Another drum query

Sorry for another drum query. Thanks everyone who helped me figure out which roadholders I'm after, really very helpful forum. Having decided it's probably early Commandos forks I'm after I'm now looking to decide which front drum brake to use with them. Currently looking to build a project combination of Triumph/Norton and AJS (mostly AJS) and I'm in the process of gathering info and parts.

So here goes what I'm after:

-It's not a cafe racer or racing bike but I would like solid stopping power, I've only ever used a Honda CB450 drum brake in the past on a bigger bike and it was a slower downer not a stopper!
-Road use so no open holes and where there are holes one's that can be covered over.
-4ls or 2ls, but no huge and expensive 4ls racing drums that is over kill for my needs.

I've been using this site to compare drum brakes:

http://victorylibrary.com/brit/2LS-table.htm

So far these are the ones I'm considering:
-Norton Commando 2ls - The best looking for what I'm after but also the worst performing, Inadequate imo (given it's result is only slightly better than a CB450 hub).
-Suzuki GT550 4ls - Not as good as they should be for 4ls but still the best performing, a lot of unsprung weight. Has a speedo drive which gives me more options with aftermarket speedometers if I don't want to use a rear wheel speedo. The most expensive in my list.
-XS650 XS-1 - slightly better than the Commando, still inadequate imo. Ugly rubber holes but does have the speedo option if I don't want to use a rear wheel speedo.
-Triumph 8" full 2ls - Best performer for a 2ls and nearly as good as a GT550 4ls, brake plate is good looking but the drum itself is ugly to my eye.
-Triumph 8" conical 2ls - Apparently same performance as the earlier triumph 8", but some people rate them badly, conical drum is good lucking but brake plate with scoop is ugly to my eye, also I cannot cover up the scoop.

I'd love to be able to use the Triumph 8" conical with a different brake plate. At the moment the GT550 4ls is winning for me however despite the unsprung weight. Does anyone have any other recommendations I can have a look at regarding 4ls or 2ls drums, given the criteria?

Acebars said:

Having decided it's probably early Commandos forks I'm after

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Don't forget, again, that what was in there originally was LONGER than LONG roadholder Commando forks.
25" tubes, everything in Nortons was shorter compared to this. ( except your N15CS and P11 etc)

Again, if you are not going with a stock bike and actually intend to ride it, a lot, Ludwigs P11 with long-long roadholders and Commando disk setup made a lot of sense.
madass on this forum sells a few versions of big drum brakes, if thats the direction you wish to keep.

Yes it must be drum brakes, I have no faith in 70s disc brakes whatsoever, imo only mild advantage is less brake fade, but as I'm no racer this has never been a problem for me.

My last 1975 Honda CB500t disc performed much worse than the older 1969 CL450 drum I replaced it with, the disc locked up with the slightest hint of winter even when recently serviced.

What is Ludwigs P11?

Cor Blimey :



Forgive the picture , tripped over it looking for a Dunstall ad . Old ' Motorcyclist '
magazine small ads , sketches . SHOWING a ' T L S ' 60s Triumph type back plate
fitted to a NORTON . :? Presumeably the Triumoh copy ? ? wouldnt be to hard to
put into a Norton Hub .

Youll have to dig through old 60s magazines , to check on this one .

===================================================================

Check THIS out ! :shock: http://thevintagent.blogspot.com.au/201 ... chive.html



p.s. the levers need to be the ' straight up ' cable ones , the curved cables spongeyer . ( the one that runs BACK of the lever )

" I'd love to be able to use the Triumph 8" conical with a different brake plate "

Fear Not ;

You need a Circa 1960 Humber 80 Hydraulic front back plate , etc , as the shoes are the same part No as the BSA / Tri Conical . A hydraulic hand lever might be needed too ,
though BMs put the master cylinder under the seat , cable operated . Used to be Hydraulic Harley rear brakes , too . :lol: Bit of work , but doable .

Yr problems going to be the Axle ? might pay to stick to one make , up front . or interchangeable parts anyway .

Acebars said:

Yes it must be drum brakes, I have no faith in 70s disc brakes whatsoever, imo only mild advantage is less brake fade, but as I'm no racer this has never been a problem for me.

My last 1975 Honda CB500t disc performed much worse than the older 1969 CL450 drum I replaced it with, the disc locked up with the slightest hint of winter even when recently serviced.

What is Ludwigs P11?

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re; "My last 1975 Honda CB500t disc performed much worse than the older 1969 CL450 drum I replaced it with, the disc locked up with the slightest hint of winter even when recently serviced."


