M72dx

[Wolfgang55]

Thanks Barry, I always wanted to understand the lean & what really was moving, but never heard it explained in such a simple form.

[Sparrowhawkdesign]

Originally Posted by Wolfgang55

Thanks Barry, I always wanted to understand the lean & what really was moving, but never heard it explained in such a simple form.

Before the introduction of the electric TILT system that Pete Smith designed when we started Champion Sidecars, the only option was to stop and adjust the length of the upper struts to eliminate the pull/push of the sidecar going down the road when conditions changed. (Load, crosswinds,road crown etc.)
As anyone that has gotten into sidecars can attest to, getting the rig set up correctly the first time can be an adventure. Because of this a lot of sidecars ended up sitting at the back of the garage and declared unrideable. The new TILT system helped make some of those first time situations acceptable at the touch of a button. The first time user was more likely to keep it on the road until they figured it out. I think that one improvement alone really helped the growth of sidecars.

I have to admit that although I have driven a lot of different rigs all over the country for years and enjoyed the instant adjustability of the TILT system, I have never had one on my personal rigs. In my case unless I'm heading out on a long trip the weight of my sidecar does not change much. The installation of some type of trail reduction lightens the steering enough that I am not bothered by the push/pull effect. My current old Guzzi rig has a Leading Link that I built. It gave me a chance to experiment with a couple different ideas and I think I'm finally happy with it now. I might still make some changes just to improve how it looks to me. It never ends!

[DRONE]

Originally Posted by Sparrowhawkdesign

The distance between the motorcycle and the sidecar does not change. The adjuster moves what would be the top mounting bolt on a standard swingarm/shock like on the rear of a motorcycle. The tilt moves the top mounting bolt up or down. That raises or lowers the sidecar and in turn leans the motorcycle. Barry

I could never figure out up and down while on the move. If the wheel is pushed down and the car is pushed up, is that down or up? And which do I want when? See what I mean? My feeble brain is just too preoccupied when I'm riding to solve these brain teasers. So I abolished those thoughts from my mind. Instead, I now have the switch for my tilt adjuster mounted in such a way that if I push it to the right my motorcycle leans right, and if I push it to the left, it leans left. No thinking required.

BTW, I really like my tilt adjuster thingy.

[DRONE]

Originally Posted by Sparrowhawkdesign

The M72DX is four inches wider than the M72D or C. The bodies of both are now mounted on isolators to help keep any motor buzz away from the sidecar passenger.

Isolators? ISOLATORS? Jay finally caved in on isolaters? Does MikePa know this?

But, serious question here, what are these isolators and can they be retro fitted to an existing M72D like mine?

[Sparrowhawkdesign]

Originally Posted by DRONE

Isolators? ISOLATORS? Jay finally caved in on isolaters? Does MikePa know this?

But, serious question here, what are these isolators and can they be retro fitted to an existing M72D like mine?

I bet MP would be chuckling about this one. Actually the problem was we didn't understand what he was trying to tell us. He said that his wife preferred the ride with them on the Ural and we took it to mean she thought it rode softer. Anybody that has seen the ones on the Ural knows they don't actually move hardly at all and only with a very heavy load. What Abenteuerfahrer brought to my attention one day was that they were stopping the motor vibration from reaching the sidecar body. DUH!

I finally found some isolators that were robust enough and designed so that even if the rubber was to somehow fail during use, they couldn't come completely apart. They are now on our M72's. I'm not sure about fitting them to earlier models as the floor construction has been changed to give more strength for this upgrade. Actually it was probably ok before but I didn't want any issues with the floor flexing.

Barry

[claude]

Originally Posted by DRONE

I could never figure out up and down while on the move. If the wheel is pushed down and the car is pushed up, is that down or up? And which do I want when? See what I mean? My feeble brain is just too preoccupied when I'm riding to solve these brain teasers. So I abolished those thoughts from my mind. Instead, I now have the switch for my tilt adjuster mounted in such a way that if I push it to the right my motorcycle leans right, and if I push it to the left, it leans left. No thinking required.

BTW, I really like my tilt adjuster thingy.

When the car is 'pushed' up the outfit leans left. Think 'lean left to go left ' and 'lean right to go right'. Yes, How the switch is mounted makes thinking about what does what much easier.

