Brake improvement: SLS to 2LS. Is it worth the swap?

I’m getting a Matchless G-15 back on the road and I see I can swap to a later Commando 2LS brake as the wheel and hub are the same. It’s my hope to use this machine regularly, and on the few rides I’ve had on it the braking was less than impressive.

Would anyone else who has made this swap on a Dominator/Atlas/N-15/G-15 care to opine on how much actual braking improvement might be gained by the change? Was it ultimately worth the expense and bother?

Or does this upgrade turn an awful brake to one that is merely terrible?

My ES2 has a 2LS, can't compare with SLS as it had that when i bought it.
A few comments though. They are more sensitive to set up, need to get both shoes working properly. On damp days i find the first use grabs with very little lever pressure, after that it is fine. They are hopeless for hill starts, you have to use the rear brake.

A 2LS will give you a better brake. But best results will follow from also using top quality linings. Is Vintage Brake still in business in the USA? They have linings that will give good results.


You can also add a stiffening kit. I think RGM and Andover will have this.

My experience using drum brakes in classic racing in NZ that the above will give you a good brake that will stop you from high speed two maybe three times. After that the 2LS will overheat and get worse. But still better than SLS.

Finally do the above plus if you really want to do the best you can with Norton drum brakes then for 2 or 3 years in the early 1950s Norton made a half cast iron half aluminium front hub. This is like a Velo hub. These hubs are definitely better for not fading.

This will give you the best drum brake based on Norton street bike parts.

Mean gene has a 4LS brake in a 19" wheel for sale you should be able to make work. A 4LS brake is a huge improvement over a SLS brake.

The SLS original equipment on my Atlas was little better than dragging my feet.

I replaced it with a TLS bought from Dunstall ..... a world of difference! Does not self augment, and IMO, will match a disc brake in a one time panic stop.
Unfortunately, these Dunstall TLS brakes are unobtainium.
T
RE: Reply #3: Mike at Vintage Brake is not taking in any new work.....he is in the process of closing out his business.

Slick

Yes you can fit a 4LS if you also change out the sliders. This is a Manx 4LS on my Dommie with Molnar sliders. But this is very expensive. Plus of course the air-scoops would need to come off for street use.

If you go with a Commando 2LS the only change you need is switching to a Commando cable to match the UNF threads.

Always reline your factory Norton shoe castings.

One look at the factory cores vs ALL the "pre-packaged" new shoes should already tell you which is a better core material.

In the Western US, Speed and Sport relines your factory cores with a choice of 2 different materials.

If it is the bike in your avatar, IMO a TLS would not look right on that bike.

Little to gain on that bike with dual purpose tires anyway.

Just reline your stock SLS shoes if they lack bite, and you should be good, IMO.

I run the stock, small front matchless brakes on my P11s and they do fine.
Could not imagine putting on anything else. Would look odd.

They actually have pretty good bite, and are adequate for the bike's power level and purpose.
And I have not touched the linings yet.

I never worry about braking on the old iron horse anymore, since I replaced the sad Matchless 7" SLS front brake on my P11 with a 4LS brake. Worth every cent, and all the time it took to make it happen. Looking odd is less important to me than having gear that performs at the level I need it to perform. Originality is not my top priority. I'm a motorcyclist, not a restorer.

I did find the 7" SLS brake adequate riding very slow in town on the street. Unfortunately, I still like to ride at a good clip where possible, and the SLS brake on front was an accident waiting to happen. Sounds to me like that is what Elfix is also saying.

That said, if I still had a modern bike in the garage to get my kicks with, I never would have changed out the front brake. As a matter of fact, I probably would have left the Norton parked in the corner of the garage a few more decades or tried selling it instead of what I have done to it over the last 18 months.

johnm said:

Yes you can fit a 4LS if you also change out the sliders. This is a Manx 4LS on my Dommie with Molnar sliders. But this is very expensive. Plus of course the air-scoops would need to come off for street use.

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Why did you have to replace the sliders to fit a 4LS brake? Not enough room at the axle between the G15 sliders?

I ride on the street with a 4LS brake. Scoops are permanent, but I don't ride in the wet or in the dirt. The street is generally not that filthy around here.

I hope to be able to ride this bike to Dawson next summer for the 2023 D2D event. I can get by with the stock brakes but they are just barely adequate and don’t give one much margin. I’ve already swapped to K70 tires so there is a bit more traction to play with on the pavement, and while I agree the 2LS will look wrong it does seem to offer a decent trade off if the braking is that much better.

I have found replacement shoes with Ferodo linings for the stock SLS brake- can anyone opine on if those are a substantial improvement? I will be arcing and fitting anything used, so the setup should be consistent.

The entire reason for the thread was to try to judge if the improvement of the 2LS is worth both the investment and how much it strays the bike from originality. I absolutely don’t mind making changes that improve the bike, as it means I will ride it and enjoy it more.

…..But I do appreciate keeping it as close to original as I can in appearance.

As an example, my 1972 Yamaha RT2 has had a host of modifications: converted to 12v, CDI, head reshaped, air box and internal exhaust changes, internal fork changes, etc. The only noticeable alteration was to mount a later front brake and wheel from an XT500 in order to get a somewhat functional brake and a 21” front wheel. The ‘73 came with a 21” so only the most advent observers of Yamaha enduros will spot that- and it made tire selection easier and the bike tracks better in the rough stuff.

