LCGB Forums

The ability to post messages is restricted to LCGB members. Any questions contact us at lcgbadmin@googlemail.com

Brakes next to useless on my S2

Technical help for Series one, two and three Lambrettas. Models include the Li, Li Special, TV, SX, GP, Serveta and API/SIL models

Brakes next to useless on my S2

Postby Scouse Scooterboy » Tue Oct 04, 2016 6:41 pm

After a full restoration job on my S2, I was not impressed with the original drum brakes at all. The front did practically nothing, and the rear did a little better (I'd say 1/2 as efective as my Vespa PX). But now after getting a good few hundred miles on the scoot, the back brake is as useless as the front. There's practically no stopping power at all. Coming to a stop at a set of lights on a slight downhill doing about 20 mph I had to put my foot down, both brakes would not stop the scoot even at that speed! I know the drum brakes are not the best, but surely they should be performing better than this? Any advice greatly appreciated...
User avatar
Scouse Scooterboy
 
Posts: 16
Joined: Mon Nov 03, 2014 8:33 pm

Re: Brakes next to useless on my S2

Postby Norrie Bodge » Tue Oct 04, 2016 7:23 pm

Norrie Bodge
 
Posts: 555
Joined: Sat Aug 16, 2014 3:34 pm

Re: Brakes next to useless on my S2

Postby Knowledge » Tue Oct 04, 2016 7:44 pm

I don't think the Boxenstop will be much help here. It is designed to overcome a common problem with the poorly located rear brake pivots. This is not likely to be an issue on an original SII casing.

There is no doubt that drum brakes can be made to work, but there is also a reason why people upgrade to a modern disc brake.

It is possible that your brake shoes have become glazed-over and lost all their bite. One thing is for sure, you are going to get some tools out and find out what the issue is. .

If you strip the drums down, you will need some emery cloth to clean the inside of the drums. You will also need to clean any of the shine off the brake shoes, assuming they aren't worn out. I would be wise to strip everything as it will be easier to dress the shoes in a vice and you can also grease the pivots and cam-arm.

Take care. The shoes might contain asbestos. Probably, best to assume that they do contain asbestos.
User avatar
Knowledge
 
Posts: 1968
Joined: Sat May 31, 2014 11:42 am
Location: Ipswich

Re: Brakes next to useless on my S2

Postby HxPaul » Tue Oct 04, 2016 8:15 pm

There is definitely some thing wrong,especially with the back brake.Series 1,2 and 3 have the same back brake and apart from the later SIL cases were some have the holes drilled in the wrong place for the brake shoe pivot pins,there all decent brakes,I have a series 2 and a series 3 and the back brakes are very good,in fact if I press to hard on the brake pedal I can lock them up very easily.On the series 2 I have the original brake drum on the front and its quite good.
User avatar
HxPaul
 
Posts: 1583
Joined: Fri May 30, 2014 9:18 am
Location: Halifax

Re: Brakes next to useless on my S2

Postby pirate pete » Tue Oct 04, 2016 8:26 pm

Fit a GP brake cam and newfren racing gp shoes and prepare to be amazed.
pirate pete
 
Posts: 12
Joined: Fri Jan 09, 2015 9:06 am

Re: Brakes next to useless on my S2

Postby Donnie » Tue Oct 04, 2016 10:12 pm

Scouse Scooterboy wrote:After a full restoration job on my S2, I was not impressed with the original drum brakes at all. The front did practically nothing, and the rear did a little better (I'd say 1/2 as efective as my Vespa PX). But now after getting a good few hundred miles on the scoot, the back brake is as useless as the front. There's practically no stopping power at all. Coming to a stop at a set of lights on a slight downhill doing about 20 mph I had to put my foot down, both brakes would not stop the scoot even at that speed! I know the drum brakes are not the best, but surely they should be performing better than this? Any advice greatly appreciated...


How exactly did you set up the brake pads and how exactly have you adjusted the rear brake as time has gone on?
User avatar
Donnie
 
Posts: 1114
Joined: Fri May 30, 2014 8:19 pm
Location: Kempston, UK

Re: Brakes next to useless on my S2

Postby dickie » Tue Oct 04, 2016 10:50 pm

I had the same experience when I restored mine. I had only ridden 'proper' motorbikes for 20 odd years and I was shocked by how ineffective the front in particular was.

I changed the front drum to reverse pull and I was amazed at how much difference it made.

I must say though that I have to be gentle with it as the dive from the forks is alarming if I suddenly pull them on.

