My speedo overheads quite a bit, ie at indicated 40 mph, I'm actually doing 31, and at 50 it's 40 ( on sat nav)
Now as my speedo has spent more time being repaired with a reputable place than on the dash board, I've given up with them
It's an analogue unit driven by the gearbox so no chance of calibrating it
If if I was to raise the rear tyre aspect ratio from 55 to 70 would this bring my speedo to a better closer level
Plus would this affect anything else with handling ??

Steve

that would depend on your tyre width. as the aspect is a percentage of width! if your on narrow tyres then a 205/60/13 may be the way forward. ive always found thats the best size on the back of a 7 with 13" wheels. id also go for yoko a048's if budget allows

I think you approaching this from the wrong angle
There are different gears you can put in the gearbox to adjust
Or look at electronic

lo-cost answer:
just put new marks on the speedo

The gears in the gearbox have been changed, and the other set are a lot worse!!
There are only two sets of gears for a type 2 gearbox

Going electronic is not really a viable option, as to have one made to match the rest of the dash, was quoted at £250 plus
And that does not include the sensors etc

Steve

I don't need a new mark, but good try!
As I just need to deduct 10 mph? And I won't be far wrong
It's more annoying than critical, and as the tyres really need to be changed as 14 years old, and were not new when I got them
And I was thinking. About a better spec tyre anyway

Just put your current and proposed tyre sizes into one of the online tyre size comparison calculators. Quick google came up with THIS but there's plenty more.

quote:

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Originally posted by snapper
I think you approaching this from the wrong angle

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quote:

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Originally posted by steve m
Going electronic is not really a viable option, as to have one made to match the rest of the dash, was quoted at £250 plus
And that does not include the sensors etc

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Have to agreewith some of the others. To make up that sort of discrepancy with tyre sizes is going to be a big change needed.

Monster 7?

Pic of my dash is in my photos

The speedo is part of a set of gauges, and I am not changing them all, as for one I like the set up and they fit the dash perfectly

The company I used have refused to spend any more time on the speedo, as it seems to go back every year to be recalibrated
Or repaired as its stopped working

The cost of having it repaired again or converting it to electric, is not worth the hassle, or the 3 months off the road
with a big ugly hole in the dash

To be honest, if its a longish journey, I use a tomtom, and if local, just rely on deduct 10mph or drive slowly


Steve

[Edited on 16/9/13 by steve m]

Does the over-reading speedo mean the odometer is adding up faster than it should be as well, then?

If the company who supplied it are fed up of fixing/repairing/re-calibrating it each year, is t it in their best interest to figure out what's wrong and remedy once and for all?!?

Coincidentally;

http://locostbuilders.co.uk/viewthread.php?tid=185258

Any use?

I went digital with mine and it made life easy, you just press a button do what you know to be a mile at any speed and it sorts itself out. When I had my analogue speedo it was a good bit out and I ended up using the sat nav and sticking tiny adhesive dots on 30,40,50 and 70 purely so I knew where I was at in speed restricted areas.

I tried different speedo drive gears in the box but they never seemed to do the trick.

Double post

[Edited on 16/9/13 by Scuzzle]