TIRE SIZES conversion?

[General Zod]

I have a 1978 GS 400 XC......

does anyone know the tire conversion of this bike?

I need new tires and dont know the conversion.

also, my bike runs spoke rims. does that mean I need tires that fit an inner-tube?

my front tire is 3.00x18
my rear tire is 3.50/3.75 H 18

can I run slight larger tires, maybe a size up?

because I want to get either whitewalls or tires that wont make my bike pull left to right when I am on the freeway riding on one of those grooved asphalt patterns....

my front tire has one of those straight line patterns that makes it ride weird....


any sggestions?

[Steve]

Most tires nowadays are either in millimeters or letters.

Here is a conversion chart put out by Dunlop that should help you decide what size you need.


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[General Zod]

ok. so my front tire is a 90/90
but it doesnt say anything about my rear tire which is 3.50/3.75H18

Most tires nowadays are either in millimeters or letters.

Here is a conversion chart put out by Dunlop that should help you decide what size you need.


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[boris]

http://www.webbikeworld.com/Motorcycle-tires/tire-data.htm

any use ?

[Nice Lad Kev]

http://totalmotorcycle.com/photos/tire-tyre-guide/index.htm

[bwringer]

also, my bike runs spoke rims. does that mean I need tires that fit an inner-tube?

Yes. Almost all tires you will find in your sizes can be used with or without tubes. With spoked wheels, you will need tubes. Always install new tubes with new tires. I also always replace the rim strip -- it's only another buck or two.

my front tire is 3.00x18
my rear tire is 3.50/3.75 H 18

These correspond to 90/90-18 in front and 100/90-18 or 110/90-18 in the back.

Last summer, I installed a set of Cheng Shin HiMax tires in these exact sizes on a friend's CB350. He has been extremely happy with the vastly improved handling, and they are wearing very well (he rides that old bike everywhere). Cheng Shin HiMax tires are a modern, reliable, and very grippy design for excellent prices. Plus, they look great. The total of tires, tubes, and rim strips with shipping was just over $100 from http://tiresunlimited.com .

Just make sure you do NOT end up with other Cheng Shin tires -- their older Barracuda and Marquis designs don't work nearly as well.

I think Avon's new AM26 Roadriders are also available to fit your bike, and should be excellent handling tires. I think these are what the vintage roadracers are using these days.

can I run slight larger tires, maybe a size up?

No. Motorcycles are not cars -- the tires are not wide and flat across the tread.

For best handling you must keep the tire width as close to stock as possible so that the tire's profile has the proper curvature. Cramming wider tires on stock rims squashes the profile and actually reduces the size of the contact patch.

because I want to get either whitewalls or tires that wont make my bike pull left to right when I am on the freeway riding on one of those grooved asphalt patterns....

Whitewalls? :shock: Um...I have not the words.

Any modern tire will not have the rain groove handling problem of the old ribbed tires.