Chassis for 2nd bike

Buzzerbiker · Nov 12, 2012

Well, winter is upon us in the north country, no riding unless we get a Chinook. Went out to my scrap pile (next to the wood pile) and grabbed a couple armloads of old frames, after grabbing the wood first and making my lair warm. I proceeded to rough in a chassis out of four different frames. From this point I have laid out my drive train ideas. That rear shock is an air shock left from an upgrade on my enduro bike. I think I will be a comfy layout when complete. I want to go 4stroke this time. The Honda GX35 is my first choice and I am going to run to the rear cassette for seven speeds. My question for my fellow bikers. Are there any alternatives to the Honda? Honda would be fantastic, but not in my budget ,yet, anyway. I 'm not wanting a 49cc china engine (too bulky for me) I have heard Makita makes a small 4stroke, but can't confirm any details. Thanks, maybe Santa will be extra good this year. .shft.

bigbutterbean · Nov 12, 2012

I dont know how much you weigh, but I'm a bigger guy, weighing around 275lbs. I know at the angle you have that seat, I wouldnt be comfortable with nothing between my arse and my back wheel. Other than that, nice work on the frame.

NunyaBidness · Nov 12, 2012

I'm not sure you have room for a 49cc motor, no matter who makes it. There doesn't appear to be a whole lot of room in the frame for any thing other than a smaller motor. Looks nice other wise and I can't wait to see it finished. I love the mtn bike motor bikes.

16v4nrbrgr · Nov 13, 2012

That's a neat chassis you built. It looks like it will fit fat tires that will go on the snow well.

Buzzerbiker · Nov 13, 2012

Hi "Big". I'm bout 200lb. The seat is just a geometry check, it'll get a big springer seat toward the end, oh that's funny! Thanks for looking, she's just roughed in for now. Have a good winter.

Buzzerbiker · Nov 13, 2012

Hi "Nunya", yeah, the 35cc Honda is what I really want. I don't want 49cc Chinese. 49cc Honda would fit, but holy cow they're spendy. I have 50cc and 61 cc two strokes in my stash, but got my heart set on a 4stroke. Will probably just have to save for a Honda. Thanks, Jefferson is right on!

Buzzerbiker · Nov 13, 2012

Thanks "16v4nrbrgr" I plan on fat tires yeah, only way to go! I am lacing up the rear wheel tomorrow. It will have a freewheel on the left side for "single speed" pedaling, and 6speed cassette on right for the engine. I know it sounds nutty, but that's what we do. It is a combo of parts from two wheels. I found just the other wheel I needed at the Salvation Army today. Yuk Yuk. Oh, That's a hot looking ride on your tag too! Good job.

squirrel · Nov 15, 2012

interesting look...
ill be following this thread through the winter!

Buzzerbiker · Nov 23, 2012

Hi biker friends. The weather has either kept me house bound,( due to severe PTD arthritis), or next to the wood fire in the garage. When in the shop though, working on bikes keeps my mind off life's little ills. Buzzerbike #2 has shaped up much nicer than anticipated this quickly. The advantage of being housebound some days is using the time to think, calculate, and doodle my thoughts. Both final drives are complete, and I went back to a straight seat post. Modified another gooseneck, and some high bars. We were supposed to get another winter storm Wed. But the wind shifted from the south, and got to 50 deg. I was in the shop to install my shifter, levers and cables: so I put on some crappy brakes ( all that were left in the spares) so I could give the chassis a shakedown. The wheelbase is 48 inches, about 5 longer than my enduro bike, and 7in. longer than a road frame,( like buzzerbike #1). The ride is phenomenal!!! We have terrible roads here, and even our bike paths suffer a lot of frost heave. I will definitely save for the Honda mill now. Still lots to do, but but will be worth it. Hope Thanksgiving was great, and blessed Holidays all. .santa

Buzzerbiker · Jan 13, 2013

Progress! After selling a bunch of leftovers and yard sale pickin's I was able to order a Honda GX 35 and centrifugal clutch. Everything is mounted up and drives are complete except that I will micro align the belt drive to reduce friction . The roads freeze dried here after a week of single digits so I was able to try it out roughly four miles. At 16 Deg.F it was running too lean to open it up, and the wind chill was amazing in 3rd gear! Nonetheless, it was fun and an encouraging initial shake down. I will not win any speed contests with this bike, but the smoothness and quiet of the Honda power is wonderful, not to mention having a torque curve flat and wide as you could ask for. The clutch engages at 4200 RPM, but I changed it to approx 3000 RPM because it pulls fine below 3500 at part throttle. Much more to do. I have an Interloc 5 speed wide ratio cassette, and a better Shimano deraileur coming this week. Will post more as it comes. Am still thinking as whether or not to add fenders and other frills. Happy biking all! dnut

2door · Jan 14, 2013

Very interesting and innovative build, Buzzer. Keep the progress photos coming. We're watching this one. Good work and thanks for sharing.

