Thanks for all the answers!
As far as chain is concerned, I remain a little uncertain
- pulls off sprocket as in pic
- rear sprocket looks fine and is original
- front sprocket I changed about 10,000 miles ago - so is aftermarket one, but it looks fine
- I think chain is original, I've had the bike for 18,000 of its 30,000 mile life and not changed it
so, from what yous say, its probably close to death but not fooked so far- will change the lot in spring me reckons.
Question about GPS giving false reading is related to variety of things;
- in me car, 130 kmh on the speedo gets 128kmh to 130kmh on the GPS (allowing for width of needle). Unless I have the most exact speedo in history (volkswagen speedo in a Seat), I started thinking that SatNavs have their speeds "rigged" to avoid you going faster as you were reassured the needle was overreading by 5-10%.
- when I put SatNav on bike, and if I do 100 kmh on the TDM dial, the bike counter shows a real speed of 98 kmh, while the TomTom Shitenav shows 103 kmh??
so i reckoned if GPS gave 100% real reading, then logic would say:
130 kmh car speedo, then approx 117-123 kmh on GPS
100 kmh on bike speedo, then approx 90-95 kmh on GPS - bike counter I expected to be more accurate than speedo, but not neccessarily 100% spot on , which it sort of is, based on Dandy's calculation of tyre diameter
So unless bike speedo under-reads and the car speedo is dead on, then I reckon SatNav is rigged to give 5-10% over-read just like car and bike speedos !
So there! hmmmm.......