Old Guys Simplex moto-peddle bike

[indian22]

Simplex Copper Gator fired off!! Kept it running till she warmed up and adjusted the Mikuni's idle to 1400 rpm. Very tight on first start much easier on subsequent starts. I'll run under no load for a couple of hours, read the plug & then take her out for a short test ride. Then drain oil,clean the strainer & refill with 10-40 wt. mineral base. In the meantime it's appropriate that I adjust, lube, locktite & tighten to to prevent the essentials from failing or falling off on the side of the road, that includes me!

Lot left to complete mostly bells and whistles, except for the exhaust system. Main thing is "it's alive" & Mel Brooks would be so proud. Rick C.

 

[Ludwig II]

When you refill with oil, you can ease the flow to the rocker box by undoing the little bolt at the back of it. When you replace it, remember to lockwire it or it will come out and dump oil all over your back wheel. I know this personally.

 

[racie35]

Congrats Indian! I'm glad it's up and running

 

[indian22]

Thanks Racie, nice to hear it fire. No load run in has gone well. Pulled the test stinger & will bend a couple of tubes in steel to get a feel for routing. High short pipe down the clutch housing side & ending at the rear wheel is my current thinking, but the short stinger ending up front & hanging down like a China doll kit pipe is also a possibility.
A high pipe routing might require a short wrap of fiberglass to keep the exhaust heat off the head. There's also the double kink problem from the exhaust port and making the turn around the cylinder. That would definitely kill a high perf engine but might not restrict a low compression, skinny cam engine like the CG125.
I've felt from the beginning that the exhaust port location on this engine was one of the biggest design problems faced by using the twin tube frame of the Simplex cycle, but there is, in the end, just enough room; though at this point I've not decided on what it will look like, I am sure I won't settle for weak performance. Rick C.

 

[racie35]

You can probably adapt a 2008 ambassador pipe to it easily like I did when I put a hf 212 on the ambassador in about that position you have

 

[Ludwig II]

I remember header length from the valve seat being between 22 and 24 inches, wrapping the pipe will make no difference at all, and keeping th pipe narrow will keep gas speed up to help low end torque.

This is the pipe on Black Betty, it did the job for us. Lifting the front wheel on the throttle alone in 3rd, so the length and diameter I'd say are about right.

 

[sportscarpat]

Just catching up on your bike build. Really nice build and good solutions to the drive system and engine mounting. How do you like those tube straps your using for the engine mounts? They look pretty solid. I can tell it going to be fast. I see a sprocket adapter on it. I have found as the engines get more powerful it gets harder to keep the wheel in position with the smaller coaster brake axles. Good solid large washers help, though.

 

[sportscarpat]

Oh, and make a SOLID coaster brake arm to frame strap. When those tear through it gets ugly real fast.

 

[indian22]

When you refill with oil, you can ease the flow to the rocker box by undoing the little bolt at the back of it. When you replace it, remember to lockwire it or it will come out and dump oil all over your back wheel. I know this personally.

How bad was the fall & did it spill anyone else on the track? Design, prepare & maintain then proceed with a bit of caution...of course a portion of good luck coupled with learning from the misfortune of others is still necessary at times to survive.

Black Betty at 24" equals the length of my high pipe routing down the clutch side from the copper gasket. 1" ID pipe ending in the 2"ID x 7" pipe I'm using for a baffle case giving a total over all of 24" and that's what I'm planning on at this time. At any rate I wouldn't think it's too far off the mark. If it runs like a pig I'll just change it. Rick C.

 

[Ludwig II]

Nobody was hurt, but the track was closed as it was late afternoon when it happened.

 

[indian22]

Oh, and make a SOLID coaster brake arm to frame strap. When those tear through it gets ugly real fast.

Thanks Pat for the props. This post has gotten pretty lengthy over the last year & I've probably not pointed out several important details. One off builds are always experimenting, learning & character building experiences. As an experienced rider/builder who does this for a living you must take note of safety & service issues, along with the cool stuff we all love about your bikes. Product liability is a huge concern I'm sure. Because of this I've double checked many details used in your builds to verify my own concepts. My bottom bracket co-axle drive is very similar to your own design. The dual springer was also inspired by your builds.
The coaster brake lever is attached to a slot bracket welded to the frame under the rear drops, probably not visible in any of my posts, but faintly visible in the attachment below. You are so right about the flimsy strap arrangement on coaster wheels being a significant danger. I also use a hardened bolt to secure the arm to bracket.
You also mentioned the small axle of the coaster & it's tendency to move about with the power of larger engines. I've addressed this by using the original Simplex 1/2" drop slots with a threaded 3/8" adapter which threads over the small axle & bolts up quite firmly with as you suggested larger washers. My reason for this initially was for a possible future move to motor cycle size wheels and tires. I also will use rear axle adjusters, but since the rear wheel has to be removed so often I've not installed them.
I used your Sportsman 3 piece hub adaptor and 56 tooth sprocket to help clear the 3" tire and handle the torque from the gear & drive train. They seem to grip the hub much tighter and I hope to avoid bending spokes. The wheels are Sta-Tru's but I have a new set of Workman's ready to mount after a few hundred miles of break in.
I'm stubborn about making this moto look like an early day bike and so am reluctant to use much in the way of motorcycle parts.
Lastly the Harley peg clamps are really heavy duty & a bit pricy, but more than equal to the task of this little engine. A pair of these things were designed to hold the considerable heft of even the largest HD rider... 8 clamps is really over kill!

