Torque Converter on a Motorized Bicycle

[Bluethunder3320]

riiiiight..... this is gonna be driven on the street.... my bad. i remember last year my friend got caught on the home built pocket bike we put together. someone called for a noise complaint and the cops stopped him.... that was the end of that. we got to keep the bike but no more street riding ever again.

the one thing im concerned about is that the GTC/ comet torque converters are made for much bigger engines so it might not work too well...

im on a pocket bike forum and i seen a lot of the X2 pocket bike trannys.

i own a x1/x2 pocket bike engine myself, and i know it inside and out. the TC isnt that bad.

[augidog]

hehe...after all i've learned, boy-o-BOY could i ever build me a monster off-road MB.

the 47R makes 2.8hp, and i'm confident that by using a 2:1 reduction i can "fool" the t/c into thinking it's on a low-rpm 5hp 4-stroke. keep in mind, i'm not after more speed but more climb. you should see some of the mountain passes i've traversed, they would have been much easier and more fun if i hadn't been constantly worried about being stranded, which i once was halfway up "loup loup pass"...check out "chuckanut drive" and "north cascades highway" to see what kind of riding i do. next season, i wanna go to yellowstone, then take the lewis & clark trail into missouri.

the TC isn't that bad.

for its intended application, i'm sure it's doable. i was advised (by an experienced DIY MB'er) against relying on one for my long-distance adventures. and the reduction/reverser box on it...well, i have used those, and had several sheared shafts, blown seals, wobbly drums...anyways...MB's, go-karts, mini-bikes, etc...we've all learned you get what you pay for.

considering the value of my adventures, i'm always willing to pay a bit more.

anyways...does anyone here actually own a GTC? i'm really interested in learning how hefty the backing plates are.

[toystory_4wd]

Something that might be worth factoring into your math- A genuine Comet TAV2 (and some other models) actually top out at a .90:1 overdrive ratio. Check the specs of whatever you're going to buy. I know if this was my project, I'd be factoring that into my final drive ratio.

Great project- I can't wait to see how it comes out.

[augidog]

Originally Posted by toystory_4wd

Something that might be worth factoring into your math- A genuine Comet TAV2 (and some other models) actually top out at a .90:1 overdrive ratio. Check the specs of whatever you're going to buy. I know if this was my project, I'd be factoring that into my final drive ratio.

Great project- I can't wait to see how it comes out.

hi toystory...well, i did take the potential overdrive into account, by not counting on it. i'm doing all my math with the converter in the 1:1 position, and shooting for the same top-end i have now. all of the lower end of the converter can be used for climbing or hauling...bike + trailer + me + camping gear + tools + spares = 500lbs...anything i get higher than 1:1 is a bonus.

you see, Tanakas are notorious for getting stronger and stronger so long as they are cared for properly, and all that really means is don't forget to add your oil to the gasoline. i have a "pure-fire" 40cc/1.8hp that has over 16000 mi on it, it pulled me (more truthfully, it assisted me) from sedro-wooley wa to kettle falls wa over rt 20 with the 25:1 gear. avg speed ~20mph, mpg 130+. now i own this (rare) new 47R...and it's the strongest/fastest personal-transport engine Tanaka ever made...hence this new drivetrain. i'm excited.

since it can pull 20:1 total now (i can't post my current top unloaded speeds or i'd have to shoot everyone here) i should be able to take advantage of 18:1 some day, at least when unloaded. 11k engine, 82" tire...you do the math...woohoo! of course, i'm aware that this 4-step system will be a huge drag compared to the 1-step belt-drive i have right now, but i consider it a fair trade-off for all the other advantages it offers.

EDIT: a genuine Comet TAV2, already in my shopping cart & waiting for payday!!

http://www.northerntool.com/shop/too...ers-components

[mrfreyguy]

After reading the thread a much simpilar option for around the same price of a Torque Converter is using a honda Z50, ATC50, CRF50, or XR50 motor. It has alot of pros with minimal cons, and in the end it should be cheaper. Also, being that a motor like this isn't rare like the current motor you have, you would have parts widely avalible . The only 2 problems I can currently think of are weight, and shifting.

[augidog]

"lifan" makes honda clones, affordable and pretty cool packages for the money. and perfect starting points for a ground-up DIY 2-wheel build...but they're extremely wide for a typical MB application. i have a friend i visited in haines ak last year uses a larger one (behind the seat) on a tadpole trike, it's both a lovely & scary vehicle. his 35 mile "commute" into town would blow your mind, it sure did mine. the trike's top-speeds are classified.

a true Motor-Assisted-Bicycle is completely pedal'able, im(personal)o. my rig can be pedaled-only, i use a way-low ratio but i can get there...it's bicycle-first, with assist second. it's a narrow niche some few of us in MB'ing enjoy, we want our rides to look like bicycles with assist on purpose, and not just fake motorcycles.

my bike has been thru many changes, and has evolved to this point kind of on her own really...i bet y'all here can relate to "she'll keep what she wants, and reject whatever she don't." there are a lot of old/vintage/rare/unique parts in my contraption, prolly 9 bicycles, a tricycle, 3 mopeds, a scooter, and a whizzer all contributed to the final product.

i'll be owning this tanaka for, like, 'ever....they just don't break down. plus i have a spare 40cc tanaka, too. plus tanaka has parts availability you can swear by. plus the centrifugal clutch is universal, i can swap-out with any similar utility engine in less than 1/2 hour.

see where i am now? the bigger engine came my way, and allowed me to consider a beefier 'train. i'm not going into a new build, just modifying what i already have...in my world, it's been amazing to watch this evolution.

it's likely i won't be using the mounting plate and cover...i can make the assembly its narrowest by using jackshafts with a bearing on each side...wait'll you see the final result, she's gonna be nifty!

