How about 215/70/15 ????Kurt my signature line tells what I've done to our trike.
Kurt our 09' had originally 32 tooth front pulley and 70 tooth rear. later and I think even now they have 30 tooth on front and 70 on the back. I had a stator repair done and when New Castle Harley had the primary off I had them install a thirty tooth on the front which I purchased from a friend and member here on trike talk. The change was great at 8 years old my 6th gear was like new cause I never got to use before the pulley switch. However after a few years and wanting to run a few Interstate highways I found the top end seemed a little gear bound and the top end rpms. were higher than I liked, not to say I'm expert on this but I just didn't like the sound of the motor at 70+ mph for long periods of time. High rpms. make heat and heat effects oil and that effects engine parts see where I'm going with this. At 70 I was running close 30-32,000 possibly a little more hard to remember of the top of my head. So I wanted to get somewhere in the middle of the rpm range, so either change front pulley to a 31 tooth and all the labor incurred cause the entire left side must be removed or go to a little higher tire for way less expense and I can have that done myself. So 202X70rX15 are now on. I got a great deal on a pair figuring if this didn't work out the utility trailer needed tire anyways. The speedo is 2mph slow at 55 (certified PSP) not enough to get you in trouble bottom end is still very nice no issues starting out like the 32 tooth pulley but the higher tires have seemed to removing the high rpm wall if you follow what I mean by that. My cruising temperatures are much lower, if I ever find my note book I logged all of this Air temp humidity time of day etc. Bottom line I lower engine temps by dropping rpms in 6th gear cruising that alone makes it worth it, now if you want change front pulley or just go with 70 series tires tires give you a chance to see without spending 1,000 on parts and labor. Now if you run an M8 it should be a win win as well with the storied bottom end torque they are creating or so I've been told. Good luck ride safe Fred
P.S.
Just to add the higher tire effected how the trike handled it really planted the front tire like never before, I could not believe it it was that good. But the downside was it nose dived like never before Junk spring and very little oil in them (never serviced I realized) I was trying to corner faster than before and my front forks were bottoming out so I upgraded to Pro Action touring works for me a little noisy but it really handles now.
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