 

[indian22]

Coaster brake lever bracket

 

[indian22]

Took a very short ride on the Simplex Copper Gator today. Successfully navigated all gears a few times. Spent most of the time in first and second a little in third. Low speeds, maybe 25 mph briefly, yet still fun. Only used the last two holes to prove they were there. Engine sounded good coming from the short stub which was reworked to come down the flywheel side today & I found out that's my best choice for the permanent system. I should have named this bike the "just barely", I'll have to someday count the parts that just barely fit and the exhaust is one of them. I'll not add the copper pipe & muffler until latter, but we did clamp it on & run it in the shop today & even without the fiberglass material installed; it did a nice job of quieting the little motor's exhaust note.

It was a good day for sure: bike started, I rode it & nothing, including me, fell off. I'm still having fun. Rick C.

 

[indian22]

Stub actually looks pretty decent by itself.

 

[indian22]

Other side.

 

[indian22]

Feeling pretty good about the test ride, but will proceed with caution as I increase speed to test handling and braking. Forks and especially the geometry I've used on the forks for this build are my major concern. I've about 4.75" of trail & usually use about 1.5" to 2.5". My axle to axle is 53.5" minimum to 55.5" max center to center. Wheel base should be adequate for stable straight line characteristics & normally increased trail also aids in that regard. I'm aware that total weight, weight distribution, area of tire contact patch, rake, fork type etc. enter into the handling of the machine in all situations...straight line, cornering, acceleration, high speed/low speed, braking etc. Input about the springer characteristics would be helpful. I've ridden big bikes and small with the dual toggle springers with mixed emotions, but never really attempted to correct any problems I encountered just lived with it as best I could. Now I'd really like to understand the design.
Dual springers are pretty & I hope mine work well on the Copper Gator, if they don't I'll soon be asking for advice.

 

[Ludwig II]

The engine doesn't need much clutch slip, does it? Wait until you have it all bedded in and then try a 7,000 rpm takeoff

 

[indian22]

Ludwig the clutch doesn't need much slip at all & engages quite smoothly. Might be that 7 K is a bit much for me at this time. I'm more at an 1800 rpm engagement point during this stage of life, but there was a day...

I mentioned having a new set of Workman's wheels on hand and a used pair of Honda 21" wheels as well. I've shown the Simplex to the local Chief of police and the County Sheriff as well. They both agreed that bike tires and pedals were fine for all roads where the bike could maintain minimum speeds posted, but would be considered a hazard on a highway where a minimum posted speed was above 35 mph. In their opinion it's a bicycle with a motor so I need only adequate head & tail lights, along with a mirror for safety equipment.

Only real concern they expressed was with the tires and brakes at speeds over 35 mph. So if I were to mount the Workman's with Simplex Coker tires 2.50 x 26" I'd be legal on county roads as well. Oklahoma DPS, I'm told, has a different set of guidelines that would require full motorcycle regulations & requirements including registration, tag, insurance & safety equipment on state highways. So I'm thinking of going the Coker tire & Workman wheel route if I just have to go a little faster on the county roads where I could cruise at 55 mph & I really don't want to make a small motorcycle out of it just keep it a bicycle with a motor on it! Rick C.

 

[racie35]

That bikes a motorcycle in most states. Adding pedals to a Harley hog doesn't make it a bicycle.
You should use 21" motorcycle tires and rims. I know you want to come across as a pedal bike with engine assist but really that's past that.

 

[indian22]

So true, but it will remain a moto-pedal & I'll leave it to others especially the local law to decide if it's either / neither or nor & ride till I'm told otherwise. It's the same as with 160 cc & 212 cc Honda clones no big deal some places, big deal in others. I've got big bikes for the highways so riding 35 mph on bicycle tires is ok by me. Sure won't have to push the CG 125 to do that & the bicycle tires can easily & safely cope with that speed on bicycles without a motor. Adding Coker speed rated tires & workman wheels at some point would allow higher average speed which I don't care about & still look like an early moto-bike & that's much more important to me than using up all the revs I can.

Ran her for about 45 minutes this afternoon & noticed the throttle not wanting to turn or return without effort. Dismantled & found the cable had frayed inside the throttle housing, I'll it replace tomorrow with a factory Honda liner & housing, it's not black but it will get me running till I order a black sheath. Better in the shop than on the road.

Clutch cable is also a about 2" shorter than perfect & the front brake cable maybe 3" shorter than perfect. I'll get those on order also. Tried to make do with some I had on hand but in this case they didn't quite fill the bill. None of this will sideline the bike from some more road time. Absolutely no leaks so far and the pedals are close to perfect for both shifting and braking. I can easily shift without moving my foot off the left pedal.

Lot left to get right; just cause I can ride the Gator doesn't mean that it is yet correct because it isn't, but I have reason think that eventually I'm really going to like enjoy riding this little moto-pedal. Rick C.