Re: Hobbit engine+bike build/photo dump

Mikey Antonakakis /

Nice work! That dyno design looks familiar ;) Really well executed!

Re: Hobbit engine+bike build/photo dump

Wow I'm amazed u controlled your bike as you ran over the bike that fell right in front of you. Amazing skill.

Re: Hobbit engine+bike build/photo dump

Joe Schuitema /

I received a blank pcb board from Alex Degnes to finish the wiring part of the dyno. If you follow him on youtube you'll see I'm copying the arduino setup that he uses on his dyno. The components are just resistors, capactiors, diode, transistor, and a 555 timer . The roller rpm sensor is a hall effect vane type. Engine rpm will be read like the trailtech does, wrapping a wire around the spark plug wire. I've got a clean roller rpm signal and will test the engine rpm signal tomorrow.

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Re: Hobbit engine+bike build/photo dump

Holy shite!!! What a thread!!

Re: Hobbit engine+bike build/photo dump

Joe Schuitema /

Its now the start of the 2018 season. The only change I've done to the bike is swap out the stock fork springs to a heavy duty version. They are much stiffer and should provide a better feel when racing. The dyno has been operational for some time now, but the past month has been below average for temperature. Today I was able to get a few test pulls done. I swapped out the clutch springs for stock and put in my heaviest weights. The idea is to get the variator fully locked so it would act as a one speed. The weights still aren't heavy enough but it was close enough to get some good data. What I'm seeing is good power up to 9,000 rpm, then dips till 10,500 and pulls again. I'm pretty sure the drop is because of the variator not staying locked. I'll get some better baselines before I make the swap to the tm24. The only correction factors are the dyno roller only, so the numbers you're seeing are at the rear wheel. Figure 20% drivetrain losses and I'm around 11.25hp with good torque.

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Re: Hobbit engine+bike build/photo dump

> Joe Schuitema Wrote:

> -------------------------------------------------------

> Its now the start of the 2018 season. The only change I've done to the

> bike is swap out the stock fork springs to a heavy duty version. They

> are much stiffer and should provide a better feel when racing. The dyno

> has been operational for some time now, but the past month has been

> below average for temperature. Today I was able to get a few test pulls

> done. I swapped out the clutch springs for stock and put in my heaviest

> weights. The idea is to get the variator fully locked so it would act

> as a one speed. The weights still aren't heavy enough but it was close

> enough to get some good data. What I'm seeing is good power up to 9,000

> rpm, then dips till 10,500 and pulls again. I'm pretty sure the drop is

> because of the variator not staying locked. I'll get some better

> baselines before I make the swap to the tm24. The only correction

> factors are the dyno roller only, so the numbers you're seeing are at

> the rear wheel. Figure 20% drivetrain losses and I'm around 11.25hp

> with good torque.

>

I heard that variator ringing, part of the package, know how to get rid of it, but other than that the bike sounded real strong

Re: Hobbit engine+bike build/photo dump

Good job, but do it without that variator rinng at idle, is a real challenge.

Re: Hobbit engine+bike build/photo dump

Joe Schuitema /

Thought I'd update the thread with what has happened this summer. I played around with the dyno some more, mostly to figure out why there was a torque dip in the midrange. Turns out its because of an internal baffle cone that I removed in the yasuni exhaust. I purchased the same exhaust but did not chop it up. Problem solved. It also showed how big of a difference a change in the exhaust makes. I've got the first exhaust that can be chopped up for testing. My thinking is that the cylinder wants a shorter pipe with a convergent cone matching the taper of the internal baffle cone that was removed. I'd like to see peak hp around 11-12,000rpm. That should push me into the 13-15hp mark.

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I was able to dyno the tm24 vs the vm20. The 24 added about 5% more hp. I saw no change in low/midrange performance. Gas mileage seems to be around 45mpg if I'm crusing at 35-40mph. I took it to two rallies and mopedgp midwest. I placed 4th in the unlimited class and beat my personal best lap time by 1 second from last year. I found the stiffer front springs improved its behavior on the track, but I'm unable to push the bike to its limits. My tire size and fear of dropping or wrecking the bike are the major factors. If I want to be more competitive, I'll need to build another bike that can be beat up. Here's a video of the endurance race. 99 laps with a full field of bikes.

After the racing, I installed a set of overdrive "racing" gears in a spare gearbox. The stock final drive ratio is 12.5:1. The racing gears drop it to 10.5:1. So roughly 20% more mph for the same rpm. I finally topped out the bike on flat ground, running both ways and averaged 69-70mph at about 11,000rpm on the stock gears. After the gearbox swap, I was able to touch 79mph at about 10,500rpm.

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If you remember from last year I cracked the windscreen at mopedgp. Treats got them back in stock and I swapped it out.

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Re: Hobbit engine+bike build/photo dump

Joe Schuitema /

I also fabbed up a new exhaust hanger. I replaced the flat aluminum with tubular steel. It weighs about the same and is much stiffer side to side.

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Re: Hobbit engine+bike build/photo dump

This bike never disappoints. You should get yourself a stock hobbit and put your machining and fabrication magic to work on that.

Re: Hobbit engine+bike build/photo dump

EH 📣FCC of the QCB /

This thing is unreal. So so so good.

Re: Hobbit engine+bike build/photo dump

Damn this is awesome news. Have fun!

Re: Hobbit engine+bike build/photo dump

That was just lurvly!!!

Re: Hobbit engine+bike build/photo dump

Re: Hobbit engine+bike build/photo dump

I'm in the process of putting together an ardyno to add on to an old cycle/scooter dyno. Do you think that the gm hei unit could be used to isolate noise on the hall sensor circuit? Ive never seen one of these so I am unfamiliar with how they work.

Re: Hobbit engine+bike build/photo dump

Joe Schuitema /

the gm hei unit only converts a vr sensor signal(sine wave) to a square wave signal. A hall effect sensor already outputs in a square wave, which is what the ardyno wants to see. I have no issues with noise on mine, as long as a resistor spark plug is used.

Re: Hobbit engine+bike build/photo dump

I like

Re: Hobbit engine+bike build/photo dump

Incelforlifebaby!hotandhorny69 646260 /

Yea this is sick

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