Scooterguy Mount With Tanaka 47R Engine

[5-7HEAVEN]

I am REALLY needing to lower gear ratios, especially in the first few cassette gears. On my daily work commute, the bike is a dog on steep ramps, gridlocked hills and even on takeoffs.

Fortunately, the solution is simple and cheap, as explained before. I should be able to swap gears this weekend. That should REALLY wake up the bike.

I'm also swapping to 100:1 Opti-2 oil. Let's see how well the 47R responds.

 

[TREEWK]

5-7

That is what is on my diy shifter bike, 24 tooth running the chain to the rear wheel. The engine is the Titan 50cc 4 stroke. Have a 12 tooth 1/2" pitch on the 5:1 reverse gear box running bmx chain to the 48 tooth sprocket on the pedal free wheel.

My rear wheel cassette has a 34 tooth 1st gear cog, that is super except in mud! The little motor is aw sum thru the gears. Can`t help but smile going thru the gears, it lets the motor stay in it`s torque range.

Have a rear cassete with a 38 tooth 1st gear cog that would be great in the woods etc. My weight is close to 300 which makes the bike even more amazing. But am a bit too large for the poor little bike!!

Am currently build a stretch cruiser with the Honda 160cc in frame with jackshaft.

Take care my friend, Ron

 

[5-7HEAVEN]

Thanks for responding, Ron. Being a 4-stroke, your engine must have more torque than mine. You're running 28.33:1. That's way higher gearwise than my 37.09:1.

What size tires are you running?

Maybe one day I'll try out an engine like yours.

Myron

 

[5-7HEAVEN]

I got up @ 330am and started wrenching. Two mounting bolts which secure the silencer/muffler had snapped, so that was fixed. I had previously bought 24t, 30t and 36t SBP sprockets. They accept 5-hole freewheels, but were drilled to accept my 4-hole pocket bike freewheel. The 30t chainring cog was spaced 1/2" from the 72t engine sprocket. Out went the 30t and in with the 24t sprocket. Spacers were removed so the 24t positioned exactly where the 30t was at. The same bicycle chain slipped right on; links can be removed if necessary.

I'll motor downhill to McD's soon. The ride home will verify if the stiff gears work well enough. All gears are quite low. First gear is a stump-pulling 46.32:1. At 39.55:1, second gear is even lower than the previous first gear. Eighth gear is 15:1, very usable for 35mph+ highway cruising. Methinks that city cruising will be between sixth gear (20.45:1) and seventh gear (17.73:1).

In the meantime, I'll measure and compare the circumference and diameter of my old 26 x 1.95 Armadillos and the new 26 x 2.35 Schwalbe Big Apples. Calculations will determine how much the gearing suffered. Never is my widest dream did I think that the larger/taller new tire would damage the bike's overall performance.

 

[5-7HEAVEN]

Sha Zammm!

I rode five miles into town to donate blood.

The ride w/the change in gearing was freaking AWESOME! It was the same route I bike to work, just a half-mile shorter. All the hills just laid down flat, or so it seemed. The engine peaked faster in every gear. Seventh gear comes in handy now. Before the gear change, I was always in fifth gear. First gear is a granny gear, and on slight inclines at walking-to-jogging speed, it comes in very handy. That steep hill which bothered my bike is not a problem anymore. However, time will tell if the 46.32 gear will work in bumper-to-bumper up that hill. If I had higher-rpm clutch springs, the engine would work better at lower speeds uphill.

The carb now is very responsive with these gears. No need to tweak the settings. Gas mileage might suffer a little, but the fun factor literally doubled!

Now I know why the bike's performance suffered when I changed tires. Besides differences in weight and mass, the tire diameter on the Schwalbe Big Apple 26 x 2.35 is 27 inches!! The Armadillo 26 x 1.95 tires were 26 inches, so that raised the gearing enough to affect the bike's all-around performance. The larger tires raised it 4%. However, the smaller bicycle chainring sprocket lowered gearing almost 25%!!

