Rear tyre size on NC700X

[Guest Dave Mac]

Hi. Can anyone clarify whether I can fit a 150/70R17 rear tyre on my NC700X?  The OEM tyre is 160/60R17, but I'm looking for a tyre with better off-road/gravel road capability, and the preferred one (Shinko 705) only comes in 150/70R17 size.   Thanks.

[Graham NZ 1,186]

Stay with the stock tyre sizes or speed readings and other things will be affected adversely.

[Dunnster 1,650]

It would probably fit but will affect the profile of the tyre. I'd stick with the correct size. What about continental Tkc 70 they come in the correct size. 

[Tex 36,816]

Very unwise messing with tyre sizes. Seriously.

[Andy m 23,463]

Should fit, its 10mm narrower and a within 5mm on the sidewall depth.

 

The Shinko 705 is just another toy-town knobblie style for the charlies, which would lead me not to mess with it. Little gain offroad, whatever handling changes on road. The septics like them because they fit Harleys and are the only tyre they can buy that isn't a whitewall. The Heidenau K73 M&S is available in the right size. The K60 M&S , a proper knobblie, is available in the wider 170/60 R17. With a proper knobblie the biggest handling change is in the rubber so you don't notice a size or two either way. If you are dumping Skidmasters or other rubbish it only gets better. TCK-80's wear faster than a students bed springs in my experience.

 

I dumped the Enfields Avon 110/???? R18 and 90/90 R19 for 130/80 R18 and 100/90 R19 K60's. The doomsayers are wrong, its better on the road and much better off. Same applies to Triumph Bonnevilles, 650 V-Strom and Guzzi V7. Been there, wore more than a tee shirt!

 

Andy

Edited January 11, 2018 by Andy m

[Guest DelBoy]

On 1/10/2018 at 22:19, Graham NZ said:

Stay with the stock tyre sizes or speed readings and other things will be affected adversely.

Bang on fella 

[Graham NZ 1,186]

Just the same, isn't it the 'rolling radius' which matters?  What are the rolling radii of 150/70R17 and 160/60R17 I wonder?  I don't think it's as simple as the simple math might show.

[Andy m 23,463]

The tyre approval gives a figure for the RR based on a calculated figure. Its a 2.8% difference on these.

 

This tool does the same http://www.willtheyfit.com

 

The actual figure will be up to 10% out* based on the rim width, pressure and load. As the tyre warms up it gets bigger anyway. There are fiddle factors that account for this in the brake calc etc. but the only way is physical testing. If it feels right, chances are it is right. You occasionally get problems where vehicle builders went for extremes and the owners even more extreme, but the NC isn't close.

 

The 2.9% difference on what I'm running on the Bullet actually cures the speedo error at 30 mph.

 

* this is how ABS tyre pressure monitoring works. By storing the differences at a steady speed, when one tyre goes down it speeds up so the ABS puts the light on. On a two axle truck it takes about a mile to pick up a 1 bar loss. The clever bit is setting a corridor to allow for temperature.

 

Andy

Edited January 13, 2018 by Andy m