Hemmings Isolastics

Im starting to think more about isolastics. From what I've heard, Mick Hemming's set is very good, his catalogue says 52 pounds. To anyone who has bought them, is that for the front and rear? or just the front or just the rear? Also, they dont need any drilling or machining, right?

Thanks,
Matt

52 pounds! And I thought the clutch pack was heavy!

My understanding is that's for front and back. Realize that you are only getting 2 items, one set for each isolastic and you just replace one side. No machining for any system. But call him if you really want to know, Angie will tell you. I'm planning on getting them soon. If your rubbers are good, it's probably the easiest way to go. I'd like to know from someone that has them too.

Dave
69S

Ah I meant to ask that too. So it only comes with the adjusters, no rubbers or anything like that? If that's the case, commando specialties has a full set for $120 each. That is a pretty good deal so i might get those, seeing that I will need a few other things from them too at the same time

Matt

Where are you seeing the CS verniers for $120? I see the front and rear separate for around $130 each, and they replace the whole shebang, kind of like the Norvil ones I think.

Doesn't anyone have the Hemmings adjusters and could speak up?

Dave
69S

Dave,
Yes I saw them for about $120 or $130 for each, not together.

Matt

http://www.norton.norvil.net/mhiso01.htm
http://www.norton.norvil.net/tech02.htm
http://www.mickhemmings.com/

So each one of those items in the picture replaces one of the "Isolastic mount collars" on each the front and rear iso? How much has to come off to replace the rear one, the front looks easy. I've been dreaming about these things, my bike with the shims at .010" doesn't really smooth out until around 4K with new rubbers in it. I'd like to try .020 since I don't thrash this bike and changing the shims are not nice, at least the rear.

Dave
69S

I was running the Hemmings collars on my 750 before the rebuild. It's a good product. When I took the bike all apart for the restoration I found that all the iso rubbers were in terrible shape so I put new vernier iso kits in. I ended up selling the Hemmings collars, but if the rubbers are in good shape the Hemmings kit is a good way to go.

Debby

The main up/dn motion to absorb is at the front isolastic and after reading for year on the need of it being softer than supplied I bench grinder beveled both my Combats big front doughnuts to leave ~1/4" flat rim for a more progressive softer sense that don't affect handling I can tell, just the smoothness on sets earlier and deeper. I stuck two extra left over old doughnuts in the rear iso for more stability w/o transmitting extra vibes. Did not bevel the rear doughnuts.

I've read about the hard and soft rubbers, that's why I got the original type replacements from OB. So my donuts are new. Just need to get over the $3000 shock from the root canal and spend some money on the Norton. The way stocks are going today, my bonds will probably shoot up. I haven't had anything in that ignorant gambling game since Bear Stearns in 08 despite what the money managers (blood suckers) say.

Dave
69S

We since my rubbers are shot, Ill need an entire new system. The commando specialties ones require no milling compared to the Old Britts one that does and its twice as expensive. Anyone have experience with the commando specialties ones? Are they good quality?

Matt

GrandPaul sells them too.

Dave
69S

rvich said:

52 pounds! And I thought the clutch pack was heavy!

Click to expand...

Hmmm....OK so the humor didn't spark much laughter. I guess that gag has been done before. I am curious as to why you wouldn't go ahead and use the Hemmings style adjuster if you needed new rubber. Is there that much of cost savings?

Russ

Ill laugh now - hahahaha.

I haven't done the math, but it probably is a bit more expensive. Im also wondering though... the CS isolastics are regular vernier style adjusters, whats different about the hemmings ones. Dont they both adjust easily in a matter of minutes?

Matt

The "Norvil" (Les Emory Norvil, not to be confused with Mick Hemmings Norvil) don't ask, are a 1 piece unit. The Hemmings "Norvil" (don't ask) adjusters replace the outer collars on one side of the early isolastics that have separate donuts and spacers. The OB ones are even different, but sort of like the Emory ones.

My understanding is the single units have a threaded center shaft the collars thread on to adjust, and the Hemmings unit attaches to the bolt with grub screws (set screws) in the isolastics and adjusts from there. The parts are not compatible.

The more I think about these isolastics, the more confused I get and it gives me a headache. If you want to study the isolastics go here http://www.members.shaw.ca/randell/isolastics.html and read it about 10 times while you have the front one apart and looking at it, that's what it took me and then I immediately forgot it after working on it and finishing. All I know is it works. It's kind of like calculus or dr/dt, you can understand it for a while and then you forget.

I doubt if one is any better than the other, but it's my understanding the single piece ones are stiffer than the parts ones because it was made for the 850 which is heavier and can take the stiffer donuts. I may be full of s$$t here too. Just been my impression. Reviews are welcome and your mileage may vary.

Dave
69S

Meh, I just used the MkIII ones and other than shortening the front mount it was no problem.

I just looked at the Norvil site, theres adjustable types that dont need milling. They are the same price as the commando specialties ones and i think the exact same. I think ill get the CS ones because S&H will be much cheaper plus I need a few other things from them.

Still no one who has used them that can speak about them???

swooshdave said:

Meh, I just used the MkIII ones and other than shortening the front mount it was no problem.

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That's the advice I've had also. I think at the end of the day the original Norton Mk3 iso is probably a better fix. Even though the front mount needs machining down.

I have Hemmings ones, they just replace Shim support plate with an ajustable Shim plate on a collar on one side only. ie shim plate now threaded to the collar and not fixed. It has a grub screw to lock it. Goes on one side, one for the front and one for the rear. Exactly the same collar length as the original, just adjustable.

I like it because it works and you can put everthing back to standard, the way it was, ie you haven't shortened the front isolastic tube. You can take metal away but you can't put it back (I learn't that in woodwork at school).

Being only the second owner of my '73 Commando and owned it since 1975, there are few mods because it always ran fine and I like it that way.