Hydraulic rear shocks and spring rate questions

#1
There are a couple of other shock threads going but I don't want to hy-jack someones thread as what I want to know is different from the other threads.

I'm building some mini's for the build off. Two of them are Sears bikes with a swing arm rear suspension.
They just have the spring sliders things they call "shocks". They just bounce in and out without any dampening.
That results in a bouncy ride.

I want to replace them with some hydraulic dampened shocks. I saw some on OldMiniBikes site but the spring rates are high, like 650 lbs. If I put two of them on the bike and I only weigh 175 lbs, wouldn't the 1300lb spring rate be like riding a hard tail mini?

Does anyone make a hydraulic rear shock with spring rates we can use on our minibikes?

On my Sears Puddle Jumper, the rear springs collapse easily and bottom quick just riding on fairly smooth ground. I experimented by adding a shock from an old Mustang. It made a huge difference in rid quality :) It however is unsightly on the bike. It is big and looks out of place, but works.

I thought of a snowmobile suspension shock. Not necessarily with a coil spring on it, just the shock. It is a much smaller diameter. Perhaps if I used two of them the mini wouldn't look so cobbled up. One on each side would be more symmetrical.

Of course a coil over spring shock with dampening would be best but I can't find any that look like they will work.
My mini's have the standard 12" rear "shocks".

Are there dirt bike or pocket bike shocks we can adapt to our mini's?

Danford1

Here is a picture of my rear shock experiment. It worked well.

Puddle Jumper rear shock.JPG
 
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#2
A couple of my thoughts on the subject:

Yes, the mini bike shocks are not shocks at all, but springs. Spring rate is the amount of weight required to compress a spring one inch.

Popular and current mini cycles, like KX-60 for example have a spring rate of 3.3 kg/mm or 170 pounds. I would guess, and it's only a guess, that a rate of 650 pounds is way too stiff.

Even at your weight of 175 LBS, you are 100 pounds heavier than the intended rider was. So it stands to reason our shocks are going to be inadequate.

I've used vintage Italian shocks as replacements on a Taco. The shocks on the Tote Gote we also Italian and iirc knock offs of the Ceriani. A lot of Italian shocks from the sixties and seventies were copies. They were rebuild-able so I sourced O rings by specification and rebuilt them, chromed the rings and painted the black and filled with (iirc) two oz of Yamaha fork oil. Worked great, didn't leak much.

I always wanted to get a few Ebay used shocks for vintage 125cc and smaller machines, including older Mopeds, just to experiment with. Never did, other than the Ceriani/Italian copies of them.

Taco with Benelli shocks:


Tote Gote Shocks:
Shocks1.jpg

Shocks2.jpg

Shocks3.jpg
 
#3
That is great info and excellent pictures. Now.... Where do I find a couple?
Do you have any for sale?

Danford1
 
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#4
That is great info and excellent pictures. Now.... Where do I find a couple?
Do you have any for sale?

Danford1
There are a set of four on ebay now for $50. I think that is a bit high. I also cant promise these are exactly what I had, but if they are, and you can rebuild them, they work very well. If you do go that route, keep in touch, as I have some of the extra rubber parts I used that might work on them.

The Taco guys looking for Ceriani shocks can use these, and unless you have a side by side comparison, it's hard to tell the difference. Ceriani of course was the pioneer for oleo suspension back in the day. There are expensive re-pops out of Great Britain if I recall. Basically, search for any Italian bike of 125cc (vintage) and you'll start to see the shocks I am referring to. Or take your chances on cheaper Chinese reservoir type absorbers on Ebay. I think a couple of members here have used them.

Wards Riverside Benelli Rear Shocks 2 Pair | eBay
 
#6
I received the 4 shocks today! That was quick service. I'll be giving him really good feedback for the fast shipping.

Now, I have questions on how to take them apart. I see in your pictures what looks like a locking ring for the spring cup.
Can you explain how to take the shocks apart?
Thanks

Danford1
 
#11
sonerenos, The shocks measure about 12 1/2" or 12 9/16" eye to eye. It is hard to get an accurate measurement.
They are over 12" center to center though...

Danford1
 
#13
Mine had very good hydraulic action with no leaks so I left them alone. I didn't rebuild the units. I just painted the parts and assembled them today.
For an occasional use minibike, I didn't see the need to do a full rebuild...

Danford1
 
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