LWB Ride Height

Started by tmsmini, May 18, 2019, 11:45:22 AM

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tmsmini

A while back I believe John Gervais posted a document with a range of specs on shock absorbers. I know I saved it, but I cannot find it.

I am trying to get the rear height set on our wagons. I have found that the shock droop controls the minimum height for the hilo/spring. Too much droop and the hilo/spring/ knuckle gets loose and can come out of the rim holding the spring in place.

I have found that the KYB Gas Adjust have a lot more droop than some others. One car has plain jane Boge shocks and the droop is much less.
I am looking at running different shocks on the rear, but want some with less length on full extension.

I don't know if it was on this forum or another, but someone had mentioned adapting straps to prevent excessive extension.

Anyone have John's document or can find it on the forum?


tmsmini

Interesting in that thread John also quoted the MiniSpares description that suggest the red dot springs be used only on the front for a road car.
I never noticed that before as I replaced all cones with red dots.

94touring

I have red dots on all 4 corners, rides just fine.  I have lowered pro tech shocks too and set relatively firm but enough cushion to let the tires bite rolling into a curve.

tmsmini

The Traveller we have the red dots on does not seem much harsher than the one with standard cones. I am about to replace the coils on the sedan with red dots as well. The suspension on the LWBs seem to react differently even though it is only a few inches longer.

I really need to get the ride height sorted on the wagons. John's chart has some info to help but some is missing. The KYB America site doesn't even list the three mini shocks they make and the Europe site doesn't list the specs the same way.

tmsmini

#5
It is terrible when you find an old thread on the MM Forum from 8 years ago that asks the same question...and it is yourself that asked.
https://www.minimania.com/msgThread/107828/1/1/Wagon_Ride_Height

I found that the cheaper shocks are made by ZF under both the Boge and the Sachs name and that they supplied Unipart for awhile.
https://aftermarket.zf.com/go/en/boge/home/

I was also wondering about standard length trumpets and checked the one I have and they were all the same length, but I remembered the LWB trumpets being longer.
Then I found this on MM:
"This is the original rear aluminum strut as fitted to the Mini Van/Estate and Pick Up plus all saloons from 1984 with 12" wheels. If you had the suspension lowered by cutting the trumpets and you want to restore to the standard ride height and appearance, these alloy trumpets make it possible but we advise the "RAC Homologated" HI-LO adjustable trumpets for a very cost effective alternative. Sold individually."

Also the new Boge shocks I just purchased are different than the older ones I have. They have the same extended length as the KYB Gasadjust

Same question just different car, now I need to compare the two

tmsmini

Still trying to understand the dynamics of the the rubber spring. Obviously the type of rubber compound and the shape has an impact.

I know the SmoothaRide Moulton components were different from stock as well.

Not that they add any valuable info, but as I had the components out I took some pictures.

tmsmini

The trumpets are LWB style and late model style(same length)
Left to right
New standard M-Parts cone, Used Dunlop branded cone, New Red Dot, New Red Dot, New M-Parts cone


Willie_B

The way I understand it is as the cone compresses more of the wide part of the trumpet comes in contact with the cone. This increases the stiffness. As you can see in your photo the base of the adjustable trumpet is not as wide as the stock ones, thus it will act different.

94touring

Smooth a rides are much taller.  Can be difficult to install on the fronts even with hi los, which are required.

MiniDave

#10
Yes, but boy howdy do the smooth a rides ride nicely! I put a set on Deighton's car and now I wish I had done my green car with them. I felt no loss of sharpness to the handling....I suppose if you were on a race track there would be a difference. But I think most of them stiffen up in the first 5K anyway as they compress down.

If you remember, when the new Minis first come off the assembly line they had a LOT of wheel gap and ground clearance.

If you go on TMF (UK) they are adamant about not using coil springs.....I had a set on Buzz (Clubman wagon) and I thought they rode nicely, BUT I was comparing them to the rock hard cones I removed, anything would have been an improvement. My understanding is the red coils were too stiff, the blue ones too soft and mushy - I bought black ones that were supposed to be about the same as standard cones in ride stiffness.

What I don't understand is why someone doesn't make a much longer spring, especially for the rear where you have so much length available. In the front, if you tuned them correctly for the weight of the car, you could make them about 3 inches longer (the length of the trumpet) thus giving more stroke on the spring and I think a better ride. Why they're so focused on maintaining the length of the spring to match the cones is beyond me.....
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

gr8kornholio

On the springs, I'd assume it's to keep it simple.  Can use standard hi-los with them, maybe even trumpets.  If they changed the spring height they'd have to design a new trumpet/hi-lo for them.  Of course, if you are going to go to the trouble in the first place of designing a spring then yea, why not just do it right from the start.

