I have a CT110 Trail (the successor to the CT90) and the stock dual sport tire size is 2.75 x 17. But, I couldn't get that size for replacements at a reasonable price so I ordered Shinko SR244s one size larger at 3.0 x 17. The 3.0 fit the rear wheel without a problem but 3.0 was just a bit too big for the front wheel so I had to go down to 2.50 x 17 for the front. Based on my experience, I'm thinking you might be able to go up to 2.50 for your Passport but rear wheel only. In any event, measure the clearance between inner fender and tire carefully as appearances can be deceiving. I thought I was going to have enough clearance for the front but when the 3.0 tire was mounted and inflated, it was just too tight a fit. I wasn't able to return it because it was technically a "used" tire so if anybody needs a 3.0 x 17 knobby dual sport that never saw the ground, I'll make you a heck of a good deal.
Bill in Seattle
--- In Honda-C70@yahoogroups.com, "mattskilove" <mattskilove@...> wrote:
>
> anybody know the largest tire size you can run on a 1981 c70? I'm working on trying to make mine like a hybrid between the c70 and the ct90 and i believe ct90 tires are a little bigger and i cant find and aggressive looking tire that is 2.25 or 2.50 to fit the c70 thanks !
>
1970-73 C70 Honda Service Manual: http://tinyurl.com/6ebwtw
1970-73 C70 Troubleshooting Guide:
http://tinyurl.com/6ebwtw (scroll to sec.7.1 page 101.jpg)
1980-83 C70 Honda Service Manual: http://tinyurl.com/hu42c
1980-81 C70 Troubleshooting Guide:
http://tinyurl.com/hu42c (scroll to sec.18-1 page 170.jpg)
1982-83 C70 Troubleshooting Guide:
http://tinyurl.com/hu42c (scroll to sec. 20-28 page 205.jpg)
1980-81 C70 Maintenance Schedule: http://tinyurl.com/z4zn6
1982-83 C70 Maintenance Schedule: http://tinyurl.com/hw35c
More resources for C70 Passports and Cubs:
http://www.shlaes.com/Vehicles/Scooter.htm
http://www.velodrome.com/HondaC70/HondaC70.html
