This is the 1982 Suzuki SP500 that I rode for Rocky Mountain ATV/MC's $1,000 bike, 1,000 mile ride challenge. It was a rough looking pile of junk that ran, but performed like a snail. After the 1,000 mile ride, Rocky Mountain let me take the bike off their hands. I have since gone through the whole bike and made major improvements, mostly through fixing things that didn't work or were in need of serious maintenance. It went from a low-compression, misfiring, knocking jackhammer to a smooth-running bike with enough compression to easily flick you off the bike or break your femur when it kicks back. It is now a fairly powerful bike that is very light for a 500. Unfortunately, the stone age suspension, wimpy frame, terrible ergos, drum brakes, and springy swingarm hold it back from carrying any speed. It is still a hoot to ride, because it has way more power than it can make use of and it feels like a guaranteed death trap because of that.

Sponsor spots for this bike are available here.

Races and events this bike has completed:

• Rocky Mountain ATV/MC $1,000 bike, 1,000 mile ride challenge.
• Glen Helen 10 Hour Endurance Race 2021 (Team effort... it made two laps)

Videos and other media:

• Rocky Mountain ATV/MC's $1,000 budget bike adventure challenge
• The BADDEST Bike I've Ever Ridden: SP500
• The SP500 Hobo Build Begins

 

Bike Setup

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Suspension, Steering, Controls, and Brakes

Front tire: Shinko 216MX 80/100-21. Available at Rocky Mountain ATV/MC

• Justification: This tire was laying around in my friend's side yard from some other project that never got finished. These are actually some of my favorite tires, so I threw it on. It has been working very well for the desert riding I do. I only wish the front brake was strong enough to take advantage of this tire!

 

Front tube: Nuetech Nitromousse Standard NM21-235. Available at Rocky Mountain ATV/MC

• It is a major pain to take the wheels off of this thing, so flat avoidance was the primary goal. I'm not a huge fan of the feel of mousses in a front tire, but I went one size up for a stiffer feel in the front and it actually feels fantastic! Recommended size from nuetech is NM21-220 for this setup. NM21-235 made for a firm fit.

Front wheel: Takasago 21x1.60 rim. Looks like an OEM wheel.

Front brake shoes: Tusk Carbon Compound Shoe. Available at Rocky Mountain ATV/MC

• Inexpensive replacement shoes that are working great. They are not disintegrating rapidly like other brake shoes I've tried. On a drum brake, wear rate is equally important as stopping power because the brakes do not self-adjust and you can lose braking very quickly on a shoe compound that wears too quickly.

Front brake cable: OEM - Available at Rocky Mountain ATV/MC

• Justification: I installed an OEM cable after a cheaper aftermarket cable broke in an irreparable way under mild braking. The pin that holds the cable into the brake lever actually sheared in half under braking. It was relatively new. Don't use a cheap cable on this brake!

Front fork springs: OEM dual-rate springs

Front fork oil: Maxima 10W fork oil - Available at Rocky Mountain ATV/MC

• This was a little bit more viscous than what came out of the forks. I'm not sure exactly what was in there before. This seems to be doing the job. The overall handling of this bike is so bad, it's hard to decide on a correct tune for the forks alone.

Handlebars: Tusk T-10 Aluminum 7/8" - Available at Rocky Mountain ATV/MC

 

• Justification: This is what it came with from Rocky Mountain, and I see no reason to change them out yet.

Grips: ODI Lock-On Half Waffle - Available at Rocky Mountain ATV/MC

• Justification: I'm a huge fan of how easy it is to swap out grips once they're converted to lock-on... So I pretty much just change all of my bikes to lock-on grips. Yes, one is blue and the other is gray.

Brake lever: Unsure if it's OEM or not. It's what it came with from Rocky Mountain.

Clutch perch: Tusk Quick Adjust Clutch Assembly - Available at Rocky Mountain ATV/MC

• Justification: It's what it came with from Rocky Mountain. Pretty nice setup though, with the ability to adjust the free-play without pliers. The lever is angled out a bit far for my taste but I'll live with it. If it ever breaks I'll switch to the standard Tusk clutch perch.

Clutch lever: Tusk Quick Adjust Clutch Assembly Lever - Available at Rocky Mountain ATV/MC

• Justification: It came with it. There's nothing wrong with it. 

