thorn mercury

[pinkbunnyok96]

what improvements have they made to the mk 3 reason being have an olf well used mercury do i refurbish rhis one or buy a mk 3

[PH]

I've had both, having crashed the first, so can make that comparison.
No, the differences are minor and they're largely the same frame, I wouldn't change unless there was a pressing need.
Biggest difference is the EBB, it's gone from a mini to full size, so you gat a full throw of the chain and there's no longer restricted chain/sprocket choices.  Maybe as a result of that , or maybe unrelated, there's a little more clearance, which I consider a plus. Possibly also tied up with that there's no longer the option of running a calliper brake on the rear. Other than that the only difference I noticed was the rear brake cable run is through loops rather than with clips, a bit of a pain fitting hydraulics but neater once done.
If there's anything else, I haven't noticed, it rides exactly the same.

[UKTony]

Just to add to the above, here’s a quote from page 28 of Thorn’s Living with a Rohloff Hub,

http://www.sjscycles.com/thornpdf/ThornLivingWithARohloff.pdf

“The Mercury Mk3 frames have several small changes– they now have slightly more clearance to allow 700 x 40c tyres and guards and also 650 x 50b tyres with guards.
The Mercury now uses the same EBB shell as the Raven Twin Mk3 tandem ...............has also allowed me to increase the chainstay length slightly on sizes #58L and #61L.”

[PH]

what improvements have they made to the mk 3 reason being have an olf well used mercury do i refurbish rhis one or buy a mk 3

It occurred to me after I wrote my reply yesterday that it wasn't clear which Mercury you have?  Years ago there was a model with the name which was a very different bike, I don't know if that was counted as the MK1, then when I bought mine it was just call Mercury, so I'm unsure which MK that was!