Lambretta standard disc brake- clarification required.

[bristolmod]

Bear with me Gents..............

I have 2 TV175 S3's- both equiped with standard disc brakes.

On the earlier (1962) one, the disc brake actuating arm is not as far forward as on the later (1965) one. Both front brakes work well with no problems, except the 1965 arm is angled further towards the front of the bike than the other. This has been at the back of my mind for ages.

Looking at an original official parts list for the S3 dating from approx 1962/3, under the disc brake section, there is listed:-

1) the actuating arm
2) "disc" (NOT the "braking disc") but a thin washer that goes between the actuating arm and the pad.
3) "braking tablet" (i.e. the pad)

Now I've always fitted new pads straight between the actuating arm and the central "braking" disc (the large item that floats on 3 off set spindles), and never fitted these small "discs"

As it happens, I've located 2 large washers in my scooter spares boxes which are identicle in size to the pads and about 1mm thick, and have inserted these between the actuating arm and the pads themselves- hey presto- the actuating arm on the later 1965 bike is now in the same position as the 1962 bike.

If you're still with me..........now have I omited these items in error over the years, or am I barking up the wrong tree?

The 1965 bike still brakes as good as ever- the only difference is that the arm is now further "back" than before (due to the increased thickness of the pads and "discs")

Any comments/ thoughts Gents?

Chris

[cezeta]

its an interesting tree top bark up, my disc failed in 96 and i was hit by a car, the scooter was inspected with no fault found. more recently sugarlump from the forum pulled my brake lever and it appeared that the cable snapped.

what had happened is the actuation arm had come to the end of its travel and the ball bearing had come to the end of the ramp, gone over the top and was sitting between the two ramps if that makes sense.

a quick fiddle and it clicked back and was fine.

iow the same year the brake failed again and i nearly rear ended a car. same thing happened.

im now on my third actuator, one is nos.. each time it failed i was on a different one.,

ive since gone over to hydraulic but you may have found the problem?? ive never seen these spacers but of course with one fitted the actuator would have not got to the top of the ramp maybe.

the disc was built by a dealer and then rebuilt by me and looked at a few times by other dealers and nobody ever questioned the spacer.

[bristolmod]

Very interesting Cezeta- a couple of years ago the 1965 bike had exactly the same problem as you experienced i.e. the brake lever went slack and the actuator seemed to "over exert" itself = no front brake!!

By the addition of these spacers, I don't think that this will happen as the lever will never get to that situation.

BTW all the pads are still very thick, and its not a question of simply "padding out" pads that have passed their sell buy date.

Interesting.................

Chris

[J1MS]

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[cezeta]

just to clarify, because of the accident i have replaced the pads at any opportunity and was fortunate enough to be given a box of ebc pads so i didn't need to be frugal.

i would tighten the grub screw so it locked the wheel then turn it back so it still rubbed and let the next few miles take the the edges off.

ive run with or without cir-clip on the disc and have had the holes in the disc reamed out and polished and it runs on ebc brake lube to make sure it does not bind.

i know people rate the innocenti disc but i think they are crap, ive tried loads. all the people that have said theirs were great, when ive had a go on theirs they were crap too. a lot of course is down to expectation. as crap brakes go...they are the best.

ive sold all but one of my discs now and use a hidden master cylinder and a scoot rs disc which is less pretty but once powder coated all over apart from the friction surface, look fine. more importantly is that they work.

my last one will be hydraulic converted. volvos and sliding into the path of on coming traffic is not the best way to end a day

[bristolmod]

just checked the old WSM (with Dick Sedgley on the cover and the TV200). That one doesn't show seperate spacers on the disc brake diagram.

However...........if you look at the photo of the TV200 on the cover, this shows the brake actuating lever to be in the same position as it was on the 1965 TV of mine!

I guese we'll never know.

As before, both pads are new on the 1965 bike and correctly adjusted by way of the locking nut and cable- its just that the arm is "forward".

Chris

[cezeta]

the important thing is being aware of the problem, no brakes is a biggy in my opinion. its not like an ignition fault thats an inconvenience, its a proper hazard.

i have to say that ive been driving like a jessy for ten years now with no confidance in my brakes.......i feel liberated now :bouncyeng:

[vince]

I dont want to tell anyone how to suck eggs, but are you doing the static adjustment before conecting the cable because if you are and the pads are good the unit cannot overcam.

[bristolmod]

no problem- static adjustment done as per the book. I've only had one instance of it "over caming".

Could possibly be that the actuating lever itself is a remade item and not within spec?

Anyway, the insertion of the "spacers" does appear to have cured any problems.

Its just odd that the original parts book shows the pads AND spacers- I appreciate that replacement pads are constructed of the friction material bonded to a steel backing. Surely original OS items would not simply be made up of the friction material only??

Could it be that replacement pads are slightly too small in depth?

Chris