[DRONE]

Originally Posted by Sparrowhawkdesign

I finally found some isolators that were robust enough and designed so that even if the rubber was to somehow fail during use, they couldn't come completely apart. They are now on our M72's. I'm not sure about fitting them to earlier models as the floor construction has been changed to give more strength for this upgrade. Actually it was probably ok before but I didn't want any issues with the floor flexing.

Barry

I have some isolators I was thinking about installing myself--only 5/8" tall--but I had not considered the floor flexing issue. Hmmmm . . . I'm gonna have to cogitate on that one some more. Or simply tell SWMBO to sit down and shut up .

[AceRph]

Would fiberglassing some 2 or 3" wide 1/4" plywood strips across the bottom of the body at the mounting locations provide adequate additional support?

[Sparrowhawkdesign]

Originally Posted by AceRph

Would fiberglassing some 2 or 3" wide 1/4" plywood strips across the bottom of the body at the mounting locations provide adequate additional support?

I know the floor is strong enough, specially at the rear mounts as that area is made stronger by the bulkhead being glassed in there. My main concern is that there may be some flex in front of the seat while stepping in. I know it won't break but seeing it flex might be bothersome to some people. I suppose an extra layer or two in this area would stiffen it up if there was a problem.

The other issue is the location of the flat bar that is welded to the frame to bolt to. Because the isolators are an inch tall the body would be lifted by that amount. Maybe not an issue but we have lowered the bar down into the frame so the body only sits 1/4" above the frame. Cosmetic mainly. Also, the isolators have a wide base with two mounting holes on one side and I put this side up to better spread the load on the floor.

Nothing there really to stop a little experimenting though. B

[Abenteuerfahrer]

Originally Posted by AceRph

Would fiberglassing some 2 or 3" wide 1/4" plywood strips across the bottom of the body at the mounting locations provide adequate additional support?

THIS WAS THEN....



Although NOt perfect, it did reduce motorcycle buzz from being transferred to the Tub by 20-30% according to my Hackette!

The low number was because I through bolted the rubber bushing/floor with a solid thru bolt thus still transferring some shock to the floor of the car,..hhmmnn...

There are better isolators on the market but never got to it as I was too eager to hit the road..







Extra fiberglass mat reinforcement with AL-bar on the floor in front and back...



1" rubbers..made from....



Don't laugh........





This is still now after 62+K miles......

Cheers....

[ClearwaterBMW]

great post above, elmer
what "know-how' and "can-do"
very well done, my friend
nice pictures, as well

[AceRph]

Did the floor flex when Hackette stepped in?

And "NO!" not b/c of anything about her.

[ClearwaterBMW]

Originally Posted by AceRph

Did the floor flex when Hackette stepped in?

And "NO!" not b/c of anything about her.

LOL...
yes, SHARON might not take too kindly to THAT comment....

[DRONE]

Originally Posted by Abenteuerfahrer

1" rubbers..made from....

Don't laugh........

I promise I'm not laughing. Sourcing oddball parts is often impossible. But for guys reading this thread and thinking about experimenting with isolators, I bought mine from Advanced Antivibration Components located on Long Island, NY. They have a VERY good e-store HERE (clicky). Excellent service and they can handle small orders from hobbyists. Tons of technical info on each item with exact dimensions. For instance, take a peek at a typical product page - here.

Note: they have an entire section dedicated to "Suspension". Unfortunately, this is for machinery suspended from ceiling mounts. (If it was that easy, it wouldn't be as much fun.)

[Abenteuerfahrer]

Originally Posted by DRONE

I promise I'm not laughing. Sourcing oddball parts is often impossible. But for guys reading this thread and thinking about experimenting with isolators, I bought mine from Advanced Antivibration Components located on Long Island, NY. They have a VERY good e-store HERE (clicky). Excellent service and they can handle small orders from hobbyists. Tons of technical info on each item with exact dimensions. For instance, take a peek at a typical product page - here.

Note: they have an entire section dedicated to "Suspension". Unfortunately, this is for machinery suspended from ceiling mounts. (If it was that easy, it wouldn't be as much fun.)

Thanks DRONE for the "clicky" link, great stuff now, didn't see it then. Might replace the laughable round sanddiscs rubbers for more of the pro ones.