rear wheel track ( Axle widths)

[sophtayl]

Hi All,

Mick here.

looking at options at the moment for a 99 Softail custom conversion, and looking for feedback on what axle widths people have in their trikes. Any feedback on stability, in particular any wheel lift in cornering, whether planned or unplanned.

thanks in advance

Cheers

Mick

 

[dwiht]

I ride a Lehman Kit on my Ultra Classic, it is 56 inches wide and handles terrific.

 

[threewheeled]

I build them for a living and have about 4 on hand and I say the wider the better

 

[sophtayl]

Hi Dwiht,
is that 56" outside to outside?

Cheers
Mick

 

[sophtayl]

I build them for a living and have about 4 on hand and I say the wider the better

Hi Kodiak, for stability, definitely agree, but wife is looking for something not so large in the rear end if you know what I mean......

so looking at options etc.

Cheers

M

 

[dwiht]

I went out and tried to measure it again. It looks like 53 inches outside body fender to outside body fender. According to the Lehman book specs, its (Renegade Touring Model) wheel base is 63.5 in., Overall Length is 103 inches, Overall width is 53 inches, curb weight is 1141 lbs., Trunk volume is 5 cu. ft. It appears the Lehman book is correct. Sorry for the misinformation in my first post. I really like the narrow profile especially when riding in a group. I can ride pretty much in either wheel track leaving good visability to the rider behind me. My daughter rides a VW powered trike and is pretty much forced to ride in the middle of the highway. When riding in rain, she has some problems with hydroplaning. I have footpegs mounted outside my crash bars so I know I am only 7 inches wider in back than in front which helps me know where the rear is as to the center line or shoulder line.<br />
<br />
Hope this input helps.

Also, I ride pretty hard and usually am on the brakes when riding with most of my two wheel riding friends when doing twisty type roads.

 

[threewheeled]

Saftey is in the width. You decide the amount of saftey you want. Most kits are made with the economics involved so are bare minimum width and require you to purchase a positive offset wheel and this is fine as long as the body will take it and most dont.
56" is a good all round start for a kit and I would say that this would be fine width for a rear on a Honda or Harley. There is much more to it than I can write here but I think you get the Idea.
If you cannot find your center of gravity on the bike then you will be at the mercy of trial and error.
Just about every Honda or Harley we have had to fix had an 1.5 inch or more to the right out of X.
This is because of economics and profit. When this is true the Compression and Tension factors go out of site for the left side. Trike will run fine as normal use but when you hit that stick or bump in the road everything becomes abnormal and you will exceed the perimeters allowed for the frame strength itself and will become a cyclic stress failure over time(Out of warranty)
kodiak

 

[sophtayl]

Saftey is in the width. You decide the amount of saftey you want. Most kits are made with the economics involved so are bare minimum width and require you to purchase a positive offset wheel and this is fine as long as the body will take it and most dont.

56" is a good all round start for a kit and I would say that this would be fine width for a rear on a Honda or Harley. There is much more to it than I can write here but I think you get the Idea.

If you cannot find your center of gravity on the bike then you will be at the mercy of trial and error.

Just about every Honda or Harley we have had to fix had an 1.5 inch or more to the right out of X.

This is because of economics and profit. When this is true the Compression and Tension factors go out of site for the left side. Trike will run fine as normal use but when you hit that stick or bump in the road everything becomes abnormal and you will exceed the perimeters allowed for the frame strength itself and will become a cyclic stress failure over time(Out of warranty)

kodiak

Thanks Kodiak,

very helpful comments.

not sure what you were reffering to with:

"Just about every Honda or Harley we have had to fix had an 1.5 inch or more to the right out of X." Are you referring to the COG being 1.5" offset to the Right from the Centreline? This is something I "assumed" would be symetrical and on the Centreline, but thinking about it, can see the potential for a deviation.....

The dimensions I am looking at at the moment are going to run at around 45" track and 55" overall width.

Wheel base is approx 67" at the moment andwill probably look at increasing it by 1-2 inches.

Will also be lowering the bike some to a ride height of 4" ( possibly 2" to lower Cog).

