Knuckles
Lives under a bridge
Thank christ......Do some creative lever blade shaping. My newly remodeled Formula RO blade comes nowhere near my knuckles....
Thank christ......Do some creative lever blade shaping. My newly remodeled Formula RO blade comes nowhere near my knuckles....
This long:The gap between the end of the grip and the brake lever clamp is huge. How long are those levers when not crumpled?
You don't need to twiddle the reach adjust knob on Shimano brakes, as it acts independently of the master piston in the bore; just wind the contact stroke adjuster (which is nothing more than a return sopper for the piston) out so you can fully fill the system, then adust it back in to suit.
I'm pretty lazy with my hope bleeds...pop the reservoir and top it up...with my xt brakes I wind the adjustments all the way out for reach and bpc. The run the juice through and firm them up. Close off and wind the adjustments to where I like them. This might work on the hopes. I'll likely try something like that next time I bleed them. If I can be bothered. I haven't felt the need before as they work so well as is.
Bleeding multi piston calipers can be a bitch, your issues of throw/bite point/pump up are bad bleed related. Even vacuum bleeding guides can be tricky.
Really need a bit of both, with all brakes. For those playing at home, most brake calipers have the fluid passages in a "H" pattern, with the hose & bleed port on the top arms of the H, the bridging passage below the port, with the pistons/cylinders in the bottom legs of the H. More recent Shimano brakes (M595 Deore & onward) have a "U" pattern routing, where the fluid comes down the hose, past the piston/s on one side, through the bridging passage then past the other piston/s to the bleed port.I've heard that sucking air out of the callipers can give a better bleed than pumping fluid through the system, so I'll give that a go.
Hey ducky, welcome back from your torturous December of bike retail. I'd like to claim warranty on two inner tubes please.....Really need a bit of both, with all brakes. For those playing at home, most brake calipers have the fluid passages in a "H" pattern, with the hose & bleed port on the top arms of the H, the bridging passage below the port, with the pistons/cylinders in the bottom legs of the H. More recent Shimano brakes (M595 Deore & onward) have a "U" pattern routing, where the fluid comes down the hose, past the piston/s on one side, through the bridging passage then past the other piston/s to the bleed port.
Anyway, what you need to do is demount the caliper from the frame, and jiggle it about so that any trapped air can escape from the slave cylinders and rise to the bleed port. Knowing your brake's porting pattern is necessary to ensure you jiggle the caliper the right way. With the top of the system closed and your fluid-filled syringe attached to the caliper, open the bleed nipple and gently suck any air out of the caliper. Be gentle, because if you're too aggro you'll pull air past the nipple threads. Push fluid in to replace the air, then suck, and repeat until no more air comes out of the caliper. Then open the top port of the system and push fluid up from the caliper; any air in the hose and/or reservoir will be pushed up to the top. If the reservoir bleed port is at the highest point, with most brakes you just need to pump fluid up until no more air comes out into your top syringe or bleed cup, but SRAM "Taper bore" levers, such as Elixir & Trail brakes need a repeat of the suck & squish process, while holding the lever in, 'cos their shits of things.
Some brakes can allow you to play with contact stroke/bite point by force-feeding the system, but they need to have a bleed niple you can close off while the syringe is still attached; close the reservoir port, inject fluid into the caliper (with no escape at the top, the added fluid volume will advance the caliper pistons), then close off the caliper nipple.
Sorry, haven't touched any of the new "bleeding edge" variant yet. I've always bled brakes as per ducky's notes above, just never thought to mention it to others.Hey Duck/Link, have you had any experience with the "bleeding edge" system on the most recent Guide and Code brakes? It looks to have simplified the bleed process somewhat - does it give more consistent results though?
On another note, here's a recent Vital review of DH brakes which may be of interest - Hope V4 just pips the new Code.
Hey Ducky - I have elixir trail brakes which I can get an ok bleed on but have never understood the process for winding in the bite point fully before bleeding. It leaves you with no adjustment other then the wind it out which is useless. Am I better off winding it in to the mid point before bleeding to leave adjustment in both directions or would this mess with the internals and ruin the bleed?Really need a bit of both, with all brakes. For those playing at home, most brake calipers have the fluid passages in a "H" pattern, with the hose & bleed port on the top arms of the H, the bridging passage below the port, with the pistons/cylinders in the bottom legs of the H. More recent Shimano brakes (M595 Deore & onward) have a "U" pattern routing, where the fluid comes down the hose, past the piston/s on one side, through the bridging passage then past the other piston/s to the bleed port.
Anyway, what you need to do is demount the caliper from the frame, and jiggle it about so that any trapped air can escape from the slave cylinders and rise to the bleed port. Knowing your brake's porting pattern is necessary to ensure you jiggle the caliper the right way. With the top of the system closed and your fluid-filled syringe attached to the caliper, open the bleed nipple and gently suck any air out of the caliper. Be gentle, because if you're too aggro you'll pull air past the nipple threads. Push fluid in to replace the air, then suck, and repeat until no more air comes out of the caliper. Then open the top port of the system and push fluid up from the caliper; any air in the hose and/or reservoir will be pushed up to the top. If the reservoir bleed port is at the highest point, with most brakes you just need to pump fluid up until no more air comes out into your top syringe or bleed cup, but SRAM "Taper bore" levers, such as Elixir & Trail brakes need a repeat of the suck & squish process, while holding the lever in, 'cos their shits of things.
Some brakes can allow you to play with contact stroke/bite point by force-feeding the system, but they need to have a bleed niple you can close off while the syringe is still attached; close the reservoir port, inject fluid into the caliper (with no escape at the top, the added fluid volume will advance the caliper pistons), then close off the caliper nipple.
Tough bickies, I'm on holidays.Hey ducky.... . I'd like to claim warranty on two inner tubes please.....
Only reason I can think of for that suggestion is that DOT fluid (especially 5.1) absorbs moisture, and expands as it does so, therefore setting the contact stroke at its shortest when bleeding allows you to back it off as the fluid volume increases over time, so it doesn't jam the brake on.Hey Ducky - I have elixir trail brakes which I can get an ok bleed on but have never understood the process for winding in the bite point fully before bleeding. It leaves you with no adjustment other then the wind it out which is useless. Am I better off winding it in to the mid point before bleeding to leave adjustment in both directions or would this mess with the internals and ruin the bleed?
Cheers
Thanks for the response. There is quite a bit of adjustment so I might try my luck at midway and see how i go.Only reason I can think of for that suggestion is that DOT fluid (especially 5.1) absorbs moisture, and expands as it does so, therefore setting the contact stroke at its shortest when bleeding allows you to back it off as the fluid volume increases over time, so it doesn't jam the brake on.
Do you think it is possible that with open systems like Hope don't suffer from this issue? Unlike closed systems like SRAM brakes where any fluid expansionn from moisture absorption is going to lock up the brakes. The hopes would just absorb or blow off the extra volume via the big bladder seal on top of the master cylinder.Only reason I can think of for that suggestion is that DOT fluid (especially 5.1) absorbs moisture, and expands as it does so, therefore setting the contact stroke at its shortest when bleeding allows you to back it off as the fluid volume increases over time, so it doesn't jam the brake on.
You finally understand, fuck, took you long enoughThey're better cause they cost loads, your mates will think your bike is awesome cause you have hope brakes (notice how I don't spell it breaks ) and they come in lovely colours.