Eldo 4LS

[steven c]

 This could explain my lack of stopping power.

[chuck peterson]

This could explain my lack of stopping power.

I used to visit a machine shop at the bottom on Dixwell in New Haven established 1929. 8 stations in rebuilding and fitting drum brakes, everything in cobwebs today …

What’s it called when you mate a drum to the brakes?

[Don G]

I believe the term is radius.  DonG

[Moparnut72]

Arcing. Probably can't find anyone who does it anymore or the equipment to do it.
kk

[guzziart]

You may want to check out this...
https://www.thisoldtractor.com/moto_guzzi_loopframe_brakes_-_turning_brake_drums_and_shoe_assemblies.html

and other brake info at TOT.

Art

[Antietam Classic Cycle]

I arc shoes to match the drums on a regular basis, it's about the only thing I use my "big" lathe for any more.





If you're buying new brakes shoes, I would recommend these:
Ferodo FSB796          220x25           Moto Guzzi  4LS front (1462 0805) (2 required)
https://www.vintagebrake.com/shoes.htm

You could also have them relined.

[73 sport]

      If the drums are't out of round or bell mouthed, the shoes can be hand filed to fit.

[huub]

      If the drums are't out of round or bell mouthed, the shoes can be hand filed to fit.

just be sure what linings you are working with.
the older ferodo green and brown lining is asbestos based.

[leafman60]

I had the awesome-looking 4LS brakes on my 850GT. The shoes were properly radiused and I spent quite a while meticulously adjusting the shoe linkages.  They became some of the most powerful brakes I've  ever had (even compared to some discs).  The self-servo effect of the shoes create a sensation similar to power brakes.  In fact, I learned to be a little careful with them so as not to be thrown over the handlebars.

I have a friend in the tire/brake business with a automobile machine shop that he inherited years ago from his father.  His often tells the story that in all of his "old" equipment was a special lathe just for radiusing drum brake shoes and drums. With the predominance of disc brakes in the last 30 years, the machine sat idle and only collected dust until he and his son lugged it out to their dumpster and threw it away. He now wishes he had saved it.

I haven't dealt with them in years but Vintage Brake used to offer custom shoe and drum fittings for motorcycle drum brakes.

http://www.vintagebrake.com/


.

[steven c]

Putting the old shoes back on.

[TOMB]

Great job using a vice to expand the shoes I'll file that in the memory bank.

TOMB

[Canuck750]

Check if you have a brake shoe relining shop in your area. Big rig truck specialty brake and clutch shops should be able to size and arc shoes to match your hub. A local specialty shop makes custom shoes and clutch reclining for most everything including trucks, cars, even elevator brake shoes.
I take the whole wheel in (after checking the rim is true) and the whole wheel is put on their big lathe, the drum is skimmed and the shoes sized to fit.
My V7 Sport 4Ls was a great stopper, not as good as a dual disc but pretty good.
Getting the hub skimmed goes a long way to good brake performance.

[Mike Tashjian]

Ok, us old guys will have to explain what brake shoe grinding is when properly done.  This is from a book I learned from way back in my college days.   It will avoid possible drag on the shoes, eliminate lining high spots, assure better adjustments, and reduce the break in period. The grinding process places an eccentric grind on the brake shoes.  This results in the ling being thinner at both ends, but leaves the full thickness in the middle, the point of greatest wear.  The clearance at both ends also provides for flexing of the brake shoes.  To check for proper shoe to drum fit, place the shoe inside the machined drum with the center of the shoe contacting the drum. A minimum of .010 clearance should be at the toe and heel of the shoe.  Service manuals will usually give proper clearances if they need to be greater.  Replacement shoes should be checked for proper fit as some manufacturers pre grind them.  I haven't touched many in the last few years but they can work pretty well when done right.

[czakky82]

Thanks Mike!