Cable pull of different levers

[BrettM]

Ok another boring topic from me.

Does anyone have any idea if you want more or less cable pull from a lever for a cable disk brake? The reason I ask is that I'm assuming my Avid Ultimate has a different amount than my XTR lever. I use the full Avid setup on one bike, and XTR and Avid on the other. The Avid setup feels better as far as the solid feeling is concerned, but the actual lever blade isn't as nice feeling as the XTR.

I'm just kinda curious if more or less cable pull will help or hurt my brake at all. I plan on testing them eventually to see which has more.

Again sorry for the lame topics, but my mind gets thinking once in a while aboots dumb stuff.

[WhiteRavenKS]

get a road avid mech brake. the pull arm is shorter or something for the lesser throw of a roadie lever. mount that up to a mtn lever (as opposed to a bmx lever) and you migt end up with some stupid kind of power. the kind of power that should have checks and balances in a three tier government.

[BrettM]

Haha. I should just post Kevin please answer in my posts from now on...I pretty much posted both my last two topics waiting for you to answer.

Road Avid eh...sounds even more fun than a hydro...

[BrettM]

Ok I'm back on with the cable disk brakes. Its starting to all make sense now. I guarantee that my Avid requires less pull to move the brake arm.

Reason being is I noticed with the XTR levers I have to run the caliper pads closer to the caliper to get the lever to hit at the same spot as if I was running the Avid. So basically with the XTR levers I have to pull way more on the lever to get power than on the Avid. So the Avid is a better idea in this sense.

So now I'm gonna try to exploit this. I want to go more than an Avid. Something along bmx lines like Dolphin actually brought up awhile ago, as well as something I saw on another forum before that aboots a cyclocross lever performing well. Something to get all the power possible. Kind of like pulling this lever will move the arm twice as far as when you pull the Xtr lever the same distance. That is my new plan.

Testing begins as soon as I can grab some other levers from my old place. Second part of my test is Avid rotors. I've never actually used them, only the Hope Gothics. For some reason I'm betting they will work even better with those after I read some stuff on the Avid site. I feel bad aboots that since I pride myself in function over looks and weight, and in this case I went with looks and weight and didn't try the function part.

[such]

well actually less pull on avid means you do get quicker response but that also means you have less power than more pull/xtr lever. think about it

[BrettM]

well actually less pull on avid means you do get quicker response but that also means you have less power than more pull/xtr lever. think about it
I've thought aboots it lots and have no idea at all where you are possibly coming from. Explain it.

I pull the xtr to the bar and the arm moves halfway lets say. Avid moves the full way. The way I figure you know how you pull a brake enough to lock, and you have to apply more pressure to keep it locked when you aren't right where you are supposed to be...well I figure it would be easier with something with less pull as the lever doesn't have to move as far.

Also this doesn't apply to 99 % of the people on here. If you just use an Avid on front just ignore this. Any setup will be pure gold and I could never tell the difference. In the rear its apparently a different story and is night and day.

[BrettM]

I just thought of a good example. Go put a xtr lever on a bmx bike that uses 990 style brakes. You know what would happen? You wouldn't even be able to get enough lock up to skid in gravel. Put a xtr lever on Cantilever brakes. Same deal. It will take the full pull just to get the pads near the rim.

[lucky13]

when high quality canti levers were still readily available, such as the XT versions,... we tryed rocking the "short pull" aka canti levers with some V's,... snot rocket.

I think this is what you are looking for right? LOTS of cable pull? If you are lucky you may find one with a cam-like leverage ratio that would give you a bunch of power, just no modulation.

Funny how the manuals would warn NOT to do this and it's exactly the thing we are looking for now.

[bwagner]

V-Type levers(XTR,etc..) will move more cable , but have less leverage. BMX type levers will move less cable but have far more leverage. The further the pivot point on the lever is away from the cable anchor point, the more cable that will be moved, the closer the two points are together, the more leverage there will be. The tricky part isthat if it's too close, there will not be enough cable pull to activate the brakes, and you'll need to run your pads super close to the rim to get contact. The XTR lever on the 990 brakes is going to have zero power, but feel solid as hell, and the pads wolud actually contact earlier than with the correct bmx style lever. I hope this isn't confusing you more, but helping you instead. Good luck

[MontyBurns]

Just compare the lever effects. Measure the distance between the pivot to the cable end, and between your finger to the pivot.

