5HP Diesel Motorbike
- Thread starter Tanshanomi
- Start date
Foot pegs are mounted.
I recycled Bultakenstein’s Yamaha YZF600R footpegs for the Benelli. I considered a bunch of locations and mounting configurations, including floorboards and adapting an entire Kawasaki ATV footrest assembly. But in the end, two chunks of 1/2″ thick alloy, some holes drilled here and there, and a bit of thread tapping got me there.
If anybody wants to assert that suspending the pegs from a pair of M6 screws threaded vertically into mystery alloy is a bit sketch, you won’t get any disagreement from me. But the fact remains that at 8 AM this morning, this bike didn’t have foot pegs. At 10:45, it did. I’m one step closer to a running motorcycle, and that’s a win in my book. If they don’t hold up, I’ll have to come up with something more involved at some later date. In the mean time, maybe just don’t stand on the pegs.
I recycled Bultakenstein’s Yamaha YZF600R footpegs for the Benelli. I considered a bunch of locations and mounting configurations, including floorboards and adapting an entire Kawasaki ATV footrest assembly. But in the end, two chunks of 1/2″ thick alloy, some holes drilled here and there, and a bit of thread tapping got me there.
If anybody wants to assert that suspending the pegs from a pair of M6 screws threaded vertically into mystery alloy is a bit sketch, you won’t get any disagreement from me. But the fact remains that at 8 AM this morning, this bike didn’t have foot pegs. At 10:45, it did. I’m one step closer to a running motorcycle, and that’s a win in my book. If they don’t hold up, I’ll have to come up with something more involved at some later date. In the mean time, maybe just don’t stand on the pegs.
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I test-fit this no-name universal fender I've had on hand to the diesel bike. I originally bought it off Amazon for The Bride, but I didn't use it because I decided it was intolerably ugly. It didn't get any better looking while in storage. Now I'm just trying to decide whether my tolerance level has changed.
I tried fitting the jackshaft assembly and engine into the frame together for the first time. The throttle and governor assembly is mounted to the rear of the crankcase, which is a bit problematic. As I stated previously, having to move the engine back that inch or so really impacts the space available behind the engine. In the end, everything fits, but I have literally fractions of a millimeter clearance for the pillow block castings. In order to leave room for the throttle arm to move, the left side has to sit juuust inside the frame. On the right, I actually had to cut away the lower right corner of the throttle arm bracket to get enough fore-aft clearance.
If the big cast brackets hadn’t fit, it wouldn’t have been a complete show-stopper, but I’d have needed to redesign my mounting brackets to take pressed flanged bearings directly into the bracket. I’m glad that’s not required, because besides the added cost that would be involved, I like the self-aligning feature and the extra mass of these cast pillow blocks. (given how much the engine is likely to vibrate).
I ran into a snag I should have expected, considering I had the exact same issue with The Bride: the order of operations for assembling together various parts that were conceived separately ends up being quite nuanced and persnickety. I must have installed and pulled the engine half a dozen times. And then, when you get everything in place, access for hands and wrenches can be very limited. Fortunately, it looks as though I can make this work.
Next up, I need to make up some spacers to replace the stacks of washers and extra nuts I used to figure out all the spacing.
If the big cast brackets hadn’t fit, it wouldn’t have been a complete show-stopper, but I’d have needed to redesign my mounting brackets to take pressed flanged bearings directly into the bracket. I’m glad that’s not required, because besides the added cost that would be involved, I like the self-aligning feature and the extra mass of these cast pillow blocks. (given how much the engine is likely to vibrate).
I ran into a snag I should have expected, considering I had the exact same issue with The Bride: the order of operations for assembling together various parts that were conceived separately ends up being quite nuanced and persnickety. I must have installed and pulled the engine half a dozen times. And then, when you get everything in place, access for hands and wrenches can be very limited. Fortunately, it looks as though I can make this work.
Next up, I need to make up some spacers to replace the stacks of washers and extra nuts I used to figure out all the spacing.
