Downhill bike brake replacement options

John U

MTB Precision
My new rig has Guide Rs. Front is nowhere near as crisp after first trip to Buller. Feels spongy, like it’s in need of a bleed. I also felt like I was on them more than my old bike. I put this down to the bike being quicker but now I’m thinking it was the Guides weren’t as powerful. My old Sunday had Saints, and then Formula R0s.
I had similar bleed issues with Saints (810s) when up at Buller. They went spongy on a couple of occasions. I didn’t have that issue with the Formula R0s.

I’d appreciate any feedback on what would be a good approach. Get Guides bled and stick with them? Get new brakes? If so which ones?
Formula seem to be rarer than they were a couple of years ago. Parts are expensive but they are single piston and I’ve got the bleed gear covered
Would Guide RSCs be any better than Guide rs? There’s some RSCs for sale here
Have 820 Saints resolved 810 bleed issues?
Magura?
Zees?
Any input would be greatly appreciated.
 

Oddjob

Merry fucking Xmas to you assholes
Sounds like a bleed issue. I've found all multipots a pain to bleed. The best way I've found is to degass liquid in syringe by blocking syringe then gently pulling back on plunger. Small air bubbles should form which you push out of plunger. Then push liquid up from dismounted calipers, while rotating and tapping, and let excess flow out of levers until no more bubbles.

This is easier to do with Shimano which has the screw in cup for the levers. Mineral oil is also non-corrosive and seems to have no use by date. Ie you can keep an open bottle seemingly forever.

On topic. I've been able to get perfect bleeds with Zees and m785s which should mean that m820s should be no problem. I've found the Zees to be plenty strong enough for me.

The new formula curas use mineral oil as well and have been reviewed well. Bike-discount/bike24/bike components have them for ~$300.

The current generation of Maguras seem to be patchy.

Personally I would see if I could get a good bleed on the guides first. If not investigate the Saints if cost is no object or get the Curas if you've been happy with Formulas previously.

Sent from my SM-G900I using Tapatalk
 

link1896

Mr Greenfield
Guide RS and RSC use the same lever linkage arrangement, so same power transfer, just RSC is a little nicer feel/usage wise with its pad contact adjustment.
 

Mywifesirrational

I however am very normal. Trust me.
Having come from a few sets of RO's (still using them on some bikes), the MT5/7 is the only brake I have since tried that I am happy with. More powerful than RO's, more modulation and besides getting a good bleed on 1 of 4 of them, they have been outstanding. 67 euro an end from bike discount at the moment. Guides, just don't have enough power for me, feel more like a trail riding brake in comparison.
 

John U

MTB Precision
Having come from a few sets of RO's (still using them on some bikes), the MT5/7 is the only brake I have since tried that I am happy with. More powerful than RO's, more modulation and besides getting a good bleed on 1 of 4 of them, they have been outstanding. 67 euro an end from bike discount at the moment. Guides, just don't have enough power for me, feel more like a trail riding brake in comparison.
How hard are they to get a decent bleed on? My first set of discs, 15 years ago, were Marta’s. They were brilliant brakes but finding someone who knew how to bleed them was like a search for rocking horse shit. Many stores said they could do it only to fuck the job up and charge me for the privilege.
 

Mywifesirrational

I however am very normal. Trust me.
How hard are they to get a decent bleed on? My first set of discs, 15 years ago, were Marta’s. They were brilliant brakes but finding someone who knew how to bleed them was like a search for rocking horse shit. Many stores said they could do it only to fuck the job up and charge me for the privilege.
If you can bleed RO's, MT5/7's will be easy.

Pretty much same bleed process as shimano, cup top / open syringe in lever, push fluid through from bottom. Only error I made was not enough fluid to ensure no air in lines (needs 40-50ml) and hold the caliper so the brake line is at the high position when bleeding, as soon as I did this my temperamental MT5 was perfect and has stayed that way. Having used two sets over the last 15 months, my only issue was user error.

The only two other things to note with MT5's - one peice pads, where as the MT7's have 4 pads per caliper, 4 pads much easier to align caliper and the stock resin pads are alright for trail riding, but the MT7 or aftermarket pads are noticably more powerful, might be worth pricing that into the equation. However, I am currently using the resin pads in the rear with a 203mm rotor, no issues with power or heat in the dry.

They also shred pads pretty fast, twice as fast as RO stock pads. Not a concern, but I wouldn't be going away for a week away without spares in tool box if the pads weren't near new.
 

slowmick

38-39"
How hard are they to get a decent bleed on? My first set of discs, 15 years ago, were Marta’s. They were brilliant brakes but finding someone who knew how to bleed them was like a search for rocking horse shit. Many stores said they could do it only to fuck the job up and charge me for the privilege.
i had a set of Marta's that tried to kill me on a number of occasions and were never really bled properly (with many different people trying). Maybe we need to get together and perform some kind of ritual sacrifice - I've still got my set in the garage. :)
 

Boom King

downloaded a pic of moorey's bruised arse
I absolutely love my ROs. I'm about to try Formula Cura which have good reviews.
 

The Duckmeister

Has a juicy midrange
Sounds like a bleed issue. I've found all multipots a pain to bleed. The best way I've found is to degass liquid in syringe by blocking syringe then gently pulling back on plunger. Small air bubbles should form which you push out of plunger. Then push liquid up from dismounted calipers, while rotating and tapping, and let excess flow out of levers until no more bubbles.
As well as this, before opening the top of the system, attach the bleed syringe to the caliper & open the nipple. With the caliper rotated so the bleed port it at the highest point, gently alternate between pulling back on the lunger to extract any air from the caliper, and pumping fluid in to replace it. When no more air is pulled out, open the top bleed port and push any air bubbles up & out. Some brakes, particularly certain Avid/SRAM levers, need a repeat of the suck/squeeze at the top; close the caliper nipple & pull the brake lever in. Suck air out, squeeze fluid in until no more air escapes.
 
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