evening gents, I would like to re-link the brakes if possible. When I bought her they had been de linked and I have been fine with them but the rear could be better, I had a close shave with a nice guy on the road to Brecon who decided to slam the anchors on and turn left with no indicators. I had to brake real hard, thought the front was going to lock-up and the back could be better,a real butt clencher. No air in the system, sintered pads,disc in good nick. It seems lots of you guys like the linked system and it appears stopping is improved with it, what will I need to get it done? is it worth it ?or can I upgrade the back brake somehow? thanks in advance russ
Presumably you were still using all 3 discs so not sure how much better it could have been in different configuration. Bear in mind the Brembo disc brakes on LM2 and other models of same vintage were only ‘good’ in the 1970’s. Unfortunately they’ve been surpassed by later brake designs, especially those on the typical modern car. As has been said on here often the original Brembo pads are so feeble as to be next to useless so taking their advice I tried Ferodo FDP108’s, much better grip BUT still need a good squeeze on the lever and pedal to stop quick.
The linked system reduces likelihood of locking up the front wheel by operating pedal only, IF there is no proportioning valve then both single front disc and the rear get equal hydraulic pressure, but rear is smaller diameter disc so braking emphasis is still more towards the front.
EXCEPT if you have a proportioning valve then most of the braking is done at the rear first, nothing much seeming to happen at the front until you press the pedal harder. At least that is how it’s supposed to work IF the proportioning valve is working properly.
AFAIK LM2 (as LM1) did not have a proportioing valve (LM3 does apparently), just a ‘manifold’ which connects rear master cylinder to one front and the rear caliper and the rear brake switch.
Be aware also that if yours has been modded for twin front disc operation from the handlebar lever then it’s likely that the master cylinder is different, because different size pistons (or whatever it is) are needed depending if it’s for single or dual caliper operation. Affects the lever travel distance. So probably not that simple returning it to linked brakes.
I found the linked system only improved braking in the wet. However, stopping at a diesel covered junction or petrol pump was awful.
As said, you’ve yesteryear’s brakes in today’s world and a defensive riding style has to be adopted.
If you can get the Spada linked system as fitted to my Mk111 lemon then that is the best.
I disagree that the discs are not as good as todays, Use Ferodo pads for iron discs.
If you still have the same callipers and master cylinders as before then you will need the proportioning vave and probably new lines.
And yes, the linked system where in an emergency you slam your boot down hard is excellent.
Hi Russell, you don’t mention if you have braided stainless or original brake lines fitted, if the latter, then butt clenching is the order of the day. A re-linked system will need correct sized master cylinders front and rear, a front and rear manifold, (usually containing the brake light switch) and a connecting pipe between the manifolds. Gutsybitz do most of the above. Best of luck.
What mods were done as part of the delink? I’ve seen other mods done at the same time and it’s worth checking this out before proceeding.
If you aren’t too bothered by originality it’s possible to add a later master cylinder and dog leg lever for the front for an upgrade.
For relinking as you asked it would be worth buying a brake line kit, either an in line or master cylinder front brake switch and the splitter which fits on the rear left frame upright.
IMHO well worth doing. I ride (un)linked bikes and can testify to the benefit of the fit.
+1 for Gutsibits who provided all the parts for my lever & brake upgrade.
All the best
thanks for the info, very clear and to the point, the chap who owned the bike before myself kitted her out with s/s lines and in the box of bits he sold with the bike there is a front brake m/c so im guessing that’s the original The front brake is not a problem it bites the way I like it, maybe ill try the freodo pads first on the back and see if theres an improvement. Do you boys think the rear m/c if original, is up to the job of stopping the back wheel? cant seem to lock that up even if I try. thoughts please gents regards russ
I have found that pulling the clutch often helps, as the heavy flywheel takes some finite time to slow down and often I’ve noticed that the rear brake works better once it’s disconnected from the engine (clutch disengaged).
that last point by MIKE, interesting, im sure I pull the clutch in without thinking but I will try to do that earlier see if that helps. thanks russ
Well I’ve shut the throttle for engine braking, which is “yeah OK”, with rear brake, then when I’ve pulled the clutch to change down, it’s like “wow!” Suggesting brakes can stop it quicker than the engine can slow down.
When the coupled system is delinked a couple of changes need to be made.At the front end the standard 13mm bore master cylinder needs changing for a 15mm or 16mm version or the lever travel will be very long. Fortunately alternative cylinders are available.
At the back end the standard cylinder bore size is too large to effectively operate a single caliper. The pedal action will be very firm but with very little braking effect. Unfortunately the rear master cylinder seems to be unique. When I delinked my Cali III I was unable to find an interchangeable cylinder with a smaller bore so instead I increased the pedal leverage by moving the brake lever link rod attachment closer to the pedal pivot point.
This cured the problem and I now have a very effective rear brake.
thats interesting ref the rear as my Darmah has the same size rear master cylinder (PS15) which just operates the one disc with no problems - have seen recomendations to swap for a smaller one when de-linking a guzzi, so i wonder if it is down to levers and linkages… . looking at de-linking the brakes on the Le Mans (after years of telling others not too ) as i rarely use the foot pedal as i find it awkward to get at with my leg wedged up against the fairing…
I’m not sure that technique is generally well regarded.
Does it have the same size rear caliper too?
It isn’t, it’s just what I’ve noticed when I’ve disengaged to change down.
yes, F08 all round… Laverdas also use the same set-up, so i’ll give it a go when/if i get around to de-linking…
thanks for all the input, new freodo pads are on the way and I will have a look at the brake linkage on the rear (gtm driver) and see if I can modify this. I have a rear m/c from my old bonnie I might hook that up and see if it can be adapted to fit. Will keep you posted thanks russ
I always felt the pedal on Le Mans / Spada / T3 etc. to be somewhat short, compared to what’s on California with foot boards say,Â Â it looks like you should be able to get a good stomp with that.Â
is it possible that a previous owner has delinked without uprgading/replacing the front master cylinder with one that can manage twin discs?
For iron discs use EBC HH pads - they might take a couple hundred miles to bed in but well worth it.