Ask the experts

[bagtagley]

Roxtar has you right here. Your symptoms and brake age are correct for this issue. It tends to be worse the warmer it gets. I have literally replaced 100's of guide levers because of this issue. Good news is the replacements work.

This was my thought as well. Doesn't take much heating, like the going from shade to sun on a particularly hot day. Mine have done it since I got the bike. It's usually my cue to switch bikes so I can take them off and take them to the LBS for warranty replacement, but instead I put the bike in the shed and forget about it until Fall. Vicious cycle.

[One (+) Sentence]

This was my thought as well. Doesn't take much heating, like the going from shade to sun on a particularly hot day. Mine have done it since I got the bike. It's usually my cue to switch bikes so I can take them off and take them to the LBS for warranty replacement, but instead I put the bike in the shed and forget about it until Fall. Vicious cycle.

Sounds crazy and not a long term solution, but if this happens on a ride you can cool the levers down by shooting em with water and your brakes will work again temporarily. I’ve even seen people with ice packs Ace bandaged on their levers to do complete rides.

I think the warranty time frame for affected levers has expired, although some shops may still have a stock of replacement levers from SRAM and be willing to help.

[Dantheman]

Sounds crazy and not a long term solution, but if this happens on a ride you can cool the levers down by shooting em with water and your brakes will work again temporarily.

Can confirm. Had this issue on the kid's Rokkusuta and they'd get so bad the bike wouldn't even roll.

[XXX-er]

There was a brand (forget name) of brake back in the day that would completely lock up when it got hot enough and I seen that happen on a 45min 900m down hill, I believe it was cuz the design used a closed system so the fluid had no where to expand and no other brands used a closed system for this very good reason

arent the guides also vented so they won't lock up due to overheating ?

[HAB]

There was a brand (forget name) of brake back in the day that would completely lock up when it got hot enough and I seen that happen on a 45min 900m down hill, I believe it was cuz the design used a closed system so the fluid had no where to expand and no other brands used a closed system for this very good reason

arent the guides also vented so they won't lock up due to overheating ?

The really early Hopes were a closed system.


I forgot about the Guide lever thing, but the issue there wasn't exactly expansion of the fluid, but that you could actually get the lever internals hot enough (via heat from the fluid) to expand and bind up. They are a normal semi-open system, but that doesn't do you much good if the lever won't return to open up the timing port.

[Roxtar]

The really early Hopes were a closed system.


I forgot about the Guide lever thing, but the issue there wasn't exactly expansion of the fluid, but that you could actually get the lever internals hot enough (via heat from the fluid) to expand and bind up. They are a normal semi-open system, but that doesn't do you much good if the lever won't return to open up the timing port.

I fixed a lot of these.
The problem was the plastic plunger piston was manufactured a hair too large and had no tolerance for heat expansion. The fix was to replace the piston with new, correctly manufactured, ones. On certain Guide models it was pretty simple (I forget which ones). On others it was a serious PITA getting the snap rings out.

[XXX-er]

The really early Hopes were a closed system.


I forgot about the Guide lever thing, but the issue there wasn't exactly expansion of the fluid, but that you could actually get the lever internals hot enough (via heat from the fluid) to expand and bind up. They are a normal semi-open system, but that doesn't do you much good if the lever won't return to open up the timing port.

I would be talking 15-20 years ago and no it wasnt the Hope product, the brakes were completely locked up and buddy had to push the bike down hill

[jamal]

I had my front guide start sticking last year in hot weather after being totally fine for thousands of miles over the previous couple of years. I feel like it was not so much an initial mfg issue and more the seals and/or piston expanded over time due to possibly the fluid or contamination of the fluid?

Rebuilt the lever last week, was not too difficult and works great now. The old one was in there pretty good and the new one slides nicely.





Kit has an msrp of something like $39, comes with a new rocker link, bushings, contact adjuster deal, reservoir bladder, little spring and ball.

[beaterdit]

Speaking of SRAM brakes, anyone have time on the new G2s? Building a new bike and was tempted by the price and *alleged* increased power and reliability. Noticed that lever bearings are only an option on the spendy 'Ultimate' option and just went with CODE RSCs again but still curious.

[nickwm21]

All this brake talk has me pondering the old question...

Why do mountain bike brakes suck?


Sent from my iPhone using Tapatalk

[El Chupacabra]

All this brake talk has me pondering the old question...

Why do mountain bike brakes suck?

Because yours are SRAM?

[simple]

All this brake talk has me pondering the old question...

Why do mountain bike brakes suck?


Sent from my iPhone using Tapatalk

Because they are shrunken versions of moto brakes using light weight materials, little seals and very little fluid. It is the best it has been but they will always be less reliable than moto brakes.

I love my Brembos BTW.

[jamal]

Also why are rotors so expensive. $50 msrp for a sram centerline. To go along with my lever rebuild I had it bled and got new pads f/r and a new front rotor. Turned into a somewhat pricey bit of maintenance. Oh wait this isn't the rant thread.

[simple]

Because dentists....

[nickwm21]

Because yours are SRAM?

