brakes doing my head in!!

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xjs10
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Post by xjs10 »

Im using the same master as you on forward controls and all seems well......took a while to sort my leverage but got there in the end........I shall post a photo of control later if i can find camera
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gtr-trike
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Post by gtr-trike »

from my own personal experience with car rear calipers and a bike master, they dont have enough piston stroke, I could bottom out the master cylinder with no probs, that was a 5/8" bike master, brakes were good and had feel, but wouldnt actually fully come on as the piston in the MC would bottom out

what are the measurements from centre of pivot point to the foot lever and centre of pivot to the brake linkage?

I have 3/4" landy master with remote master, 2 hoses, one to right caliper and then from right caliper to left caliper

I ride on rear brake only, mainly as I dont have front brake on mine LOL, hauls up my heavy lump of a trike with no bother, and can lock 1 wheel easily below about 30mph

I have a slight brake imbalance that Im working on, my own doing as the calipers are self adjusting using the handbrake operation, but I only have the handbrake currently fitted to one side

if they worked fine but now dont, it has to be a deterioration of a component or leak in the system I would have thought
heavy is good, heavy is reliable, and if it does fail, then hit them with it :caveman:
levvin

Post by levvin »

hi gtr...

they were never fantastic, wouldnt lock up...

but reading your comments guys, maybe the leverage is an issue?

the pads could have glazed up through not biting hard enough?

that could explain gradual loss of brake.

theres no leaks anywhere, no spongyness, the pedal is really solid...only an inch of pedal movement before it goes so hard its like pushing against the floor!

the lever is only around 5" long from pivot to foot bar, and dog legged left-to-right to centralise over the foot peg.

i'll dig out a piccy later...off to service a boiler now,

Lev:respek:
xjs10
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Post by xjs10 »

Photo of my setup....might not win any prizes for design...but it works for me.

No prizes for guessing what is covering my master cylinder........Levvin should know straight away.
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impudentone
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Hmm!

Post by impudentone »

I remember Lev that when you fitted the remote servo you were chuffed to bits by how good they were? So surely it's got to be something you have fitted since then ?? Would your fire extinguisher affect your brakes?? Sorry for joking because I know how frustrating it is to have dodgy brakes, you just Can't relax and enjoy ride out! Sigh! :D

You know I have had a lot of problems with my brakes but we seem to be on the right track now and it appears to be mechanical...sorting out all the angles involved in the leverage.

They are a fair bit better now and he is gonna have another go at them.

I think the pads are pretty glazed up now so I thought I could file them when the wheels are off and he is going to experiment with getting a better angle.

How much should the piston move in the master cylinder?? 3 quarters landy one with good old drums still.

I think it moves about half an inch, no more, does that seem right??


THE MOST DANGEROUS BIT OF MY TRIKE IS THE BIT THAT JOINS THE SADDLE TO THE BARS!!:loco::triker:
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gtr-trike
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Post by gtr-trike »

ok measure the lengths and lets see what its all about

I work to 6 or 7:1 pedal ratio, it works for me

will double check mine later, remember to measure from the centre of the pivot boss, not just the length of the control piece

get some pics up and we can have a looksee

but I have to wonder as I already said, you raved about how good they are, then they started going downhill, has to be a problem with parts, rather than setup
heavy is good, heavy is reliable, and if it does fail, then hit them with it :caveman:
levvin

Post by levvin »

:biker:thanks peeps...am getting camera out now....

the brakes were never as good as say, in a car, which surprised me as theres only two wheels...

the servo was bit of a sod to get right, but once id fitted the best sized vac pipe, it made an instant improvement.

however, that was fitted as i was working on the engine, if you remember, and i pushed the boat out and fitted new calipers at the same time.

i think now ive put almost 1000 miles on it since, the braking isnt any good anymore, but theres no leaks and no air, the pedal is solid as hell...no give in it whatsoever...to get more posative braking i literally have to stand on the pedal really hard.

if the leverage is wrong, could i be glazing up the pads which would explain the gradual deteriation of the brakes? it was deffo sharper with same setup minus servo when i had the original xs1100 brake pedal...but that was cut up to help make the new system.

the issues are pointing to the forwards....so i'll post pics and measures in a mo...after coffee...decaff stuff following dr deaths advice....my knees seem less painful...back to thread...

Lev
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VmaxRik
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Post by VmaxRik »

All good stuff so far.

Easy way to check if your brake lever isn't long enough, temporarily fit something to extend the brake pedal, oh i dunno, maybe a big piece of pipe or something. Push the trike forward and then give the new lever a shove and see if the brakes lock up, it's a bit Heath Robinson but it will show you if your levers too short. (remember a car brake pedal can be a foot or more long to get that all important leverage) and you've only got five inches darling.

Both of ours run pedals over a foot long, mine's nearly 16ins (yeah baby!!) and they both stop like supercars, Julias will make the rear tyres "chirp" at 70mph if you press hard enough.

Her old VW had an 8ins pedal with another drop arm under the body that gave another six inches of mechanical advantage, frankly that was over braked for a light weight VWya.

Also, if the pads you bought are cheap aftermarket ones, they can and do glaze over. Try, if you can still get them, a set of bronze sintered type pads. Ferodo and others used to do them, stop you on a sixpence but only last half as long as a normal pad.

Sooo....if the brake pedal pedal is 5ins long and the bottom lever arm (under the pedal pivot point) to the master cylinder push rod is say a couple of inches long, then you only have a 3ins brake pedal in reality, way too short to make things happen.

I wasn't really advocating the use of motorcycle stuff, just trying to use the system as an example of mechanical advantage.

Front brakes then....obvious stuff 1st. Check your fluid level, pads for wear and any seepage from the master cylinder. Them move onto the discs, stick a micrometer on them and check for wear ( they do have wear limits), then check for disc run out (is it warped). If you've been riding hard on the brakes and you hit some water, if the discs are well worn, they will warp in an instant....been there, done that.
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lepchaun
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Post by lepchaun »

hi lev my imput when i took my trike for first mot no back brakes at all working the pedal was very hard i could stand on it and notting would happen but i needed to c what else it needed before i spent anymore money on it so this is what keight at mot place told me to do bring master cyclinder closer to centre of brake pivot as to much leverage at that side of pedal and it wont work i did as he said it works great put foot on the brake it moves 1/2 to 3/4 of an inch and it went straight true mot put some piccies in for u to look at but u will have to look closely hope this helps THE LEP
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VmaxRik
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Post by VmaxRik »

Plus, look at the length of Leps brake pedal, looooong for leverage,
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This nation wasn't given to our forefathers, it was wrought over a 1000 years of bloody war and the efforts of those who came before.
Let it not be us who bears the sin, of giving it away to the enemy within.


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