What do you think of this frame for motor bicycling?

[lowracer]

I am thinking of getting this frame for my next motorized bicycle project. It is a Dirt Jumping frameset for 26" MTB wheels & very heavy duty. Weight almost 6 lbs of Aluminum.
Opinions welcome...
-lowracer-

 

[Crazy Horse]

Re: What do you think of this frame for MB'ing?

Two word's "Do It"

Peace Crazy Horse.

 

[lowracer]

Re: What do you think of this frame for MB'ing?

Oh yeah, forgot to mention that I was planning another front wheel drive v-belt setup...Here are a few more pics of the parts for it. I also included a pic of a fellow MB'rs bike from which I drew inspiration...
-lowracer-

 

[Crazy Horse]

Re: What do you think of this frame for MB'ing?

lowracer, that's a gonna be a real sweet ride Kudo's I like alot !!!

Peace Crazy Horse

 

[lowracer]

Re: What do you think of this frame for MB'ing?

Crazy Horse,
Thanks... I ordered the frame today. Got it for $90 + $50 shipping, new on eBay. I'm thinking of stripping most of the parts off one of my 3 unmotored bikes & selling that frameset on eBay (1990's Litespeed OBED titanium hardtail). The bike hardly gets ridden anymore & is too lightweight to motor. Has sweet parts on it though...lol
So it begins....(again)

 

[lowracer]

Re: What do you think of this frame for MB'ing?

Ok,
I got the new engine ordered on eBay for $90
I got a nice used Comet pulley clutch ordered for $40
Hardware from Lowes & my local Ace Hardware for $30
The rest of the bike parts I already had to complete the build.
Will post pics as parts start arriving.
This is getting a bit too addicting...lol
-lowracer-

 

[happycheapskate]

Re: What do you think of this frame for MB'ing?

Who are you buying from? Sounds like you have a good vendor for deals!

 

[lowracer]

Re: What do you think of this frame for MB'ing?

happycheapskate,
I just watch eBay items sell to see what they sell for & try to do the 'Best Offer' option when available. Thats how I bought both the engine & frameset.
-lowracer-

 

[lowracer]

Re: What do you think of this frame for MB'ing?

Did some more work on the new MB project.
Here are some pics
-lowracer-

 

[Dan]

Re: What do you think of this frame for MB'ing?

Very cool Low Racer. What are ya doing for gear reduction? The mount looks great. Like it was manufactured.

 

[lowracer]

Re: What do you think of this frame for MB'ing?

Dan,
Using the gear calculator, this setup shouldn't need any additional reduction.
I come up with the following:
3" engine pulley (comet centrifugal pulley clutch)
15" wheel sheave (whizzer sheave)
25.25" wheel diameter w/tire on (MTB rim w/1.5" slick)
A max torque rating of 3000 rpm = 45.1 mph
If I get 45 mph, I accomplished what I set out to do.
My other MB w/a Subaru Robin gets 36-38mph max.
I'm no speed demon, but like to keep up & take the lane on the roads I travel for safety
Just waiting on a few more parts to arrive & some slight rack modification until I get this ride ready to roll
-lowracer-

 

[Dan]

Re: What do you think of this frame for MB'ing?

So cool LowRacer. Will you be keeping the governor? Just guessing here, but that engine will out live us with your set up. I am waiting on parts to do some thing similar and am really enjoying your posts. I have yet to try them but friends swear by em.

Waiting on back ordered parts and man thats a bummer. All excited looking at your pics.

Really liking your concepts http://motorbicycling.com/f42/bmp-friction-drive-kit-converted-v-24697.html

 

[lowracer]

Re: What do you think of this frame for MB'ing?

Dan,
Thanks for the props.
I'll keep the governor provided it doesn't cause any engine bogging. I think its a good idea as long as it doesn't restrict the max torque & HP rated rpm points. Max torque is @ 3000 rpm & max HP is around 3600 rpm. Once I get it on the road we'll have to test it out.
The seatpost collar & crankset bearing came in the mail today & I've now got the crankset, pedals & chain installed. I had a set of Sweet Parts Sweetwings cranks laying around & just needing a new 6805 bearing. These are the precursors to todays common bottombracketless cranks...Very Sweet!
-lowracer-

 

[lowracer]

Re: What do you think of this frame for MB'ing?

I installed the front brake & got the motor mount just about finished today.
I'm using 2 old school 1/2" skateboard truck riser pads made out of heavy rubber.
The 4 engine bolts will go thru these riser pads & it will absord alot of vibration. I ran this Lifan 152F (97cc) engine on the concrete to see how she sounded & it purrs like a kitten. Here is a pic of the pads.
-lowracer-

 

[scotto-]

Re: What do you think of this frame for MB'ing?

I think that frame is fantastic period. I've always liked Rocky Mountains framesets, they're second to none. Your rack is really great as well, nice job in all aspects of construction (looks like no welding was neccesary). Nice choice of the 4-stroke powerplant as well....that thing should rip!

My only concerns (not yours), is the handling. I'm seeing faceplant and endo's being a factor with all the weight upfront like that. The engine, rack and drivetrain will weigh as much as the entire rest of the bike....I think jumping the bike would be out of the question....right? Don't get me wrong, I like your build a lot, I'm just wondering how it's going to handle...especially at 45mph.

Cheers man, keep it coming, I'm intrigued!

 

[lowracer]

Re: What do you think of this frame for MB'ing?

Scotto-,
I have another Rocky Mountain RM7 with a 4 stroke Robin up front & no problems with weight distribution or endo's. The heaviest thing on the bike is me & having the seat a bit lower & set back more than my 'pedal only' bikes keeps everything balanced.
The bike handles fast turns extremely well & better than I expected when I first put it together.
Yeah, I am not a welder but one heck of a hack saw & drill kinda guy...lol
All the metal was purchased at either my local Lowes or Ace Hardware store.
-lowracer-

 

[scotto-]

Re: What do you think of this frame for MB'ing?

Great to hear man, keep up the good work....looking forward to the bikes completion.