Could have been the wrong master cylinder fitted :?:

I don't ever want to ride another bike which is fitted with drum brakes. My dislocated chromo-clavicular joint still hurts now and then. Remember this ? :
drums-big-drums-t8626.html

Bernhard said:

re; "My last 1975 Honda CB500t disc performed much worse than the older 1969 CL450 drum I replaced it with, the disc locked up with the slightest hint of winter even when recently serviced."

Could have been the wrong master cylinder fitted :?:

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No it was all stock, and recently serviced with braided hose, a slight improvement, it's well known that the 70s disc brakes are poor made no difference if you swapped the Honda ones from other Honda models as they were the same, I was really involved with Honda CB500ts really took a liking to them and the two best improvements for the brakes were either to go dual setup from a late 70s/early 80s XS650 or ditch the discs and find a CL450 / CB450 front drum, even saw a few Triumph conicals being put on them a vast reported improvement. No more "why am I not stopping??!?" in the rain moments!

acotrel said:

I don't ever want to ride another bike which is fitted with drum brakes. My dislocated chromo-clavicular joint still hurts now and then. Remember this ? :
drums-big-drums-t8626.html

Click to expand...

Can you elaborate? Was this from racing? Tried 70s Honda discs in the rain or near freezing? I'd swap those for drums any time. Really dislike fear mongering without something backing it. Motorcycling is a dangerous past time fullstop. Don't like big drums either 210mm is pushing it for example.

Check THIS out ! :shock: http://thevintagent.blogspot.com.au/201 ... chive.html

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Matt thanks for this, having looked at his conical and early 2ls I am thoroughly turned off by the idea, the bike imo is a desecration, ugly and hipsteresque, the conical with the early 2ls looks thoroughly lopsided like the drum was mounted incorrectly or something. So that idea is out.

Dunstall ad . Old ' Motorcyclist ' magazine small ads , sketches . SHOWING a ' T L S ' 60s Triumph type back plate
fitted to a NORTON . :? Presumeably the Triumoh copy ? ? wouldnt be to hard to
put into a Norton Hub .

Click to expand...

I'd like to pursue this, I can't see the photo very well at all but I understand this is an ID 8" norton hub with the triumph tls back plate? The norton hub is the look I'm after and the pre-conical triumph 2ls back plate is nice also, question now is the braking contact area decided by the brake shoe width or the drum width or both and if so how this combo would rank with the drum brakes by method (ID x Width)?

Having already used a CB450 front hub with similar performance to the Norton 2ls Commando I'd really like something better and the Triumph 8" is reported and by method roughly 1.5 times more effective a brake.

The Suzuki 4ls is only 1/6 more effective than the Triumph 8" 2ls by method so I'm not sure it warrants its exorbitant by comparison cost, at that price better to get a replica 4ls.

Here it is again:

http://victorylibrary.com/brit/2LS-table.htm

Acebars, Back when I raced my short stroke 500cc Triton, I used to enter Allpowers C grade races which involved disc braked two strokes, and big four cylinder bikes. My bike was fitted with 7R AJS drums, front and rear. The front brake had an extended lever on the backing plate, and I used a soft lining on the front shoe, and a hard one on the rear. That way, as the brake heated up, I always had sufficient to stop. The brake needed only one finger to operate it, and if you grabbed a handful you were dead. It had to be that way to be competitive in the company of the disc braked bikes.
I hadn't race d for about 8 months, and I rode at a club meeting at Winton. There was one guy who had a 650 Triton, and I always fought with him in every race over about 12 years. This day he was riding a disc braked Laverda, and I blitzed him down the back straight . However I inadvertantly over braked into the right hander in front of him, and he got past me. He then pulled a stupid, and popped in and braked hard in front of me. I grabbed the brake, and broke the front wheel free. The bike went into the crashing lock to lock tank slapper, and because I was a bit out of practice, it launched me. I slid down the road on the top of my head with my legs in the air at about 70 MPH. By the time I reached the ripple in the bitumen, I was on my side. The ripple caught my shoulder, and the chromo-clavicular joint was separated, and I was in pain for a year.

acotrel said:

However I inadvertantly over braked into the right hander in front of him, and he got past me. He then pulled a stupid, and popped in and braked hard in front of me. I grabbed the brake, and broke the front wheel free. The bike went into the crashing lock to lock tank slapper, and because I was a bit out of practice, it launched me. I slid down the road on the top of my head with my legs in the air at about 70 MPH. By the time I reached the ripple in the bitumen, I was on my side. The ripple caught my shoulder, and the chromo-clavicular joint was separated, and I was in pain for a year.

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Ouch really sorry to hear that, I won't be racing the bike, and for the street use I'm looking for including winter use the drums are definitely better for my application.

