Inboard disc brake options...

[Scouse Scooterboy]

Considering an inboard disc brake on my S2.

Are they a massive improvement on the original drums?

What are people's experiences and opinions of the Scoot RS one?

[HxPaul]

I use one on my series 3 with a reverse pull cable from SR and it works very well.The brake is a ScootRS inboard disc,I bought it from chiselspeed some time ago,but it seems that ScootRS have stopped trading.

[Knowledge]

Are they a massive improvement on the original drums?

I would say that a well set-up drum and a well set-up (cable operated) disc were of similar performance. To get the best out of any disc brake, you need the mechanical advantage of hydraulic operation.

Some years ago, someone unearthed a quote from Innocenti who described the need that drove the introduction of the original disc brake (the first one ever to be fitted to a production two wheeler) as the fact that the drum brake could lock too easily when you pulled the lever. This makes you think that if the disc brake was less easy to lock, then perhaps it was not as good at stopping you. Or is that me being cynical?

[Warkton Tornado No.1]

Post by Knowledge » Thu Oct 13, 2016 4:03 pm

Scouse Scooterboy wrote:
Are they a massive improvement on the original drums?


I would say that a well set-up drum and a well set-up (cable operated) disc were of similar performance. To get the best out of any disc brake, you need the mechanical advantage of hydraulic operation.

Some years ago, someone unearthed a quote from Innocenti who described the need that drove the introduction of the original disc brake (the first one ever to be fitted to a production two wheeler) as the fact that the drum brake could lock too easily when you pulled the lever. This makes you think that if the disc brake was less easy to lock, then perhaps it was not as good at stopping you. Or is that me being cynical?

Once upon a time......I would have agreed totally with this view.

However, with advances in materials & knowledge(!) regarding optimising the disc brake (disc pads, cables) I think they can be made to work very well with substantially more feel than a reverse pull drum.

One thing I do agree with is that there will be mechanical losses is the semi-hydraulic set-ups.

IMO, a disc brake should be either fully hydraulic or fully cable.

It must be long overdue for those that seek to be the ‘shop window’ or even recommend certain products to organise a ‘shoot-out’ of the various front brakes now on offer, in-board or out-board.

BTW. It is interesting to note that Big Bob West has returned to the race scene & photos indicate he still uses an inboard brake.

[dickie]

However, with advances in materials & knowledge(!) regarding optimising the disc brake (disc pads, cables) I think they can be made to work very well with substantially more feel than a reverse pull drum.

One thing I do agree with is that there will be mechanical losses is the semi-hydraulic set-ups.

Ive got reverse pull drum and while it's very effective I don't think I've ever used a brake with such poor feel.

And while I know you're right about semi hydraulic set-up I still hope you're wrong as I've spent a bloody fortune on one for my current project.

[Warkton Tornado No.1]

Post by dickie » Thu Oct 13, 2016 6:03 pm

Warkton Tornado No.1 wrote:

However, with advances in materials & knowledge(!) regarding optimising the disc brake (disc pads, cables) I think they can be made to work very well with substantially more feel than a reverse pull drum.

One thing I do agree with is that there will be mechanical losses is the semi-hydraulic set-ups.



Ive got reverse pull drum and while it's very effective I don't think I've ever used a brake with such poor feel.

And while I know you're right about semi hydraulic set-up I still hope you're wrong as I've spent a bloody fortune on one for my current project.

Perhaps the ‘semi’ is just a case of getting used to it, GULP

However, in all honesty, & I’m judging you as having sound engineering principles from your other recent response about fork springs.....

I’m curious to know what made you select that type

[dickie]

However, in all honesty, & I’m judging you as having sound engineering principles from your other recent response about fork springs.....

I’m curious to know what made you select that type

Pure vanity. I think master cylinders and outboard discs just look too modern for a series 2.

And yes from an engineering point of view it's a poor decision but then again, so is owning a 50 year old 2 stroke when I can get a perfectly decent sv650 for quarter of what this is costing me to build. Oh well.

[Warkton Tornado No.1]

Post by dickie » Fri Oct 14, 2016 2:58 am

Warkton Tornado No.1 wrote:

However, in all honesty, & I’m judging you as having sound engineering principles from your other recent response about fork springs.....

I’m curious to know what made you select that type

Pure vanity. I think master cylinders and outboard discs just look too modern for a series 2.