Tom

Buzzerbiker · Jan 14, 2013

Thanks 2Door. I used to put it "Age and treachery trumps youth and exuberance every time", good either way! Appreciate the encouragement. Have had a couple hair pulling moments, but it is going to be worth it I believe. I cut 45 deg notches every 3/8 inch in the belt ribs today, that cuts the kinetic loss tremendously on a low torque engine. Disassembled the rear end and painted the rear half since I am waiting on a new cassette, etc. Removed the caged ball bearings in the hub and went with the balls only. You get 9 instead of 7 bearings that way, better to haul my fat self around. Should have more pics next month. Take care friend. usflg

Buzzerbiker · Jan 15, 2013

Since I am waiting for parts, decided to strip it down and paint. Added some sheet metal to give a little retro vibe. I'll take a week off now and scheme on how to make up some LED lighting that looks old school. .sno.

Buzzerbiker · Jan 31, 2013

Hi all, it's back together and running. I used the dead space below the shock to put in a storage box with a faux oil tank kinda look. Eventually I would like to put some cruiser fenders and retro style lights. Rode 10miles and froze, but it was still some fun! I have GOT to figure out how to fatten up the top end as it still won't run at full throttle, at least at 20 deg. I built a hot air duct to the carb and it helped a little, but WOT in 3rd, 4th, or 5th gears it leans out bad. Still, I was able to cruise along at 25mph in 4th, and 27mph in 5th by keeping about 75% throttle. 30mph cruise should be very easy once I get enough fuel on top. What is really really good is the lack of vibration and pleasing exhaust note, QUIET! Anyhoo, it's a real gas, and I still have plenty of time till spring to work on tuning. Good riding all. .trk

16v4nrbrgr · Feb 1, 2013

I am totally loving your bike! That's a configuration I would love to have for a daily ride, a 4-stroke with gears and full suspension. Beautiful drive train solution by the way!

Are the LHD crank from a BMX? I'm digging the separate LHD chain so there's a backup pedal chain even with gears.

Buzzerbiker · Feb 1, 2013

Hi 16, thanks. It is gonna be a great commuter/fun ride. The bottom bracket is a square splined MTB with the RH crank and 34T center gear mounted on the left side of theBB. I welded up and turned the right side of the BB to accept a # 30208 cartridge bearing to support the 16X48T cluster gear, and put the left crank on the right side of BB. The rear hub is a steel pressed type so I could remove the left flange, and add a threaded flange on the left side for an 18T BMX freewheel. Naturally that creates issues with thread directions. I used Loctite 262 on the pedals, and on the left freewheel I used 680 sleeve retainer plus three tiny tack welds. The small serviceability issues this may pose in the future are nothing compared to time of building it! In fact I have a complete spare rear wheel assy as a backup, they're very simple to build if you buy yard sale or thrift store bikes for parts. I put some good Shimano side pull brakes on it, but if finances permit, I may get an RST fork and front disc down the road. Thanks everyone for the encouragement, I will post more as I get the tuning issues sorted out. The carb is of course a diaphram type, and if it has screws they are buried. Maybe have to buy one on ebay for dissection!!!!!! Thanks again, happy biking all. dance1

killercanuck · Feb 1, 2013

Great looking bike! Love the jackshaft-through-frame design, very innovative. There's probably a couple threads around on that carb's specifics, but something you can try...

When wot'n and it starts to slack/bog, turn on the choke some, not full right away, but gradually work up to full. If it starts running better, its lean, if it gets worse then its rich. That should give you a good starting point on jetting.

Buzzerbiker · Feb 1, 2013

Thanks Killer. I'm gonna pull the carb tomorrow, and looksee. I added more hot air today, got 30mph, but it's WAY lean. If I screw it up I can get a new one for 24 bucks. There is one brass plug on it and I hope there's a screw under there. Thanks for the kudos. Later. .shft.

Buzzerbiker · Feb 5, 2013

Well. I got it really dirty! 88 miles of testing ,tuning, and re-engineering since Saturday. The carb has no adjustments, but I found an exploded view on the Walbro site. It has a main jet with a .001" orifice! My smallest welding tip cleaner is .0011". So, I ground an old spoke to a little less than .001, and tapered it slightly, then VERY carefully worked it through the jet till my tip cleaner would just pass. Lean condition solved! Top speed is still 27-28 mph, a tailwind will push me over 30. So next, I built a pipe for it, and just left the engine cover off. It runs REALLY good for 35cc, but no increase in top end. My conclusion is that even though it will turn over 8000 rpm, the torque drops off rapidly over 6500 because of cam profile, and 7000 rpm is all it will turn in 5th gear. 5th gear is approx a 20:1 ratio, and works well, it would not pull a higher gear, period. 1st is 48:1, and the mega range cassette was a perfect choice. I you want to go 30mph with this engine, you'll need to build a board tracker to get down out of the wind. As is, for cruising 26 mph or less it is just AMAZING. I love it. Have used roughly a half gallon of fuel, and that running WOT 90% of the time. My last 12 miles today were at 15 to 22 mph just idling along in 4th and 5th. Winter is coming back tonight, so am really happy for the week's work, but I can't wait for real nice weather now. Good riding friends. .trk

Buzzerbiker · Feb 6, 2013

My bad, I need to correct my bad typing. On the main jet, the orifice was .010", enlarged to .011"

Chassis for 2nd bike

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