Topic: Largest rear tire for '71 cb750

[dlocke]

What is the largest rear tire that will fit on a '71 cb750

[Kong]

Do you mean with a stock bike/rim, or a modified bike?

[dlocke]

It has a stock rear wheel

[MCRider]

It has a stock rear wheel

It has a 2.15 rear rim. The largest tire that should be put on this rim is a 4.75 (some say 4.5) or a metric 120 (some say 110). wider tires can be fitted, but not recommended as they may not seat on the rim properly and the wear patterns may cause weird handling characteristics.

Also, wider tires will foul the chainguard first, and in the extreme the shocks (via the chainguard) and brake stay bar. Though those sizes mentioned should fit up OK.

[Kong]

Well, you need to decide what tire you plan to use and then go to the manufacturer's web site and see what rim widths they both recommend and set as the acceptable range of rim widths for various tires.  Here is a link to that sort of information for one popular tire:

http://www.bridgestone.com/products/motorcycle_tires/products/battlax/bt45.html

Notice that there are several sizes of tire that you could use with your 2.15" wide rim, but the widest of them is 120mm wide.  Just as a side note, many tire places will not put a tire on a rim that doesn't meet the manufacturer's recommended rim minimum - it is the nature of the law that greatest liability will be laid on the one who did the stupidest thing for money, and it is that liability that any reputable tire store will be trying to avoid.