New user/chopper build

K

Kohler-Chopper

New Member
#21
#21
Shelby, to answer your question, the music is "Trampled Underfoot" by Led Zeppelin.

Qucifer, the build time was roughly 195 hours which includes time taken to run around and buy parts at stores. We were required to keep a work log of our projects, so I kept one as close and accurate as possible. The top speed I have not yet actually tested, but I must say it begs for more around 50mph or so. This might sound a bit "Rick-diculous" (SNL skit which I thought was funny) but I made a speed chart/graph with two input variables: the engine speed (rpm) and the torque converter ratio (all of the other parameters such as pulley size and tire height are constants). The top speed of the bike could actually be around 120mph at 4000 engine rpm. Now you all know the Comet CVT's are infinitely variable (within their min and max of the pulleys) so really the speed is undeterminable because a function cannot have two independent variables (unless the use of a second equation exists to form a system of equations, you know from your algebra days in high school). Since I only had one equation (Comet would not give me the "engineering" specs to the 94C/100D system to have a second equation) I had to treat the torque converter values as constants, so I chose the low ratio of 3.49:1 and a high ratio of 0.78:1 for the max and min and then chose a few ratios in between to help broaden the curve.

The 94C/100D has a much better low and high range than the 40 series we had. So when I'm driving the bike, it starts out easy due to the low low range of 3.49:1. However, around 50mph or so, the rear pulley hasn't even opened up yet and the engine pulley is only 1/3 of the way exposed. So this bike has a huge speed potential just like the speed chart/graph predicted. But there is no way in hell I am going to take the bike even up to 80mph since I do not trust the rear tire haha(even though it is 4ply). This way the Kohler can turn about 2000 rpm while the bike does 50mph.

I hope I haven't confused any of you, but I wanted you to know it is possible to determine your bike's speed analytically knowing the engine speed, tranny ratio, final drive ratio and tire height.

It seems I can now upload more pics, so I will finish up the bike build.

Enjoy.
 
K

Kohler-Chopper

New Member
#22
#22
The exhaust was one of the last major items to construct. Here we made our own head flanges and used EMT from Home Depot to sculpt the pipes. It enlarges from 1” to 1.5” via a special cone we made from a piece of flat stock:
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The handle bars were another item where no build pics were taken, they just sort of got made quickly. Figuring out the internal throttle took some time, but we finally got it. Then the seat was made and battery tray. The kickstand, brake pedal, master cylinder mount and caliper mount were also made. At this time the switch box and brake light were also constructed. At the end of March, the bike looked something like this:
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K

Kohler-Chopper

New Member
#23
#23
Now it needed to be disassembled and welded fully. Luckily we only had one minor inconvenience from warping which was on the triple clamps. Some shaving of a bearing race solved the problem. Lots of sanding the weld beads and slag off produced a very shinny frame for which it was ready for yellow DuPont Vari-Prime primer. Next went on a grey coat of primer sealer. After that a few days worth of puttying took care of any unsightly weld joints/seams.
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K

Kohler-Chopper

New Member
#25
#25
For the color, we used some DuPont Chroma-Base basecoat/clearcoat which we had left over from painting an F-150. My girlfriend suggested giving the bike some added colors in the form of some simple pin striping. I never doubted her and the results speak for themselves. Painting took two weeks as the weather in FL is hit or miss. One day it was cool and breezy, the next it was hot and humid, all in the first week of April!
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K

Kohler-Chopper

New Member
#27
#27
Within minutes after completing the reassembly, gas and oil were added and the Kohler came to life with a mean rumble emitting from the straight pipes. After it warmed up, I twisted the throttle and the 94C clutch grabbed the belt and away I went.
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After completing this project, I would say it has been the best and most satisfying project done yet. I couldn’t have done it without the help of my dad and girlfriend.

The bike performs exactly as I expected it to. I’ve never ridden a Harley or custom before but I must say it does feel like a “big bike”. I’ve definitely had it up to 50mph and it was begging for more but the lack of road prevented me from “testing its limits”. The Kohler has so much torque it’s unlike anything else I’ve ever ridden. It wasn’t this much of a thrill when it was on the go kart due to obvious reasons. The rumbling V-Twin still gives me goose bumps when I first mount the bike. The bike is plenty fast the way it is so I would be a fool to remove the governor. I have some videos of the bike on youtube.com so check them out.

http://www.youtube.com/profile_videos?user=4x4E150
 
65ShelbyClone

65ShelbyClone

Well-Known Member
#28
#28
You're not kidding about the torque. Kohler only provides a power curve for the 25hp on their site, but using that to figure torque is easy. I calculated about 37lb-ft at 2000rpm from 14hp @ 2000 and it only climbs from there.
 
