ST70 Top Speed

Hi All,

The engine of my 1972 ST70 was screaming in third gear but It was only reading 35mph on the speedo, surely this bike should go a bit faster than 35. The engine seems to be on its rev limit so maybee the gearing is wrong, the bike is geared with 15 front sprocket & 38 rear, the speedo is marked for 3rd gear for 45mph.

What should the top end of a 1972 lady dax be?

Should do about 40 - 45 if your engine is in good condition.
Also depends on how many cheese burgers you eat

Hello Blue,

Yeah that sounds about right, or if your lucky 50mph if you can slipstream a milk float

Blue, where did you get your avatar from, as it looks like it could be a good basis for a club badge?

All the best Si

The bike's only done 3.5K miles & the engine sounds as sweet as a nut. At 35 the engine sounds as though it's at the top of it's rev range, I cant see it reving any higher, I know I'm getting a bit porky these days but even down a long hill it only just touched 40.

Does the gearing sound correct to you guys.

When was the last time it was serviced?
Plug, Points, timing, tappets, air filter, etc.

If you have a Sat nav hook that up on the bike and get a GPS speed reading.
If you don't but have an iPhone get Navfree which as the name suggests is free.
You can then get an exact GPS reading.

Where are you located Sam?

Funnily enough I was using Navfree & the reading was about the same as the speedo. I recently did an oil change & adjusted the clutch apart from that It hasnt been serviced in a while, the engine is virtually silent with no nasty noises coming from it, plus it starts 1st or 2nd kick even after it had been laid off since last October. My point is that I dont think there are any more revs left in the engine it really is screaming at 35mph.

Say that Ill check the ignition & give the carb a clean,

Simon,
I borrowed it from the internet
I'll send you the original if you send me your email address.
Not sure about copyright though but hey, I'll try and contact the original artist and see what he says.

Best,

Blue

The inlet tappet was a bit tight & the timing out a few degrees, adjusted both but still no difference in top speed, maybee I have a detuned model.