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I have warmed up to the Yamaha XV535 tank shell, and I’ve started figuring out how to mount it to the frame. At the front, I attached it to an existing bracket on the frame (originally for the coils, possibly?) using a length of M8 threaded rod and a couple of alloy tube spacers cut to fit the slightly off-center bracket. I happened to have some flanged M8 washers that fit the ID of the alloy tubes perfectly and leave no slop or play once everything is snugged up. I do wonder how much it will shake once my thumping engine is running. Some sort of stabilizing bracket might be needed, and I still need to work out the rear mount.
When I designed the jackshaft brackets, I included provisions for adjusting the primary chain tension. The bottom pillow block mounting bolt hole is oval, so that the jackshaft can shift fore and aft. However, I needed to ensure that the two pillow blocks were adjusted the same distance, and I needed something more positive than bolt torque to prevent driveline torque from pulling things out of whack. I designed 4-position tension adjuster plates. The range of adjustment is pretty small—only about 3.5 mm at the jackshaft—but the primary chain is not terribly long, and #35 chain only has a 10mm pitch, so it should be fine. I had SendCutSend drill and tap each bracket for a M5 socket head screws that acts as a locating pin.
I had to buy a 6.5mm drill bit to get a slop-free fit over the screw head. Despite having a Chinese drill press that wanders more than a desert cougar at night, I actually managed to fabricate the plates out of alloy pretty accurately. One hole on one plate is slightly out-of-round, but not enough to effect function. I decided not to worry about making the outside shape look pretty.
I was half expecting some sort of glitch to surface when I installed them, but they didn’t get in the way of anything else, and they function precisely as intended. It’s certainly better than no adjustment at all.
I had to buy a 6.5mm drill bit to get a slop-free fit over the screw head. Despite having a Chinese drill press that wanders more than a desert cougar at night, I actually managed to fabricate the plates out of alloy pretty accurately. One hole on one plate is slightly out-of-round, but not enough to effect function. I decided not to worry about making the outside shape look pretty.
I was half expecting some sort of glitch to surface when I installed them, but they didn’t get in the way of anything else, and they function precisely as intended. It’s certainly better than no adjustment at all.
Work on the diesel bike continues. A rear sprocket to fit my Yamaha rear wheel that takes #35 chain isn’t really a thing, so I modified a go-kart sprocket to fit. I had a heck of a time getting it set up on the lathe properly, in large part because the cheap sprocket was about 40 thou out of true with itself. Evidently, the outer diameter of the blank is cut separately before the teeth are stamped, so they were all different heights. The center diameter and the spoke holes were also not concentric. I had to file down the inside of three spoke holes until I got it chucked up accurately. I then cut out the center so that it’s a nice, tight fit on the wheel flange.
Then I had to drill bolt holes. Since there are four bolts on the wheel and six spokes on the sprocket, two of the bolts ended up in slots, rather than complete holes. It’s not as strong, but plenty strong enough for 5 HP and 35 MPH.
I bought 10 feet of RLV “Gold-on-Gold” chain, to get something stronger than cheap, no-name chain.
Then I had to drill bolt holes. Since there are four bolts on the wheel and six spokes on the sprocket, two of the bolts ended up in slots, rather than complete holes. It’s not as strong, but plenty strong enough for 5 HP and 35 MPH.
I bought 10 feet of RLV “Gold-on-Gold” chain, to get something stronger than cheap, no-name chain.
Do you know at what rpm the diesel engine idles at? I think the spring in that clutch is going to make you rev pretty high before you get any response. My guess is you will be wasting about a 1,000rpm before you get any response. Very nice build job, lot of work and time in the project but it is coming along nicely.
I’ve used these blank sprockets before to mate with odd hubs. https://ebay.us/m/PounBA
My WAG is that the sprocket will ultimately need to be bigger, but I’ve never played with a diesel before, so it may have the torque to move a taller gear efficiently enough. Guess we’ll see! 
(I know says countershaft sprocket when it's actually the crankshaft sprocket; I modified my generic motorcycle gearing spreadsheet).
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