[fowler]

why are the bikes speeds calssifyed

is it bacause there is a speed limit on these things

[augidog]

ha...the joke was that blatant braggin' can only lead to trouble with these things, we're talking about a class of on-road vehicle with a lot of freedoms. i feel that abusing these freedoms just isn't a good idear, but i'm in a very small minority. generally speaking, self-restraint is something you only find in the dictionary any more.

the generally accepted definition of a "legal" MB is

working pedals ie a real bicycle
single-speed-assist *or CVT ie no manual-shift
50cc
30mph
subject to all traffic laws

for my travels i add

bicycle built to the task
serious lighting not bicycle-blinky stuff
dot helmet
hand-signals by habit
medically covered

after 6 years, and many thousands of miles, my visible good-attitude has kept me entirely out of hot water...never been chided in any way by the police, anywhere.

the rules/laws vary by area, from tough to non-existant. my alaskan friend rides a stretch of wilderness highway where going 50mph is better than not...plus it's alaska, eh?

my bike with a full-load is a beauty of a 30mph cruiser, but without the trailer the 47R can do 45mph...on (ahem!) private roads. i also own the tanaka OEM expansion chamber, which i haven't run yet. no need.

man & machine

think about what i'm putting together here...sure it looks like i'm making a zoomer, but at the other end of the spectrum a 6%+ grade will be less work than using an exercise bike in front of the television. once i get my pedaling & assist ratios right, i'll be playing that converter like a fiddle.

[r_chez_08]

If you are not using the backplate and cover just get a 30 series driver, driven and belt.
It should cost you under $150 here http://www.bmikarts.com/shop/?shop=1&cat=168
and you can get the comet style driven for $30, driver for $75 and belt for $30 Yes its chineese but its half the price on offer and will definanently be up to your motor.

[augidog]

roger that, r_chez', i saw the $65 drive & $33 driven...but i think i'll spring for authentic Comet pulleys. by the by, must be lucky timing, but places (like BMI) that i shopped before last weekend didn't have Comet parts, now it seems everyone does, and for prices that i think will give the chinese stuff a run for the money. i've emailed the new Comet people, they replied promptly, and they're backordered but they'll sell direct, so that's my plan. i'm in no hurry...once it gets cold enough i'm going to work...i'll get the pulleys in place first, then measure my center-distance, then i'll order belts.

[r_chez_08]

Ok fair enough. BMI has always sold genuine comet as far as I know. There may have been a blip after comet went bust however.
I just added up the cost of all the genuine stuff and it came to $160.90 + shipping. Cheaper than the tav2 but it may be more money than direct from comet.

[augidog]

you got me: i meant to say "complete TAV kits" were scarce & now they're not.

[Blazkowiez]

Originally Posted by r_chez_08

Ok fair enough. BMI has always sold genuine comet as far as I know. There may have been a blip after comet went bust however.
I just added up the cost of all the genuine stuff and it came to $160.90 + shipping. Cheaper than the tav2 but it may be more money than direct from comet.

We just got 3 clone driven clutches from them the other day to see what they were on their website. They're Chinese but still work just fine. Just as a heads up.

[r_chez_08]

Originally Posted by Blazkowiez

We just got 3 clone driven clutches from them the other day to see what they were on their website. They're Chinese but still work just fine. Just as a heads up.

I have a clone clutch on my mini bike, no problems yet, apart from a tight belt.

[augidog]

save now, pay later. i'd rather pay now and not worry about it later.

[r_chez_08]

Yep, just saying that id you are not going to use the additional tav2 parts, why buy a kit? Just buy genuine parts.
I wouldnt reccomend getting a clone, i got one by accident.

[augidog]

well, there's maybe a slight change in my design, i might could place the whole TAV on the left side (vs under the seat) and it'll counterbalance the engine that hangs off to the right. they both weigh about the same.

besides that, it looks like the cost of pullies-only + shipping are almost as high as an entitre kit. for a few extra bucks i get a belt, jackshaft, and 2 bearings. and if i don't use the whole kit, i can resell what i don't need at clearance prices.

[augidog]

Comet Industries TAV2 new in box...$168 delivered!

http://cgi.ebay.com/ebaymotors/?cmd=...313%26_fvi%3D1



(boy it's been a long 3 days)

[sexyvicta]

what about adapting a cvt off a 50cc twostroke scooter?

might look at bit ugly but you can pick them up cheap secondhand

edit: oh i see you already got that comet thing

[augidog]

well, my parts are starting to come in. the TAV2 assembly turned out to be way too bulky for my application, so i stripped the pulleys and will be making custom jackshafts. my sprocket/freewheel combination fits together like hand & glove, no custom work needed. this will all fit inline quite nicely, but it is going to weigh more than i was anticipating...i'm going to use more reduction from the engine to the TC, and hope that i get some flywheeling benefits from all this heavy stuff.