Old Guys Simplex moto-peddle bike

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indian22

indian22

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Dec 31, 2014
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Oklahoma
Hey Silver bear hope your weathers a bit better. Shiny is good but progress is better let's hope one leads to the other. There will be some modification to the frame, nothing radical, mainly motor mount issues & any additionional frame supports required. I'll not require any frame cutting, wheel base and height left stock & steering head angle will work as is, it appears. Drive off center stand needs a mount which will add a lot of structural support to the subframe tubes. I really want to retain the original stance of the Simplex.

No fenders front or rear on this one & the crash bars/foot pads will not be used either. Minimal is my goal.

SB I kinda build in my head & shiny paint interrupts the process. I'll build till it looks right, cutting and welding, adding and subtracting until I get the sum total I'm searching for. It usually looks like crap at that point, but that's when you strip it down one last time for metal finishing & paint (sometimes) and final assembly.

The frame looks bad now and will look a lot worse before it gets better...the old Chevy truck I'm working on is a good example of what I've described. I don't know when I'll start building but I'm starting to get a vision of what it will look like when I've finished & that is a big step in the direction of a harmonius outcome! Rick C.
 
silverbear

silverbear

The Boy Who Never Grew Up
Jul 9, 2009
8,325
670
113
northeastern Minnesota
Weather here in northeastern Minnesota is like any other February. Cold and more cold. -32 last night.

We all build differently. I mix it up, I guess. I like to have at least part of a build painted so I can visualize what it will look like. Some people are better at visualizing than others and can see the whole build in their heads before they even start. I have to stop and stare frequently and then kind of wait for the bike to tell me what it wants next. I try to see it before I start, but it always turns out a lot different than what I had thought. That's okay so long as I'm happy with it when I'm done.

It's fun to see someone else's vision come into focus.
SB
 
S

sportscarpat

Bonneville Bomber the Salt Flat record breaker
Jun 25, 2009
1,839
471
83
california
Cool looking build. Heads up on the Sunlite forks. Take the rubber bumper under the spring perch and flip it to the top side of the perch where it should be. Takes the rebound shock load off the forks and stops them from banging around on bumpy roads. It also reduces the swingarm angle.
 
Ludwig II

Ludwig II

Well-Known Member
Jul 17, 2012
5,071
783
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UK
I don't know much about cdi for them. My racer had a Rex Caunt supplied race ignition. If you can get things turned to a correct taper, what about a pit bike/monkey bike ignition? Logically though, there will be a specific spark box for them.

The oil in the engine as received should be treated as an unknown type, drained and replaced with a mineral grade, about 10/30. Change every 200 mile-ish until you hit 1,000 and you should have it all bedded in by then. On start up, the valve gear rattles until the oil finds it's way up, it will noticeably quieten then. It's a good idea to drill and lockwire the blanking bolt at the top as well (it's a handy place to insert a pressure gauge feed), as I had it come out once when testing. The first thing I knew about it was when I executed a perfect flinging away of the bike in a corner.

The filters live behind the big hex headed cover on the bottom left of the cases. Remember to always clean the groove of the centrifugal filter as well as the wire one.

Valve clearances according to the Haynes Manual (hereafter known as The Book Of Lies) are .002" inlet and exhaust, but the exhaust likes a little more, say .004".

The valve size is down to Honda equipping millions of ohc/ohv singles with the same valves as the old XR200, and is therefore too much. We got 14hp out of Black Betty with the 22mm carb, for tractability you might even go down a few more mil, as we wanted big fat mid range with the cam we used.

I think the gearbox gap may be a cultural hangover from the days when German influences were a major inspiration for the Japanese industry. 1-2-3 for town and pulling away from a standstill. 4 is for normal highway use, and can reasonably be "too high" compared to the others. 5 is an overdrive, to be used where tailwinds and downhills are your friend. I could of course be entirely wrong, but not everyone is genius like wot i are.

Rob Smif built the bike, he did some things which were deceptively simple. The carb, under the rules at the time, required a 22mm restrictor. He turned one up that went from the rear of the manifold into the inlet tract and blended absolutely smoothly in order to ensure best gas flow.

The same thinking applied to the exhaust pipe. There was the minimum of internal mismatching on the sections as they met each other. The diameter and length we used was suitable for our set up, you could probably go down 1/4" to improve torque and help bridge that gap between 3 and 4. The length was also optimised for us. Longer for the standard cam seems logical.

