Partial Tire Thread: 180 v. 170 Rear on Norge

[Bill Hagan]

Lots of tire stuff here,b\ut I cannot find anything specific on the downside, if any, on putting a 170 on the rear vice the stock 180.

Back tis evening from a 1500-miler and my MPR3's are just shy of cording. Great tires.

Need to replace, tho, and am inclined to put on MPR4 GT's.

The 170's are 170/60ZR17 72W.

A few questions for those of you who know (and care  ).

First, any reason those won't fit my Norge's rear wheel?

Second, any drawbacks to the narrower rear?  Have long thought the wider tires were a marketing and vanity ploy more than needed for the Norge, tho she is a plump filly when fully loaded and two up. 

Also wondering if the GT -- stiffer sidewall, etc. -- useful, ditto the above weight, or too stiff than needed and make ride harsh and handling less responsive.

Many thanks.

Bill

[bad Chad]

I usually ask myself,  "what would Jim Baron do?" And go from there.  Good luck.

[Bill Hagan]

What?

All this knowledge and experience out here and no comments, even flaming ones?  I'm deeply hurt.   

Seriously ...

* That 170/60ZR17 72W will fit?

* No "downs?" 

* GT good idea on 180?

* As needed on 170, given narrower width and thus (inferred) greater rigidity on sidewall in standard MPR?

Thanks.

Bill

[Vasco DG]

No reply Bill because I have very little to offer.

Back in about 2007 I experimented with a 170 section on the back of my G11. While it did quicken up the steering I never pursued it with a matching front simply because it felt *Wrong*. My poorly informed guess is that with a matchinly narrowed front it could feel sprightlier but I actually preferred the stock sizes and reverted to them. I have stuck with that with the G8 and the Mana. (shrug?) Works for me....

Pete

[Bisbonian]

I put a 170 on the back of my 1200 Sport a few tires ago. Mostly because it was quite a bit cheaper than the 180.

I don't remember any sort of issues, I don't remember anything about it so that must mean it didn't have any real effect.

On one of my past motorcycles rear tire wear was horrible, less than 5000 miles per tire. One of the suggestions at that time was to go with the next lower size as it tended to flatten the tread portion of the tire (wider rim width spread the tire out more) and gave a few thousand extra miles. And it was cheaper. And supposedly it quickened the handling.

[rocker59]

On the 5.5 inch wheels, either 180/55-17 or 170/60-17 will work, and are correct fitment.  The 180/55-17 is also used as an alternative for the 190/50-17 on 6-inch wheels, for the same reason the 170/60-17 is used on the 5.5 inch wheels.

I went from the OEM 180/55-17 to a 170/60-17 on my V11 LeMans Nero Corsa very early in the bike's life in order to improve handling.  Both turn-in and stability at extreme lean angles were improved with the change.  Also, the tendency to want to stand up while braking in a curve was reduced with the change from the 180/55 to the 170/60.

I wholeheartedly recommend giving the 170/60 a try.  No need to change sizes on the front.  The 120/70-17 is ubiquitous.

For a touring-oriented sport-touring tire, I used the Metzeler ME800 REINFTL rear in 170/60-17 and it was good for 10,000 miles.

I also used the Michelin PR3 in 170/60-17 on the bike, and it was a great all weather tire, with nearly as long treadlife as the ME880.

[Bill Hagan]

Many thanks.

Just ordered -- before I read yours, MIke    -- MPR4 GT's in stock sizes.  I am very interested in trying the 170 next time for the reasons you mention.  I recall the change in the Ballabio with such being very positive.

The MPR3's gave better mileage than any tire on the Norge so far -- checking exact, but 6K+/-, which is at 1500 more than my "usual" 4-4.5K to cords.  Much of that was fully loaded and two up (Kathi weighs little; I, think big) in (what passes for me as) spirited riding on challenging and fun roads.  I was very pleased with the wet & dry performance, too, tho the last 500 or so miles gave a rock-hard ride as the rubber cushion was near gone.

Felt a bit guilty using Revzilla's great little videos to influence my decision -- see, e.g., the overview of Michelin tires and the drill-down to the MPR4 series here: http://www.revzilla.com/motorcycle/michelin-pilot-road-4-gt-tires -- then buying from Winchester Motosports, but local is local, and WMS matched the Revzilla prices and gets 'em to me more quickly, with no up-charge I'd pay for mounting tires I'd bought elsewhere.

The paragraph I just wrote reminds me to do a little more dealer praising.  I cannot say enough good things about WMS.  Great service (Mike is a talented tech who loves Guzzis) and parts support (Mike -- Mike II, as we call him  ).   If you are even remotely nearby, give 'em a try.

Bill

[guzzibob]

Can't speak to 170 vs 180, haven't tried it. However, have been totally happy with the 180's and see no reason to change. Can speak to using PR4GT's however, as that is what is currently on my Norge. Been very happily using Pilot Roads of whatever version was current for quite some time-unless I need a tire far from home & have to take what I can get. Have 9000 mi on the front. Certainly shows some wear, but not yet down to the wear bands. If I were to go on another 3000 mi trip like the one I came off of recently, would probably change before I left. Maybe. Have 4000 mi on the rear, with tons of tread left everywhere, nowhere near worn out. My Norge gets most of my long distance stuff, less of the local canyons & mountains than my Tontis, so tends to wear tires out down the center. Still, it does see some canyon scratching. When I changed to the PR4GT front, seemed to me a bit more planted feel in the twisties than the 8900 mile, just to wear bands PR3 it replaced. Didn't really notice much difference when I changed the rear, and that replaced a Michelin Power that I had to get while on the road (toast at 4k). Certainly do not feel that the GT's produce a ride that is harsh in any sense. I never ride 2 up, and weigh about 170. On trips I use the heavy stock bags, medium size Givi top case, and a seat pack, all pretty loaded. At home I take the bags off & go light. I will continue to use the stock size PR4GTs, at least until Michelin comes out with the next version. I would expect you to be pretty happy with them, as am I.