I conquered Cotton Wood Pass today starting from Buena Vista, Colorado up the the Continental Divide at 12,126 feet. I'm claiming title as unofficial world record holder for riding a MB at highest altitude. Any doubters can join me on my next ride and I'll even provide a bike for you to borrow.
Equipment used:
Schwinn Searcher Comfort Bike: 100% stock except for tire tubes which have 5x thickness slime tubes. Tires are from Walmart.
ThatsDax HT Engine with over 200 hours of use on it, purchased new in 2008. It gets a pair of new rings each year but I haven't done that yet this summer.
+ Speed NT carb, 65mm jet (run 70mm at home)
++ e-clip on needle valve on top most setting
+ Added BGF sland head when new
+ Run on castor oil blend since day one. Ran 32:1 mixture of 50% Sig AA castor oil blended with Supertech TCWIII 2 stroke oil. Engine saw cylinder head temps up to 450 deg F on occasion with temps over 350 deg F the entire time.
+ Additional engine modifications: Improved head studs that I JB welded into the block. Nothing else done to this engine.
+ NGK B7HS Spark Plug (runs cooler than usual B6HS I use)
Exhaust
+ Sick Bike parts expansion chamber with added muffler. I removed muffler about 1.5 miles from summit to help keep motor "on the pipe".
Powertrain:
+ SBP shifter kit with 9 tooth drive gear chained to a 48 tooth freewheel chain ring.
+ BGF Centrifugal Clutch
+ Mega range 7 speed cassette
+ Shimano tourney derailleur
Fuel: 2 fuel tanks, one in front and a rack mounted tank. Rear tank had special blend of fuel containing more than usual 10% ethanol and a little more oil than what I normally use. The extra ethanol used to account for richer mixture at high altitudes but really wasn't needed. Stock fuel cost me about 3mph in top speed which is not worth the hassle of using 2 different fuel blends.
A special thanks to my wife Toni for putting up with me.
Equipment used:
Schwinn Searcher Comfort Bike: 100% stock except for tire tubes which have 5x thickness slime tubes. Tires are from Walmart.
ThatsDax HT Engine with over 200 hours of use on it, purchased new in 2008. It gets a pair of new rings each year but I haven't done that yet this summer.
+ Speed NT carb, 65mm jet (run 70mm at home)
++ e-clip on needle valve on top most setting
+ Added BGF sland head when new
+ Run on castor oil blend since day one. Ran 32:1 mixture of 50% Sig AA castor oil blended with Supertech TCWIII 2 stroke oil. Engine saw cylinder head temps up to 450 deg F on occasion with temps over 350 deg F the entire time.
+ Additional engine modifications: Improved head studs that I JB welded into the block. Nothing else done to this engine.
+ NGK B7HS Spark Plug (runs cooler than usual B6HS I use)
Exhaust
+ Sick Bike parts expansion chamber with added muffler. I removed muffler about 1.5 miles from summit to help keep motor "on the pipe".
Powertrain:
+ SBP shifter kit with 9 tooth drive gear chained to a 48 tooth freewheel chain ring.
+ BGF Centrifugal Clutch
+ Mega range 7 speed cassette
+ Shimano tourney derailleur
Fuel: 2 fuel tanks, one in front and a rack mounted tank. Rear tank had special blend of fuel containing more than usual 10% ethanol and a little more oil than what I normally use. The extra ethanol used to account for richer mixture at high altitudes but really wasn't needed. Stock fuel cost me about 3mph in top speed which is not worth the hassle of using 2 different fuel blends.
A special thanks to my wife Toni for putting up with me.
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