Frankenbrakes and brake improvement discussion
- Thread starter Udi
- Start date
Now imagine brakes that would not need rotors, but that would perhaps engage against the rims directly? Great leverage ratio - increasing with wheel size, no additional weight, lots of surface for heat dissipation... 
Big surface that easily gets easily dirty and wet, a nice load bearing surface you happily reduce in its thickness, a surface that has heat sensitive materials attached to it (ask a roadie), a surface in a perfect shape for pressing a friction pad against it.
Find the mistakes.
Ad rotors: received some answers, no bad experiences regarding glazing so far, but no proof of it not happening. The Shimano rotors used for temperature comparison are the non IceTech spider ones. He has no plans on comparing them to IceTech. That's it.
I agree with Udi, an expensive "upgrade" not making any sense, imho.
Find the mistakes.
Ad rotors: received some answers, no bad experiences regarding glazing so far, but no proof of it not happening. The Shimano rotors used for temperature comparison are the non IceTech spider ones. He has no plans on comparing them to IceTech. That's it.
I agree with Udi, an expensive "upgrade" not making any sense, imho.
Kill the messenger.I was told that there would be NO maths.
Wot? I'm too stupid to get this joke.
And a circumference of about... uhm, 650b?
Formula used to have an online store, just as little as a month ago. It used to have on it a service/parts kit for specific brakes model. I can't find these anymore. Does anyone know how to find those anymore? I think they used to be called a "red box", but maybe I'm making that up.
It seems like they are rebuilding their distribution network. They used to run a special company in Germany doing the distro and service work. This company has been shut down and a big distributor has taken over the work for Germany and Austria. Maybe the same is happening over at your shore. Did you try to contact any dealer running Formula products and asking him?
They are not an intense business, allegedly.
They are not an intense business, allegedly.
I haven't seen much discussion about brake bleeding technique. came across this today and thought 'that was interesting'...
thoughts from the peanut gallery?
I'm not sure if this method can drain out all air if you already have a messy system. You gonna end up with a lot of dirty rags, that I'm sure about.
I guess Marshy has a lot of experience wrenching on brakes that are used in a very demanding way. Would be interesting to know how often he is doing this.
Maybe we could also bring in some information about other brakes here as well.
I guess Marshy has a lot of experience wrenching on brakes that are used in a very demanding way. Would be interesting to know how often he is doing this.
Maybe we could also bring in some information about other brakes here as well.
Yeah not my choices or way of doing things either, but I don't think he really did anything wrong.
Obviously works for him and good on them for sharing.
Worth noting, IMO the rubber cap keeps dirt out of the nipple just fine, but the big reason you shouldn't pull on the syringe on a bleed nipple brake is because the nipple connection is not airtight (like a grubscrew connection ala avid/formula/trickstuff is). If you pull on the syringe on a shimano/hope you'll pull air into the syringe around the bleed nipple threads and think that it's coming out of the brake when it isn't.
However there's nothing wrong with pushing a syringe full of fluid up through a shimano brake, it's a much faster way of getting all the black wear material out. Can gravity bleed a little first if worried about dirt.
Being able to draw a small vacuum does make bleeding (from empty, or with air inside) much easier so the screw-in syringe fittings are superior. Bleeding can mean two different things - changing the fluid, and actually getting air out - different techniques are needed.
One thing I definitely would have added though is washing the caliper at the end / alcohol spray.
Obviously works for him and good on them for sharing.
Worth noting, IMO the rubber cap keeps dirt out of the nipple just fine, but the big reason you shouldn't pull on the syringe on a bleed nipple brake is because the nipple connection is not airtight (like a grubscrew connection ala avid/formula/trickstuff is). If you pull on the syringe on a shimano/hope you'll pull air into the syringe around the bleed nipple threads and think that it's coming out of the brake when it isn't.
However there's nothing wrong with pushing a syringe full of fluid up through a shimano brake, it's a much faster way of getting all the black wear material out. Can gravity bleed a little first if worried about dirt.
Being able to draw a small vacuum does make bleeding (from empty, or with air inside) much easier so the screw-in syringe fittings are superior. Bleeding can mean two different things - changing the fluid, and actually getting air out - different techniques are needed.
One thing I definitely would have added though is washing the caliper at the end / alcohol spray.
No need. he dried the oil up with the towel.
adding alchohol is likely to dry the pistons/seals he let the oil lube.
The tip about wetting new pads and rubbing them together to make them grabby is a good one.
Not that you're all that likely to get a chance to bed pads in in the dry over here.
No, he distributed the oil all over the caliper with the towel, and it will stay there until washed.
That's just asking for contamination, not a big deal when you're a WC team with free pads and rotors, but for average joe the first step to brakes that work well is brakes that are clean.
If we want to nitpick, the correct lubrication for the pistons is grease (not oil, which will vanish at first bike wash).
What kind of grease @Udi ? Will slickhoney do? I used to put a little shimano mineral oil around the sides of the pistons of my old slx brakes using a q-tip. I haven't done it yet on my m615 deores. The rear brake pistons are at uneven heights when I squeeze the levers. Friend of mine at a shop took the caliper apart and cleaned it but piston height is still uneven.
DOT brakes: Finish Line PFPAE, I've explained here in detail
Oil brakes: Rubber grease, eg. Castrol Red Rubber Grease
It's best to assemble with the grease initially, but pumping the pistons out (obviously not all the way) and cleaning with isopropyl alcohol, followed by greasing and cycling works (repeat the greasing and cycling a few times for stubborn pistons). The cleaning step is important not just for dirt, but to eliminate any oil/fluid which will only serve to dissolve the grease and reduce its longevity. Once they are greased, push the pistons all the way back in and clean everything including the inside of the caliper, detergent and a sponge are fine. Make sure you center the rotor in the caliper's rotor slots when reinstalling.