 
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indian22

indian22

Well-Known Member
Dec 31, 2014
4,722
7,697
113
Oklahoma
sportscarpat said:
Cool looking build. Heads up on the Sunlite forks. Take the rubber bumper under the spring perch and flip it to the top side of the perch where it should be. Takes the rebound shock load off the forks and stops them from banging around on bumpy roads. It also reduces the swingarm angle.
Click to expand...
Thanks Pat for the great practical tip. I know you've had extensive experience with the dual springers and wouldn't still be using them on your beautiful, quality builds if they didn't perform to your expectations. Your new "pea shooter" fork design is killer. I'd be proud to own any of your bike models or one of each!

I've used the Sunlite duals & single springer forks on several builds without major performance complaints like excessive "jack rabbitt" or banging, but, they don't compare to the ride of the high dollar dual air mountain bike shocks...no reason to expect they would. Huge difference in the amount of $$ & engineering from different ages. The springers have always "looked right" on both motorcycles and bicycles and I prefer that "look" to all others & am willing to give up a bit of comfort in order to enjoy "it". I just finished three motorized bikes & used a different style of fork on each - Mountain bike, single springer & triple tree, all turned out well and please me, which goes to say that I'm not knocking any other other fork style...just stating my preference. Rick C.
 
indian22

indian22

Well-Known Member
Dec 31, 2014
4,722
7,697
113
Oklahoma
Ludwig II said:
I don't know much about cdi for them. My racer had a Rex Caunt supplied race ignition. If you can get things turned to a correct taper, what about a pit bike/monkey bike ignition? Logically though, there will be a specific spark box for them.

The oil in the engine as received should be treated as an unknown type, drained and replaced with a mineral grade, about 10/30. Change every 200 mile-ish until you hit 1,000 and you should have it all bedded in by then. On start up, the valve gear rattles until the oil finds it's way up, it will noticeably quieten then. It's a good idea to drill and lockwire the blanking bolt at the top as well (it's a handy place to insert a pressure gauge feed), as I had it come out once when testing. The first thing I knew about it was when I executed a perfect flinging away of the bike in a corner.

The filters live behind the big hex headed cover on the bottom left of the cases. Remember to always clean the groove of the centrifugal filter as well as the wire one.

Valve clearances according to the Haynes Manual (hereafter known as The Book Of Lies) are .002" inlet and exhaust, but the exhaust likes a little more, say .004".

The valve size is down to Honda equipping millions of ohc/ohv singles with the same valves as the old XR200, and is therefore too much. We got 14hp out of Black Betty with the 22mm carb, for tractability you might even go down a few more mil, as we wanted big fat mid range with the cam we used.

I think the gearbox gap may be a cultural hangover from the days when German influences were a major inspiration for the Japanese industry. 1-2-3 for town and pulling away from a standstill. 4 is for normal highway use, and can reasonably be "too high" compared to the others. 5 is an overdrive, to be used where tailwinds and downhills are your friend. I could of course be entirely wrong, but not everyone is genius like wot i are.

Rob Smif built the bike, he did some things which were deceptively simple. The carb, under the rules at the time, required a 22mm restrictor. He turned one up that went from the rear of the manifold into the inlet tract and blended absolutely smoothly in order to ensure best gas flow.

The same thinking applied to the exhaust pipe. There was the minimum of internal mismatching on the sections as they met each other. The diameter and length we used was suitable for our set up, you could probably go down 1/4" to improve torque and help bridge that gap between 3 and 4. The length was also optimised for us. Longer for the standard cam seems logical.

Click to expand...
Thanks again for real world info I can, am and will use. Really glad I held back on ordering the Mikuni carb (28mm) & stainless tubing for the intake manifold & exhaust as my metal distributor sells in 20' lengths only and mistakes in stainless are pricey, as is purchasing two motors for one build.

No non-sense racer you've got there...I like!
 
Ludwig II

Ludwig II

Well-Known Member
Jul 17, 2012
5,071
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UK
My little girl won her class, the only pushrod, the orphan everyone said we should abandon because she wasn't good enough. The most common comment when people see the pictures?

All Business.
 
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indian22

indian22

Well-Known Member
Dec 31, 2014
4,722
7,697
113
Oklahoma
silverbear said:
Weather here in northeastern Minnesota is like any other February. Cold and more cold. -32 last night.

We all build differently. I mix it up, I guess. I like to have at least part of a build painted so I can visualize what it will look like. Some people are better at visualizing than others and can see the whole build in their heads before they even start. I have to stop and stare frequently and then kind of wait for the bike to tell me what it wants next. I try to see it before I start, but it always turns out a lot different than what I had thought. That's okay so long as I'm happy with it when I'm done.

