Narrow LRR Tires For Project

[Hasbro]

Been playing around with a single seat or double seat inline high mpg car design and have been trying to find a good tire. I'm sure in a couple of years they will start releasing pretty cool choices. Here are some that I've considered:

135 SR15 Nanking. Too heavy, I think.

These are motorcycle sidecar tires that a guy on Grassrootsmotorsports.com suggested. Pretty cool, 18-19" x 3.5-4". If these are viable the design parameters would be very different as it would allow for a much lighter vehicle- possibly under 600 lbs. Regular motorcycle tires would a great choice but the rounded tread is iffy.

Have seen these on a couple of prototype cars, probably experimental?


This is sort of what I was thinking- ultra light:

YouTube - George Fortins electric car,gfortin@cox.net

My thoughts are a little different: lower cg, aero body, canopy type top, electric or 20-40 hp? combustion motor, negative camber! I think the tires are bicycle cruisers or 29ers?

There appears to be two different types of vehicles developing.
One would weigh 300+ lbs., have an electric motor setup, with speeds up to 50+- mph. Limited range commuter.
Two would weigh 500-600 lbs. or more, have a higher speeds, combustion motor, good for long distances.

Any feedback is welcome.

[Puggo]

Hi,
I'm looking into the same vehicle type and have friends with a Citroen 2CV. See the Michelin Historic Catalogue. They're cheap tyres and narrow for the weight desired.
125R15X is their designation. Also 2VC hibs run only 3 studs for lower weight. Note the transmission includes inboard disc brakes.
regards
Puggo

[Bicycle Bob]

I've heard complaints that motorcycle tires have not been improved along with car tires, so a sidecar tire might be very primitive indeed. Is it even a belted tire? If you can find a way to actually obtain some of those Michelin VR 262s, please let us know. They wouldn't answer my query about their tires for the solar race cars. I'd appreciate any good data you find on rolling resistance. Most of the research seems to be proprietary.

[Puggo]

Hi Bob,

Are the Michelin VR 262's a special tyre? It's not listed in their catalogues.

cheers
Puggo

[Bicycle Bob]

They seem to be. Let's ask Hasbro how he even got a picture of one.

[some_other_dave]

People with vintage cars who want the "right" look want all sorts of odd-size tires. Many of them can be found at: Coker Tire - Coker Tire

I also know people who have ordered Vredestein tires because those were available in the right sizes, and they seem to be happy with them. A tire with some narrow sizes can be found here: Vredestein Tires - Quatrac 2

Unfortunately, the low demand for these sizes of tire usually means the prices can be more than you would expect.

-soD

[RobertSmalls]

I've got a similar idea for a project car kicking around in my head, and, unfortunately, the smallest, lightest, LRR tires I've come across are the OE tires for the Honda Insight. They're P165/65R14, and about 13 lbs each. Four of them and four Insight wheels is about 100lbs of rotating mass. The load capacity of 937lbs is overkill for any Honda, let alone a two-seat tandem project car, but until Firestone starts selling 16"x2" (P50/85R16?) LRR tires, what are you going to do?

I've thought about bicycle tires on bicycle rims, especially for an ultra-light, low-speed vehicle. Low rolling resistance tires are available, but the load capacity is probably <200lbs per wheel, and the tires are round for leaning into corners. You might be able to run them on a 500lb NEV/NGV, but I wouldn't expect incredible stopping power or cornering.

[Bicycle Bob]

A major issue with bicycle tires would be tread wear. I ran Moultons on a 100 lb streamlined HPV, and they would only last for one road race. I have considered taking a bike tire or motorcycle tire and making it into a radial by winding on a belt. That could improve the pressure capacity. ____ Goo adhesive, originally developed as a shoe sole repair, lasts well on kid's bike tires that have developed flat spots from dented rims. It is frustrating trying to design for a vehicle type with no good tire choices.