'04 Sportster trike 21" front tire problem

[BearE]

Hiy'all.
I just got my 2004 Sportster xl1200c low-budget conversion up and running. I did the conversion using the Trike Life DNA kit (axle, lines, swingarm) off eBay, and it went very well.

I have yet to install the 4 degree Frankenstein trees waiting on the shelf, as I'm working on bugs as I move along.

Today's presenting problem is with the 21" front tire. Going around corners at low speed (<20mph), it feels as though the tire is trying to peel itself off of the rim. As this feels a tad disconcerting, I've decided against going faster until I hear more from the collected genius here on the forum.

The tire is a Metz Marathon 880 MH90-21 with, I believe, a 2 ply tread and 2 ply sidewall.

Should I be hunting for a 21 with a stiffer sidewall, like a Heidenau (and I'm not sure ANYBODY makes stiff walled 21 inch skins).

All this being said, this being a low budget job, I'd rather keep a 21 on there and not alter the steering geometry, necessitating even further parts expenditures.

Anybody want to take a shot at this? Thanks in advance.

-BearE

 

[Papa Zook]

Install the rake kit and I think you will find your problems solved. Another very important factor in handling is tire pressures. Run max recommended air pressure in your front tire and 20-24 LBs in the rear tires. After doing those two things let us know how it handles.

 

[BearE]

Will do, sir.....

OK, Zook, I'll try the new trees first thing.

I have already played with the rear pressure to good result: one of my helpers had filled the rears to 40 (!!!!!!) for some reason as yet unclear to me, and my first trip down the test road resulted in serious tank slappage on any braking, front or rear. Dropping it to 21 removed all wobble.

The trees will give me something to do this weekend besides dousing firework related small conflagrations, courtesy of my genius neighbors

I'll report back on my trike-related findings.

Thanks much ThumbUp

-BearE

 

[Darth]

The rake kit will make a big difference. When we did the trike conversion on my wife's Sportster, it did not steer well at all until the rake kit was added, then it steered much better. The narrow 21 inch front still had some issues, so I swapped it out for a 19 inch front wheel that you can run either a 100/90/19 or a 110/90/19 tire... huge difference! The overall diameter is almost identical between the 21 and the 19, but the 19 gives you more patch area on the ground and overall handles better.

 

[BearE]

Got 'em on.

Well, I finally got my raked trees properly installed and running down the road (no small chore) and the difference, as Zook promised, is like night and day.
If anything, the steering is TOO responsive.

I have not yet installed the short(er) Low Life air shocks, so that may very well fix the tweakyness of the steering. I also hope to install a hydraulic steering damper. We'll see how it goes.

But for right now, I'm a happy guy because I can hop on and go for a ride any time.

Thanks, one and all.

-Barry

 

[BearE]

Eureka!!!!

Well, I was unable to install the air shocks, as the bottom "eye" is too wide to mount up on the right side next to the differential.... too close to get a bolt through.

So I scouted around and scored some cheap used 10.5 inch "slammer" type shocks to run in the interim and to test my theory regarding lowering the rear and its effect on steering.

My theory proved correct. The twitchy steering is much tamed. And it should be even better with the (even) shorter air shocks, once they are modded and in place. Should be a better, softer ride as well. These slammer things are pretty much rigid.

But at least it steers OK now. With the Air shocks, it should be a dream. Next up: fab a bracket for my steering damper, install and adjust that setup, and go from there.

Hi-dee-ho.
-BearE

Well, I finally got my raked trees properly installed and running down the road (no small chore) and the difference, as Zook promised, is like night and day.
If anything, the steering is TOO responsive.

I have not yet installed the short(er) Low Life air shocks, so that may very well fix the tweakyness of the steering. I also hope to install a hydraulic steering damper. We'll see how it goes.

<snip>

-Barry