BSA Triumph Conical Hub Brake Twin Leading Shoe adaption:

Thanks for information, I will research some more..!

Cheers

John H

Found some Brake tests in which the Conical hub comes out quite well, with an equal rating to the 1968-1970 BSA Triumph brake, only Moto Guzzi V7 , Benelli Tornado, Suzuki GT's and Harley Davidson twin drums fairing better, except for exotic stuff, 10 inch drums, Fontana, Ceriani, Grimeca, Oldani & Yamaha Race drums, often which are 4 shoe units!

The Commando unit rates much lower down, plus anything designed that needs a stiffening plate means essentially something inherent in the initial design must be inadequate.

People in the UK make silly rhymes up and believe this as truth! In most cases it is bad maintenance or people who just don't grasp how things can work more effectively when time is taken to adjust and maintain them properly Having said that often with a little thought manufactured units can be improved on, even after sadly, 50 years factory inspired development!

Previously Mikael Ridderstad wrote:

Hi John, when you mention Harley Davidson, I guess you refer to H-D Aermacchi. Remember the 350 racer had more than adequate brakes. Front was the best 4LS I've ever tried. Rear was a bit scary so we disconnected one shoe. I've read that they was made by Fontana.

The Test data was based on the units of the Big twins.

Previously ian_soady wrote:

That table is interesting but just gives theoretical performance. As I remember it, one of the main gripes with the conical hub was the short cam length which didn't give enough mechanical advantage. As the outer cable operated one cam and the inner the other, effective travel was double what it would have been with a link rod as on the earlier Triumph brake (and indeed the Norton one). Hence mechanical advantage was about half.

http://sumpmagazine.com/classic-bike-workshop/images/conical-hub-brake-complete.jpg

http://www.anglo-bobbers.com/Triumph_1969/images-tr0009/1969_Triumph_Trophy_Bobber_468x366b.jpg

The results came I believe from a variety of sources, I know there Conical hubs theoretically could suffer from lack of bulk and metal in the hub part, for heat to be dissipated through, this is why the Conical brake plate in combination with a Norton full width hub it might produce an amazing unit!

There are extended brake cam arms available for the conical hub brake plate, for greater leverage. However, perhaps the whole mechanism could be redesigned with an adjustable 8mm link bar and a different cable run, almost like a combination between the Conical Hub and earlier unit. The strength of the Conical hub over the Commando unit is the brake plate itself is of a much stronger construction and does not need a stiffening plate!

if i find an answer and a better Unit amalgamation it could help save riders of old classic machines having to spend a lot of money at M&S on new underwear!

Previously Mikael Ridderstad wrote:

Hi John, when you mention Harley Davidson, I guess you refer to H-D Aermacchi. Remember the 350 racer had more than adequate brakes. Front was the best 4LS I've ever tried. Rear was a bit scary so we disconnected one shoe. I've read that they was made by Fontana.

as far as I can tell it's all Big Twin data!

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

Previously Colin Peterson wrote:

I had an A65 with the late '60s TLS on the front for a while, I remember having no complaints about it. The brake, that is â the vibration, on the other hand ... I've also heard that the conical hub TLS just needs setting up right. If the Commando TLS works better with a stiffener, would that be the easiest and cheapest option?

I don't like the idea of having to re-engineer a manufactured unit with an add on stiffening kit. RGM do a manufactured stiffer Brake plate which is a better option, but at I think £350 + VAT, I may be able to come up with a cheaper solution using a more interesting route!

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Previously Andrew Heathwood wrote:

Thought I'd have a look for some road test braking distances to contribute some practical data to the debate. This is the best I've found so far from this thread http://www.britbike.com/forums/ubbthreads.php?ubb=showflat&Number=322268

February 1968, Cycle, 1968 TR6R Acceleration 0 - 60 ...................5.9 sec Standing Start 1/4 Mile ..............14.2 sec @ 92.1 MPHMarch 1969, Cycle World, 1969 TR6R Stopping Distance from 30 MPH .........38 Ft Stopping Distance from 60 MPH ........147 Ft Standing Start 1/4 Mile ..............14.85 sec @ 89.28 MPHFebruary 1970, Cycle Guide, 1970 T120R Stopping Distance from 30 MPH .........33 Ft Acceleration 0 - 60 ...................5.1 secJune 1972, Cycle World, 1972 T120RV Stopping Distance from 30 MPH .........29 Ft

Stopping Distance from 60 MPH ........118 Ft Acceleration 0 - 60 ..................5.7 sec Standing Start 1/4 Mile ..............13.91 @ 94.53 MPHMay 1973, Cycle World, 1973 T140V Stopping Distance from 30 MPH .........30 Ft Stopping Distance from 60 MPH ........117 Ft Acceleration 0 - 60 ..................5.1 sec Standing Start 1/4 Mile ..............13.65 @ 93.94 MPH

The 69-70 bikes would have had the original 2LS, the 72 bike would have had the conical hubs, the 73 bike the standard front disk. Although riders and conditions will vary, on the face of it the conical hub TLS braked bike compares well.

