Scotty Chop – Frankenstein 77 XS650

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My build started as a motor that I bought online from a guy in Minnesota who had the motor sitting on the side of his house. He shipped it to me in CA and that’s when it all began. With no prior experience working on these bikes, I took my time and did some research on what kind of parts I would need to get in order to build a good, reliable, fun bike. It started with the motor and after tearing it apart, I decided to send the crank and cam to Hugh @ Hugh’s Hand Built to be rephased. While I was waiting for those parts to come back, I decided to paint the engine cases, cylinder, and head with black hi temp engine enamel. Then I installed new seals, and bearings and new oil filters. I also replaced the old rotor with one of Hugh’s PMA setups and also picked up a PAMCO ignition for the rephased engine. Since the engine was rephased, I needed to run dual coils, so I used a couple of Yamaha YZ450f coils and NGK spark plug caps.

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While I was working on the motor, I found Voodoo Vintage and really liked the frames David Roy was making. I contacted him and we talked about what I was looking to do and we came up with a good frame to fit my specs. The bike has a custom steering tube made to fit modern Yamaha dirt bike triple clamps and steering bearings. David also made the rear axle plates cut out to 25mm to fit the custom rear axle I made to fit the Yamaha dirt bike rear hub. When I got the frame, I still had to add bungs for the tank mounts, foot pegs, rear axle adjusters, blinker mounts, battery tray, steering stop, seat mount, rear fender mount, and various other fittings.

The forks I got from Ross over at Enzo Suspension bolted right up using pro circuit triple clamps from a Yamaha YZ450f. I built the wheels at home – 21”x2.15” front and a 19”x2.5” rear with Talon carbon fiber hubs and custom spokes/ nipples. I wanted to go with larger than normal tires and 21”/19” are standard dirt bike sizes so I thought it would give the bike a good look. I decided to go with some classic tires – Avon speed master front and firestone rear.

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Another cool piece on the bike is the modern 4 stroke dirt bike Kehin Carburetor and 1 into 2 intake I made with the help of Damon @ InHouse Racing. I had an old carb lying around and thought it would be perfect for the bike.  We got some 1.5” tubing and bent it into a “U” then started cutting sections to make fit. I made the intake mouth on a lathe to fit the carb’s I.D. so the air would flow smoothly into the engine. The intake was ported and smoothed out for great airflow into the head. The carb sticks out just Dan over at Pandemonium Choppers helped me out with the exhausts. They are straight pipes with no baffles or mufflers. Once I bolted them on I felt like adding to them, so the guys at Pro Circuit gave me some stainless steel expansion chambers and some 1.75” tubing for the turn outs and I gave the exhausts about 6-8” of length. The bike is not deafening loud. It has a really nice tone and the surrounding cars can hear me.

Rebel gears made me the custom sprocket to fit my hubs and 520 o-ring chain. It is the smallest rear sprocket to fit the hub. So to get the gearing right, I went up on the countershaft – currently running 18/37t and had plenty of pull off the line and good power to get up to 90mph. The sprocket is aluminum and had it anodized dark brown along with all the other aluminum parts. Titanium bolts secure it to the hub. The foot pegs are titanium dirt bike foot pegs with custom brackets and a custom made shift linkage and rear brake set up. The seat is from Sully’s Customs and I used a mountain bike air shock to give myself some cushion.

I wired up the whole bike myself after drawing up a schematic. I ended up using a coffee can that mounts under the seat and houses all of the electronics – fuse block, starter solenoid, flasher relay, and all the other connections. I wanted to make it simple and clean but have every component on its own fuse and color wire. I have the headlight, blinkers, brake light, coils, running lights, and electric start each independently wired. I used a handle bar switch I ordered online for the headlight, blinkers, and starter button. Front and rear brake are set up independently and hooked up to a Duo Lamp brake light that has a license plate light incorporated. After cracking a few brake light housings due to vibration, I figured I should rubber mount it and it has been fine ever since.

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I wanted the bike to be completely street legal and safe here in CA. As this is my first full custom built bike, I made sure everything was there for the DMV and CHP inspections. Along with making the bike safe, I decided to use dual piston derbies brake calipers both front and rear for good stopping power and an oversized front brake rotor. The motor runs really good. Since finishing the build, I went ahead and rebuilt the engine with a 750cc kit. The larger wheels give the bike a good stance and they work well. The rake of the bike is good, very stable at speed and corners decent. The bike sits low and drags exhaust from time to time. All in all it took about a year to complete. I work as a motorcycle mechanic for a race team so a lot of my weekends were spent away racing, I found time and made it work little by little.

There were a lot of people involved who helped, gave me parts, let me use their shop, and gave me advice – Damon Konkright @ InHouse Racing, Derek Despain, David Roy @ Voodoo Vintage, Hugh @ Hugh’s Handbuilt, Ross @ Enzo Suspension, Randy and Darren, Jerry and Alex @ Pro Circuit, Geoff and Bryan @ Joker Machine, Cameron Brewer, Nutec Powder Coating, Precision Anodizing, Trail Tech, and everyone else for the help/ motivation to get this bike built. Stay tuned for a website with more custom builds and bikes – scottychop.com

But for now you can check out the bikes on instagram – @doesntknoww or #scottychop

Hope you enjoy! Scott Dimick

Comments

  1. Ingwar says:

    OK
    nishtjak poluchilos!

  2. Alex says:

    Great work Scott. I really like the look, use what you got and dont hide it, looks engenering,,,,and mean, but meaner with the mirrors down.

  3. lou says:

    love it! All the modern dirtbike parts work great with the classic bobber layout. Looks rugged. I like the color too, perfect bike if you ask me!

  4. lou says:

    would love to see a shot from the other side too!

  5. Max Rippage says:

    Awsome! Now aren’t you glad you paid attn. in shop class!

  6. El Gaucho says:

    Very cool combo of front end parts. Spoked 21″ with a speedmaster tire on inverted forks, but it totally works. Not a huge fan of the tank, but everything else is rockin.

  7. William A. says:

    I love this bike! Very well done!
    Awesome job on the rims too!

    KIller!

  8. Matt says:

    Looks awesome Scott. Great use of a coffee can 🙂

  9. Nobody says:

    Agree on the tank, You need to move the coils and put on a different tank…deep tunnel….so it sits lower and flows with the line of the bike..keep up the good work!