barb and olive off and properly set a new one in and I've never had issues since
Great point! I have a few spare olives and enough hose so I will install fresh ones on the next bleed. I've experienced that once on SRAM when I kinked my hose.
Hey All, this is borderline brake tech... more of a brake question then anything.
For all the TRP DHR Evo users (The previous generation, not the new Evo X) what are you doing for dropper post remote mounting? I previously had a wt light action remote, with a discrete 22mm clamp that played ok with the dhr evo levers. This last weekend, I went to move a wt remote pro over to the bike with the DHR Evo's and there is virtually no way to get them to play together ergonomically. I emailed WT components and they pointed out that while TRP claims that their levers are I Spec-II compatible, that TRP altered their version of I-spec and not directly compatible with WT (and sounds like most other) ispec clamp designs.
So... what dropper levers are people using with this brakes, and how do you have them mounted?
Going to circle back here. Just got an orbital sander to breath new life into some of the "dead" rotors I've accumulated.
Holy smokes did it work super well, a bit of 150 grit to 220 and they look brand new.
You don't even need to use an orbital sander. I just take a sheet of 150 grit, spin the wheel on the frame and hold the sandpaper against the rotor one side at a time. You don't need much pressure or time - just trying to clean off the surface deposit of pad compound.
Awesome! Glad you tried it out. Switching between pad compounds has never been easier.
This is a great tip. I already have an random orbital sander chilling in my closet. Easy to do.
Yeah, but an orbital sander is way easier in my opinion. Granted you might scuff up some of the pant/markings off the brake surface itself, but it was a price I was willing to pay.
I've tried the sandpaper to rotor on the bike for years and never got it to work.
Most I-Spec II adapter have a lip at the end, I just cut that lip and it worked well for the time I had my set of DHR Evo and wolftooth dropper / sram shifter.
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