I have that exact set pictured and they were horrible, course I probably shouldn't state that in case I ever try to sell them.
I am the GR8KORNHOLIO! Are you threatening me?

Saussie Aussie 1965 Australian MK1 Mini.
"Beavis" - 07 MY/MY MCS, B/MY Konig Daylites, JCW sideskirts, TSW springs, TSW lower rear control arms -- Exploring the country with new friends since 11/09.

tmsmini

#12
I think the Smootharide adjustable trumpet is even wider that the Ripspeed hilo. I have a set on the other Traveller as it came with those trumpets. I have standard cones on it though.
I will have to check the widths of the trumpets when I have a chance.

I used the coil springs on a sportspack mini for about ten years. I never really had problem with them. The trumpets this set has are made for coil springs so with the switch to rubber I had to buy new Hilos.

Even on the sedan with the red dot cones and the adjustment of the Hilo/rubber cone assembly so it is not loose on full droop, the height is way too high. It seems with the shape of the standard cone being more "pointy," the assembly could he held in place when fully unweighted, but the height would not be compromised.

I wish they indicated what components are in the kit:
https://www.minisport.com/mslms0400-moulton-smootha-ride-kit-by-mini-sport.html

They sell two, one for 13 and one for 10/12.
No indication that I see on what is different

Jimini II

Call Mike Guido he is the US sales rep for Mini Sport. I am guessing he may not have the answer but he can find out an answer for you a lot quicker 321 890 9888 is his cell number.

MiniDave

When I put the set on Deighton's car they only offered the one set (his car has 10"s) and it came with the cones and the hi lo set. You can buy just the smooth a ride cones tho.
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

tmsmini

#15
I contacted Mike and will call tomorrow. I will update with anything I learn.

Talked to Mike. It sounds like you need a complete kit to make things work. The adjustable trumpets are unique allowing the fitment of the taller Smootharide cones. The trumpets also take a different knuckle joint. The difference in the kits is a softer rear shock for the 13 inch due to the shorter low profile tire. maybe the fronts are softer as well.

tmsmini

I started this as ride height for LWB, but it really applies to all. One might end up loading down an LWB more than a sedan requiring a height adjustment. But the basics are the same. The subframes are the same after all. The later cars with larger than 10 inch wheels share the same trumpet length at the original LWB cars.

I am working on the sedan at this point, but I had the same issue with the LWB cars. I have the hi-lo set as loose as I feel it can be at full droop. The ride height is till way too high. If I lower it any more the hi-lo will fall out at full droop.

Do I just need to go to lowered style shock to remedy this as they have a shorter extended length?


94touring

I have shortened shocks and my car is pretty slammed.  I will try and see how loose my hi los and cones are when it's jacked up.  I know its fairly loose but no risk of coming apart if I went airborne.

tmsmini

This is a link to the LWB specific SPAX shock:
http://minispares.com/product/Classic/Suspension/Shock_Absorbers/Spax/C-STR308.aspx

It lists the closed and extended lengths for a number of their shocks. I have not checked it against John's shock document.

94touring

#19
Looked up my protech shocks and they are 303mm front and 347mm rear at full open for reference. 

Edit: and are £220 for a set of 4.  I recall shipping being high though. 

tmsmini

#20
This is what is in the link:
Standard
C-STR306 for front with closed length 228.50mm.open length 327.50mm
C-STR307 for rear with closed length 261.25mm.open length 385.25mm

Lowered
C-STR304 for front with closed length 218.50mm.open length 312.50mm
C-STR305 for rear with closed length 251.25mm.open length 365.25mm

LWB Rear
C-STR308 closed 271.25mm. open length 410.25mm

FOR EXTRA TRACK PERFORMANCE SEE
G3275 for front with closed length 218.50mm.open length 312.50mm
G3276 for rear with closed length 251.25mm.open length 365.25mm

PS: It looks like the performance version has the same length specs as the lowered versions.

94touring

347mm would be the shortest at full travel in the bunch. 

94touring

You could measure down your shock from the bottom of top cover and put a mark X amount of mm's in difference between your shock and any of the others, then jack up the arm till that mark lines up with the bottom of the cover.  Then see if you have slop in the cone/hi lo.

tmsmini

#23
I need to open a new rear KYB I have and measure it.

I attached Jon's document as I could not see where I had linked it before.

jeff10049

what about using a limit strap/cable to limit drop? can be made to hook to same points as the shock. Slip over the shock stud on top and bottom.