CB 450 brake:
200mm 2LS, 30mm wide,15mm axle, 40 hole, excellent internal-to- external
leverage ratio, robust hub, cast iron bearing and actuating cam bores, long
linings (more area than the 5mm wider Yamaha), shoes wrap around the posts, a
pretty good copy of a Fontana. Two versions: one at 11lb. 2 oz; the other at
10lb. 6 oz. Clevises riveted on. The CB72/77 is similar, with 36 hole
hub. Both use a stay
mount. 42mm bearing OD make larger axle sizes possible.
Yamaha
XS650: 200mm 2LS, 35mm wide, 17mm axle, 36 hole, good pre-holed hub and scooped
backplate, swap bearings for 20 or 25mm axle, lug mount. 3 things not to like: wimpy 6mm link rod in
compression, master and slave arms work through different leverage ratios, actuating cams do not locate shoes.
Suzuki T500:
200mm 2LS, 40mm wide, 36 hole, 15mm axle, the lightest of the "Big 3".
Too light, apparently, as cracking seems to be a question of when, not if.
Rusty Foard tested one of Tim's cracked hubs at the Naval Lab, and it only took 200lbs
of side force to explode it. Rick Breckon welds reinforcing ribs in, but the
bearing bore seems to suffer. Trick looking hub, dinky bearings lock you in
to a 15mm axle. Okay leverage ratio, pressed-steel lever arms, lug mount,
4.5mm link rod. Lug mounts can be used on non-lug forks with a plate from
fender mount to axle and attached lug.
180mm
brakes--these can be made to work, but the leverage ratio of drum
diameter-to-contact patch is real critical in this area. Best of the bunch
is the CB160--a small version of the CB 450. The 180mm Yamaha is pretty
good (see Jay), and the CB350 can work with some backplate blueprint work. I
think the double sided 180mm SLS Grimeca is a bit of a toad. It's
weighs 11 lbs., 2 oz., has just OK linings, and the brand new one I have in here, has extremely sloppy
actuating cam bores. There does not appear to be ANY machined surfaces on the shoes or backplates, save threads. The axle and actuating cam bores
appear to be
as-cast, with attendant tolerances. Even the splines and thrust faces on the
actuating cams look to be as stamped/forged. Most discouraging are the
"dead" end of the shoes, which are only semi-parallel to the
actuating cam faces.
That said, it can be made to work.
Aftermarket
4LS:
230mm Grimeca--Big bang for the buck, but at 21+lbs (a little less
than a stock water buffalo), you better not care about turn-in. Stock shoes O.K.
210-230mm Fontana replicas (about 14 lbs in mag): Best-Dick Hunt, comes with
2520V available here; cheapest-Menani, needs relining, poor quality
. Molnar--getting
better, comes with 2520V. George Beale-comes with 2520V. Smith-Shoukai;
heavy (AL), needs relining and rebushing, new.
