Joined
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6 Posts
Hi all at mtbr, my maiden post and alas it's a complaint / problem but that's usually what I'm not about.............
I'm 50 years old, live in SE Australia and ride only easy forest trails, plantation tracks and occasional social rail trail ride weekends. I'm a cautious rider - never had more than 18" of air under me - most of the time 12" of air under me is sufficient to get me my thrills. Nearly all of my MTB riding is done in dry and partly dusty conditions - 20km/hr downhill for me is really fast..........
I built up my 2017 Yeti SB6c frameset with XTR M9000 brakes. Yeah, yeah - I know the SB6 is way more bike than I am rider but what the hell, I deserve it.
I also have a 2008 Giant Trance 0 - this one I built up with XT M8000 series brakes. The XT brakes have never given me a moment of bother - just finished the 2nd set of resin pads, a complete oil refill and bleed and the third set are now bedded in and working exactly like new resin pads work on XT - pretty damn good for a low risk rider like myself.
My problem is with the SB6............ the bike I love the ride characteristics of the most but the build that has given me the least amount of joy since it was finished in late 2017.
The SB6 :- the original set of pads (resin) I bedded in with a very gentle method, 15km/hr to nearly stand still - maybe 35- 40 repeats and not much more than 50% pressure on the lever. The front worked fine for maybe 200km of dry dusty trail riding then honked / squeaked with every application of the brake. The rear was initially quiet and worked for less than 100km before it began to do the same.
My learning curve grew upward fast. I've learned to emery paper the pads, clean, rinse and dry - sand the rotors lightly etc. Same deal - same distances before troubles started. I've used isopropyl alcohol, acetone and commerical in a can brake cleaner at different times.
I upgraded from the Avid Clean Sweeps to Sram Centerlines with new resin pads. The results got me slightly longer distance service for the front but the rear squealed from the start and never got better. The pads glazed so badly I ditched them for a new pair and this time I used a more forceful bedding in method - down a really long steep hill, yanking on the brake for a few seconds then cooling for a few seconds and repeating - 15 repeats. I got two 30km rides in before the pads glazed again but this time only making noise at the very end of the braking cycle ie walking pace to a halt.
Since then I have tried a pair of sintered pads on the Centerlines - front OK but no real initial bite - rear brake was really bad- could never get it bedded in and glazed the pads 3 times before ditching that idea.
Changed to a barely used pair of Magura rotors and upgraded size to 180mm - fresh resin pads and alas the same thing. Front works well for a couple of rides before glazing hard and the rear for about half as long before glazing hard.
My rotors are clean and well aligned. My pads have been new from the start and my sanding / cleaning attempts have been thorough. The hose line banjos are torqued right, no leaks and the pistons are well sealed - no leaks. Every time I remove glazed pads there is no rotor drag and the pistons appear to have retracted just fine.
I'm pretty much at my wit's end with this one. 5 pairs of resin brakes (Shimano and Swiss Stop) and one pair of (Shimano) sintered brakes later I'm at a complete loss. This is a 4 year old thorn in my side that I can't fix. I've attached a pic of a typical pair of glazed over pads - these are from the rear after 2 x 25km rides admittedly I hardly giving the brakes a hard workout on those two rides but you get the picture..........
I'm yet to try sintered pads on the Magura rotors and that is next but aside from that I'm thinking best to ditch the whole brake system and try something else and yet that makes no sense...... as it's the pads that are letting me down?
I like to do all my own bike maintenance, have built up 7 road bikes and 4 MTB's and I like my stuff to run as close to perfectly as possible. Howling glazed over brakes does not come even close to perfect - I've effectively had no value and certainly no joy from my M9000 brakes. I really see this as a personal challenge - even if my brake system is no good I really want to know why it's no good - it's driving me nuts.
Any suggestions - what am I missing here?
I'm 50 years old, live in SE Australia and ride only easy forest trails, plantation tracks and occasional social rail trail ride weekends. I'm a cautious rider - never had more than 18" of air under me - most of the time 12" of air under me is sufficient to get me my thrills. Nearly all of my MTB riding is done in dry and partly dusty conditions - 20km/hr downhill for me is really fast..........
I built up my 2017 Yeti SB6c frameset with XTR M9000 brakes. Yeah, yeah - I know the SB6 is way more bike than I am rider but what the hell, I deserve it.
I also have a 2008 Giant Trance 0 - this one I built up with XT M8000 series brakes. The XT brakes have never given me a moment of bother - just finished the 2nd set of resin pads, a complete oil refill and bleed and the third set are now bedded in and working exactly like new resin pads work on XT - pretty damn good for a low risk rider like myself.
My problem is with the SB6............ the bike I love the ride characteristics of the most but the build that has given me the least amount of joy since it was finished in late 2017.
The SB6 :- the original set of pads (resin) I bedded in with a very gentle method, 15km/hr to nearly stand still - maybe 35- 40 repeats and not much more than 50% pressure on the lever. The front worked fine for maybe 200km of dry dusty trail riding then honked / squeaked with every application of the brake. The rear was initially quiet and worked for less than 100km before it began to do the same.
My learning curve grew upward fast. I've learned to emery paper the pads, clean, rinse and dry - sand the rotors lightly etc. Same deal - same distances before troubles started. I've used isopropyl alcohol, acetone and commerical in a can brake cleaner at different times.
I upgraded from the Avid Clean Sweeps to Sram Centerlines with new resin pads. The results got me slightly longer distance service for the front but the rear squealed from the start and never got better. The pads glazed so badly I ditched them for a new pair and this time I used a more forceful bedding in method - down a really long steep hill, yanking on the brake for a few seconds then cooling for a few seconds and repeating - 15 repeats. I got two 30km rides in before the pads glazed again but this time only making noise at the very end of the braking cycle ie walking pace to a halt.
Since then I have tried a pair of sintered pads on the Centerlines - front OK but no real initial bite - rear brake was really bad- could never get it bedded in and glazed the pads 3 times before ditching that idea.
Changed to a barely used pair of Magura rotors and upgraded size to 180mm - fresh resin pads and alas the same thing. Front works well for a couple of rides before glazing hard and the rear for about half as long before glazing hard.
My rotors are clean and well aligned. My pads have been new from the start and my sanding / cleaning attempts have been thorough. The hose line banjos are torqued right, no leaks and the pistons are well sealed - no leaks. Every time I remove glazed pads there is no rotor drag and the pistons appear to have retracted just fine.
I'm pretty much at my wit's end with this one. 5 pairs of resin brakes (Shimano and Swiss Stop) and one pair of (Shimano) sintered brakes later I'm at a complete loss. This is a 4 year old thorn in my side that I can't fix. I've attached a pic of a typical pair of glazed over pads - these are from the rear after 2 x 25km rides admittedly I hardly giving the brakes a hard workout on those two rides but you get the picture..........
I'm yet to try sintered pads on the Magura rotors and that is next but aside from that I'm thinking best to ditch the whole brake system and try something else and yet that makes no sense...... as it's the pads that are letting me down?
I like to do all my own bike maintenance, have built up 7 road bikes and 4 MTB's and I like my stuff to run as close to perfectly as possible. Howling glazed over brakes does not come even close to perfect - I've effectively had no value and certainly no joy from my M9000 brakes. I really see this as a personal challenge - even if my brake system is no good I really want to know why it's no good - it's driving me nuts.
Any suggestions - what am I missing here?