26" Trial Bikes
The 26" trial bike in the familiar mountain bike size.
Generally, one can ride a 26" bike starting from a height of 165cm.
The choice between a 20" or 26" bike is more a matter of personal preference than body size.
Of course, if you are 190cm tall, you are naturally more suited for a 26" bike.
Adult beginners usually find it easier to ride a 26" bike than a 20" bike.