The CB1100 Community Forum

Ready to pull the trigger on a pair of these. With the 4.25 rear rim these tires are within the guidelines for fitment. The rear is a 160/60-18 this may throw off the speedo a bit, how much I'm not sure. The wider tire and profile may also slow up turn in as well ( although these tires are more rounded than stock) I think I'm going to give them a try. Always had great success with my Pilot Power 2CT's. I could always drop the front a 1/4 or 1/2 inch if the steering is heavy.

Edit: Link
http://motorcycle.michelinman.com/tires/...road-3#dim

I put a set on a BMW R1200RT, loved them. You will too.
I'd consider them a few steps up in performance from my stock 205's.

CIP I been thinking about the speedo. I might be wrong but here goes : the speedo reads off of the abs sensor. So a smaller or larger tire should not matter when we put our bikes on center stand and ran them to 120 mph to check rpm in 4th 5th and 6th gear even if we did not have a tire on the rim at all the speedo would still be the same! I might be wrong but would a bigger or smaller tire change the speed of bike even thou it's reading correctly at the abs sensor wheel?

If you have a larger diameter tire the wheel will spin slower at any given speed than the smaller tire. Too take this to extremes, imagine your little 13" trailer tire spinning like crazy at 75mph while your jacked up Ford pickup with monster tires fairly pokes around at 75mph (but humming like crazy, but that is another problem).

Same speed, different rpm's.

The ABS sensor only see's the rpm's. In the software that converts that rpm to mph a few things are assumed to be constant like the tire diameter and the speed will be incorrect if the assumed figure does not match reality.

The new cars & trucks run the speedo off of the Trans speed sensor so if you change tires it does throw the speedo off. Older bikes that used cables on the front wheel if you changed to a smaller tire it would make the gear spin faster throwing the speedo off. But reading off of the wheel it self I don't see where it would throw off the speedo no matter what size tire you run. But again I might be wrong!

(05-27-2014, 11:54 PM)Ridem32_imp Wrote: [ -> ]CIP I been thinking about the speedo. I might be wrong but here goes : the speedo reads off of the abs sensor. So a smaller or larger tire should not matter when we put our bikes on center stand and ran them to 120 mph to check rpm in 4th 5th and 6th gear even if we did not have a tire on the rim at all the speedo would still be the same! I might be wrong but would a bigger or smaller tire change the speed of bike even thou it's reading correctly at the abs sensor wheel?

Here's the data, tire are almost the same in diameter, which means no need to alter front end and speedo is is off .5 at 60mph almost no change. Gives you a better performance tire with a little more meat.

http://www.tacomaworld.com/forum/tirecal...-160-60r18
[url=http://www.tacomaworld.com/forum/tirecalc.php?tires=140-70r18-160-60r18]
[url=http://www.tacomaworld.com/forum/tirecalc.php?tires=140-70r18-160-60r18]

Good info.

(05-28-2014, 12:15 AM)Ridem32_imp Wrote: [ -> ]The new cars & trucks run the speedo off of the Trans speed sensor so if you change tires it does throw the speedo off. Older bikes that used cables on the front wheel if you changed to a smaller tire it would make the gear spin faster throwing the speedo off. But reading off of the wheel it self I don't see where it would throw off the speedo no matter what size tire you run. But again I might be wrong!

Never think about the rim diameter, but rather the diameter of the tire, or more importantly the revolutions per mile. You can have 2 tires that are "the same size" but list different revolutions per mile. Those little differences add up and don't only add up to speedometer error, but to odometer error as well.

I think on my abs mode the speed sensor reads off of the ring mounted on the wheel so no matter the size of the tire the speed and odometer should not change! I larger tire would have to turn more then a smaller tire would but the speed should read the same due to the reading coming from the ring on the rim. That's just what's stuck in my head. Heck I could be wrong but just can't see how a bigger tire would change speedo reading when the sensor and ring still the same size

(05-28-2014, 02:53 AM)Ridem32_imp Wrote: [ -> ]I think on my abs mode the speed sensor reads off of the ring mounted on the wheel so no matter the size of the tire the speed and odometer should not change! I larger tire would have to turn more then a smaller tire would but the speed should read the same due to the reading coming from the ring on the rim. That's just what's stuck in my head. Heck I could be wrong but just can't see how a bigger tire would change speedo reading when the sensor and ring still the same size

Changing the size of your tires certainly does throw the accuracy of the speedo and odometer off. The ABS sensor only gives the software one piece of the equation... RPMs. Doing the math for distance and speed (which is just distance/time) requires knowing the geometry of the wheel itself since a larger wheel travels further with each rotation than a smaller one does. Changing the geometry of the wheel without changing the equations the software uses will produce an inaccurate result. The more dramatic the change, the more inaccurate the result.

Since we are talking about relatively minor changes to wheel diameter here, I'm sure that the speedo inaccuracies would be fairly negligible (+/- a fraction of 1 mph). However, the odometer reading would become increasingly inaccurate as your bike ages and, assuming your bike has a good long life, could eventually be thousands of miles off.