Can I ask what exactly happened when the front wheel broke free, I have no idea what a 7R AJS is just been viewing one on google, how was it mounted to your braced to your forks? Was it a defect in the way the drum was mounted or just a total failure, i.e. could have it been avoided under the same user input? I have read racing 2ls is not the best idea because of the stress it can induce on one side of the fork, leading to bending/warping and potentially failure, was this a 2ls or 4ls?

Well I found a big front 2ls drum I'm after, it's on the photo below on a Gilera Piuma.

Only trouble is this is a bigger drum than was originally on a Gilera Piuma and given I can't find any replica 2ls makers maybe impossible for me to find out what this actually is or actually find it.

It's not only beautiful but will give me more than adequate stopping power I'm after.

Magnesium Oldani ?

Not the same bike though.


Having once had a CB450 with single disk - same disk as the CB750 - I'd have said that 'savage' was not in its vocabulary.
Not that I ever met any ice...

Looks like the eyetalian is the way to go , then .

Swept area / shoe dia. x width . But the length of the shoe is relevant too . Pressure Sq. in . Which is why a good no flex / squish cable set up is important . & the in line stop light switch is a no no for best operation .
THEN THERES THE LINEINGS . Copper impregnated italian disc pads worked when they were warm . Took two seconds , quicker to jump clear till then . So some ' raceing / metalic lineings WEAR the Drum / Disc ,
and are for ' continuous ' on / off circuit type use . Puttering along after ten minutes theyr COLd , and Dont Grip till theyve warmed up again . Like Raceing tyres .
So chooseing linings needs some consideration . Soft ones are grippier cold , dont wear the disc / drum , but overheat / get ' heat soak ' earlier . Worth avoiding if you live at the top of a 10 mile downhill road on the edge
of a precipice .

The ' Dunstall ' picture - brake was akin to the photo there , the Brake Plate assembly at least . INSTALLED in youre standard domminator etc hub , same as later Norton 2LS hub / commando hub . ( just for the record ) .
Thought the pic nifty . Gleeson Bros entered a 1950 T - Bird with girders , on Methanol with TWIN single sided Triumph cast steel front brakes ( TLS - one SLS Ea. Side ) They were the types who STARTED the Classic Raceing
scene in the U.K. ( Two hubs similar to photo , cut in center & welded back to back , look a bit like a Vincent Brake .

The CONICAL Twin Leader had greater lineing width than the earlyer ( pre 71 ) hub . but mickey mouse actuation . The late 50s Humber / hillman SHOES are the same part no . ( Bendix etc ) so Ergo - the Hydraulics Fit .
If you cared to machine fittings up as neccesary .

Looks like youve found the Bees Knees , anyway . But take time ensureing nothings half a**sed . A fault could lead to emulateing acc's effort .

All free with no binding & no ' sponge ' take up spring , gets it all hair trigger - OFF as well as ON . which can be as important , if not more .

Acebars, my accident had nothing to do with the way the brake was mounted. The 7R AJS hubs have snail cams and rollers on the backing plates to push the shoes against the liners, and with the extended lever it only took a very light touch to apply the brakes firmly. The reason I crashed was that I over reacted very slightly and caused the brake to momentarily stop the wheel from turning . When I lost traction at the front, the forks and wheel started gyrating uncontrollably. Because I hadn't be riding recently I didn't get my hands off the bars quickly enough, and I was flicked over the front of the bike. You never have those problems with disc brakes. It is almost impossible to set one up so that you are afraid to grab a big handful. There is no self-servo effect.
Another thing about drum brakes is that it is possible to set them up so that the brake stays on after it has been use d, This can mean that due t o the self-servo effect, the bike se lf-steers itself wide in turns . I crashed four times in one day at Philip Island due to a drum brake. Steering geometry on most bikes is set so that the bike becomes stable under brakes , if the brake drags you can find yourself dodging trees .

Acotrel, I thought you said you broke the front wheel free? By that I understood the brake plate came free from the fork?

I won't be racing, at most maybe track days for confidence does sound like they may have not been setup correctly or too powerful, I have limited brake knowledge but I know self servo or sticking is one too watch out for one in drums, massive return springs and such can help alleviate this.

I'm not debating discs aren't better, but I do know from experience that most 70s brakes are crap for road use also drums look the part for what I'm after. I'm after a solid all arounder with looks and performance, my bike is probably going to be around 200kg or more so fairly heavy, no racing bike.

Looks like the eyetalian is the way to go , then .

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Absolutely, definitely a looks first, performance in close second bike.

Magnesium Oldani ?