It's fun to see someone else's vision come into focus.
SB
Click to expand...
Dang -32 degree, hope your keyboard is heated along with everything your protected by!! The older I get the more I love warm weather & it's mild here compared to your environment.

I'm stareing at frame & parts this moment & enjoying it, it's part of my process. Earlier it was the truck that attracted my attention no progress toward completion attempted and none intended. I'd read your post & wondered if either of these antiques would speak to me yet both remain silent and somewhat petulant in their apparent desire to remain as they are and most reluctant to change into what they might become. Perhaps the shapeing of metal to my will and vision...returning the castoffs to service violates some fundamental law of the universe, but bend they must in order to satisfy my curiosity & a desire to restore the dull or common and the discarded to luster and usefulness. Then again creative day dreaming might also be a sign that I'm too lazy to pick up my tools and build something. It's open to interpretation! Rick C.
 
Ludwig II

Ludwig II

Well-Known Member
Jul 17, 2012
5,071
783
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UK
While I think, most of what your engine does best is up to 7,000 with that cam, with a probable low compresson ratio. It will roll through to over 9, but all it does is sound busy. Do not change down early as well, wait until the revs have dropped away when braking. The valves have a tendency to lose their heads if you ask them to return home too hard.
 
indian22

indian22

Well-Known Member
Dec 31, 2014
4,722
7,697
113
Oklahoma
Ludwig II said:
While I think, most of what your engine does best is up to 7,000 with that cam, with a probable low compresson ratio. It will roll through to over 9, but all it does is sound busy. Do not change down early as well, wait until the revs have dropped away when braking. The valves have a tendency to lose their heads if you ask them to return home too hard.
Click to expand...
More good advice & observation! With 7,000rpm as a goal & 15 teeth on the primary sprocket & 46t or 48t on the rear perhaps I can get a little bit more use out of fourth gear on the outskirts of town or gearing suggestions ???

Bent some DOM tube into 22" bars, bead blasted & painted black for now, mounted into a BMX stem which will be coupled to the 1" dual springer with an alloy 1" to 1&1/8" adaptor. I think it will look good & the narrow bars will allow me to squeeze between parked cars and such.
 

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indian22

indian22

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Dec 31, 2014
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dirtyoldcrusier said:
Wow, looked what i seen on E-Bay today!
Looks like the one I seen at the car show earlier this year. Man wish i had the money for it.
Click to expand...
That blue automatic is a dead ringer for an AMCA Nationals winner a few years back that scored 100 points...guy by the name of Bill E. had a beautiful perfect restore...my recollection is his was a 1958 & the ebay heading shows 1957...anyway if it's the same bike & he relists. I'd be interested 'cause it could well take years & many $$ to put one back together to make a 100 point National winner in class. Thanks DOC for bringing it to my attention. Rick C.
 
indian22

indian22

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Dec 31, 2014
4,722
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Oklahoma
The Simplex I'm thinking of didn't have a rack on back (though one could have been added) and the fork springs were chromed...I would also imagine that the owner of such a nice restore would also list the correct year of manufacture, all leading me to believe they're two really nice... yet different bikes.
 
indian22

indian22

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Dec 31, 2014
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Oklahoma
Going to the shop with the Simplex Cajun-gator for a major clean up of all non essential brackets and mounts as well as removal of the crash bars and footpads. The more I look at the frame the more it looks like a 1920 era boardie (if Simplex Servi-cycle had been around then). I won't be putting fenders on this one. Photos next week. Oh yeah the name Cajun (made in New Orleans) & gator, which will "crawl" when I peddle but "bite" when challenged, lol. Rick C.
 
indian22

indian22

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Dec 31, 2014
4,722
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Oklahoma
Old steel can be a challenge for sure. Just came from Chainmakers Panther thread & was saddened that it didn't come to completion due to to tube rust. He put some fine work in on it.
I just came in from the shop where I'd been cleaning up the Cajun-gator frame. I knew there would be some issues with frame integrity, and there are, primarily in the lower tubes. Problems had been filled in and painted over. I called my steel distributor and a 20 foot stick of 1 inch DOM is on it's way. Of course I won't require that much for the repairs or a stretch of the frame (I'm now considering a 3" length increase) since the frame has to be cut for proper repair anyway, but the small diameter tube is handy to have around the shop. No point in building on a weak foundation! Rick C.
 
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