Source of coil spring/shock • Source of coil spring/shock • USCA Sidecar Forum • United Sidecar Association %

#1 · May 26, 2022, 9:29 am

Hello Everyone,

I'm working on getting my 1980 Coupe Royale road worthy. As a test yesterday I took it our with 160# of weight in the seat. Rig ran sweet until the hard left at speed test. It handled well but the old Monroe coil spring and Monroe air shock gave up the ghost. The fender settled onto the tire and stayed there 🙁 So for a 1/4 mile to a safe pull off I did my part for mosquito control with nice blue smoke. After nursing it back home I discovered the ancient Air Shock was the culprit, jammed in the lowest position.

But the real culprit is the misaligned fender, if it were in the proper position it might clear at max compression of the old shocks without hitting the fender.

So long story to the question. Where can I find data sheets on coil over shocks. I need a min of 10 3/4”, ride hight of 12” and max 14 1/2”

Changing the fender location would be a PITA and Monroe doesn’t provide any actual data that I can find, just advertising fluff.

Edward

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#2 · May 26, 2022, 10:31 am

After letting the shock issue marinate for awhile, I looked across the garage at my 1981 R100RT and BINGO, the rear shocks look right and the rear of a MC needs that same relative massive weight gain the SC sees. So since the BMW is on long term repair after a electrical fire, I stole the rears off to gift to the SC. Hope to get out later today and test.

Edward

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#3 · May 26, 2022, 8:56 pm

You mean the fittings at the top and bottom of the BMW shock match the fittings on the old air shocks? And they were the right length too???

That kind of thing NEVER happens to me.

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#4 · May 27, 2022, 6:49 am

Looking fwd to the update.......

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Lee / Summer Grove, Louisiana: Ural cT, CJ750, Burgman/Texas Ranger, Zuma 50F, MB5, TW200, CRF250L, GTV300

#5 · May 27, 2022, 12:04 pm

Hello Drone, yes the old Monroe use 3/8in studs/bolts for mounting like an old VW Bug. The 1981 BMW also uses studs/bolts but have a 10mm hole which is just a smidge over 3/8in(9.525mm).

The mounting on the SC are different heights, the rear which had the Monroe Air is 1 3/16 inch higher. The BMW GAZI shocks, which I’ve never heard of and can find on the web, have adjustable lower mount which gives about 3/4inch difference between min/max adjustment. These shocks have almost 3inch to bump stop range.

So with the longer in back and with 165 pounds in the seat, the sag is set to slightly less than 1inch on the front and slightly more on the rear. I think this should work fine. See anything I missed?

Pictures are with the weight in the seat.

Edward

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#6 · May 27, 2022, 1:09 pm

Oh and I didn't turn those Monroe shock the right way showing the MADE IN USA text. I venture a guess they are now proudly made in the FAR EAST 🙂

Edward

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#7 · May 28, 2022, 5:53 pm

Never would have guessed the old Motorvation required TWO shocks. Anyway, looks like a great solution.

Now for the road test?

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#8 · May 30, 2022, 9:54 am

OK The 1st road test after shock exchange was 95% success. The SC loaded to 170lbs, The hard left at speed was undramatic and general control was nice. The only wobble I experienced was during a slow acceleration at under 10mph. But in a moderate acceleration with with more weight transfer no wobble detected. At 55mph on a smooth road with a noticeable crown I needed to keep a constant slight push on the right bar. At lower speed say about 40 no push needed.

The alignment settings are 9-1/2” SC tire lead, Toe-in 1-9/16” and MC lean out with me aboard is 1.7deg. Even with the 16th over 1.5” toe-in the tire temps were pretty good 86,87,88 across the face inside to out. I think I might bump the lean out to 2deg

The pics at a local lake. I was shocked there were not any adults and kids playing in the water. But then the water is still pretty cool here at 44.4deg N lat.

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