Motorbike Tyre Guide

This page contains some information about motorbike tyres.

Basic codes

The year 2000 Honda Hornet 600 requires tyres bearing the following codes:

FRONT: 120/70ZR17 (61W) (Michelin/Bridgestone)
REAR: 180/55ZR17 (73W) (Michelin/Bridgestone)

Lets look at the first of these...

120/70ZR17 (61W)
120	70	ZR	17	61	W
Width of the tread in mm.	‘Aspect ratio' – in this case, indicating that the sidewall height is 70% of the tread width.	The presence of an R indicates the tyre is of radial construction. B is bias-belted, "-" is cross-ply. I've no idea what the Z refers to but presumably it's a variation of the radial construction.	Rim diameter in inches.	load-bearing index	The speed index (see Speed Ratings below).

You might also see M/C indicating it's a tyre for motorcycles only, or TL indicating it's a tubeless tyre.

Codes on the tyre sidewall

The following was lifted straight from The Wheel and Tyre Bible, a very good, comprehensive guide to tyres. I recommend you read it if you need more technical information than provided here such as further details about the speed ratings and load index.

	Key	Description
	A	Manufacturers or brand name, and commercial name or identity.
	B and J	Tyre size, construction and speed rating designations. Tubeless designates a tyre which requires no inner tube.
	C	Denotes type of tyre construction.
	D	M&S denotes a tyre designed for mud and snow. Reinforced marking only where applicable.
	E	Load and pressure marking requirement (not applicable in the UK). These go from a load index of 50 (190kg) up to an index of 169 (5800kg).
	F	ECE (not EEC) type approval mark and number.
	G	North American Dept of Transport compliance symbols and identification numbers.
	H	Country of manufacture.

Tyre selection guide

This guide was taken from BFM's online catalogue. They sell a wide range of tyres and whilst I haven't bought anything from them personally (I haven't yet bought a pair of new tyres from anyone) they have been recommended a number of times, both by friends and on discussion boards such as that at the Hornet's Nest.

Basically, reading the diagram from left to right, you trade dry-weather grip and performance for wet-weather grip and durability. Note that there are a huge range of views on which tyres are best for any given bike, and it largely depends on riding style. Check out any of the numerous bike forums for opinions.

Speed Ratings

This table shows the speed rating codes.

Code	J	K	L	M	N	P	Q	R	S	T	U	H	V	W	Z
Max Speed (mph)	62	68	75	81	87	93	99	106	112	118	124	130	149	?	> 149

References

• http://www.hondahornet.co.uk/600spec.html Honda Hornet CB600F and CB6000S (faired) Specifications
• http://www.bridgestone-eu.com/articles.asp?ID=1212 Bridgestone tyre FAQs
• http://www.chris-longhurst.com/carbibles/index.html?menu.html&tyre_bible.html The Wheel and Tyre Bible
• http://www.bfmmotorcycles.co.uk BFM Motorcycles Online Store
• Bike magazine.

Last modified: 01/05/2006 (most likely earlier as a site migration in 2006 reset some dates) Tags: (none)