'Whatsit'

I've seen these sprocket rings on a few Huskys now. Does it reinforce the sprocket or protect the brake backing plate? What exactly does it do?

just adds a little unsprung weight on the off chance your suspension is working well

I was told it was to help reinforce the hub especially on the 87-88 bikes because they didn’t have the same hub design as the earlier bikes(85 and 86 hubs had an extra rib or two around the sprocket mounts). I guess anything to keep them together.... that’s just what I heard

It will not work on an aluminum swingarm bike. The bolts need be countersunk and adding a thickness would not fit.

What it might be for is to use 530 chain and not have it rub the tire if put on the inside.

interesting thought but I have had a few 500's and never thought twice about the hub, never had an issue

wouldn't that throw the chain out of alignment?

I wonder if it an attempt to use an Enduro wheel in a Motocrosser(to close a gap)? Can't tell form the pic if is is MX or Enduro rear brake...

Andy

"wouldn't that throw the chain out of alignment? "


If one used 530 chain (3/8) on 520 sprockets (1/4) shimming out the sprockets an eighth inch will make the inboard side plates in the same place they were (when drifted as close to the tire as possible). I just guessed that because I made a spacer like that to run those Husky wheels on something else that had a 530 drive sprocket. Note how the bolt holes are two six per circle but the second set not in the middle of the first set. I have shall I say a stack of sprockets, some have a set of smaller holes, some have a set of countersunk holes but they are all evenly spaced.

How about if that is to be used as reinforcement for sprockets that are cut in half?

Fran

its made from a sprocket eh....got me beat

Here are some pics of what I meant....
85 hub



87 hub



Not in same same spot as the op but the only use I know of. Not everything was better in 87 haha

I have seen an 87 430 hub with one of the sprocket mounts cracked... I wouldn’t call it a common occurrence but on a well beat bike that is how many years old I’d imagine anything is possible. Everything has a life span.

it's a CR hub due to the low brake arm

typically the reason to remove needed material from the hubs was unsprung weight
the typical reason the brake hub parts broke

was not rechecking the torque of the sprocket bolts
the smaller holes were the early ones and required checking the torque on the bolts more often
the later ones used a tapered head capscrew, self centered and offered a larger area of load spread

They did take about a pound off the 88 rear hub. I do not have any 87 stuff. The first Husky I bought I was warned about steel sprockets leading to hub damage, that was from a guy who went over to Honda in 1986. Some aftermarket steel sprockets may not have been drilled quite right and if the bolts were forced in instead of oblonging the holes as needed problems result. All my newer stuff has sprocket bolts of the general length of the 1988 hub. As for the 86 to 87 changes I think the seat gas tank and shock linkage was an improvement. Probably the way some of the tubes under the engine were positioned but some stuff not so. I never broke the hub on my 88 te510 and had a cut knobby on it for a while.

As I stated earlier the countersunk holes are needed for clearance on the aluminum 85-88 aluminum swingarm.

Post 10 does offer a good "guess" but no need to be double drilled that I see at this time.

Added later. The countersunk holes seem necessary to clear some part of the tongue and groove on the brake backing plate and the swingarm. Pretty sure the 85 still used the stay to the bottom of the swingarm not the tongue and groove. wr xc te ae

the 85-86 sprocket bolts were not countersunk
the tubes under the engine were triangulated for strength and to take some load of the cases
the 85-86 seat and tank was narrower but the 87-88 seat allowed you to move farther forward
yeah as you said some things better some not

This is correct as far as I know. My 85 bolts aren’t countersunk but my 87 ones are. Could be done easily enough though. Unfortunately for the op the thread has been slightly derailed oops

not really derailed...good information really

I used to see that on Husky race bikes in Baja in 1987/88. Racers would cut down an old sprocket and then cut it in half to make 2 "C" shaped pieces and bolt them to the inside of the hub between the spokes and sprocket flange.

so this is a problem area?

I would assume so. My '87 510 still has the earlier wider sprocket flange but the 4-strokes were running a year behind the 2-strokes as far as chassis components. I think it only affected the black fuel tank bikes of that era.