And yes from an engineering point of view it's a poor decision but then again, so is owning a 50 year old 2 stroke when I can get a perfectly decent sv650 for quarter of what this is costing me to build. Oh well.

Hmmm.

I get mixed messages about this kind of thing! This is not a criticism in any shape or form, just an observation & my honest opinion:

The ‘look’ of anything is all in the ‘detail’. Unfortunately, despite our denial of being any kind of anorak, we all ‘look’ intently @ the ‘detail’ of any rebuilt scooter.
99.9% of our fellow enthusiasts will see straight away the hydraulic connection to the non standard inboard disc brake in any case.

So, you have to wonder (well, I do!) what has been achieved?

[soulfecker]

At my last MOT, it was commented that my reverse pull drum was as good as a modern disc at 98% . And that was from a scooter mechanic that generally says "every thing is shit"

Paul

[citydaz]

I bought an inboard disc brake from Mike Phoenix a couple of years ago for my mugello 186 Li series 3, and it has been the best of kit i have bought.
Stopping power, control, confidence.
what else can i say?
just buy one!

[Martin s]

I tried allsorts of "race" shoes in my innocenti front drum, and sanding and all that and it was still crap. Bought an indian front drum and scootopia shoes, fitted it all together without doing anything and it's the best drum brake i've had in 28 years. Whether i'ts the fact that it's a new drum and any shoes would have made it better I don't know...

[Martin s]

I've also got an inboard front disc which has worked that well since being built 12 years ago by a well known scooter shop, I've never had it apart...Will be stripping it soon though to see what the score is for building another disc.

[Seamus murphy]

Ive just bought an original disc brake thats been stuck in a shed for yrs lm going to refurb and reverse pul it but what are the best pads to buy and where from cheers

[HxPaul]

I use Newfren sintered pads in mine,stopping power is great.You can buy them from most good Lambretta dealers.

[Rich Oswald]

I use Newfren sintered pads in mine,stopping power is great.You can buy them from most good Lambretta dealers.

+1

[citydaz]

how often do you need to replace pads?
Im a bit of a digital rider - all on or all off.

[Rich Oswald]

how often do you need to replace pads?
Im a bit of a digital rider - all on or all off.

With sintered, probably a little bit more often than with standard as they are softer compound but how long depends on type of use,

Rich'

[swissdean]

could never get on with mine..my set up was: scootrs inboard disk, i rubbed down the three dowels so disc would slide easily, removed the circlip, smoothed sides of newfren sintered pads, tried a different disc, added a scootopia stronger lever arm, installed reverse pull proper set up and used aircraft grade cable to resist stretch..and it was still shite..

the whole lot is just about to go on ebay

refitted my drum with new drum outer hub and the amazing bgm pads and all great

[Warkton Tornado No.1]

Post by Rich Oswald » Wed Oct 26, 2016 10:56 am

citydaz wrote:
how often do you need to replace pads?
Im a bit of a digital rider - all on or all off.


With sintered, probably a little bit more often than with standard as they are softer compound but how long depends on type of use,

Rich'

As far as cable operated front brakes are concerned, I had a reverse pull TV175 SII drum (with damper links) that was very good but lacked feel. As a consequence, it was good to race but made any rider nervous on a wet road.

So hydraulic disc brakes became the norm in racing & as a consequence, sintered pads were made by modifying motorcycle pad material to fit.

Now, those of us that want to retain the originality of cable operated brakes have witnessed the ‘crossover’ of sintered pads to our reverse pull disc brakes.

So it was easy for me to just put some of my existing sintered pads in my road scooter. (BTW I retain the anti-rattle circlip & the dowel holes are not modified. The brake is assembled with Copaslip which is also on the back & sides of the moving pad)

My road going front brake is adequate but I reason that it could be further improved with an even stouter cable, say 3 mm inner.

However, I can’t imagine why Newfren pads would be vastly different to any of the various pads I have in ‘stock’ but personally, I’ve never worn any of those pads out. I would imagine that the disc would wear as much, if not more than the pads....

[dickie]

However, I can’t imagine why Newfren pads would be vastly different to any of the various pads I have in ‘stock’..

That's generally my attitude too, but I changed a zxr400 and an r6 both from ebc hh sintered pads (well respected and in widespread use in club racing) to carbone lorraine (sbk3 I seem to recall) and the difference was amazing; stopped quicker with more feel.

I guess it's simply that they have a higher friction coefficient that can be easily adjusted by modulating lever pressure.