I have carried out some preliminary weighing of the Bike as a 2 Wheel unit in stock trim, and have a preliminary location of CoG at approx 47" back from front wheel and 19.5" up. This puts it roughly in the Middle of the Oil Tank (give or take). (this is the factored weight distribution adding in a nominal rear weight for the axle and wheels etc)

Adding 2" to the wheel base, lowering and installing the rear axle arrangement should lower and pull the CoG back, just putting a hard point in space is a bit of a challenge at the moment.

Still need to keep total weight under 990 lbs for vehicle class.

Any and all guidance is much appreciated.

If this is way off, feel free to tell me.



Cheers

Mick

 

[sophtayl]

I went out and tried to measure it again. It looks like 53 inches outside body fender to outside body fender. According to the Lehman book specs, its (Renegade Touring Model) wheel base is 63.5 in., Overall Length is 103 inches, Overall width is 53 inches, curb weight is 1141 lbs., Trunk volume is 5 cu. ft. It appears the Lehman book is correct. Sorry for the misinformation in my first post. I really like the narrow profile especially when riding in a group. I can ride pretty much in either wheel track leaving good visability to the rider behind me. My daughter rides a VW powered trike and is pretty much forced to ride in the middle of the highway. When riding in rain, she has some problems with hydroplaning. I have footpegs mounted outside my crash bars so I know I am only 7 inches wider in back than in front which helps me know where the rear is as to the center line or shoulder line.

Hope this input helps.

Also, I ride pretty hard and usually am on the brakes when riding with most of my two wheel riding friends when doing twisty type roads.

Hi dwiht

Thanks, thats very helpful.

I have a target of <990 lbs so will need to work hard at it.....

Cheers

Mick

 

[threewheeled]

you are looking for the CoG for the determination of a righting moment, the results of which would determine the proper safe width and would also give you your load point of NO return (Flip point)... You have to do your CoG with total height and running load weight of rider and gear and not just the bike by itself. This is all variable such as setting it up for you only with your weight and gear. Then if you take a passenger you will have to just know you are top heavy and the stress loads and POR are much closer than you think. Typically 26 to 28 degrees off CoG tire to tire outside. Sense your extended fore and aft with a trike and talking about a cruiser the CoG(fore and aft) is a mute point and will be a plus automatically and the balanced weight will be increased on the front end. Like I said before, this is needed just for the factor.

PS. Use the CoG for the bike by itself and do not use the length of the proposed trike. The Full trike length is a built in saftey factor of about 7% and about 10% at 6 inches.

kodiak

PSS...X factor= Square of trike. Do not offset...

If CoG is offset on bike then center it in your drawing.

The CoG needed here is from the ground up...

kodiak

 

[sophtayl]

Hi Kodiak,

thanks. Gives me some better definition and things to work through.

I didn't weigh at full running load- I will do and work on those numbers.

Im understanding that the 26-28 degrees is based at the rear axle centreline to the intersection point of the CoG. Will work back from this figure.

I will draw something up to confirm.

Thanks for your help. Your sharing of your knowledge is much appreciated.

Kind regards

Mick

 

[1550vt]

kodiak:

I am happy to have found someone that can talk the right language and maybe help me out with an ill handling FLHTCU Lehman Renegade. In long sweeping right-hand turns (like Interstate ramps) she slumps/leans to the left. It has scared all the hair off my head and I have been all over it with a fine toothed comb. My current suspect is the front stabilizer link and I plan to pick a a new one up this week. Left handers are firm and solid, but when you put this trike in a sweeping right hand turn, it will almost make you want to park it.

It's much worse loaded with the wife and all her baggage. No shock problem, no swingarm connection issues, no tire pressure issues, the X is within 1/16 of an inch and the axle positions in the cradles is exactly the same (2 inches) on either side. The belt runs true and measurements from each shock-mount bolt to the front fork bleed screw on either side is exactly the same at 67 1/4 inches. Sitting still, she is aligned as close as humanly possible, but in the turn....something has to be moving and I suspect some give in the stabilizer link.

When I took it off, the rubber insert on one joint looked pretty bad and it can be moved (slightly) by hand. I am thinking in the LH the heim joint is butting up against the mounting bolt on the engine and it can't move then in those RH, it is "giving" the other way throwing the yaw out to the left on the rear end. Am I barking up the right tree? I am bumfuzzled!

If you are still around, I would like to hear from you.