Topic: K2 front tire

[beemerbum]

Wanting a vintage look, I have installed a Dunlop K81 4.25-18 on the rear. The recommended tire size for the front is 3.25-19. It seems the only front wheel Dunlop K81 available is a 4.10-19. Will this fit the 1972 CB 750 front wheel without interfering with fender etc? A K70 in 3.25-19 is available. Would the dissimilar tread patterns look offensive to the purist? This bike will never be ridden at the recommended maximum speeds of these tires.

[69cb750]

Avon - https://www.ebay.com/itm/Avon-Speedmaster-Rib-3-25-19-54S-Front-Motorcycle/123729871428?epid=1111821356&hash=item1ccee00244:g:npMAAOSw5EJe-exQ
IRC - https://www.ebay.com/itm/IRC-GS-11-TIRE-FRONT-3-25X19-BW-301811/193099911758?epid=171176397&hash=item2cf5a6d24e:g:v9wAAOSwh1paGeWy
Metzler - http://forums.sohc4.net/index.php?action=post;topic=185065.0;last_msg=2142862

Dunlop K87 - https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=dunlop+k87&_sacat=0

[bryanj]

Yes it will fit perfectly, its the metric equivalent of the 3.25x19

[HondaMan]

Wanting a vintage look, I have installed a Dunlop K81 4.25-18 on the rear. The recommended tire size for the front is 3.25-19. It seems the only front wheel Dunlop K81 available is a 4.10-19. Will this fit the 1972 CB 750 front wheel without interfering with fender etc? A K70 in 3.25-19 is available. Would the dissimilar tread patterns look offensive to the purist? This bike will never be ridden at the recommended maximum speeds of these tires.

Intersting numbers on the modern version of the K81 tires...
The original rear tire (4.00x18) in K81 trigonometric size was 5.10x18. It was 1/8" taller than the 4.00x18 when mounted.
The replacement front for the 3.25 to 3.50 x 19 front was 4.25x18. It sits as high as the 3.50x19 tire when installed.