Andy

Thank you very interesting. I left all my Bike magazines from the 70s and 80s at a mates and when i went back 4 them they had gone!

Previously Bruce Mitchell wrote:

Unfortunately he is currently too busy to provide much of an answer but it doesn't sound good.

"I've looked at using the conical brake, but there was a snag which I can't fully recall. Seems to me that it was a clearance issue with the hub, or in arranging an abutment for the torque stop peg."

I might be able to get more out of him in a week or so....

Bruce

Thanks would be a interesting development!

Previously anna jeannette Dixon wrote:

Previously john_hall1 wrote:

Found some Brake tests in which the Conical hub comes out quite well, with an equal rating to the 1968-1970 BSA Triumph brake, only Moto Guzzi V7 , Benelli Tornado, Suzuki GT's and Harley Davidson twin drums fairing better, except for exotic stuff, 10 inch drums, Fontana, Ceriani, Grimeca, Oldani & Yamaha Race drums, often which are 4 shoe units!

The Commando unit rates much lower down, plus anything designed that needs a stiffening plate means essentially something inherent in the initial design must be inadequate.

People in the UK make silly rhymes up and believe this as truth! In most cases it is bad maintenance or people who just don't grasp how things can work more effectively when time is taken to adjust and maintain them properly Having said that often with a little thought manufactured units can be improved on, even after sadly, 50 years factory inspired development!

hello john you have forgotten one maker of racing brakes Robinson10inch 4leading shoe and 12-inch leading shoe 4 LS the best TLS brake and self-adjusting were on my Wartburg353mk1 estate it stopped thatwell it would throw you through the windscreen if you were not careful, and these engines could be tuned quite easy if you know what your doing the engines were very robust and would takelots of hammer on the motorways as longas you were using the rightoil and mixed well I always used morris 2T oils and clocked up over 200,000 with no bother engine were easy to strip aside of the road you could remove them in 20 minuits and remove the crank and pistons without removing the cylinder head, you turn in on its head and remove six m8 bolts and then 8 x m10 bolts removed the chrankcase bottom half and then the crank and pistons and refitted them the same way I nad a number of cranks and piston sets all new one crank I fitted had kawasaki z1000 race bearing fitted and the bloc reported and tunend it was really fast hit 110 easy and stayed there all days if you wanted to I fiitted a duel currcet and servo braking system with new copper pipes made a big diffrence very keen brakes then I do miss the old burg it was a very usfull motor and had a lot of carring space, in the back you could get a double bed inside, away keep doing your resceach yours anna j

Anna, Race drums are different beasts are they not, they aren't much cop for road riding too fierce and too big air scoops and full of holes!

Cheers

John H

Previously david_evans wrote:

Brilliant Anna, the original post was question about 8" brakes and suddenly we're onto 10" four leading shoes and dinosaur two stroke cars. Flux capacitors next.

You rumbled a new book an Inter-Galactic Wartburg, powered by dead carbon life-forms, braked by servo-assisted drums, able to travel at warp speeds and manufactures spares for old Norton's as it transverses the skies, because the NOC can't seem to get their act together! Co-Pilot is Phil Hannam, it also has the ability to complete a return journey, unlike the technology riddled new cars and motorbikes being foisted on us by meddling politicians and self-interested parties and is not subjected to ridiculous EU Laws! Tesla rules and Brexit is emblazoned across the hull and anyone who mentions 961's and Limp mode are instantly vaporised!

In another altered reality, NOC Exec are instantly put in a state of stasis and Norvil & others, Ebay, prices have tumbled down to realistic values so Owners can have a spending binge!

Meanwhile in a another room, (the Boot), Pa Norton is resurrected cloned and reprinted on a 3D Printer and will save Norton yet again and a Blueprinted Geoff Duke is almost ready to roll, incidentally the Commando never existed either and has been wiped from history, whilst as "Warty1" blasts across the skies, Constellations are drifting past in the shape of feather-bed frames and Bracebridge Street Factory from various angles.....bliss

alls well that ends well......

Merry Christmas to one and all!

John H

Previously paul_standeven wrote:

I once knew a race engineer who spent hours making a '68-70 BSA / Triumph 2ls brake plate into a conical hub, because the conical was such a bad stopper. It involved a lot of welding and re-machining. Actually, that '68-70 plate goes easily into a Norton alloy shell. That's what he would have done had he known. Machine off the outer rim of the BSA 2ls plate, and make a spacer between wheel bearing and plate, perhaps dress off part of the brake lining as it will run on the alloy on the outer edge of the shell, and make a brake torque pin to fit the forks

I used to have a BSA with the '68 type brake, and it was a real honey. So light that (stationary) you could squeeze the lever to the bars like a clutch lever, but you could decide exactly how much tyre squeal you wanted. I have never tried a more friendly yet powerful drum brake.

