Here are two of my modified front brake plates, one that fits over the hub, 1955? and one that fits in the hub. later!
They need a clean and polish, the one with the gold grill, uses a cover off some Yamaha to make an air-scoop as the original had gone West. Having looked at bought in brake plates drums and their cost, decided I would rather do a touring holiday, when allowed 2020, than spend the money on high-priced exotica.
It's a balanced between aesthetics and function and the cost of underpants!
John
Shows Front brake efficiency needed
Results of Drum Brake Tests:
In Index of Efficiency B; 30% factor normal road riding, 40% factor performance/Road racing
Norton brakes Atlas 88/99 come in at B = 126, barely adequate @ 30% weight Machine chassis weight factor;
Commando B = TLS 143
BSA Triumph Full width/Conical TLS B = 186;
The Gold Star standard brake comes out B = 121, with a Pearson 2LS conversion this increases to B = 138! The main problem with the Norton set up seems to be the reduced Brake shoe area compared to BSA Triumph set ups, as the brake shoe with @ 1 1/4 inches is smaller that 1 1/2 inches BSA/Triumph twins/Triples and the BSA Gold Star @ 1 3/8 ths.
Se attached Table which relates efficiency to Mph!
- Log in to post comments
Strengthening bridge
I read in The Classic Motorcycle mag an article on a plunger ES2 in which the owner, Jim Hill, had fitted a strengthening plate across the two pivots of the front brake drum to increase braking efficiency by stiffening the plate. Has anyone got any pics of this or tried it? Is it a straightforward job? I do find the front brake on my '55 ES2 a bit lacking in the anchor dept.
George
- Log in to post comments
http://victorylibrary.com/brit/2LS-table.htm
Jeffrey diamond.
Interesting articles and stuff on here!
In the Table below, the brakes are grouped by drum ID, then sorted by index of efficiency with strongest first. A link
appears next to the description, click to see a picture of that brake (some links are not functional yet). Terms used mean:
“*”: converted to 2LS.
“K”: weight of the assembled hub in kilograms.
“S”: # of spokes in the hub.
“A”: axle diameter in MM.
“Brake Shoe”: lining width.
“Drum Type”: number of leading shoes and drums.
“Area” (swept area): brake drum ID × shoe width(s) × Pi, in square inches.
“R”: ratio
“BEC”: brake effectiveness coefficient
“ß” index of efficiency
Ratio is a “leverage factor” (developed from a Mac program by Douglas Wright) which weights the effect of replacing the trailing shoe with another leading shoe. The improvement of the single shoe is 27.9%, therefore: Ratio “S” = SLS & dual SLS at 1.0000, Ratio “D” = 2LS & 4LS at 1.1395.
BEC: swept area × the drum radius.
“ß”: BEC multiplied by the Ratio to give an arbitrary relative strength rating for comparison.
Copied from Victory Library Jeff diamond.