Greetings from 8000 ft.!

[Pycngryn]

Howdy Howdy!
A huge” Thank you” to all those experienced motor bikers who post their knowledge and valuable info on this forum. Your time and patience is greatly appreciated by us Newbies.
I recently discovered motor biking while looking for a lightweight , portable, motorcycle or scooter to do vehicle shuttles to the end of river float trips. Living in the mountains at 8,128 ft. above sea level, I was concerned that the Chinese 2 stroke engine may not perform well or be able to handle the hills around here. After a lot of research and information gathered on this forum, I jumped into my first motored mountain bike build. There were a few challenges and a few setbacks. Finally, I’m became the proud father of an awesome, motored mountain bike that runs great, lots of power on the hills, 39+ mph on the flats and I have not yet gone WOT. Yee Haa! Here is my setup for :
THE RED BARRON
-19 “ Specialized M2 Stumpjumper 8 spd. circa 1995 (very tight engine
fit, custom front mount)
- Judy Rock Shock and Front disc brake (absolutely necessary)
- 2011 Grubbe Skyhawk Silver Slant head 66 cc (milled,
portmatched ,copper gasket sealer)
- SBP Shifter Kit (extra Chain Ring spacer mods and added inside
chainguard)
- SBP Exhaust Expansion Chamber (up mounted position ,custom leg
protector and mounts)
- RT performance Carb 15.5mm from thatsdax - #64 jet (I gave up
on the CNS Carb)
- NGK BPR7HIX Iridium Spark Plug and upgraded cap and wire
- Custom front light system and lots of reflector tape for safety.
- Gel seat, fenders and thorn resistant tubes

Lessons learned after first build:
-Go slow, be patient, and do upgrade modifications upfront and assembly right the first time
-Install “Jump Stop” on shift kit correctly (I put mine in backwards, causing catastrophic derailments that wound up ruining the the front sprocket freewheel $69)
- Don’t waste time on getting the CNS carb to work, get the RT Performance carb from thatsdax. Aside from shortening the throttle cable and switching to a #64 Jet, it was plug and play. The rotating fuel intake, throttle cable noodle and overall small size helped a lot getting things to fit in this tight frame.
-Good brakes a must!
I can’t wait to get started on another bike for my girlfriend and then a boardtrack replica for this winter’s basement project. Until next time, -- build smart, ride safe, love life.

 

[2door]

Welcome to the forum. Glad you've joined us.
Good looking ride you have there. Good luck on your second build.

You have a couple thousand feet on me, I'm at 6K, but the little HTs seem to run fine at the higher altitudes
Have Fun, Ride Safe.
Tom

 

[Fulltimer]

It sure was a tight fit! Great looking bike too. BTW, I'm at 5' elevation!

Terry

 

[rustycase]

WoW P !!!

39mph on the flats @ 8k ft asl is fantastic!

You have done an excellent job building the Red Baron considering small engines lose 10% hp per 1k ft asl !!!

My old 5hp suction dredge was short on power at 5K asl when I ran my air compressor in addition to the pump!

Nice looking bike!
gonna try a ski up front in the world famous Park City snow????

Best
rc

 

[Goat Herder]

Greetings from 6000 ft. Looks good great job!

 

[Drewd]

Very nice ride. Could you share with us info about your custom leg protector...it looks very nice.

I'm at 6600 feet and am trying to break 12,000 ft this summer but something always seems to go wrong and as recently my clutch started slipping badly several weeks ago on my 2nd attempt to conquer Cotton Wood Pass.

 

[Pycngryn]

For my leg protector I used the heat shield from the kit exhaust pipe.
I bent the shield to conform to the shape of the front half of the expansion chamber and used a length of 1/4" aluminum rod bent to conform to the back half of the ex- chamb. and bolted it on to the heat shield using a large washer in back and the holes already drilled in the shield. I used a section of exhaust pipe silicone tubing supplied in the kit, squished in-between as a spacer and one hose clamp near the front to hold the protector to the pipe. I put a bolt in the other pre-drilled hole in the shield to prevent the hose clamp from slipping down the shield as I tightened it to the exhaust pipe. It works great! I comfortably ride in shorts and touch my bare leg to the pipe all the time and I never get burned the protector gets just slightly warm even on long rides.

 

[2door]

Nice idea on the heat shield. It only takes a little air space to isolate the heat source from the surrounding metal. Your concept should be incorporated on all X- Chambers offered. Thanks for sharing your talent.
Tom