hi all!
My rear tire (Metz110/90 - i have a gsx400e aiiiight?) is coming to an end so soon i`ll have to replace it. I have a quite nice spare front tire Metz110/80 so i thought.. ..what would happen if i put it on the rear? As it is as wide as the rear and i can`t think of any other difference from rear, why not? C`mon slap me with your opinion!  :nana:

Size and thread pattern. Thread pattern is the more significant  in my opinion.

So you mean, i will slip to hell because of its for-front-use-only-thread-pattern?

Nope.  I don't think so.  I am no expert in this area and have never used a rear wheel for front or vice versa. Mebbe some of the more experienced riders here may care to throw some light.

I could use that information too... as using Mez Tourance rears

The thing against using a front on the rear is the way the tires are constructed. The plys are layed in such a way that the fronts are designed to obsorb "reverse" or braking forces and the rears are designed to obsorb "driving" forces. So you would technically have a delamination threat.

That said,
I know quite a few racers who routinely flip radial DOT tires so that both sides of tires get used on tracks with mostly right or left hand turns.  And I know a guy who does land speed racing on a GS450 who uses a 110 front on the back without any problems.
Another solution that occured to me if you can't find a 110 rear, that is about the right size for 125GP rear tires. Perhaps you can find yourself a hard GP rain tire (the kind with lots of grooves).

I'm no tire engineer, but I believe the profile is different on front/rear tires. Fronts have more of a peak than rears that aid in leaning the bike into turns. I would think having 2 fronts might make the bike a little unstable/squirrely in a straight line. I couldn't say how drastic the change would be, but I can't see how it wouldn't affect the handling characteristics of the bike.

I don't think a front tire is designed to take the drive loads induced by the engine.

Isn't that what I said?  

old skool...was to run a front tire backwards on the rear of the bike....rear to front...same thing
that way the braking forces are in same direction as driving forces.

I saw either a traction or GMD rider with a 120/60 front tire on the rear of a GS a couple of years ago

black, round, and hold air are good requirements for a tire

Except when you reverse a standard front tire to run on the rear, you lose it's water displacing properties.  Instead of directing water from the center to the outside of the tread, you do the opposite.

Quote from: JamesGIsn't that what I said?  

Oh yeah... , I feel silly...

(got your check, thanks...)

Thanks for the input guys! I feel like i`ll try it  some day and take some test rides to see how it goes.  

Hey tres,

Got some additional info on this subject from www.superbiketyres.com

CAN MOTORCYCLE TYRES BE REPAIRED?

Motorcycle tyres have to be repaired within the limits of British Standard BS159F. Unfortunately, this does not allow repairs on tyres with a Z speed rating or above. Most of todays sportsbikes of 600cc upwards are all fitted with Z or W rated tyres, therefore, these cannot be repaired within the British Standards. A temporary repair can be carried out to get you home or to a local garage, but the tyre would have to be replaced, the use of sealants is not recommended by tyre manufacturers and their use voids any warranty on the tyre.

ARE SPEED RATINGS IMPORTANT?

Yes. The speed rating of a tyre is in relation to the performance of the motorcycle, therefore the correct rating has to be fitted in accordance with the motorcycle manufacturer's recommendation. Failure to do so could and probably would void any warranty or insurance claim.

CAN I MIX TYRES?

Yes and no. It is a good idea to keep front and rear tyres a matched pair. All tyre manufacturers recommend this as the performance parameters from different manufacturers are different. You can mix say a BT56 front with a BT57 rear. These are both Bridgestone tyres but with slightly different characteristics, in laymans terms the 56 is grippier than a 57, and the grippier tyre always goes on the front, this is an OK mix. A Bridgestone rear and a Dunlop front is not agood mix.

WHEN IS THE BEST TIME TO TEST TYRE PRESSURES?

Always check tyre pressures when the tyres are cool. Hot air expands inside a hot tyre giving you different readings. Always consult your handbook for correct pressures and adjust for two up riding or sustained high speed use if recommended in your handbook.

CAN A FRONT TYRE BE USED ON THE REAR?

Most tyres are made for either purely front or purely rear use. However some manufactures produce tyres to fit either front or rear, but these have directional arrows on the sidewall for front or rear use. If a tyre is made for front use only, then you cannot put it on the rear and visa versa for rear use.

DO NEW TYRES NEED TO BE RUN IN?

Yes. When new tyres are fitted they must be run in for approx. 100 miles with no excessive accelaration or braking, they should then be checked for correct seating on the rim and the tyre pressures checked. New tyres are slippy. Ignore this at your peril. Unfortunately we have had customers in the past who have ignored this advice and have fallen off their bike within five yards of our workshop entrance. You have been warned!!!

CAN I FIT A WIDER TYRE IN MY MOTORCYCLE?

It is not a good idea, unless it is recommended by the motorcycle manufacturer, or you have changed the wheels. Fitting a wider tyre on the same rim often deforms the natural profile of the tyre and can therefore cause adverse handling problems. Also, a larger tyre on the rear of a bike can slow the steering down.

DO I NEED TO REPLACE THE VALVE WHEN I CHANGE THE TYRE?

Always replace the rubber snap in valve for deterioration and if in doubt then replace it, always using the correct type and with an air tight metal valve cap.

DO I HAVE TO USE THE TYRES RECOMMENDED IN HY HAND BOOK?

Some motorcycle are very sensitive to different tyre combinations, however, the tyre manufacturers test their tyres on most models of superbike and normally can recommend a fitment for your particular model. If in any dobt then contact your local dealer, not the bloke down the pub.

SHOULD MY NEW TYRES BE BALANCED?

Yes. Although tyres are made to very fine tolerances, there is nearly always an imbalance between the new tyre and the rim. An unbalanced wheel can cause irregular wear and vibration.