The Honda Maintenance manual states: The front tire is 3.25S19 The rear tire is 3.75S18
3.25 = about 83mm 3.75 = about 90 mm Most people over-tire their bikes, though I question the user benefit of this practise. The dealers would rather sell off their stock on hand. So, I warn you to beware of tire salesmen, even though they talk the good talk. They've had way more practise selling tires than most of us have at buying tires. I think you should go by what the manufacturer (not dealer) recomends these days for the rim width you have. Measure, then look at some websites for Dunlop, Metzler, Bridgestone, Michelin, etc. I remember seeing charts in the tech sections with that data, but, don't have a ready pointer. I have 3.25 19 ME33 on the front and ME77 4.00 Metzlers on my 77 550F. And these seem a good combination and are wearing evenly so far. The bike handles true to the way it did when new which is very nice. I have had and still have ME 55A 120/90 Metzlers or my 550s. But, they wear out in about 5000-7000 miles and mostly on the center of the tread. (No, I don't do many high speed leanovers, anymore). I think this uneven wear was due, however, to the need to over pressure the tire to keep the tire from squirming side to side. The rim is too narrow for this width tire and pinches the bead together. This takes away sidewall support and you have to compensate with higher tire pressure. This narrows the contact patch and increases wear near the center of the tire. There are those on this list that have different opinions, though. Believe whoever you wish. Prior to Metzlers, I had Dunlops in the same size (120/90). But, although they were nice and sticky, they wore out very fast; 2000 maybe 3000 miles. Same center of tread wear out pattern. The bike handles pretty funky when the rear tire has lost its arched profile. Lloyd SOHC4 #11 72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F, 78 750F Michael Kuban wrote: >I've been rebuilding my 77 550f for the past few months (it is winter after >all) and I need new tires. >Anyone have any suggestions? > >I don't even know what size I'm supposed to have because the bike came in >boxes with no tires. > >Thanks, > >Mike Kuban > > > >
