The input shafts for hobbit transmissions are bending or breaking off entirely when using the motomatic rear pulley and too much power. I made a brace that adds a bearing to the other side. Problem solved, no more weird vibrations at high speed, no more breaking shit. It's just 1/2" tube, some flat stock and a skateboard wheel bearing.
Very cool. Great idea on where to place it.
I can tell you though that the issue with these Motomatic pulleys might not be solved with bracing. I did a 3rd bearing with mine as well but could never get rid of vibes at top speed. They are forever unbalanced. It's the fault of the gy6 assembly. It was never designed to be locked onto a shaft. Those pulleys even vibrate on the stock gy6 17mm shafts, but the bearings allow more vibration absorbtion.
But yeah very cool design for a 3rd bearing. It will save your gearbox for awhile....
Btw, did you turn the inside of the pulley threads to accept the bearing? Cuz as I remember it, it was not a nominal size, like 22.5mm or something.
> JBOT Admin Wrote:
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> Btw, did you turn the inside of the pulley threads to accept the
> bearing? Cuz as I remember it, it was not a nominal size, like 22.5mm or
> something.
No, the skateboard bearing was a perfect fit, 22mm od. You have to Dremel it with a sanding wheel a tiny bit so it's a slip fit. There were no threads where the bearing sits.
The threads are on the outside.
I was just referring to the inner area.
Good job (edited)
The motormatic variates in a direction opposite of stock and while I have one I won't use it. The whole shebang is wrong. Or at least that's my belief.
That's not the issue.
Don't ask me why I know that.
Dear Patrick,
I'm sorry no one seems to care about your brace. I do. I'm impressed and it's awesome.
I am probably going to steal the floating bearing slip fit technique.
I can't do your brace tho because of my manual hobbit shifter, but it looks great. Any issues with the belt hitting the brace at full variation?
Bolt it on top and bottom to ur wheel and it’ll move with the belt tension and out of the way.
That's how I did mine.
But this is mostly just as easy.
Slack the 2 bolts and adjust the wheel then lock down.
> Ana L. of the Aurora Roras Wrote:
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> Bolt it on top and bottom to ur wheel and it’ll move with the belt
> tension and out of the way.
I wadded up some tape to hold the bearing. Will this work? pat box 2.0
(edited)
Patrick I would try the brace. It makes perfect sense. Let me know how much u need to Fab one for me if u feel like it. . I would put the motormatic on one of my hobbits......the Athena that I've put onto cheetachromes case with matching transfers. Though now the OEM side cover don't want fit. I know I'm the one that harps on leg protection of spinning items , if u fabbed a few simple plates that cover but can be removed simply...oh yeah
Patrick your invention makes perfect sense. If u fabbed up a few more I might be down to buy one. Better yet could u in addition fab up some kind of removable cover to protect legs.
Digging thru junk I found a piece that could do it with a few mods.
> JBOT Admin Wrote:
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Any issues with the belt hitting the brace at full
> variation?
It clears it just barely at full variation, I might try to slim it a bit by using 3/8" tube next time. But yeah it works.
Good ideaR Patrick! The thing was a belt guard for a mower deck. I drawd a few lines to trim it and rebend the corners. That’s a good start anyway, I’ll have to get a good bearing from my son’s stash.
scootertrash, that looks great man.
Yeah buddy!
Next,, Cut off anything that doesn’t look like a moped part. :)
Good place to mount a tail light. (edited)
Adding stiffeners to the edges. 5mm rod
I went ahead and painted it yellow for safety. See that Marc!
Anna or scootertrash I do notice. Isn't that tacked into a subframe of custom design. All that tubular stuff ? The
The thing!
Check out this badass brace. Yamaha Viking
Here’s a quick way to get a bearing on the end, m8 with 1.25 thread coupler impacted with a skateboard bearing? screwed on. Prolly only need 1/2 the coupler length. Build out from there to attach it to the swingarm.
That's a good idea,
I am concerned though about the threaded end shearing off. Especially with the malossi gears.
The shaft is so hard that I think it might shear. I broke off some of the end threads by accident with a puller.
The stock shaft is really soft so maybe even easier to shear (edited)
Cut the braces short so they smash it together;)
Haven’t had the threads shear off yet, I was surprised the coupler nut was still hard to hand tighten after putting it on, taking it off 5 times or so, there was a shit load of loctite remains but damn, it wasn’t cross threading as far as I could see.
The same disposable steel used in the stock cranks! (edited)
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