since going -1 on the front sprocket my speedo has about a +5mph error (used my bro's 01 stock f4i to verify)...recently i went to a 190 50 road pilot on the rear...my question is: when going to a lower profile tire what effect does that have on the speedo? will i see +miles on it or will it counteract some of the effect from the -1 front sprocket?

James

no of course not, i realize that mine probably wasnt accurate to begin with, however i think the f4i was accurate from the radar display the local LEO has placed down the road from me...i hope to get one of those speedo correction devices soon tho...i doubt that the police would believe me if i said i my speedo was not calibrated and that i couldnt have been doing 200 mph like it said I was :)

I opt to verify using my GPS. My Boxster was 10% high (which fell into Porsches range of accetable accuracy, not mine), my ST1100 is about the standard 7% high in its ead but it gets closer to accurate at higher speeds. I have yet to check the blackbird with my GPS but the local city governemnt was very kind and installed a radar posting station right by a friends house just for us sportbike riders who wish to see how fast we can go and correctly verify our speeds... based on that (whcih has corresponded with my GPS thus far) my bird (all stock) is also about 8% high in its read.

Steve

Not sure your 190/50 tire varies in height much from the 180, but the profile will definitely suck, and handling will suffer.

You would want a larger tire to compensate for the change in speedo, and several companies are now offering a 190/55/17, that is supposed to handle the 5.5 inch rim better, too.

If it were me, I would have stuck with the 180, and gone with the speedo re-calibrator.

my brother put a 190 on his f4i and i just loved the look...i am an old school hot-rodder (late 60's mopars) and there was something about the wide tire look that i liked...i needed a tire and so i thought i would try it...so far i like it...it hooks up quite well but havent had a chance to find any twistie roads in mobile as of yet