In perspective, riding my bike is like rowing the gears in a 1957 Chevy with a V-8, close-ratio four-speed tranny, a 4.56 rear end...and a fifth gear overdrive!!!

So much fun! Best of all, the new sprocket is in the exact position of the one it replaced. There's no chain-jumping!!

 

[5-7HEAVEN]

This Bike Is Done!

I need to move on to other projects. My Honda 150cc scooter needs minor work, so I can alternate using it as a commuter w/this bike. I also have to get a Trek bike w/2.2hp Mits engine and Staton gearbox/NV roadworthy. And my twin 460's Project Kona 29er needs to progress. There's also a Diamondback 29er w/Tanaka 47R and 8-speed. And there's the Whizzer.

There's something weird about my 8mm/T8F engine drivetrain. You can adjust chain tension perfectly. When you turn the pedals, the chain gets real tight, then it loosens up then tightens again. I thought it was loose motor mounts/pivot points. Then I realized it must either be my wobbly Chinese freewheel or my Chinese pocket bike 72t chainring sprocket. It could also be the Chinese 11t gearbox sprocket, or a slightly bent bottom bracket cartridge. One of the sprockets might be out of round, but ya can't see it with the naked eye. I could prolly verify this by making several triangulating reference points near the chainring. I could chance buying another ebay sprocket for $15. I could also try to have a custom sprocket fabbed by this particular member/vendor, if he ever returns my pm's and email. I have the expensive HD 5-bolt chainring freewheel. I could redrill a new 72t cog to accept the HD freewheel.

Nitpicking costs $$. It's not affecting the bike's performance, and the 8mm chain's not breaking.

I'm leaving the chain issue alone. Maybe I'll fab a chain tensioner, which would be the cheapest, simplest solution. The stiff gear change was the bike's saving grace for versatility. Now all I have to do is fill up at the gas station and perform regular maintenance.

 

[5-7HEAVEN]

A chain tensioner was fabbed for the 8mm T8F engine drive chain. A fat skateboard wheel was grooved, then bolted on a 6" flat piece of steel. I just need to get a spring, maybe a small turnbuckle for tension adjustment.

Then I'll be done.

 

[5-7HEAVEN]

Maintenance included replacing a broken 14g rear spoke and a new chain. The existing chain looked okay, but it's taken a beating for many months. I replaced it and keep it in my bag as a spare.

The chain tensioner is finished and works well.

I just posted pictures of this bike in the photo gallery.

A chain guard should be fabricated and installed.

Then I'll be done for sure.

Update: I just bought this chainguard.

http://www.amazon.com/Mini-Pocket-C...2QCI/ref=sr_1_9?ie=UTF8&qid=1321250129&sr=8-9

 

[5-7HEAVEN]

Windscreen

I bought a windshield years ago, and it sat on my shelf. It looked like this one:

http://www.ebay.com/itm/Gy6-Scooter...DefaultDomain_100&vxp=mtr&hash=item27aaa7621c

On Sunday, I FINALLY installed it on my bike. It took a couple hours.

Pictures are on another thread in Discussion section. I like it, but need to brace it. Caution is advised, because a metal brace rod can turn into a spear to impale you.

Maybe I'll just use automobile door trim around the windshield edges to brace it.

 

[5-7HEAVEN]

Enroute to work, I ran over an unknown object on a wet road. If I had tried to swerve quickly, the bike and I would've gone down. As soon as I ran over the object, it whipped upward, demolishing my front derailleur and breaking my 8mm engine drive chain. Surprisingly, the bicycle chain survived, so I pedalled to work. The next day, I brought the bike back in a truck. Vacation had just started, so I'll have 6 more days to fix it. Besides ordering 8 feet of 8mm chain and a few master links, I also ordered a new bike chain. I'm also busy installing a $14 tach, a chain guard and other goodies.

Also in the makings is an oil dispenser. This will be bolted onto the 4-liter tank, and 1 oz of Opti-2 will be poured into it.