Tire Qweep on different systems - Repost

chacha

Chaff Your EHC!!
Calendar Participant
Some interesting background on tires posted by Cyril Huze (Cyril Huze Post)


Choosing the wrong tire can lead to tire failure or worse…Replacing your tires just requires to copy down the numbering of your current tires. Problems may arise, and it happens more often that you can think, when upgrading to a new brand or size. First things to do is to match your tires to the speed and load ratings. For example, no racing tires on a cruiser and tires adapted to the weight of your motorcycle. There are 4 main motorcycle tire designations (cruising, sport, off-road and racing) For each designation, you need to understand and how to convert 3 different measuring systems used by tire manufacturers, inch/metric/alphanumeric.. The Inch Measuring System. Used for stock and very basic tire sizes, the inch system of motorcycle tire numbering does not see common use. The Metric Measuring System. The most common of the tire size designations, known as the metric measurement, begins with the section width. The inch system is akin to the car tire measurement system..The Alphanumeric Measurement System. Invented by the British and largely phased out by metric tire numbers. Alphanumeric codes are uncommon on today’s tires.
Below tables giving the tire size, speed and load rating conversions across all 3 numbering systems.

 

LA_Dog

Go Fast, Go Faster
Good info,thx- A good source of help on tire selection is Avon Tires- they provided a lot of tires for the early Dogs, not sure aobut the later models- but their tech guys are pretty spot on.
 

LA_Dog

Go Fast, Go Faster
"spot on“...except for that splitting thing, do a search on Avon tires on here and you will see what I'm talking about.
let me clarify- not saying buy Avon tires, i'm saying this is a good source to get info on fitment for Dogs if you're not sure what to get F/R. Take that info and pick up any brand you'd like. This will probably be more helpful to early Dog owners. For example, I was not sure of the OE sizes for my bike when I first picked it up. Avon has a lot of specific knowledge on fitment sizes for the BDM bikes. I got some size numbers from them and cross referenced them with other brands. Unfortunately for my bike I am limited with Avon on the rear due to the 16" rim, so I had to go with an Avon 160 B16 rear. No dice in ME, Dunlop or Mich. Can't fit a 180 either.

I looked through some of those split threads on the forum- quite shocking. although no one posted up what specific model of rear tire - I'd sort of expect radial tires to exhibit this since they are not designed for the massive TQ of a large inch V-Twin on a 600lb bike (unless they are of a more sturdy radial design as in my second post below). Bias ply of correct load rating should not have issue though, so if these were all Avon bias tires splitting on the rear like that, that's pretty scary.

a couple of members posted the MH90-21 front as having cracking, which is supposed to be a high load rated tire- and ya that really sucks!
 
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LA_Dog

Go Fast, Go Faster
Noticed a lot of members switching to ME's and having good results- There's a specific reason the Metzler radials do not exhibit the same type of lateral splitting as the Avons (if the failed Avons were indeed radial models)- Metzler makes their radial carcass tire that is also steel belted around the circumference. So that added belt should hold the tire up to a lot of TQ / keep it all together. The Avon radials do not have added belting so heavy TQ is eventually going to pull the radial bands apart or cause tread separation. This was a big issue for car tire makers back when radials were introduced.

Dunlop introduced rear radial models specifically for HD / Victory, which are also reinforced / tested for heavy bike / high TQ type of use.


Michelin not sure I have not checked. But you rarely if ever hear about an issue with a Michelin tire (other than the cost to buy one!) :D


So Avon's radial rears are probably peachy for sportbike use, but seems they have not upped their game to make at least a few rear radial models suitable in the same way Metzler / Dunlop have on certain models of their radials.

Bias ply belted tires should never split due to how the design is laid out- but they are stiffer due to this so they are usually not the best handling tires. One benefit of bias besides strength is a "flatter" profile, and they won't grow taller (as much) as the bike speeds up like radials can. Here is a pic of radial vs bias ply construction on a tire. #10 & #12 is radial construction, #14 & #16 is the orientation of bias ply design.

 
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