Topic: Rim Width question

[cobra2411]

Ok so I think I finally have decided on Rims and Tires for my CB750F1 but I still have a question. The plan is to use a 2.15 x 19 rim up front with a 100/90 D404 tire and a 2.50 x 18 in the rear with a 110/90 D404.

Down the road I might want to go back to inch tires and run a 3.25 up front and a 4.00 in the rear. Will they be ok on the wider rims? All I've ever seen was comments about wider tires on narrow rims.

[scondon]

You can find the suggested rim width min/max on many tire manufacturers web sites. It's been a loooong time since I was pondering a similar question regarding what is the best rim width for a given tire, but I "think" that 4.00 tires fall in the "suggested" range for 2.5 rims.

Try Pirelli or Avon websites for the correct info

[betterthanurs916]

According to Avon's website:

Reccommended rim width for 3.25" tire: 2.15"
Reccommended rim width for 4.00" tire: 2.50"

I was thinking about some aluminum wheels for my 550 with inch tires, and these are the exact sizes I plan to go with. You'll be fine

[Kevin400F]

Sounds like a pretty good plan.  Looks like you've gone up one size in rim width as compared to stock.  The 100/90-19 might be just a hair wider than the OEM front tire (3.25-19 if I recall correctly), whereas the 110/90-18 rear is probably more like a 3.75-18, as was originally fitted to the CB550 of that era.

With the 2.50" wide rear rim, you could run a 120/90-18 tire if you wished....it might be a bit closer in general appearance to a 4.00-18.

Kevin

[cobra2411]

Wouldn't going to a 120/90 shorten the trail because its taller and therefor make the ride at higher speeds a little twitchy?

Also
100mm = 3.93"
110mm = 4.33"
120mm = 4.75"

So the 110/90 rear is pretty close to the stock 4.00 inch tire.

I've moved away from the idea of putting real wide rubber on the bike as the conclusion I came to is it won't make much difference in the turns. Also I'm really starting to dig the vintage look so that's what I'm going for. Yeah I know the D404's are vintage looking but the sizes are.

[Kevin400F]

Be careful getting too literal about the old "inch" tire sizes.  As an example, the excellent Avon AM26 Roadrider is available in 4.00-18.  Actual tire width per the Avon tire spec chart is listed as 4.6 inches.