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I bought a 1979 Suzuki GS 750L a year ago, and the rear tire needed replacing. The rear tire that was on the bike was a Continental 4.50H17A K112 I am not sure what the A K112 means. This number converts to a 120/90-17 metric size. However when I bought this size, (Bridgestone) it has a smaller profile hieght and width. The overall height is close to 2 inches smaller than the 4.50H17. I really would like to have a tire closer to the size that I replaced. The rim size is 17xmt 2.5. Should I go to a 130/90-17

I also need to match the rear tire with a new front tire. The tire on the front is 3.25 H 19.

Thank you in advance for any help.

Greg O.

What make of bridgestone did you get ?

The bike is older, it's recommended that you use a Bias-ply (Not radial) tire.

My sources are showing that a '79 GS750L should have a:

Front 3.25 - 19 (100/90 - 19)
Rear 4.0 - 18 (110/90 - 18 )

Sooo. Either my sources are wrong,your model number is wrong, or your bike's got the wrong rear wheel (This is called "Previous Owner Disease")

I AM showing that a GS750E takes a 17 inch rim rear tire, so that may be what rim you have. At any rate, tire sizes actually differ by manufacturer. I've found Bridgestone spitfires typically work for older bike applications. If that's what you have, either match the front to the rear, or you could step up to a 130/90 as well.

The Bridgestone is a BattLax BT 45R. Does the R mean it is a radial? This is the tire a motorcycle shop sold me.

Greg O.

OK, nope the BT45 is a bias ply tire (The R means it's a rear fitment)

You should get a bt45 for the front to even them out and you should be good to go.

If you don't like the tire, bridgestone's Spitfire s11 series has always treated me well, and they seem to fit better on older bikes. I think they are the same price (or cheaper) than the battlax's too.