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I don't think it's a mag hub although the brake plate looks similar. Given that I doubt I'll be finding that hub anytime soon (no success whatsoever online so far), I think I should stick to what is readily available for the time being and keep my eyes out for that one.

So back to square one, Suzuki 4ls is out because it's as heavy and only marginally better than the Triumph 2ls and for the money I could be looking at a far superior Robinson 4ls. Conical is out because I can't find a decent looking and working brake plate + it's only a little lighter than the earlier 2ls + I can't find that humber plate you suggested anywhere? Also I don't think I'm experienced enough for major brake modification

So leaves me with only 3 options:

The Commando Drum - Apparently I can make this work better with an inside plate mod.
2LS earlier Triumph Drum - Good stopping power but very heavy
XS-1 XS650 - Middle of the to above, rubbers don't look great on the drum.

I'm seriously tempted by the Commando drum, hoping that that plate mod will make it much more effective, reason is it looks great and will require no mods to match to the roadholder forks, maybe a great place to start.

So chooseing linings needs some consideration . Soft ones are grippier cold , dont wear the disc / drum , but overheat / get ' heat soak ' earlier . Worth avoiding if you live at the top of a 10 mile downhill road on the edge

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'Tis a no brainer for me, soft liners, no racing linings!

I manufacture 7 (I think) different front brakes for Nortons, this is NOT a sales pitch. The Norton Commando 2ls drum brake is a good brake. It needs to be set up correctly to work efficiently. I replicated this brake casting it out of high tensile alloy then fitted brake shoes with .010"-.015" shoe to drum clearance, then fitted the stiffening kit. it works.
again I must state this is not a sales pitch for my products, only stating that the Commando drum brake can be made to work.

I have no problem even if it was a sales pitch.

As soon as I make up my mind over which brake to do if I pick the Commando brake and buy one will most likely be in touch.

The Triumph early 2ls might be great my only fear is how much unsprung weight it will add and whether or not I can easily fit it to the early commando forks.

Acebars, I think you need to think about what you are going to use the front brake for. A drum brake looks good, however a disc brake is much safer. On my Seeley, I use two Suzuki discs with two Lockheed calipers fitted with the older style asbestos pads. It is extremely safe and powerful, it stops the bike from very high speed like hitting a wall. I've used carbon racing pads, however they are less effective, never seem to get hot enough on our shorter circuits.
When I used the 7R AJS brake, I used an ME36 green lining on the front shoe, and an MZ41 lining on the rear shoe. The ME36 lining is very soft, and will stop the bike very well when cold. The MZ41 will start to work when hot. If self-servo is causing the drum brake to lock or drag, bigger springs will not stop that from happening. It depends more on where the cams are located on the backing plate. I think you will find that obtaining suitable lining compounds for drum brakes, might be difficult these days. If your bike has any sort of improved performance, I suggest you might do much better to fit a single cast iron disc with a decent caliper - you will be safer.
My Seeley never gives me the anxiety that my old Triumph did, and much of that was about the drum brakes. I still haven't used the 6 speed TTI box in anger yet, however I think my Seeley will be very difficult to beat, even in races against 1300cc methanol fuelled CB750 Hondas. I know I'm speaking ahead of the game, however I've raced enough to know what this bike will do. All I need do now is find the funds to race again.
If you do decide to use a drum front brake, don't forget to chamfer the leading edges of the linings well back. If the leading edge heats up and becomes sticky, it can spit you off the bike at high speed.

acotrel I hear you and thanks for the advice appreciated, if I was racing a bike I would definitely do as you suggest, but I think I've made it clear it's not a race bike but a road bike so I will only on some occasions be going 70mph or more on a motorway.

From my road experience I refuse to use early disc brakes on my road bikes (although I've only experienced the early Honda ones CB500ts and CB500/4), for several reasons 1) They lock up and the slightest hint of winter 2) They work very poorly in wet weather (of which there is a lot of in England) 3) They are more maintenance than the drum brakes 4) They are more maintenance in particular if they keep on seizing at only 5 degrees C or less. Hence why I also want a closed dry brake like I mentioned before.

I think I'm going to go for the big old heavy Triumph 2ls my only concern is it's unsprung weight, but I understand the Norton Roadholders are the best forks Britain ever produced for larger production so hopefully it will cope.

Acebars, a friend uses two 8 inch Triumph hubs, back to back, on his 650 Triton racer. The weight is not a problem. I appreciate what you are saying about the weather affecting the brakes. My comment was only relevant to places without extremes. In that situation a mediocre disc brake is far superior to any drum brake. If a disc brake ever drags, simply apply rubber grease to the seals.