Moved from SRAM to Shimano to now Magura. All different flavors of struggle


Sent from my iPhone using Tapatalk

[One (+) Sentence]

Speaking of SRAM brakes, anyone have time on the new G2s? Building a new bike and was tempted by the price and *alleged* increased power and reliability. Noticed that lever bearings are only an option on the spendy 'Ultimate' option and just went with CODE RSCs again but still curious.

I’ve been on G2 RSC’s since last summer. I’m generally satisfied. The lever feel is really excellent and the adjustments make really noticeable changes.

They do feel underpowered to me. Especially for a 4 piston caliper and especially in comparison to the Hayes Dominions I used in ‘18 and the first half of ‘19. I’m using 180mm rotors with metal scintered pads. I might try Galfer pads and rotors because I hear from reliable sources that they actually will add some power, but ultimately I’ll probably seek out another set of Dominions.

[beaterdit]

I’ve been on G2 RSC’s since last summer. I’m generally satisfied. The lever feel is really excellent and the adjustments make really noticeable changes.

They do feel underpowered to me. Especially for a 4 piston caliper and especially in comparison to the Hayes Dominions I used in ‘18 and the first half of ‘19. I’m using 180mm rotors with metal scintered pads.

Good to know thanks! Sound like decent brakes but glad I stuck with CODES for the power. FWIW though, if they feel underpowered you should throw on a 200 rotor up front. More power and better heat management. I don't consider 180 rotors for the front anymore. Firm believer that you can't have too much brake!

[HAB]

Moved from SRAM to Shimano to now Magura. All different flavors of struggle


Sent from my iPhone using Tapatalk

Yeah, pretty much everything has some sort of issue. I am super impressed with the Dominion A4s after a handful of rides but don't have nearly enough time on them yet to have any idea how they hold up.

[smmokan]

Moved from SRAM to Shimano to now Magura. All different flavors of struggle

I've been using 4-piston Shimano Zee brakes since last fall, and they're bombproof. I just replaced the pads last week after about 6-7 months of use, and with the new TruckerCo pads the brakes are like-new. I've bled them once, but only because I had to disconnect the rear to get it out of an internally-routed frame. Otherwise, no issues whatsoever.

I also have the new 4-piston XT brakes on my GG Smash, and I love those as well. I like the lever feel of those over the Zee brakes, but I've only had that bike for a few months so I can't comment much on durability and reliability quite yet.

[Dantheman]

Firm believer that you can't have too much brake!

Funny story: Sam's dirt jumper has Dominion A4s F/R. With a combined bike and rider weight of maybe 75 lbs it may just be the world's most over-braked bike.

but ultimately I’ll probably seek out another set of Dominions.

[/fistbump]

[rideit]

I would be talking 15-20 years ago and no it wasnt the Hope product, the brakes were completely locked up and buddy had to push the bike down hill

20 years ago team Giant gave me a few used Hope’s, they ALL did that. Completely froze up within minutes on Teton Pass. I called them ‘Hopeless’ from then on.

[El Chupacabra]

20 years ago team Giant gave me a few used Hope’s, they ALL did that. Completely froze up within minutes on Teton Pass. I called them ‘Hopeless’ from then on.

"Sure Stop" or "Reliable" would be a much more reassuring name for bike brakes than "Hope."

[XXX-er]

Speaking of SRAM brakes, anyone have time on the new G2s? Building a new bike and was tempted by the price and *alleged* increased power and reliability. Noticed that lever bearings are only an option on the spendy 'Ultimate' option and just went with CODE RSCs again but still curious.

you've got to ask yourself one question: 'Do I feel lucky?'

[toast2266]

you've got to ask yourself one question: 'Do I feel lucky?'

I think he needs to ask himself 5 questions:
1) do I want a brake that has a history of failure that might be fixed (or maybe not), or
2) do I want a brake that has a 60% chance of occasionally, and without warning, pulling all the way to the bar, or
3) do I want a brake with bleed fittings that'll strip out and with pads that aren't super common, or
4) do I want brakes that are unproven and are built by a company that seems to be perpetually on the verge of bankruptcy, or
5) do I want to spend way more money on something that's fancy and may or may not work well, but no one really knows because only like 17 people on the planet actually own them?

Pick your poison.

[HAB]

I think he needs to ask himself 5 questions:
1) do I want a brake that has a history of failure that might be fixed (or maybe not), or
2) do I want a brake that has a 60% chance of occasionally, and without warning, pulling all the way to the bar, or
3) do I want a brake with bleed fittings that'll strip out and with pads that aren't super common, or
4) do I want brakes that are unproven and are built by a company that seems to be perpetually on the verge of bankruptcy, or
5) do I want to spend way more money on something that's fancy and may or may not work well, but no one really knows because only like 17 people on the planet actually own them?

Pick your poison.

I hate how on the nose this is.

You just forgot 6) do I want brakes that come in shiny anodized colors and seem to hold up okay, but don't really have any power, and couple that with questionable lever ergonomics?

Not to mention that for 5) even if you are willing to spend the equivalent of a down payment on a decent car for pair of brakes, you can't actually have them for like 9 months.