Dave wrote on 03/11/16 at 09:52:00:cheapnewb24 wrote on 03/11/16 at 07:14:07:To modify or correct the ideas I mentioned, the chart also seems to suggest that higher profile tires don't fit very wide rims as well compared to low profile tires. It seems that low profile tires like large rims and high profile tires like smaller ones.
You are looking at the chart without considering what it represents. The wide rims are a new fangled idea, and one that came along as tire and suspension technology (and fads) changed. New bikes have wide rims and low profile tires....some for good handling and some for macho looks - and the improved suspension systems have allowed low profile tires to be used on modern motorcycles. (Roads have also improved - and narrow rims and balloon tires helped to protect the rims from damage on early roads).
Older bikes had limited suspension travel - and the taller tire profiles functioned as a part of the suspension, and the narrow rims were necessary to allow the tires to have curved sidewalls that could compress and rebound.
The tire chart just reflects the fact that the newer bikes have wide rims and low profile tires - while the older bikes have narrow rims and high profile tires. The chart doesn't reflect that the different aspect ratios are "generally" made for bikes that have entirely different functions....low profile for sport bikes, medium profile for sport touring and touring, high profile for vintage bikes or modern cruisers. (All rules and common sense are thrown out for those foot wide tires used on show bikes).
Isn't the chart there to tell what
works, regardless of what is popular? I'm not thinking design-- what it's "made for." When mods are done, they are often things which were not really meant for that bike in the first place. The chart should be for which combinations
work well within a reasonable margin, not for
typical installations. It's all about what
works, not all these complications and special applications. Any rebuttals?
Maybe for some reason high profile tires are not recommended for very wide rims. Maybe the bead seating is not as secure? I wonder.
Any ideas?