One of the numbers may possibly have worn off or has become invisible for rust or dirt. Of course, not all V.I.N numbers have 17 characters. Older vehicles often have fewer. The last five digits are generally of little importance anyway, as they usually denote a batch number, and not a make, model, year or specification.
most have 17 numbers
17 digits
17
17 numbers & letters
Since 1965 to 1971 VIN Numbers where only 13 digits. Here is a site to explain VIN numbers (see related link)
The VIN is 17 digits long.
17 digits in VIN. 10th digit signifies model year.
Unless this is a pre 1981 bike, this is not a vin. A vin must be 17 digits. If it is an older bike, no way of checking the vin numbers on them.
17
8 digit of the vin num
2006 xv1700a
Vin numbers have been a standard 17 digits starting in 1981. Prior to that there was no standard and could be any number of digits.