The one on the top is the front type and the other is the rear. It needs replacing as its through to the canvas, while the front still seems almost new.
Its a bicycle, so my weight should be equally distributed between front and rear wheels, unless I'm leaning back so much that I'm pulling a wheelie for most of my cycle.
I haven't been doing unnecessary skids since Michael, Danny, Bobby and I were kids. The necessary ones fortunately have been few and far between, certainly not enough to account for the tyre wear.
I have had the occasional wheel spin. Sadly not as I accelerate away, but because if I get out of the saddle going uphill I lean too heavily on the handlebars. But that makes sense - I'm over the front axle which the takes the weight lightening the load on the rear wheel. Push down on the pedal and the wheel slips.
Luckily, a spare tyre has now been fitted so normal service will not be interrupted.
