The Stock Bike

jpmobius

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Tune-A-Fish said:
Yep... that's the result of discipline and a quality environment. Nice work mang :eek:
Dale said:
Nice bracket.
The RD 400 tank will look fantastic...
This is great quality build mobius.
Subscribed. - But I guess it's gonna all be over pretty soon :)
westgateok said:
Wow that looks great man!
Thanks guys! Yea, I don't have many more pictures of the build progress so the best I will be able to do is write some notes on some pictures of the completed bike.
 

jpmobius

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Dale said:
Btw, is that a bug eye sprite in your avatar? At first I thought it was a triumph TR, then a Healy ... But then saw the plate ?
Yes. 59 Sprite. I rebuilt it for a friend a few years back. It was a real mess. He bought it literally in a bunch of boxes and crashed on all 4 corners.
 

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jpmobius

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Here are a few pics of the coil installation. A couple of stainless steel brackets. I really like the forward routing of the plug wires – the stock situation has really short wires which share space with lots of other things and are too cramped to put an inductive timing light pick up on. The single coil also allows the control cable routing to be vastly improved since it takes up so much less space than the stock twin coils.
 

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jpmobius

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Here are some pics of the seat pan and cowl. Not quite finished in these shots. Construction is of very fine woven fiberglass cloth (sometimes referred to as “finishing cloth” – I don’t remember what the weight is) and epoxy resin. I made a fairly complex throw away mold to create much of the underside, but the top and body architecture is of mold-less construction and you can see the green florist’s foam I used through the transparent glass. This functions just like the stock pan, although it is considerably lower. The Half-moon shaped recess at the front was needed to clear the top of the air filter. If this bike had a stock battery, it would stick up through the top of this pan. It uses some custom stainless steel hinges I made up that fit the stock chassis pivots, and the catch is the same design as the stock one though it is shorter to fit the pan and also made of stainless. The hinges and catch bolt to aluminum plates embedded in the glass very much like the stock hinges and catch bolt to the stock pan. The pink patches are just Bondo used to contour around the plates so another layer of cloth can be smoothly laid on top. The big holes are for rubber bumpers to snap into which sit between the frame and pan. There are 6 total. The 4 small holes are for bolting the seat itself on which is made just like this part with embedded plates for the bolts to thread into. The whole thing turned out very light – I didn’t weigh it, but I’d guess less than 3 lbs., more than half of which is the seat itself as the foam padding is quite thick and surprisingly heavy. It is super comfy though. It has a prop rod too, an altered stock piece which also uses the factory track on the frame. This seat and base actually will "bolt on" to a stock bike if you remove the battery and oil tank filler neck and cap, so I asked a friend of mine (someone that actually knows what they are doing!) to make a high-tech silicon mold of it after it was finished. If I ever want to make another one it will be a lot easier!
 

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jpmobius

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So I think these are pretty much the last of the “build” pics I have of this project. Except for the bodywork, which was considerable on this bike, it’s pretty nearly complete in these pics. Most of the wiring is organized though not loomed up yet. – Fairly simple on this bike but the bulk of it is from scratch. Chain and sprockets are finished: a #520 conversion from the stock #530, and slightly shorter gearing, 15/41 instead of the stock 15/40 drive/rear sprockets. You can see the Banshee permanent magnet dynamo and ignition trigger. Also, the injector oil fill cap which is under the seat on a stock RD can be seen. It is still there from mocking up much earlier and won’t be used, but you can see how much lower the new seat is compared to stock. The factory seat easily clears the top of the cap, while the new one needed a recess in the front to clear the air filter. Engine still needs heads and intake finished but is mostly there. Unless I find some more pics somewhere, the next ones will be of the finished bike!
 

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jpmobius

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xb33bsa said:
wow ;D ..hay can you tell us the rider weight the bike is set for and the rear spring rate ?
I don't remember off hand the spring rates for either end. Rider weight including gear was set at 190 lbs. (if I remember rightly) Race Tech recommended the springs based on that and my estimation of the bike weight of 320 lbs and the experience and riding style of the owner. I assumed they are better at figuring out the correct parts than I am so I simply bought what they said I needed. I probably have their recommendation recorded somewhere in an email. I set everything up to begin with per their recommendations also, and the thing was so good right out of the gate I didn't change anything. I did think it would be too stiff for the owner though as I weigh more than he does, but he says he loves it. I don't know if he has made any adjustments himself. Using the totally scientific "eagle eye engineering" method suspension sag looked pretty even and probably has 3/4 to 2/3 travel available with him sitting on it and held vertical so it certainly would seem close. That's the only check I did aside from driving it myself.
 

jpmobius

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Well, here is the finished product. There are some details I think worth trying to show, but since I don't appear to have any build photos of them, I will look for some good shots out of the "completed" file and try to describe the work in future posts. But here are a few shots in the mean time. There is one big change from when these shots were taken, and unfortunately I don't have any pics. The owner wanted DG heads on it (DG cylinder heads were a radial fin design aftermarket head sold with a gold anodized finish back in the 70's). I told him I refused to put gold heads on the bike (he also wanted red cylinder heads which I also refused! This all before he ever saw the bike - I find it simpler to refuse customer input on the aesthetics than to haggle over colors or finishes). We did end up compromising and getting a set of reproduction heads from Ottoco (before they sold out to HVC cycles) custom machined for the altered 350 cylinders (actually this was an accident on their part. They machined them for RD400 cylinders, and I had figured to have to do this myself) and anodized black instead of gold. I really liked them. The black was really low key and blended excellently with the generally black scheme. The best thing is that they really changed the overall look of the engine - that big vertical polished outside fin on the heads really makes for a distinctive look for this series of Yamaha's. So that trademark look to the motor is gone, but the radial design in black is quite low key and to me looks more like an unknown factory bike than a custom. Those gold DG heads are super obvious but in black you have to do a double take. Shame I don't have a pic!
 