Edit - swapped the Molykote suggestion for RRG, the NBR seals used in oil brakes should be fine with both, but the RRG will be safer (and cheaper too).
Oil brakes: Rubber grease, eg. Castrol Red Rubber Grease
It's best to assemble with the grease initially, but pumping the pistons out (obviously not all the way) and cleaning with isopropyl alcohol, followed by greasing and cycling works (repeat the greasing and cycling a few times for stubborn pistons). The cleaning step is important not just for dirt, but to eliminate any oil/fluid which will only serve to dissolve the grease and reduce its longevity. Once they are greased, push the pistons all the way back in and clean everything including the inside of the caliper, detergent and a sponge are fine. Make sure you center the rotor in the caliper's rotor slots when reinstalling.
Edit - swapped the Molykote suggestion for RRG, the NBR seals used in oil brakes should be fine with both, but the RRG will be safer (and cheaper too).
Slick honey should work OK (note: for mineral oil brakes only) if you follow the procedure I wrote.
Any food-safe silicone grease will work OK too (note: for both mineral oil and DOT brakes).
I find it helps if you hold the piston (w/ plastic tyre lever etc) that moves more freely, and grease + cycle the "lazy" one.
Not sure if anyone caught this, as it was in a review of a gearbox bike, but
andMike Levy said:
it sounds like they're making their own 'franken brake' of sorts...Mike Levy said:
The last time I rebuilt my oros this is the email I used to get parts. No promises because it’s been a few years. (2013) I still have my k24’s hanging in my garage. They were one of my favorite brakes of all time. I wish I would have stocked up on parts.
rdavis@formula-italy.com
@Udi when my shimano m615 rear brake gets hot (e.g. from dragging) the lever moves outward and one time the pistons even locked the rotor. Shop guy took the caliper apart and also bled it and it didn't lock anymore but the main problem remains and yesterday when it got hot I noticed only one piston was moving. Brake returned to normal after a while. Can this be solved by a good bleed/more thorough cleaning?
Not what you want to hear, but I'd say no.
Shimano build disposable brakes these days, it sounds like it's time to buy a new one.
Bummer. I dropped it off this afternoon at my friend's shop to have it checked. I replaced it this morning with my old slx m665 brakes (bought ca. 2008) that I had not used in more than a year or two years and it still works. I'll update here if I get the deore fixed or not. Thanks for the help.
Anyone know if I can leave the old barb and olive on a SRAM hose when swapping Guide levers or do I need to use the new style screw in barb and screw on olive supplied with the new lever?
You can usually get away with leaving the old barb and olive on (although it's not recommended, for safety a new pair should always be used, etc). Just tighten it up a little extra and then hold the lever pressed with the rubber boot pulled back after bleeding and watch for leaks. 90% of the time it's good to go.
If the lever actually comes with a new pair though it's probably a good idea to use them, unless your hoses are too short.
If the lever actually comes with a new pair though it's probably a good idea to use them, unless your hoses are too short.
I didn't want to have to shorten one of the hoses as there's not much slack. I was swapping the brakes onto a different bike while also putting on the new levers.
I'll take another look, thanks.
Someone hit Udi with the rep button please.
I'll take another look, thanks.
Someone hit Udi with the rep button please.
Done. What a bunch of nerds (with Udi as chief nerd). Glad I joined ridemonkey.
we're glad to have you here. maybe
Building new 27.5 trail bike. I think I'm going to use my T1's in the interim, but would like to possibly try something new. Upgrade to Cura worth it? Or should I try something new completely off the reservation?
Side note, does anyone know if the standard formula/avid bleed kit still works on the Cura's? I have a nice Avid pro bleed kit that it'd be nice to still be able to utilize.
Side note, does anyone know if the standard formula/avid bleed kit still works on the Cura's? I have a nice Avid pro bleed kit that it'd be nice to still be able to utilize.
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Curas are mineral oil, Avids are DOT, so you won't be able to use the old bleed kit with them. I'd still go for the Curas if I was you.
You can actually use the Avid Pro bleedkit just fine - those syringes are of high quality, and they use standard o-ring sizes so all you have to do is take take all the o-rings out and get them matched at a seal shop (or measure them), and replace with standard NBR (Nitrile) seals for use with oil. There are some hidden o-rings inside the fitting/s from memory if you want to be thorough, but mainly just need to do the piston one + threaded tip one.
I've been using an aliexpress copy of the same kit (wasn't super cheap, an excellent copy with slightly nicer fittings in fact) and it's been going for years with both fluids. If you want to be safe just make sure you wash the syringes with detergent after each use - I've made a habit of it, and usually store them with the plunger unscrewed and removed for good measure.
I've been using an aliexpress copy of the same kit (wasn't super cheap, an excellent copy with slightly nicer fittings in fact) and it's been going for years with both fluids. If you want to be safe just make sure you wash the syringes with detergent after each use - I've made a habit of it, and usually store them with the plunger unscrewed and removed for good measure.
I reckon I'll just go with my newest pair of T1's and try the Cura's at some point. Pinkbike just posted a review of the Cura's and that quick release hose system looks pretty sweet(new bike has fully internal routing for the rear brake). Good to know about the orings, thanks for that. Got a link to the knockoff kit you bought? Did you bother replacing the orings in that or will a thorough flush after each use be sufficient for a while?
Not adding anything useful to say to the conversation, but finally got around to mating my front mt5 caliper to an old SLX br666 lever. It has been the best brake i have ever run and i will likely being purchasinf another set for my DH bike this summer.
With shimano, it seems that when they switched to ceramic pistons things went down hill. Anyone try the metal ones sold on ebay?