A 110 I bought earlier this year, had a trashed seat pan. It was held together by duck tape more than metal; a total write-off.
I've been out of the 110 circles for a bit and thought a used seat pan wouldn't be too expensive. Wrong.
These aren't exactly super sought after trikes. They're common and nothing special trikewise. No way I'm paying through my nose for a used, partially trashed, seat pan for one of these. A used pan I'll have to make minor repairs to and rivet the cover on anyway; no thanks.
My 110 is in good shape for a rider, but not good enough to drop double the purchase price on a semi-junk seat pan. So...
...I thunk outside the box and came up with an idear.
The 110 fenders/seat are simply held on by the brackets, which all bolt onto the fenders/seat pan. That's pretty simple, just make some plates that'll allow the brackets to bolt to the fenders without the seat pan.
For anyone breathing heavily, those are not melted/burnt spots on the fenders. That discoloration is from the lockjaw seat pan. After a tack weld, it's pulled off for final welding.
That was all done with strap; nothing special, and that's the goal. I'm not trying to go idiotic on the complexity of this.
I was thinking about using a bicycle rear shock, but at max angle (going by 30 degrees), that still puts the seat too high. The other option would be to lay the shock down by using a linkage system, and that goes back to not getting stupid complicated with this project. A linkage system would require figuring out the geometry/math of it all, spring rate, travel, and a whole bunch of stuff that isn't worth two inches of travel. That would add more wear points and be heavier too.
I had a bicycle shock in hand while figuring this all out. Time spent holding, looking, and using angle finder.
The other option is an air bag/spring. I have one from an 18 wheeler cab that a friend gave me to try for this, but it's still too long when compressed.
I found that TC Bros sells an air spring for chopper seats that is perfect for this build, but the price is putting it on hold for the moment. I've been unemployed for a year, so I'm doing the wobbly wheel, shopping cart version (burning plastic in a burn barrel for warmth edition).
The TC Bros air spring.
http://www.tcbroschoppers.com/air-powered-spring.html
After turning to YouTube for some inspiration, I found this for the squishy function...
Anyone who knows what it is, raise your hand. It rhymes with dong, like the sound a bell makes or Vietnamese currency. Ask you wife about what her dog likes (I bought it at a pet store). There are some Harley riders who love this black rubber. Have I covered all the innuendo?
Everything aside, with the current mounts, the fender is solid on the trike. I rode it around, standing up, but that super sucks on a 110 because they're too small for an adult. The bars are at my knees and at any moment I feel like I'll go over the bars or loop it out. Part of this suspension seat build is to build a taller seat so the trike feels more comfortable for a taller rider. There is not a 'desert' or tall seat available for the 110 AFAIK. I totally don't get how adults are riding 70's around. Maybe it's like midget porn.