I will sticky it and modify the title. This will serve as the gearing database (like the jetting database).
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Bike year: 2007
model: EC250
mods: LTR powervalve cover, LTR jet kit, FMF Gnarly pipe & Turbine core II spark arrestor/silencer, top secret blend of premix
Gearing: 13T/50T and 13T/52T
Top speed: Too fast, too quick... I don't care for top speed since I ride singletrack. On doubletrack connector trails, I guess the top speed is around 60 mph but never cared to look.
What kind of ridding do you do: Singletrack trails with a variety of conditions. Michigan trails are lots of sand with some rock and firm soil. No clay. Typical tires are Michelin S12 or Maxxis SI.
Result: 13T/50T was what my bike had from the previous owner. It worked well, but I found myself mis-shifting to neutral on technical singletrack (hill climbs, tight trees, etc.). I switched to 13T/52T to give me more acceleration and low end torque. Now, I use 2nd & 3rd gear more for singletrack and avoid going to 1st gear (unless absolutely necessary).