This way: (finger to pivot)/(pivot to cable) = mechanical advantage

The higher it gives, the more power you can develop but the more cable you move to do so. It's called a law of physics.

Short (BMX) levers give less power but move more cable.
Longer levers (either on cheap bikes or high-end brakes) give lots more power to the pads, but you gotta run'em close to the rim/disk.

Please note that when I say short or long levers, it's compared to the pivot-to-cable distance. Everything's relative.

[BrettM]

Ok I did some measuring and I am gonna assume that each lever has the same distance to move to the bar when pulled. However the xtr lever's pivot is 3/4 of an inch farther away from the barrel adjuster than on my Avid. I think that is what I'm after.

I have no idea how to explain this properly or physically or mechanically or whatever but here goes. I have no idea why but I set the pads up farther away from the rotor than on the xtr and the pads still hit the rotor at the same point in lever blade throw as they would on the xtr. That is what I want. I want the pad on my caliper as far away from the rotor as possible, but with a lever that still makes hit at the same point during throw.

Here is my assumption. On a set of cantis or road brakes or bmx brakes you can't use a v brake lever. It will just never work. On a set of v brakes you can't use a canti or road or bmx lever. It will just never work. On an avid I am guessing it is closer to the middle somewhere. A V lever is the best idea I would bet as it gives great power but still modulation. I want to fuck that modulation. I know how to do that, I don't need my lever doing it for me.

Now it gets hard to explain. I'm trying to figure out if another style lever will let me run my pads farther out. If its pivot point than the xtr is the longest distance, and it takes the most to move a pad. Avid is less of a distance and moves more pad. I want to see if I can find something that moves even more pad, but still works well. This is what I don't know. At some point things should go from feeling good to great to horrible. I just wanna find out if the Avid is as good as I can get or not.

[rtorrenga]

The farther away the barel adjuster, or cable attachment point is from the lever pivot the more cable travel, but less power. The closer to the pivot is just the opposite. I would assume that almost all cable disc brakes would require the amount of cable pull of a V-brake style lever, since few companies make canti-style levers. Using a canti style lever or bmx 990 brake style lever will result in more power, but it will be mushy as hell. Try to use a canti lever on a v-brake. It stops really well if you have enough travel to actully touch the rim, but the lever feels like crap.


I would suggest trying to find an older set of xt v-brake levers. They came with removeable chocks to adjust the position of the cable mounting point on the lever to adjust the amount of power and cable travel. I think some avid levers are adjustable similar to this, but they use a threaded adjustment.

[BrettM]

If nothing else I have decided to ditch the Xtr levers and run the Ultimates. The feel of the lever isn't as bad as the other Avid levers and it feels much stiffer and better than my Xtr setup. On the plus side they also use a system that allows you to take them off the bar without removing the grips and are lighter than Xtr by a gram. Weight is nothing, but the removal deal is kick ass.

[rtorrenga]

The ultimates should work very well. They have the speed dial power/leverage adjustment which it sounds like you are looking for.



http://www.sram.com/_media/images/common/avid/popups/largerimages/SDultimate_05_lever.jpg

[BrettM]

I have them on my other bike with the Avid cable disks. Riding those before is what showed me that the Xtr just isn't cutting it. The Xtr has a speed dial as well. Well more of a dial, its not that speedy really. Thats not what I'm after. Keep those constant on both and the Avid outperforms it hands down. Its very noticable when grabbing each lever side by side.

[BrettM]

oops.

[Devilish]

Have non of you even begun to think of the fliping basics...nope thought not. When you get any brake they do specifly a leaver for it...Aamainly Shram say to use there own..wonder why that its..erm cos there is a leaver thats been desinged to work better than a hydro system with the cable disc!!!

Your problem is called compaterabitly issues and no sense...or wrapped up in the moment

[BrettM]

Have non of you even begun to think of the fliping basics...nope thought not. When you get any brake they do specifly a leaver for it...Aamainly Shram say to use there own..wonder why that its..erm cos there is a leaver thats been desinged to work better than a hydro system with the cable disc!!!

Your problem is called compaterabitly issues and no sense...or wrapped up in the moment
Don't post in my topic anymore.

[Devilish]

Yeah sorry i was a bit out of line but i was just shoukced how it came about the use of the right leaver...sorry again

[Cryo-Cube]

The farther away the barel adjuster, or cable attachment point is from the lever pivot the more cable travel, but less power. The closer to the pivot is just the opposite..
^ he is right.

