custom tires for geo metro (motorcycle tires?)
 

I'm looking for some tires to fit on my geo metro. I've already thought of some way to build my own but I'm wondering what type of existing options there might be. I saw these on the custom hyperRocket project that was built, but that thread seems to not get any answers on it.

Basically I would like to get some thin tires for the front of my geo project. It's going to be a 3 wheeled vehicle that does not look like a geo when i'm done. Made for commuting around town. Motorcycle tires will have less friction and make the non-powered steering easier to turn.


http://ecomodder.com/forum/attachmen...1&d=1262677376

Those wheels on the hyperrocket are stock Ninja 250 front rims and tires.

So did the guy build a custom hub to attach it to the axel? Or is there some rims you can buy pre made for doing this?

The stock tires on a Metro are the thinnest tires on any mass produced vehicle. I upgraded my size to a slightly wider tire for stability. Sure, it hurt fuel economy some, but why compromise safety? You already have one of the best MPG kings on the road and there are other ways to increase your mileage that will no effect safety.

An instant 5 MPG increase can be had by dropping in a 3Tech economy cam and gear.......
3tech

Thin tires doesn't equal better fuel economy.

There is some evidence that larger tires might be better in the long run.

But you also have to consider that there is a wide range of rolling resistance values within a given tire size, so careful selection of tires can make or break any gain you might get from changing sizes.

Motorcycle tires are built for leaning, which leaves fewer options for reducing rolling resistance. With so much air drag, riders seldom notice tire drag. I'm curious about how you plan to build your own tires. There is almost nothing made for very light cars, and even less data.

I should say I'm not necessarily looking to increase MPG with this mod. I'm using the front end of a geo metro. When I'm done with this, it's not going to look like a geo.

It's going to be for commuting around town. Motorcycle tires will have less friction and make the non-powered steering easier to turn.

Perhaps there is a different forum I should be posting in?

What are your goals? If not better mpg, then what?

My experience has been that MC tires are much more expensive and don't last nearly as long as car tires. MC tires will handle differently, and not be as good in adverse weather.

Reverse Trike?
 

Are planning on ending up with a reverse trike, ie, two wheels up front, using the Geo Metro suspension and drive train?

Will you be leaving the wheels under the body or exposing them like the picture you included?

I would leave them under the body and just work on smoothing the flow from front to back.

What will you use for your single rear wheel? If the front wheels are providing turning, power and braking, then I would leave the stock sized Geo Metro wheels there.

I would probably go with a single Geo Metro wheel in the back, but I like consistency and common parts (keep the fourth for a spare!).

If you are making a hybrid or in some way not reducing the weight by much, a wider large wheel might be needed.

Of course, I am not an engineer nor do I play one on TV.

Space-Saver spares are a possibility. I don't think that parking effort should be your major worry, if you keep the steering wheel setup. Even heavy trucks can be set up to not need power steerinig.

If your steering is still too "heavy" for you, you can change the steering feel by changing the caster angle of the front wheels, which can be accomplished in several ways using the stock parts, at least by a few degrees.

If you use MC tires on your car, you will have next to no wet traction, a higher RR figure in many cases, and a fairly slide happy front end, assuming you're using a MC tire that's thinner than the OE Metro tire.

There are car tires that are thinner than the Metro's, but you just don't find them that often. Maybe some place like Coker Tire would have them? Some cars came with 10" rims and tires.

You could also get highway-rated trailer tires, but you still end up with higher RR and such.

If you do end up using MC tires on the front, you'll want to adjust the camber setting so that you can use the shoulders of the tire when steering, to make up for the leaning effect that motorcycle tires are designed to accommodate.

That will afford you the highest possibility of not sliding off the road at the first hint of wet or uneven pave.

The Citroen 2cv uses 135 X 15. Many odd sizes are available for classics, but few are as efficient.

Anyone that can build their own tires has earned my respect! :thumbup:

Those 135 Citroen tires are only an inch and a half wider than a typical 100 width M/C tire. Heck a 155 section tire is only about 2 inches wider than the same M/C tire.

That being said, 100 width m/c tires made for touring, pumped up to 50 psi would provide a pretty darn narrow contact patch. Probably pretty low friction with the right tire choice. Tire longevity would be less than the car tires, but that's not the point.

For lowest steering effort go with thin small diameter tires and the lowesT vehicle weight possible. The longer contact patch of m/c tires acts like a rudder trying to keep the tire straight. Make sure the steering and suspension attachment points are very rigid. Body flex is a contributor to heavy, vague steering. Little 145x12" Metro doughnuts will do a fine job for what you're after.

Motorcycle tires are expensive, and wear fast.

I suggest you increase these in size...
http://www.bodycontouringimplants.com/images/bicep.jpg

Sounds like you just want to build a custom 3 wheeled vehicle using the Metro as the platform.

In that case, I think all work with motorcycle tires, or anything of that nature, would be completely custom and unless someone on this forum has done so, I don't know if they can be of any real help. The best advice would come from the maker of the car in that photo that you posted.