Another DH Project

[lostrack]

How's it working out so far moto?

[motomoto]

Awesome. I am finally fixing a problem I have had all along. The V-10 frame I am using has a lot
of monkey motion in the suspension which adds up to 35 mm of chain growth from the
rear suspension fully extended to fully compressed. So when the chain is under load from
the motor and you land from a jump or just hit a bump that compresses the suspension,
more stress is put on the chain as the distance between the crank and the rear axle
increases. (chain growth)
I was going to build a new swingarm that had significantly less chain growth, but decided
on another solution that would fix other problems also. I am building a torque limiting
clutch between the 2 crank sprockets. When the drive sprocket that sends power to the
rear of the bike reaches a certain torque level it slips. Simple as that.
If the bike is landed with the throttle wide open, the only motor and drive train momentum
shock that the chain will experience will be from the drive sprocket and the chain itself.
The result will be that I can now finally ride it like a motocross bike on a motocross track and
not have to hear the bad noises from the drivetrain that I usually hear, like when I climb a rough hill.
Normally I have to back off on the throttle to save the chain.

[sn0wchyld]

sounds groovy... can you link us to the torque limiter your using?

[motomoto]

It's from scratch.

[etard]

Sooo sick and dirty I had to close the browser when my Gf walked in on me drooling!

Don't forget about the Riverside race around the same time as Grange. It may be a better surface/track or do both if you can get the time. I'll be at both, so I will be glad to see you there. Also, if you bring dirt tires to the Grange race we can shoot some video of us wooping through the desert around the track (I'll have my KDX at this race).

[motomoto]

I have a couple more videos. I still think I can hit 60. I just had my two cheap 5000ma 24 volt batteries
and I had to nurse it because they would hit the low voltage cutoff easily even though they were fully charged.
Today I only could do 54 mph. I am putting a couple more batteries on for the next run.

http://youtu.be/ae2FmDdT9aI

http://youtu.be/kWv9Dny7lzk

[waxman123]

Wow what a great build !!!!

[motomoto]

Thanks.

Just to let you know, I am not posting stuff just to draw attention to myself. I am basically
the kind of guy who doesn't need any approval from anyone but myself. I am happy in my own little world trying
to make my dreams come true and wanting it to happen faster!!

So I have been working on this project for over a year now and I am testing to find out what my
top speed is. My first attempt resulted in a 54 mph run and realizing that I needed more batteries.
Today's run resulted in a 66 mph run and what I think is the limit of my set up.

Most of what I have done came from Matt Shumakers work. I just put my own spin on it.
He did all the trial and error research combined with an engineering mind and came up
with the correct answers which resulted in some bitchin' toys.

Also I wanted to mention that the reason I don't imbed my Youtube videos on the page
is that the resolution is low and they can be watched in 1080p the way I do it.

So, here are today's videos and the last of my speed runs for a while.

http://youtu.be/PcyKhL6sb4A

http://youtu.be/lYR2L3ak0EU

[sn0wchyld]

...... I am basically
the kind of guy who doesn't need any approval from anyone but myself.....

well tuff titties moto... 'cause you got mine. that bike sound schaweeeeet, and looks like sex. ever tried down shifting under light power while breaking? I'd love to hear that!

http://www.youtube.com/watch?feature=player_detailpage&v=v8CIDdKvUkg#t=23s

[jk1]

How does the rear derailer handle the motor power ? what is your maxium power ? is their any skipping gears under load with so much power ?

What chain thickness are you using for the motor chain and also the rear derailer chain ?

[motomoto]

When I originally designed the project, I had the first stage reduction at 4 to 1 resulting in a 60 to 1
reduction at the crank. The motor I was using at the time was 6,000 rpm, so I could pedal along with it.
The result was too much torque causing the rear cassette to skip and break chains. So I changed the initial
drive ratio to 2.25 to 1 which transmitted less torque and more rpm and made the rear cassette and
chain happy and also resulted in using the larger sprockets for the same speed engaging more teeth.
I haven't had skipping or chain problems since.

For the speed run I changed the initial ratio to 1.75 to 1 because I wanted to be using the larger rear sprockets
at high speed and power. The crank was approaching 500 rpm, so the drive train was spinning 5 times faster
than what is normal.

I would say the power was approaching 10 hp. If you watch the display panel on the run it shows the Kw in
the bottom left hand corner.

The short chain to the crank is a BMX chain and the derailleur chain is standard.

Just to let you know, I am not posting stuff just to draw attention to myself.

I would like to add that I post because I hope I am contributing something of value to others like
Matt S has done. I hope to think we are all trying to push the envelope and take each other to new
heights. I think I have helped explore the derailleur gear change set up possibilities.

[recumpence]

I wanted you guys to know, Kim and I are collaborating on a couple cool projects. He is a phenominal machinist. What Kim brings to the table is, not only great machining, but a knowledge of bicycles, dirtbikes, and how to make stuff look really cool! He also has a good mind for developing mechanical stuff. I have a couple designs he is looking at machining for me and one of his ideas is [hopefully] being implemented in an absolutely insane drive system that should be the highest power single motor RC based system I have developed to date.

Kim does not like pushing products. But, I don't mind doing it......

Anyway, I am looking forward to having this connection with another great guy. I have a decent circle of guys who each bring something valuable to the table. Together [with each of us doing what we do best] far better products can be developed. Together, we can do what one person, alone, cannot.

Sorry for taking your thread off the beaten path (pun intended).
I just wanted you guys to know Kim and his work will be seen more and more on this forum over the next few months.

Back on topic!

Matt

[Rouckie]

for me your post is of great help! thanks

[lostrack]

Hey Kim,

How's the 3220 holding up? Are you using it regularly now?

Have you got a temp sensor in it? I'm interesting in installing one in the windings of my 3220 - the case gets to 100F so I'm sure the windings are warmer.

How's this project with Matt working out?

Enjoy the sun:)

[coldfusion594]

Subscribed!!! haha
I like the belt drive... very fancy

Do you have any pictures of the rig through its paces?

Just had to comment, thanks dude!

[LightningRods]

Thank you for this tremendous build and your generosity in sharing so much information. Looking at your final conclusions of (1) excessively brutal power delivery, (2) difficulty in keeping front end on ground, it reminded me of another two wheeled conveyance from long ago. You're an old fart like me. You should remember the '71 Suzuki TM 400 Cyclone. It has often been referred to as The Most Dangerous Motorcycle Ever Made. There were some standard fixes that you might consider working into your next build. I'm attaching a link to an article on taming the Cyclone for your reference. Again, thank you for your artistry and your generosity.
http://vintagemx.com.au/taming-suzukis-tm400

[Whiplash]

Long time no see! Any updates on this monster!??

[EvoBikeShop]

Great build!