rear tire confusion

[jeepersheart]

ok let me start this by saying yes I know search... I did and read for almost 2 hours.

I have an 07 classic LT its my first bike so bear with me Im still learning all about them. Anyway my rear tire is just about bald in the center so I need to replace it, and have settled on the metzeler 880 (see I told ya I searched). my question is with regards to the proper size, should I go with 180/70, or 200/70, or 170/80 (i think I saw one post referring to that size). I dont know how the different sizes will affect my ride or performance. Any insight would be greatly appreciated as my head is spinning right now.

PS Im a bit stupid when it comes to what the different numbers mean in the sizes, My jeep has 35/12.5/15 tires 35 inches tall 12.5 inches wide with a 15 inch rim... why cant they all be that simple?

[Graybush]

There are some pretty detailed threads on this. I had one bookmarked so I'll give you the link for it. Seven pages about tire size and its effect on speedo and odo readings. I have a 200 and love it. It won't feel like a completely different bike but it is more relaxed when cruising and moves the shift points up. Seems like somebody always wants to talk about how a 200 rear tire is sloppier and doesn't handle as well since it's wider than the stock 180. I think that's a topic more suited for comparing the classic and custom front tires. I haven't noticed any bad effects from having the wider tire. Anyway, I promised a link.

Results--rear tire size speed & odo effect

Edit: Sorry! I screwed up the link. It should work now.

[VulcanRay]

Greybush, I can't open that link. Can you repost it?

[jeepersheart]

thanx I'll check out that thread... I think Im just concerned about how it will affect the ride being so new to riding I dont want something that will make it more difficult for me

[big worm]

well you cant go wrong with running the stock size !!!

[whiting57]

I run 200 rears on both my bikes ... it will drop the rpm and correct the speedo ... use the air preasure on the tire, not the kawasaki manual .. it makes it a far easier ride around town and more pleasant on the highway .... with the correct preasures, there are no adverse affects. 200 70 15. Means ... 200 mm wide, 70 is the side wall or aspect .. 70% of the tire width .... 15 is the rim size. The overall difference is a larger circumference .. but it will fit with out any modifications.

[Graybush]

Originally Posted by jeepersheart

thanx I'll check out that thread... I think Im just concerned about how it will affect the ride being so new to riding I dont want something that will make it more difficult for me

Don't overthink it. You won't hurt the bike or yourself just by changing to a 170 or 200 tire. I like the 200 better than stock. Here's a copy of a post I made earlier this summer:

Originally Posted by me

I've ridden the mountains with stock Dunlops and with Metzelers which are far and away better tires. They handle better, are better in the rain, and more stable in turns. I do a lot of floorboard scraping and wish I would have changed sooner. Even with a 200 it's very easy to set and hold a line and even do quick flicks back and forth. A few weeks back I did a pretty hard swerve to avoid a pothole on an unfamiliar road and there was no hesitation or heavy handling at all. The guy riding behind me commented that he didn't realize my bike would move that quickly.

[Richard Kerr]

I think Whiting and Greybush have covered it. I'm running an Avon 200, all about the same, it is slightly wider than the Metz. I don't think I would go back to stock, handles too nice.

[johnnyplano]

Originally Posted by jeepersheart

PS Im a bit stupid when it comes to what the different numbers mean in the sizes, My jeep has 35/12.5/15 tires 35 inches tall 12.5 inches wide with a 15 inch rim... why cant they all be that simple?

Stock 180/70-15:
Tire width = 180 mm = 18 cm
Tire sidewall height = 70% of the width = 180 x .7 = 126 mm = 12.6 cm
Rim diameter = 15 inches

170/80-15 means:
Tire width = 170 mm = 17 cm
Tire sidewall height = 80% of the width = 170 x .8 = 136 mm = 13.6 cm
Rim diameter = 15 inches

200/70-15 means:
Tire width = 200 mm = 20 cm
Tire sidewall height = 70% of the width = 200 x .7 = 140 mm = 14 cm
Rim diameter = 15 inches


So, the 170/80 has a 1 cm higher sidewall. That equates to 2 cm larger diameter than stock - about .8 inch.
The 200/70 has a 1.4 cm higher sidewall. That gives you a 2.8 cm larger diameter - a little over an inch.

Both of the larger diameter tires will roll you farther for each revolution of the wheel. That means lower engine revs to roll the same speed as the stock tire.

[HOGBOY]

Ran Deals gap last weekend on my 2008 Classic after installing the Metz 880 200. Stuck to the road like glue. Vast improvement over stock in my opinion. The higher shift points really helped in transitions in and out of curves.