Qucifer

Qucifer

Member
#29
#29
Thats definitely a work of art. Have you looked into street legalizing it? I built a mini chopper frame for a customer, and he had mentioned that its not too hard to make them street legal. I never got to see the finished product, so I am not sure if he ever got it licensed. Your bike would definitely be the coolest thing to ride around town.
 
K

Kohler-Chopper

New Member
#30
#30
Funny you mention that. I actually have the paper work to get it titled sitting here in my desk. After graduation, I went to my local tag agency office (thank god the line was short) and asked the kid some questions. He pulled out a huge 3 ring binder and gave me some forms. Then he said I need to get the bike inspected at the DMV, and if it passes, the inspector can give me an FLA number (sort of like a VIN, but issued by the state rather than manufacture). Then I take out my letter and numbers punch set and stamp the number somewhere easily readable on the frame and then have it notarized. After that mail off for the title.

The hardest part is getting it inspected, they told me as it is a $40 fee. So everytime it doesnt pass, I'm out $40. Luckily Florida has really lienient motorcycle laws. Most of them I have included in my bike by carefully studying the FL statutes. The only thing that is not clear are whether or not rear view mirrors are needed. Everything else is fine. However I worry about the rear tire. Clearly it is from a lawn mower, but will the inspector catch that or let it pass? Who knows for sure.

I'll let you all know how it goes once I get around to that.
 
kbs8ball

kbs8ball

Active Member
#33
#33
Awesome job Robert...nice to see a dead axle on the rear...I hate the look of the live axle set ups...that thing is gonna fly with that monster v twin...get some good tires...lol...Nice write up and pics....
 
delray

delray

Well-Known Member
#35
#35
calender bike for august,mini of the month. :thumbsup:
hey Kohler-Chopper, nice bike . have you seen where some of guys will put a briggs vtwin 16hp on the old cushmans and repro-frames too.
also did you watch american chopper where they installed a vtwin kohler engine and use a transmission. i think they use an old stlye harley tranny ? they didn't really show alot of that part of the bike?
:scooter:...............:thumbsup:
 
K

Kohler-Chopper

New Member
#36
#36
Delray, I've wanted a v-twin minibike for quite a while. The Vanguard-Cushman conversions have been done since the early 1990's, way before I even knew B&S produced v-twins! They are more popular now as the price of the Comet 40 series have come down some, thus spurring people to try it. I can post a website or two if your interested.

In late 2003 when American Chopper built the "Dixie Bike", I felt cheated thinking they stole my idea to use a big lawnmower engine on a custom made bike. Well more money = more power right. So they shoved a 992cc 30hp Generac v-twin in there and of course added a bunch of custom parts to get prob 50-60hp from it. Then they added a 5 or 6 speed HD tranny to it. They didnt give any specs of course. So basically it turned out to be a full sized chopper with a lawnmower engine in place, not really what I had in mind for my build. I went to Daytona Bike Week 2004 with my g/f and saw their bikes on display. Of course they only want you walking on the "better" side of the bikes. We have this same engine on our generator and it is awesome, but I'm not allowed to mess with it for obvious reasons!
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Now I have my bike just the way I wanted it and best of all it's an automatic!
As fun as my big bike is to ride, believe it or not, I still get the urge to ride my other mini as it is more agile and "peppy". It now has a 3.5hp Kawasaki engine on it instead of the dreadful Tecumski.
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(The orange bike is my cousin's and was built from the parts I gave him after my first mini died, the one I talk about in my first post.)
 
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minidragbike

minidragbike

Supporting Speed Nut!
#37
#37
I remember seeing that minichopper on there before.

There's nothing wrong with being a copy cat. I personally wouldn't pay that much for that chopper, but I guess it depends on the person.
 
delray

delray

Well-Known Member
#40
#40
good info to look at Kohler-Chopper,thanks:thumbsup:
i like the 18hp vangraud under the seat
:scooter:..........................
 
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