My $Free.99 Project

Likely stock sized tires, haven't made up my mind on those yet. A slight gear reduction will be good for less vibes at highway speeds.

Tires will likely be Spitfires or Commander II, unless I can find something better
 
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18-30 gearing is pretty high for one of these, unless maybe you weigh like 140 lbs. soaking wet, lol.
 
Before anybody up northeast gets all concerned about the tall gearing keep in mind that when I traveled up to the metroplex to pickup the exhaust from wannabe from North Houston , I averaged 92.3 MPH with a gas stop and was being passed constantly. You need that kind of gearing to keep the thing away from redline and not getting run over by pickup trucks It make 4th a useful thing.
 
If i was tearing into the engine, I'd do the overdrive 5th, but I got the 30t for free and the only way to get back to stock gearing is to use a 15T front sprocket. Everything I've read said that dropping the ratio a skosh is best for reducing highway vibes (> 60 mph) and maintaining overall driveability.

Typical highway speeds here are 70+. I'm 225+ w/ riding gear, BTW. Now I don't plan on riding the highway constantly, but I would like the bike to be comfortable. There's not much options for tire diameter either, as a 130/90-19 would give me the best acceleration vs a smaller tire...
 
I think 16/30 sprocket gearing is a good plan to try with a 130/90-16 ;)
Tune it and ride it fast ! It would be fun to top it out with a tail wind even
 
Got the seat latch cleaned and lubed, works great now. Used the ultrasonic cleaner to get most out and then filled up the rest with some white lithium grease. Even lubed up the keyway. Works properly now!!!

Trying to psyc myself up to do the fuse box conversion (using a blue sea block I had Laying around, hope it fits under the seat) then will start getting the wiring back in order.

Also need to fix the wiring harness on the RH switch housing. Someone in the bikes past kind of butchered up the wire ends, so might need to transplant the connector block
 
What you have to keep in mind is we're only dealing with about a 50HP bike here. Gear it too high and it won't pull 5th to redline. I've tried both a 32T and a 33T on my 18" wheel. The take-off power in the lower gears really takes a noticeable hit with the 32T. You kill the bike's "fun factor" if you gear it too high. You lose most of that satisfying "lunge" in the midrange through the lower gears.
 
Is a reduction from 2.00 to 1.88 going to be that noticeable?

Sprocket specialists makes 520 front sprockets that fit without any issues. Quoting them: "Ours has a shoulder on it and is 530 chain pitch thickness at the body but 520 on the teeth." Nice option in case it's needed.
 
Trade offs; with your weight and 50HP get it geared that high and you'll be downshifting for every hill.
I weigh 185 in gear. Madness is a 750 went down from a 17/33 to a 17/32 It has a 120/70/18 tire it might pull a 17/31, since it gets aluminum sprockets I may get to try that yet. Ywain (so far a 650) is a getting a 17/31 but is rolling a 130/70/17 rear tire.
 
Interesting, and good to know. So, the bike had an unused set of sprockets on there, 17/36. I suppose that will keep the low and mid-power present huh? :-D

I'll keep these and just get a 530 chain, as I can always change the rear sprocket to suit later. I can use the 520 chain on my bobber build as it's a minimal/lightweight bike and throw a 14 or 15 tooth up front or something...
 
new fuse box isn't going to be an issue at all, so wiring will (hopefully) be wrapped up soon so I can test all those systems. Once that's working and "fault free", then I'll be testing compression and whatnot and (hopefully) getting some noise made.

Also got the rear wheel mounted up and all appears well there. Need to rebuild the rear caliper, maybe send the rotor off for grinding sometime. Still waiting on front fork stuff for emulators so I can get the front wheel mounted. Also need to get the clutch worm gear modified and then I can install into case. Things are moving along!

Will hopefully be having a little winter-cleaning process and post some parts up for sale soon. Pics incoming soon
 
5twins said:
What you have to keep in mind is we're only dealing with about a 50HP bike here. Gear it too high and it won't pull 5th to redline. I've tried both a 32T and a 33T on my 18" wheel. The take-off power in the lower gears really takes a noticeable hit with the 32T. You kill the bike's "fun factor" if you gear it too high. You lose most of that satisfying "lunge" in the midrange through the lower gears.
Click to expand...
When my bike was new, it wouldn't pull redline in 5th. Stock sprockets. It did blow through the ton.
 
If you want to get maximum top speed, get a torque chart of *your* engine, and multiply it by the various gear ratios to get your propulsive thrust. Map it out like this ol' XS1 chart.

256-Performance02.jpg


The goal is to find the optimum gear ratio that crosses the "running resistance" line as far to the right as possible...
 
17/30 makes 4th gear = to 5th with 17/34 . Same top speed in 4th . 5th gives lower revs and better gas mileage at more normal speeds. Need to go faster downshift.
 
Got me a rebuilt rear caliper w/ stainless line and new pads from @XS650ROB, thanks for the deal!

Also got the Blue Sea 6 fuse box grafted in, wires are a bit tight, but they work. The stock rubber strap will go over the fuses and keep it down that way, it's not super tight, so should be adequate. There's just enough room under the seat, otherwise I might use some Velcro under the fuse block.

Upon inspection of my wire harness, I might be replacing some of the connector blocks w/ replacement units from VintageConnections.com. Some are worn out/slightly melted or outright missing/cutoff.


Running total: $1347.71
 

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So the harness I have (got it from Hugh) is from a 1980 special. Not a big deal, and thankfully the right side controls were already compatible. Gauges are from a '78. Will be removing the reserve lighting module, flasher cancelling and need to figure out what to do w/ the light checker (would like to remove it). I'll also do the wire bypass for the on-off headlight switch. Need to get the pamco w/ e-advance and the PMA wiring complete as well.

That being said, does anyone have a useable left side handlebar switch? Also, still waiting on the suspension guy to get my parts prototyped. Hopefully soon, I'm ready to get the wheel back on...
 
What to do with the light checker will depend on whether your new harness is from an '80 Special or Special II. The Special eliminated the light checker so no issues there, just don't install it (there's no place to connect it). The Special II still had it, and it was the more complex 7 wire unit. Power for the tail light passes through it so if you remove it, you'll need to put a jumper wire in to provide tail light power.

Neither '80 harness should have provisions for a headlight on-off switch in the right handlebar control. I think you'll need to do some wire re-routing. Both of those harnesses send power for the headlight from the RLU to the hi-lo switch. You'll need to re-direct that to your on-off switch first, then from there to the hi-lo switch.
 
Well, found an unlabeled box with a bunch of other odds and ends in it, all from a '78!! Complete wire harness, handlebar controls and turn signals. So that's a nice surprise, I'll have to re-do the fuse block, but that's NBD now that it's all screw on terminals. Also got some new grips.

Found receipts for other odds and ends that I forgot to include.

Running total: $1427.34
 

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