Slow progress but progress (DIY two seater tadpole trike, 9hp Honda diesel)

[redneck]

Originally Posted by Old Mechanic

Next issue, the rear tire. The OE Harley tire is a 165-70-17. I don't want to use a motorcycle tire or it will just wear out quickly in the center. I also can not use a tire whose section width is more than about 6.5 inches. The motorcycle tire on the wheel now is about 6.5 inches in sectional width and the clearance between the tire and drive belt is practically nothing, maybe 1/8th inch (no belt yet). It seems like the best solution I have found so far is a tire made for antique cars available from Coker tire, a 550R17 with is recommended for a 5 inch wheel (which is right), with a sectional width of 5.5 inches and tread width of 4.5 inches. It will cost me $250 for one tire.

The diameter is 28.5 inches which will lower the overall final drive ratio with 708 revolutions per mile.

regards
Mech

Oops, I missed this post...


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[Giovanni LiCalsi]

Motorcycle touring tires are getting longer lasting and more aggressive tread with more silica in the base rubber compounds.


Metzeler figures they’ve got the solution with the new “O” version of their new Roadtec Z8 Interact tire in 190/55 ZR 17 size, for heavy sport-touring bikes like BMW’s K1600s, Honda’s VFR1200 and the Triumph Trophy.

It’s supposed to have 30 per cent longer life than their previous “C” version of the tire. It’s a dual-compound tire, with 100 per cent silica content on the shoulders, and high silica content in the middle stripe. That’s supposed to reduce slip in general, but especially on wet surfaces – something you can’t avoid during serious touring.

[diesel_john]

phoenix 4.5/27.0-17

[user removed]

The section width of the phoenix tire is 7 inches which would make hit the drive belt. I do appreciate the information and that fact it would be considerably less expensive.

regards
Mech

[Beau]

Not that I get a vote, but it seems staying with a motorcycle tire might be be easier in the long term and less expensive in the short term.

[2007 ion2]

it should also lead to higher economy...

[user removed]

My feeling about any non passenger car tire is the vehicle's interaction with the road will more resemble a passenger car. With two passenger car tires on the front I think a motorcycle tire could create unpredictable handling consequences. Without the vehicle leaning in turns, as a motorcycle leans, the specifics of motorcycle tire design would be compromised. I am fairly sure that commercially available tadpole trike designs use passenger car type tires.

I think this thing will handle nicely, the CG is very low but the weight on each wheel will be a fairly small percentage of each tires capacity. That should tend to make it slide versus rolling over. Only time will tell if that assumption is correct, but as of this point in time, I am much more in favor of the passenger car tire, expecially since I have found one that "fills the bill" as far as dimensions and clearance. A significant plus is the height of the tire wheel combo which reduces the overall final drive ratio and should mean fewer tire revs per mile.

regards
Mech

[MV8]

Hello Old Mech. I joined back in 2008 and have just corrected my logon so I could fully register so I could post. You are my first post. Don't you feel lucky? Maybe not.

Anyway, neat build. I've also been working on a diesel reverse trike on locostusa. I've got a link to it and some pics in the album in my profile. It is a single seat, kubota 3 cylinder diesel 1105cc, polaris cvt, and mostly vw bug everything else. I've compromised my aero by designing for 3 pieces of flat, laminated glass. Lots more to do, but it hasn't been my highest priority. Again, enjoying your build.

Steve

[some_other_dave]

Originally Posted by Old Mechanic

With two passenger car tires on the front I think a motorcycle tire could create unpredictable handling consequences.

I agree with your thought process here:

If the car leans toward the outside of a turn (as cars tend to do!), then the motorcycle rear tire will tend to want to go toward the outside. The car tires will likely have less of this tendency, due primarily to having more squared-off shoulders. Which spells more traction at the front than the rear--OVERSTEER! Could be fun, but ....

I realize that the 205-width tires are wider than you want, but I felt I needed to address Christ's comment: In the VW and old Porsche world, we put 205s on 5.5" rims all the time; it is the preferred tire size for many of the stock wheels for those old cars. And many Hondas run either 195s or 205s on 5" wheels.

OM, good luck with finding the right tire!

-soD

[iveyjh]

DiamondBack trike looks "lean" and mean - Images

I saw this today and thought you might be interested.