TLS drum project

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acadian

acadian

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I've had the original TLS drum from my 71 sitting on the shelf and collecting dust for 15 years now, that and a stiffening kit, new stainless linkage, an 18" Akron rim, and a spoke set.

My intention has always been to clean up and sell the TLS as I'm running a fairly well sorted single disc on the bike with a Nissin MC... it does the job.

I finally got around to cleaning up the brake plate and installing the stiffening kit. I turned down a drift as per OldBritts to press the short pivot pin, installed new screens etc... I arced the new Ferodo shoes on the mill, cleaned up and lightened the drum as well.

TLS drum project

TLS drum project
TLS drum project

TLS drum project
TLS drum project


I'd forgotten how pretty the Norton TLS is, and when I test mounted it in the forks I thought "why not give it a go?" I've got a drum fork slider sitting on the shelf but am not really inclined to strip my existing disc side fork and install the Lansdowne in a drum slider, all just to test out the brake.

I know, I know... it's going backwards in the stopping power department, but what the hell.

So I machined a bracket that mounts to the caliper boss. The bracket is bushed where it mounts to the TLS torque stay, I also had to machine a 1/4" wheel spacer to take up the space between the drum and disc sliders, and lastly some standoffs to properly space the bracket to the drum plate.
TLS drum project

TLS drum project


Finished assembly
TLS drum project
 
Clever. It will be interesting to hear your impressions of a back-to-back comparison.

Ken
 
Paul Dunstall recommends fitting 20 thou of an inch shims between the ends of the shoes and the cam and arcing them in a lathe. With a drum brake, it is fairly easy to set them up so they will lock as you brake. When I was a kid, I was approaching Siberia Corner on Phillip Island at about 90 MPH . I had barely touched the brake before I found myself rolling down the road on the non-skid surface. With disc brakes, you just fit them and forget all that dangerous bullshit. The only bad thing that can happen is when you use a single chromed disc and run out of brakes if you go into a corner too hot.
 
acotrel said:
Paul Dunstall recommends fitting 20 thou of an inch shims between the ends of the shoes and the cam and arcing them in a lathe. With a drum brake, it is fairly easy to set them up so they will lock as you brake. When I was a kid, I was approaching Siberia Corner on Phillip Island at about 90 MPH . I had barely touched the brake before I found myself rolling down the road on the non-skid surface. With disc brakes, you just fit them and forget all that dangerous bullshit. The only bad thing that can happen is when you use a single chromed disc and run out of brakes if you go into a corner too hot.
Click to expand...

I fit shims under the feet of the shoes before I arced them in the mill
 
Beautiful work, whether you like the stopping ability or not. Can you give some detail on how you did the screens for the drum? It appears as though you have used some kind of stainless insert?
 
Acadian, can you tell us how you arced them on the mill? I am more familiar with arcing them on a lathe.

Stephen Hill
 
acotrel said:
Do you want a description of the pain ?
Click to expand...

What pain?

I'm just interested in his impressions of the difference between riding the same bike with both drum and disk front brake. I've ridden and raced a variety of both drum and disk braked bikes, and never had a crash due to the brakes not working properly. All my crashes were either due to a mistake in judgement on my part, a mechanical failure, or getting taken out by another rider. And one of my worst crashes was from grabbing too much front brake (dual front disk Commando PR) at the end of a straight, but that was my fault, not the brake's. But I've never had the chance to ride the same bike with both drum and disk front brake, so I find it interesting to see what acadian thinks of the difference.

The fact that you once crashed from too much front brake doesn't make all drum brake bikes into death traps, any more than my experience makes disk brakes unsafe.

Ken
 
Reminds me of guys back in the day that had a chopper with NO front brake!
 
You can only go as fast as you can stop. I also got caught at the end of the front straight at Calder Raceway. I was holding the brake on hard, trying to stop and the leader heated up and grabbed. I got flicked over the front at about 100 MPH and slid off the corner into the escape road. But it was not all bad - my two young sons were standing there watching me. So I never had the anxiety of watching them race motorcycles.
 
Onder said:
Reminds me of guys back in the day that had a chopper with NO front brake!
Click to expand...


A friend was driving along a country road one day and saw the police and ambulance people carrying a guy out of the trees. His chopper had taken him off the road. Steering geometry modifications can be dangerous. Choppers were idiocy. 'Because I can' is never a good reason for doing anything.
 
Stephen Hill said:
Acadian, can you tell us how you arced them on the mill? I am more familiar with arcing them on a lathe. Stephen Hill
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Bolt brake plate to a rotary table that is centrised, mount rotary sandpaper onto chuck, feed table to shoes and with battery powered drill with a socket rotate drum/ rotary table. Tip; put .020 tho shims under shoe flats until u have turned down shoes to exact diameter of brake drum.
 
lcrken said:
What pain?

I'm just interested in his impressions of the difference between riding the same bike with both drum and disk front brake. I've ridden and raced a variety of both drum and disk braked bikes, and never had a crash due to the brakes not working properly. All my crashes were either due to a mistake in judgement on my part, a mechanical failure, or getting taken out by another rider. And one of my worst crashes was from grabbing too much front brake (dual front disk Commando PR) at the end of a straight, but that was my fault, not the brake's. But I've never had the chance to ride the same bike with both drum and disk front brake, so I find it interesting to see what acadian thinks of the difference.

The fact that you once crashed from too much front brake doesn't make all drum brake bikes into death traps, any more than my experience makes disk brakes unsafe.

Ken
Click to expand...

How many ways can you set a disc brake up wrong ? And how many ways with a drum brake ? If you want to use a drum brake for racing, buy an Oldani or a Fontana and you might stay alive. In Australia, there is one historic class in which all front brakes must be drums. A decent drum brake costs about $5000. Anything else puts your life at risk. If I was going to race in Period 3, I would probably use a Norton brake - but I would be very careful. Every big crash I have ever had, has been due to a drum front brake. I used to have them machined by BGT in Melbourne, who did all the race brakes for the top guys over a period of about 40 years.
 
rvich said:
Beautiful work, whether you like the stopping ability or not. Can you give some detail on how you did the screens for the drum? It appears as though you have used some kind of stainless insert?
Click to expand...

Edit: I think you're referring to the button screens on the drum side: 1" holes machined between the ribs, the screens are stainless hole plugs sourced from an audio supplier - https://www.efc-intl.com/products/hole-plugs-metal-plug-button-ventilator-screen-type.htm

TLS drum project


Stephen Hill said:
Acadian, can you tell us how you arced them on the mill? I am more familiar with arcing them on a lathe.

Stephen Hill
Click to expand...

Exactly as Bernhard described, on a rotary table. I initially considered turning the plate on my lathe, and set up a mandrel to do it, but changed my mind last minute as I felt more comfortable going the sanding route rather than the cutting route. I turned down this sanding drum and glued some alu-oxide sand paper to it. The little drift is what I turned down to press/rivet the short pin

TLS drum project


storm42 said:
Very nice, would you be able to weigh the assembled hub ?
Click to expand...

Total weight of hub + plate + bracket assembly = 13.9 lbs

Turning the wheel spacer out of 616 was the most challenging part, went through an insert on my boring bar

TLS drum project
 
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I really enjoy these threads where you guys machine all these cool things.
Way out of my league.
Very interested in seeing the finished product.
Carry on................
 
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