Handguards: Tusk D-Flex Pro Handguards - Available at Rocky Mountain ATV/MC

• Justification: It came with these. If one ever broke, I'd replace it with the standard Tusk aluminum handguards w/ MX shield.

Rear brake: Tusk Carbon Compound Shoe. Available at Rocky Mountain ATV/MC

• Inexpensive replacement shoes that are working great. They are not disintegrating rapidly like other brake shoes I've tried. On a drum brake, wear rate is equally important as stopping power because the brakes do not self-adjust and you can lose braking very quickly on a shoe compound that wears too quickly.

Shift lever: Not sure what it is. Almost seems like OEM, but the shaft diameter was not correct so it was loose on the shift shaft. I had to modify the spline area so it would clamp onto the smaller shaft.

Rear brake pedal: Appears to be OEM

Footpegs: OEM

 

Rear shocks: Progressive Suspension 13-1240B - Available at Amazon

• Justification: It came with these from Rocky Mountain. They weren't bad but they were assembled incorrectly and became damaged because of that. I replaced them with brand new versions of the same shocks. When I ordered these, I did not realize it may have been possible to use the 13-1241B model to get an extra 18mm of travel and increase the ground clearance of the bike. This could have then been paired with a fork swap from a bike with a disc front brake.

Rear shock springs: Progressive suspension dual-rate springs. The soft section is a 1406 model 200lb spring on both sides. The stiff section is not marked (that I can see).

Seat: Appears to be OEM

Seat cover: Appears to be OEM

Rear wheel: Takasago 18x2.15. Appears to be an OEM wheel.

Rear tube: Nuetech Nitromousse Standard NM18-285 - Available at Rocky Mountain ATV/MC

• The rear wheel is a HUGE pain to remove on this bike, making flat prevention the highest priority.

Rear tire: Kenda Trakmaster II 110/100-18 - Available at Rocky Mountain ATV/MC

• Justification: Cheapest knobby that fits, and they just happen to be very durable which will be great for endurance racing!

 

Electronics

Headlight: None (removed)

Tail light: None (removed)

Spark Plug: NGK DR8EIX - Available at Amazon

• Justification: Replaced the blackened DR8EA the bike came with for this iridium upgrade version.

Stator: TBD

Ignition controller: OEM

Regulator/Rectifier: OEM

Coil: OEM

Battery: None (removed)

 

Fuel, Intake, and Exhaust systems

Fuel tank: OEM

Petcock: Brand new OEM

Carburetor: 32mm PWK-style OKO carburetor with Dial-A-Jet "enhancement pump"

• Had this PWK laying around, so I tried it out on the SP500 and it gave the bike a lot more power and snap than the original CV carburetor, so I went forward with a carb swap. I tried it with and without a Dial-A-Jet "enhancement pump" and the bike had more power while also running smoother with the Dial-A-Jet regardless of jetting. I will need to make a full review of the Dial-A-Jet now. It is so much more than an externally adjustable fueling circuit. Dial-A-Jet available from Rocky Mountain ATV/MC

Jetting:

• 140 Main
• 38 Pilot
• Keihin ECF needle - 4th notch (1 notch above richest)
• Standard float height but switched to Keihin needle valve
• Dial-A-Jet at middle enrichment, drawing from lower left side of float bowl

Air filter: Uni UP-4245AST (available on Amazon) with Filterwears K130 pre-filter (available on Amazon)

• The original airbox was basically melted in half so I ditched it completely and used an Uni slip-on filter instead.

Exhaust pipe: OEM

Muffler: Original, cut down by a few inches by a previous owner. I added in a Fish Moto Kit 20 spark arrestor.

 

Engine Components

Camshaft: OEM

Piston: OEM

Clutch: OEM, new

 

Oil filter: OEM

 

Final Drive

Countershaft sprocket: JT Sprockets 13T Steel Front Sprocket - Available at Amazon

• Smallest front sprocket available... In an effort to reduce reliance on first gear.

Drive chain: Primary Drive 520 ORH Gold X-Ring Chain - Available at Rocky Mountain ATV/MC

• Justification: The chain rusted out really bad while I towed the thing around with my Yotahome. I had one of these on hand as a spare, so I threw it on. It's a mild upgrade over the previous O-ring chain (less friction than O-rings).

Rear sprocket: JT Sprockets 48T Steel Rear Sprocket - Available at Amazon

• The largest rear sprocket available... also in an effort to reduce reliance on first gear. This bike is geared TALL from the factory to take advantage of the low RPM power.