Schwany said:

I never worry about braking on the old iron horse anymore, since I replaced the sad Matchless 7" SLS front brake on my P11 with a 4LS brake. Worth every cent, and all the time it took to make it happen. Looking odd is less important to me than having gear that performs at the level I need it to perform. Originality is not my top priority. I'm a motorcyclist, not a restorer.

I did find the 7" SLS brake adequate riding very slow in town on the street. Unfortunately, I still like to ride at a good clip where possible, and the SLS brake on front was an accident waiting to happen. Sounds to me like that is what Elfix is also saying.

That said, if I still had a modern bike in the garage to get my kicks with, I never would have changed out the front brake. As a matter of fact, I probably would have left the Norton parked in the corner of the garage a few more decades or tried selling it instead of what I have done to it over the last 18 months.


Why did you have to replace the sliders to fit a 4LS brake? Not enough room at the axle between the G15 sliders?

I ride on the street with a 4LS brake. Scoops are permanent, but I don't ride in the wet or in the dirt. The street is generally not that filthy around here.

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I had to replace the sliders to get the appropriate brake anchor locations. This brake is a replica 1963 Manx Norton 7 " 4LS. Magnesium. Made about 15 years ago by Greg Summerton from Adelaide Australia. He made about 10 at that time but has now retired and is no longer in business. He actually sold the complete wheel doing the final machining of the drum after the rim was spoked and tensioned. He is a very careful engineer who did a lot of work with JAP V twin engines for speedway and car racing. Did a lot of speedway and road racing sidecar machines.

It is a plug and play replacement so you can build up one of each and swap them in and out to your liking.
Complete old TLS brake plates pop up every now and then, and for not a lot of money. Easy.

johnm said:

I had to replace the sliders to get the appropriate brake anchor locations. This brake is a replica 1963 Manx Norton 7 " 4LS. Magnesium. Made about 15 years ago by Greg Summerton from Adelaide Australia. He made about 10 at that time but has now retired and is no longer in business. He actually sold the complete wheel doing the final machining of the drum after the rim was spoked and tensioned. He is a very careful engineer who did a lot of work with JAP V twin engines for speedway and car racing. Did a lot of speedway and road racing sidecar machines.

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Oh, I see. They are braced against the sliders. Yeah, that is different from the 230mm Ceriani 4LS copy I'm using that weighs about way too much. It's easy to make a set of flat plate braces that are attached to the 2 fender mount lugs on the sliders. Never have had stock forks on my basket case though so don't know if that would be doable. Thanks

Brake anchor on the slider. Right side and left side. This is a 1963 Manx front brake replica. The final hurrah for Manx Factory drum brakes.

I'm not advocating this for street use. It is on my old race bike. The price for this set up including sliders would be north of US$4000. Back then I had a job.

I went ahead and ordered up a 2LS brake “kit” from RGM which includes their high friction shoes, as well as new rear high friction shoes. It’ll likely be next spring before it’ll be installed and tested (the snow approaches) but I’ll report back once the swap is completed

Elfix, Good on you. I have an Atlas with a Commando TLS brake without the stiffener kit. It works just fine. It is a better brake than my Commando factory disc brake. I also had a similarly equipped G-15 with a hot commando motor. That brake was fine too but needed a fork brace for the long fork tubes. I changed out the tubes and made it a CSR.

Drum brakes are good if you don't need to use them in anger. They change as they heat up. And TLS is more dangerous than SLS. The plated single disc on the MK3 Commando is better, but not much. In a difficult situation, you can watch your life coming to an end.

acotrel said:

Drum brakes are good if you don't need to use them in anger. They change as they heat up. And TLS is more dangerous than SLS. The plated single disc on the MK3 Commando is better, but not much. In a difficult situation, you can watch your life coming to an end.

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I agree drums are not as forgiving as a disc, and it was basically impossible to lock up a small diameter SLS on my P11. In that regard it was safer, but I came real close to hitting the rear bumper of cars on the street more times than I can count. Always had to use both front and rear brakes.

My 230mm 4LS took about 1500 miles of bedding and getting used to it to feel good on the street. Before that it was scary, and I hit the deck in the wet first time out. I won't ride in the wet anymore unless literally caught out in it unexpectedly. Now I can hit the brake in anger, but only street anger in warm weather dry conditions. On a racetrack it might be another story and I'd end up sliding on my back. Drums do fade, but it would take a lot of speed and heavy braking to make a big 4LS fade to completely useless like a SLS does.

Seems to me a TLS once bedded in would be a big improvement over an SLS for use on the street.

Acotrel- I respect your opinion on drum brakes and can see where it comes from. Everyone I have spoken with who raced or races with drum brakes has had similar things to say. My bike will probably end up on the track next summer, but only as a pilot machine for teaching new riders the course- certainly not for going fast or trying hard.

To me the issue is to balance what improvements can be made while still retaining the spirit and history of the machine. Beyond a certain level of modification one’s vintage bike is no longer a vintage bike- and yet still not to the ability or performance of a newer machine. I doubt any amount of changes would bring my G15 anywhere near the level of my 701 Vitpilen.

My solution has been to have a lot of bikes and to try to enjoy them for what they are…. Even though that’s not going to keep me from swapping on a double leader onto the Matchless. It needs SOME brakes if ridden on the roads with the other lunatics.