More cable pull means less power but a more on/off feeling.
Are you trying to get more power or a better feel?

[BrettM]

Are you trying to get more power or a better feel?
Better feel for sure. My Avid setup feels a lot stiffer and nicer to me than the Xtr setup. Power isn't a problem, but I guess the Avid will help in that area as well.

Devilish I think this topic is way over your head. No offence but the Avid feeling the nicest is a coincidence in this case. The way I see it, it will work the best on any brand of cable disk brake.

[Cryo-Cube]

ok then the most important thing here is the pivoting point radius not the lever lenght, aka the lever height marked red.
a longer lever will increase power but in the same time resulting in less pull.
since that is not what you want, the pivoting radius has to bigger or both--> a bit shorter lever + a bit longer pivot radius. Though, a slight change in pivot radius lenght will have a bigger effect then a slight lever lenght change


http://mitglied.lycos.de/digitalglove/lever.jpg
http://mitlgied.lycos.de/digitalglove/lever.jpg

[BrettM]

Ok I don't think its as simple as I thought anymore. Its really pissing me off. There is a ratio involved now. It's not as simple as what pulls more or less cable. It's how much cable is pulled, compared to how far the lever blade moves. I'm guessing what would make one lever better than the other would be the placement of the lever blade pivot point???

[lucky13]

Better feel for sure. My Avid setup feels a lot stiffer and nicer to me than the Xtr setup. Power isn't a problem, but I guess the Avid will help in that area as well.
I don't know Brett, it seems you are looking for perfection (aren't we all eh?) but even as a hardcore hydro user, I have to admit that even your XTR's felt amazingly great. So if the ultimates are a step up from that, way to go!

If the lever feel is solved (or close to) then maybe the next link in brake performance would be different pad compounds/rotors, like you mentioned in another thread. Then again, right there in your quote, you don't seem to have a power issue,...

Which brings us to Cryo-cubes comentary that is spot on. The ultimates offer the adjustability that the XTR's don't: Modulation "ratio" or as they call it "Speed dial".

***Since you have them mounted, just experiment. One extreme is mushy but graby, the other extreme is solid but marginaly less grab. The trick is to find the right lever "feel" and then adjust your caliper cable anchor to get the right amount of cable pull/pad contact you want. ***

I'd wrench it myself, but the fast boat to Vic is $90 more than my budget,... besides it sounds like you almost have it whiped.




Maybe next year I'll be joining you in the postmount disc set up forray... I'm thinking of mixing hydro levers and calipers from different manufacturers and different fluids. i.e. Gustav or LouiseFR lever and shimano or avid calipers (because of the post mount).

more research...

[BrettM]

Which brings us to Cryo-cubes comentary that is spot on. The ultimates offer the adjustability that the XTR's don't: Modulation "ratio" or as they call it "Speed dial"....
My xtr brakes had a speed dial deal too. The actual setup difference is I get to back off the caliper pad 2 more clicks with the Avid setup. Gives me more room to set it up drag free. As for nicer lever feel, I think it might just be the lever. It is a nice cnc job. I'd bet it is more rigid than the Xtr.

I'll be trying out the Nokon cable setup now that I can sell off the Xtr levers. Should give me an even stiffer setup and more reason to dial down that speed dial and get into even more power with a better feel.

There are a couple of very unknown disk pad companies out there I may try out, as well as doing some rotor research. I'm sure now that the Hope Gothic can't be the best, but looks the best for sure. Not that it matters tho, but I'm searching anyways.

I'm still after a hydro setup, but that is even more work than this. One day I guess.

[chronic]

So are your brakes lacking power, or a good solid modulating sort of a feel that hydros provide?

[BrettM]

So are your brakes lacking power, or a good solid modulating sort of a feel that hydros provide?
Neither. When you pull a cable brake you can pull it as far as you want really if your hands are strong enough. It will mush its way right to the bar. When you pull a hydro brake if you try this you will snap the lever in half. It goes so far and then no more. That is what I want. That stiff feeling.

[chronic]

Ahh, I guess your best bet would be the nokon cable housing. But I dont know how you would completely eliminate this with out solid cable, as that twisted cable is always going to provide some stretch...? Do any companies make a braided cable? Although that wouldn't work so well as the cable wouldn't go around corners very well.

Good question.