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K7 VCT
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Speedo again
So I have fitted the new sensor and after a lot of swearing it's done. Testing up to 95 its steady as a rock, it used to twitch a bit . However after 95 the needle drops to 20-40 mph and goes a.bit mad. Gap is set.to 0.72mm which is well.in tolerance is build guidance. Any ideas. Btw it was on track testing incase anyone asking
Jonathan Kay
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That's with the new type of sensor?

Which guidance are you referring to?

The Club's Technical Guide recommends 0.6 to 0.7 mm.

Jonathan

John Vine
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Try widening the gap to 1mm, followed by a road test.  If the speedo still drops out, increase the gap in small increments until it displays reliably.

JV

K7 VCT
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As the speedo sensor has a led to test operation before driving, if I make the gap to big it doesn't pick up. Will give it a go Sunday.

Orange is my new black

Ballistic orange 310s
John Vine
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Out of interest, at what gap width do you find the LED not lighting up (for every tooth)?

JV

K7 VCT
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Hi John, will get back to you when I investigate Sunday

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K7 VCT
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Ok, so took wheel off again and turned the hub while watching the led. 3/4 if a turn led is flashing but later 1/4 nothing.? Adjusted again to .663mm and now have led for the full turn. Will pop out later for a test . Fingers crossed.

Orange is my new black

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John Vine
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It sounds as though your reluctor ring may not be rotating exactly true. If so, this will cause the gap to vary slightly as the shaft turns.

Did you happen to note the gap measurement when the flashing stopped?

The 0.663 looks like converted imperial?  ChrisC, who contributed the stuff on the new sensor in the Speedometer Guide, recommends a gap of 25 thou (= 0.635mm).

JV

K7 VCT
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My feelers gauges are an American set, so yes its .663mm, I think the ring may be as you say. Having retested in on private road I can confirm that it's now steady as a rock. Thanks for all your input folks.

Orange is my new black

Ballistic orange 310s
John Vine
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Good news!

Having retested in on private road...

That's handy. Wish I had one nearby.

JV

K7 VCT
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Luckily have someone with a 2 mile long flat as a billiard table straight ish driveway that's 3 metres wide

Orange is my new black

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