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xb33bsa

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that is amazing ! it is perfect in every way the way a motorcycle should be built with performance as a strong priority and the skill and knowledge to bring it together in a beatiful form. insipiring to say the least
BRAVO SIR
 

jpmobius

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Here are some details I am pretty happy with. Sorry not to have any build pics.

Paint.

I’m super happy with the paint. There are no decals. I couldn’t get the gold like I wanted in a decal so shot everything first with a pure silver high metallic base and candy gold – Aztec Gold I think from House of Color first. Masked off everything and painted the red which is some 2K single stage I had laying around I think from a BMW. Remasked the stripes and lettering and shot the black which is just straight pure black base. A little clear and there you are. That gold is absolutely dazzling in the sun despite how super thin the lines are. I was worried there would be too little exposed for the effect I wanted but it turned out great. Would have been awful if I had made the gold any more prominent. Wish I had thought to get a picture in the sun. This is nearly identical to the stock 1974 RD350A paint scheme graphically. The ’74 is maroon, (forget what they called it) but the fonts and stripes are exactly the same aside from re-scaling them a bit.
 

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jpmobius

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Air intake grills.

I think this is my favorite modification to this bike. I really dislike stuck–on non-functional “performance” parts that are purely cosmetic. Like a hood scoop on a car that not only doesn’t feed the engine but doesn’t even let air in (or out) to cool the engine bay. Stock RD’s have this very thing; little plastic louvers on the side cover and oil tank that are just non-functional trims. I suppose they don’t look bad, but the poser aspect has always bothered me. I have seen a fair number of bikes where the builder removed them and filled the recesses in, and you can immediately tell why Yamaha added them; the covers look just too plain without them. I doubt opening them up is actually a performance improvement, but it can’t hurt! So easy enough on the right side cover – just open the fake duct with a die grinder and job done. The left side is another matter, and takes a LOT of determination to match the right side because the left side is the oil tank, and cutting out the duct there cuts straight into the tank rendering it useless. Well on this bike I decided to go ahead and see just how much trouble it would be to make the ducts functional.

Basically I cut the back half of the front of the tank off and welded in a “wall” back up to the front of the tank to seal off the open section. It was then a simple matter to carve out the false duct opening to make it functional. I did a number of other mods to this tank as well: The factory filler pipe that led under the seat was removed and patched over, and the dip stick and vent tubes likewise eliminated. There is also a sight glass in the lower front corner to visually inspect for low oil. Since I feel this is too hard to see making it fairly useless I eliminated it as well. I silver soldered on a steel bung with a vented alloy cap as you can see and while I was at it I flooded my welded up bits with silver solder because I was paranoid it might leak – not the easiest welding work on the very thin sheet Yamaha stamped the tanks out of.

I wanted to make some screens for the openings but decided they looked cheesy with just a flat piece of screen so I made up some 3 dimensional dies out of aluminum plate and pressed up the screens you see here in my bench vise. The first set looked like crap because the wires in the screen intersect at 90 degrees, so I made a jig to clamp a piece of screen in to skew the wires to the correct angle. A lot of work for a simple part and I had to make two sets of dies as there is a right and left side. I simply epoxied them in from the back side after I finished the paint work. Like I said, it was a lot of work, but I still have the dies if I ever want to do this again!

Actually both the side cover and the oil tank are not in their original locations, though it is nearly impossible to tell without having a stock bike to compare to. The reason is that the stock bike is quite asymmetric - the oil tank bulges way out compared to the very much flatter side cover, so I moved the side cover out as far as possible without it conflicting the kick lever and moved the tank in as far as I could and still get to that cap. Also moved them both up a bit to tighten up the gaps. A fairly negligible change but I think it's the small things add up to making an overall nicer finish.

Here is a pic of an original tank for reference.
 

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jpmobius

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Here is a better pic of the seat hardware. The latch is factory except for the bail, spring and pivot pin which I made up from stainless steel.
 

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jpmobius

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stroker crazy said:
Respect!

Crazy
xb33bsa said:
that is amazing ! it is perfect in every way the way a motorcycle should be built with performance as a strong priority and the skill and knowledge to bring it together in a beatiful form. insipiring to say the least
BRAVO SIR
trek97 said:
Thats a gorgeous machine.
coyote13 said:
Thank you all for the kind words. Means a lot coming from folks on this board.
 

trek97

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Hey jp, a little something you may find interesting...

http://www.dotheton.com/forum/index.php?topic=66541.msg764202#msg764202
 

jpmobius

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brad black said:
outrageous. how many hours are in it?
Ha ha. Still trying to pretend I can count that high! I would say that it is 50/50 between the thinking of what to do and the actual doing. Much of the doing is reasonably quick if I have done it before, but there was a good bit of new territory for me on this bike.
 

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