The real problem with the conical brake plate is leverage. That's why you can buy accessory brake arms which are 1.5 and 2 times standard length. Apart from that, it requires careful setting up, particularly to prevent the weight of the cable pushing on the upper cam. That done, it's quite OK as a brake. It may be significant that the late '60s / early '70s BMW bikes fitted with a similar cable arrangement have the cable approaching the brake horizontally.

Paul

Yes,, from what I can gather it designed round BMW unit, I also heard the Brake shoes are a car type and the same as an MG! The slots in the shoes are thought to weaken the shoes and have no function on the BSA/Triumph unit!

One things for sure the BSA/ Triumph Conical Front Brake plate is massively webbed, has pillars and has adjusters too it also relies on sliding housed tappets, activated by cams to get movement which can be greased and has a scoop and cooling slots cast in it, on the grounds of strength alone it should make for a better option! Cable runs can be tailored to some extent too.

Some B25 owners and B50 owners both of which I think have the slightly smaller 7" unit, claim they can virtually stand their bikes on the front wheel! Okay, I know the weight is down on a 4 cylinder Special based round a Dominator, but I will have the larger 8" unit to play with if needed!

Cheers

John H

Previously Bruce Mitchell wrote:

Unfortunately he is currently too busy to provide much of an answer but it doesn't sound good.

"I've looked at using the conical brake, but there was a snag which I can't fully recall. Seems to me that it was a clearance issue with the hub, or in arranging an abutment for the torque stop peg."

I might be able to get more out of him in a week or so....

Bruce

I thought I had replied, cheers any information would help!

Previously john_holmes wrote:

Pre conical the TLS on B25 and B44 was 7", all conical front TLS are 8" even on the B25.

I had a 1970 B44SS with the 7" TLS unit fitted. I didn't know that there was only one size of the conical TLS, I thought I had seen that in the Conical hub brake, there was two units, but it would make sense to only make one larger unit! Guess the smaller capacity machines got a good deal!

Previously anna jeannette Dixon wrote:

Previously david_evans wrote:

Brilliant Anna, the original post was question about 8" brakes and suddenly we're onto 10" four leading shoes and dinosaur two stroke cars. Flux capacitors next.

hello there is nothing wrong with remanissing the dinosaur two-stroke car were very reliable unlike cars of today that are not reliable and you pop the hud and you can'tfind the dipstick never mind the spark plugs, and as for fixing it at the side of the road forget it, phone the AA and take to the scrapyard, rock and roll old cars are better then the new ones my old Nissan Bluebird still passed an EUtype 6 emissions test in the mot withouta cat fitted it runs that clean and that dinosaur car blow off a v8 ranchcro on the m62 going over the peninens, the ranchcro set on fire from underneath it was in flames as I looked back in my mirror we were hit well over 110 mph that a tuned 353 wartburg 991 estate for you these cars have won the 1000cc class, thousand lakes rally many times the toughest rally in the world makes darkar look like a cake walk, yours anna j

Love the flying Wartburg, was this before of after orbiting the "Domed" Earth!

Went down to where my wheels are at the present, the BSA/Triumph brake plate fits and rotates with no problems, no sure if the Triumph BSA front axle is a different width, but bushing would cover any discrepancies here!

A slight hurdle are Brake shoe widths which I think on a Norton are an Inch and and an 1/4 (31.8mm), even on the TLS Commando unit" This compares to the BSA/Triumph smallest shoe width on 7" units of (34.9mm) to an inch and 5/16, (41.3mm), on the 8" TLS Conical unit.

My composite drums through the bolt together mechanism and nuts standing proud will definitely only take an inch and a quarter width shoes.

None of these obstacles are essentially a definite spoiler to the project. Still looking at link up and adjustment mechanism possibilities. Perhaps a different lever and solid adjustable bar type.

I am surprised that Norton drum drakes were of the narrow shoe width type when compared to Triumph and BSA, obviously swept volume of the drums internal diameter x brake shoe width x Pi @ 3.142 is then therefore reduced from the BSA Triumph value of approx 40.8 to 31.4 square inches on Norton machines!

Perhaps that is where the better braking coefficients come from on the BSA /Triumph machines, but working against this is the more friction you have, the more heat you produce, which then leads to brake fade if not cooled appropriately so then there is a greater need for cooling fins and air scoops too!

Looking for some pics I saw of cooling fins cast in Manx Norton Racer brakes hubs, even on the rear brakes, I think the photo I saw was a Francis Beart machine.

Gold is an par excellent conductor of heat, but I guest gold-plated drum hubs would attract the wrong type of attention!

Cheers

John H