Saturday 20 June 2009

MPH Speedo - again !

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The final speedo solution - probably not.

My need for a clear legible and accurate speedometer for the GP8000 is starting to turn into an obsession. I found these on eBay and thought I'd give them a try.
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=300322400500
They arrived promptly and certainly seemed neatly made. 100mm is the correct size for the GP800 so after a little bit of trimming, I offered it up to the Speedo. This is where we found snag #1.

The GP800 has a 100mmm diameter speedometer but the cowling makes it fairly deeply recessed - and the cowling encroaches on the speedo by a couple of mm all round. I didn't think that trimming by that amount would be a particularly neat solution so I decided to (gulp) remove the speedo.

This involves a considerable amount of bodywork removal. If you've ever wondered what a GP800 looks like naked, here it is in all its glory. Dismantling to this degree is not difficult but it is fairly time consuming. You will definitely need the workshop manual(thanks Jim) to find all the various screws and the correct order to remove them. Even then there are two screws not mentioned in the instructions (although they are fairly obvious). I can also pretty much guarantee that at least one of the trim clips will fall into the void somewhere. Once the body panels are removed, taking the speedo out is a little fiddly as the electric screen mechanism gets in the way. A degee of leverage on the "dashboard"helps.

With the speedo removed the job is now looking much easier. I did consider stripping down the unit itself in order to scan the dial face and make a proper job of it - but to be honest it looked a little scary - and I'm sure that water ingress would be the inevitable result. Perhaps when the bike is out of warranty in another years time I might give it a go.

Fitting the sticker is very straightforward. I debated trying to set the numbers correctly for "real speed" as opposed to indicated speed but I decided that would potentially compound any errors and anyway the GP800's speedo gets progressively more innacurate as the speed rises so it would ony be correct at one speed. I decided to stick to marked speeds as I have the GPS speedo for accuracy anyway so I just lined up the 0 position. Once fitted I was left with some sticky residue from the tape I had used to hold it in place while lining it up. I tried simple cleaning but here is where I made my mistake. When cleaning things like this, they always say "try a little on a small area first". I can see why ! If you're planning to do this, remember that nail varnish remover will take off ink from speedometer conversion stickers. You can see the evidence of this (and my attempts to rectify the problem) at the 100 and 110 mph positions - thanks to "write all" CD pens.

In use it's fine - it's aesthetically OK but obviously not matched to the GP800's instruments. Most importantly it gives you the "quick glance" indication of speed so essential on todays roads. The degree of error in the GP's speedo means that an indicated 30mph is about 29, 40 is about 36-37, 50 is about 44-45 and by the time you get to 70 your actual speed is bareley over 60 - but that's the GP800's problem not the speedo sticker.

In all, recomended to all GP800 owners in the UK.
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