I read an old road test on the TR1 which says at 4000 rpm the bike should would be travelling at 70mph (113kph) but while out riding yesterday my TR1 was only travelling at exactly 60mph (96kph) at 4000 rpm. This seem high revs for that speed or is this correct?

I do not know the sprocket sizes on my bike because I still have the enclosed chain.

Thanks
Rick

With sprockets 16/35 and a Tire with -let´s say - 2.06 Meter circumference(is this the right expression? ) i did the math as
following : 4000 Rpm divided 1,66 for primary gear div. 0.909 for 5.Gear div. 3.029 for sec. gear , then times 2.06Meter  for Tire rotation and driven distance in a minute , times 60 for one hour, is something about 108000 Meter per Hour, or -much easier- 108KmH, maybe your speedo is wrong?

Hi Ali, yes that is the correct expression. Maybe the speedo is reading wrong but I can say that the speed feel slow at 4000 rpm to me.

I have another similar querie. The TR1 is often compare to the much older Vincent black shadow, now the Black shadow only produced 55 BHP but had a top speed of 125 mph. This seem strange to me when the TR1 has more BHP but only 108 mph approx. The weigh is slightly less than the TR1 but not much less at 208kg

Wiki - The Black Shadow, capable of 125 mph (201 km/h), and easily recognised by the black coating on the engine and gearbox unit known as Pylumin, and large 150 mph (240 km/h) speedometer, was introduced. The engine produced 54 bhp (40 kW) @ 5700 rpm in Black Shadow trim.