There's a real need to recalibrate myself if I ride my lambretta soon after my triumph.
dickie
 
Posts: 1845
Joined: Thu Oct 02, 2014 12:32 pm
Location: Tyne and Wear

Re: Brakes next to useless on my S2

Postby Knowledge » Wed Oct 05, 2016 9:12 am

There is a popular belief that it is not advisable to do a reverse pull conversion on drum brakes. It was a conversion designed for original disc brakes.

A nylon-lined cable will benefit the brake no end, even if it is running the traditional route. Original brake shoes (which do contain asbestos) were always better than those shoes which came afterwards, IMO. If I find original brake shoes, they get put aside for use another day.

Your brake problem is solvable Scouse Scooterboy, but you are going to have to work at it.
User avatar
Knowledge
 
Posts: 1968
Joined: Sat May 31, 2014 11:42 am
Location: Ipswich

Re: Brakes next to useless on my S2

Postby coaster » Wed Oct 05, 2016 1:05 pm

All good advice above but also make sure that the angle between the cable and operating does not go beyond 90 degrees when the brake is on full as this is the point of maximum leverage.
User avatar
coaster
 
Posts: 2678
Joined: Fri May 30, 2014 1:00 pm
Location: Norfolk, Flying 8 Balls

Re: Brakes next to useless on my S2

Postby Meds » Wed Oct 05, 2016 5:21 pm

Check And see what is happening at the brake operating arm.
Try operating the pivot arm by hand to see if it is, free working and locking the wheel, then try using the lever/pedal to see if it's the same, this isn't fool proof but might save you ripping apart the brake unit when it's the cable stretching, the outer compressing or the alignment/cable route is at fault.
I
Meds
 
Posts: 431
Joined: Sat May 31, 2014 10:08 pm

Re: Brakes next to useless on my S2

Postby Scouse Scooterboy » Wed Oct 05, 2016 8:19 pm

Thanks everyone. Few things to check out and hopefully get a bit more stopping power out of the brakes...
User avatar
Scouse Scooterboy
 
Posts: 16
Joined: Mon Nov 03, 2014 8:33 pm

Re: Brakes next to useless on my S2

Postby MK Monty » Wed Oct 05, 2016 9:26 pm

First thing I would do is whip the rear drum off. Worth doing if only to prove your rear oil seal has not dropped oil on you shoes. By now you will have whiteness wear on the shoes. I would be surprised if you have even contact on the shoes. I found I was only using a 1/2 inch wide strip round the shoe and even then only on just over half of each shoe. Have a go at the high spots that are in contact to get more of the shoe in contact. A shoe trimmer is the best way but sand paper or a rasp type file may get the bulk off. I have in the past had to remove the steel pad on the cam end and file the end of the shoes as one was hard on with the other being unused. I'm afraid the quality of new shoes are not as good as the old ones so if you had a set that came with the bike I would be digging them out the scrap box. I have an outboard disk on one of mine but my series 1 standard front drum is not far away. The rear looses grip with the road and locks up if I stomp on it so I use the front most of the time with the rear if I need it. They can work very well.
User avatar
MK Monty
 
Posts: 340
Joined: Sun Jun 01, 2014 10:32 pm
Location: Stockport

Re: Brakes next to useless on my S2

Postby Scouse Scooterboy » Fri Oct 07, 2016 8:22 pm

MK Monty wrote:First thing I would do is whip the rear drum off. Worth doing if only to prove your rear oil seal has not dropped oil on you shoes. By now you will have whiteness wear on the shoes. I would be surprised if you have even contact on the shoes. I found I was only using a 1/2 inch wide strip round the shoe and even then only on just over half of each shoe. Have a go at the high spots that are in contact to get more of the shoe in contact. A shoe trimmer is the best way but sand paper or a rasp type file may get the bulk off. I have in the past had to remove the steel pad on the cam end and file the end of the shoes as one was hard on with the other being unused. I'm afraid the quality of new shoes are not as good as the old ones so if you had a set that came with the bike I would be digging them out the scrap box. I have an outboard disk on one of mine but my series 1 standard front drum is not far away. The rear looses grip with the road and locks up if I stomp on it so I use the front most of the time with the rear if I need it. They can work very well.


Thanks MK Monty. Useful and welcome advice. Ta
User avatar
Scouse Scooterboy
 
Posts: 16
Joined: Mon Nov 03, 2014 8:33 pm


Return to Series 1, 2 & 3

Who is online

Users browsing this forum: Andy_S, Google [Bot] and 29 guests