Tire size-Handling-Speedometer Accuracy

[Guest]

Hi,

I'm not trying to start a "this tire is better than that tire" debate. I just wanted to pass along my observations. I've been using Bridgestone Spitfire S11 tires for years. For me they work well. They're fairly cheap, long lasting, and let me scrape my boots in the canyons.

I put on a new set last weekend and decided to follow the collective advice and try a 100/90-19 on the front instead of my usual 110/90-19. I must say that the handling is improved. The bike turns quicker and easier and feels a little more sporty, if you can say such a thing about a GS850GT.

I've also noticed that during my commute on the freeway, where the speedo used to read 70 mph at 5000 rpm (which is pretty dead-on accurate), it now reads 74 mph. This is just a little annoyance that I will get used to. I guess I'll even get 5% better gas mileage now. But that will be a false economy.

After I wear this one out I'll decide whether or not I'll stick with that size. I kind of liked the 110/90 on front because most of my riding is on the slab, commuting, visiting my parents an hour away, running errands. The bike seems a little more "planted" but it was a little harder to steer when I get to having fun in the canyons. I suppose if I did more canyon carving I'd be more inclined toward the 100/90.

Anyway, I just wanted to share this little profound glimpse into the obvious. Those if you with similar bikes and riding habits can tuck this away for future consideration. Thanks for letting me share.

A few pictures of my new tires in use are in another thread: GMR Sunset Ride. (I've always used a 130/90-17 on the rear.)


Thank you for your indulgence,

BassCliff

[Steve]

Of course, the displayed speed is going to change with the smaller tire, but have you compared speed to ACTUAL speed with a GPS?

All three of our 850s have 100s on the front. At an indicated 70 mph, the GPS speeds range from 68.5 to 71, which is close enough for me.

.

[BassCliff]

Hi Steve,

As soon as I figure out how to mount my phone on my bike and then utilize the GPS in my phone to monitor my speed, then perhaps I'll get some more accurate velocity numbers. Perhaps one of these apps? http://www.appbrain.com/app/gps-spee...GPSSpeedometer

All the best to you and yours,

Cliff

[bwringer]

100/90-19 is definitely the correct size, and the bike handles better with that size front tire, but I guess you know that already.

Just as another data point (or idle anecdote), when I mounted up a GPS for the first time, I was shocked to learn that the speedo on my GS850 is dead accurate.

[DanTheMan]

The speedo on my 1100 is dead accurate, but, no matter which tire size I put on my 850, it stays off to the fast side by 4-6 mph. I decided to try the 110s on my 850 this time, same error as with the 100s. Could be tire profile height has changed some too on my Pirellis since they are now Scorpion Trails instead of whatever the old designation was?

[BassCliff]

Hi Brian,

100/90-19 is definitely the correct size, and the bike handles better with that size front tire, but I guess you know that already.

It was your sage wisdom that made me decide to try the 100/90 on the front. I'm diggin' it.

Just as another data point (or idle anecdote), when I mounted up a GPS for the first time, I was shocked to learn that the speedo on my GS850 is dead accurate.

I know my speedo was pretty dang close with the 110/90 on the front. But I think I can get used to a little speedo error.


Thank you for your indulgence,

BassCliff

[SqDancerLynn1]

I have the 110 on mine.. I dropped the forks down till they almost touch the bars

[Dogma]

More anecdotal data:

The 100/90-19 (High-Max) on my 850GL reads about 75 at 70 IIRC
The 100/90-19 (VenomX) on my 1000G reads about dead on, maybe 1 mph slow.

[Gssheller]

Hi Steve,

As soon as I figure out how to mount my phone on my bike and then utilize the GPS in my phone to monitor my speed, then perhaps I'll get some more accurate velocity numbers. Perhaps one of these apps? http://www.appbrain.com/app/gps-spee...GPSSpeedometer

All the best to you and yours,

Cliff

This is my favorite speedo app. I can place my phone in my tank bags map area with the clear cover and check my speed easily. It also has some neat side features which I like.

http://www.appbrain.com/app/ulysse-speedometer/com.binarytoys.speedometer

Hope this helps!

Brian