02-02-2017, 01:15 PM
(02-02-2017, 01:12 AM)LongRanger_imp Wrote: Ferret, my '78 CB750F2 came with Comstars and I'm pretty sure they had tubes. I'll check my owner's manual tonight. I used to run bias-ply Continental K112's on the rear (and RB2's on the front) -- remember those? They were the PR4's of the day!
From my '78 CB750F2 owner's manual:
"Riding with underinflated tires will cause the tires to slip on the rims damaging the inner tube valves."
"We recommend that punctured inner tubes be replaced. Inner tubes should be patched only in emergency situations when replacement tubes are not available."
"The innertube size must correspond with the tire casing size or it will cause the tube to wrinkle or to be stretched beyond its designed capacity. In either case the innertube will be weakened increasing the possibility of failure."
And then it describes how to remove and replace a tire, being careful to not pinch or puncture the innertube.
And now that I remember it, I had a flat tire on this bike in 1979 near Boulder, CO, and had to have the bike towed to the shop to have the tube replaced. It was on a Sunday.
Also, for kicks, the OE tires were a Dunlop K87 Mark II on the rear and a Dunlop F6 on the front, apparently for use with or without a tube according to this period advertisement:
[url=https://books.google.com/books?id=i8_7wR77B1UC&pg=RA8-PA108&lpg=RA8-PA108&dq=Dunlop+K87+Mark+II&source=bl&ots=5ZThZq7aCQ&sig=HSNB5eWXterQemrZIzUuktHJPnI&hl=en&sa=X&ved=0ahUKEwigkPio-fLRAhXHhFQKHQrhAgQQ6AEIQDAI#v=onepage&q=Dunlop%20K87%20Mark%20II&f=false]https://books.google.com/books?id=i8_7wR...II&f=false
But the Conti K112 / RB2 that I used were only available in tube-type for the sizes required (4.00H18 / 3.25H19). Too bad new tires aren't this inexpensive anymore.