Heavy Hauler Project



I posted this in the wrong forum, so I am reposting it here, where it belongs.
Hi All,
I am building a motorized bike (actually 2-one for me and one for my wife) that will allow me to do long trips on the bike.
I will be starting with a yet-to-be-chosen quality mountain bike. The bike will have an aluminium frame, shimano deore ls or xt components, and disk brakes, likely Avid.
The bike will also have a freeradical, from www.xtracycle.com, installed, to allow for some serious cargo. The engine will be installed as low as I can get it, behind and below the seat.
I will build the drivetrain for the engine myself.
I intend on carrying myself, the bike, a trailer, my 60lb dog, plus 200lbs of cargo. I figure the total weight will be 500lbs.
My goal is to travel with this load at 30mph (no faster), with a little power on reserve to maintain speed up a hill.

My questions are:
1) What horsepower would I need?
2) Will a standard bike chain work as the drive chain for this engine?
3) Is there a freewheel sproket I can use that will handle the engine needed, and be compact enough to fit on a bike?

I know 500lbs is a lot for a bike. about 100 of it will be the dog, who will be in the trailer, towed behind me.

I know this is a strange project, but it is what we want to do. With that much weight, I don't know how much I'll be able to peddle, but as long the the engine runs, it won't matter. =)

Oh, the trips we want to take will be as long as 350 miles one way

For the drivetrain, I am thinking about a second derailer system on the left, with maybe 6 cogs on it, to give me a selection of gears.
My reasons for this are:
1) Proven shifting system
2) Readilly available parts
3) Light weight
4) Low part replacement cost

I "think" I'll need 4hp to suit my goals. Lance Armstrong can feed about 1/2hp to his bike. With proper lubrication and maintenance, can a bicycle drivetrain be expected to live 3 or 4k miles before needing replacement when having to handle 8 times the max hp it would normally see?

I do plan on using steel cogs for durability. Might have 1 aluminum one in just to see how it lives compared to the steel.

I have some ideas on how to get the needed 4hp and stay under 50cc for legal reasons, but that's another thread!

So, what do you guys think? Let me know what your experience has been with high hp nd high load motorized bikes.

Argh Newbies!

I tell ya , I just hate when a newbie comes to a forum, doesn't bother to read anything, and posts questions that have been asked...and answered a million times! Drives me up the Wall!

Oops. I did that today....sorry. I am reading the thread on shifting gears now....
If I accidentally asked a new question above, please answer me, otherwise....ignore the lazy newbie!

lol, i love it...thank you for paying attention and pitching in...and for the chuckle first thing in the morning.

everyone is welcome to run a project thread...do your research on the forums, jump in on discussions for clarity or to contribute to the development of ideas, then bring what you learn or decide back to this project and let us know what's up.

if you'd like to be a bit more help, post links to topics that have helped you with the project...more crosslinking keeps the place percolating.
i moved it into intro & he started a new one to avoid confusion with a registration problem i had to work out...all good.
I have a aluminum Canondale that takes a lot of abuse from me and my scrubber drive. I would recommend one of these in a heart beat. You can pick up a good used one off Ebay for around $300 which is in line for a common China built bike.
Surly Cargo Bike/Wheels

Surly bicycles a division of Quality Bicycle Parts will soon be selling a new Cargo bike frameset. Its being developed and built in partnership with the folks at Xtracycle. It was shown at Interbike last fall and was supposed to be available this past summer. But there seemed to be some glitches in production from overseas and I've recently read that the first production run of bikes is soon to be available. If you do a GOOGLE seach for Surly Cargo bike you will turn up several hits with photos of the prototype. Kona Bicycles is also making a Cargo bike called the UTE its a one frame size fits all bike and the design does not appear to me to have room for a motor. Photos of it can be seen at http://www.konaworld.com Click on 2008 bikes /asphalt / ute .

With the kind of weight you are talking about, you would benifit greatly from using 48spoke rims and hubs. Staton Inc in Okla City makes a super heavy duty hub that may be what you need to support all that weight and it is available in a 48 hole drilling. This hub also is threaded on the left side with left hand threads for installing a motor driven freewheel. I'm not sure you could attach a rear disc rotor to it though?

In that lost intro thread, I mentioned the Tanaka 40 GEBE could probably do it, with the lowest drivegear, at 25mph or so. MARY in Orange County might have one up for sale....

I doubt total weight will be 500. Dog 100, Bike 50, Gear 50.

That leaves 300 to carry. No 300 pound man should expect 30 mph on a bike, the wind alone will set you back 10.