MOPED ARMY

would this work?

I wanted to make one out of a bicycle trainer. basically taking the systems from goldsprints and converting to torque/hp for a moped. Like rollers with a known resistance and a tach, you could get something pretty representative I think

pretty sure i've seen phone apps that can record g-sensor data

Vidometer is a free app that shows speed, g’s, elevation. If you set it up and make markings on a test area, there would be some very accessible numbers to compare performance.

I saw it here first, so thanks to someone on MA for finding this.

a fantastic way of finding your horsepower if you havent got a dyno, is to find someone who HAS got a dyno. 50v with av10 parmakit 82cc, low comp 135 psi , doppler streetcup pipe making it rev higher than the 176/126 low tune porting wants to. 12/54 gearing hits 62mph gps. 13 54 goes a bit faster as it pulls all the way on the level.

I started with a 40hp electric motor and quickly found the stator/rotor wasn't going to have enough inertial mass. Added a steel sleeve to get the diameter and weight to get good dyno results. Rotor is about 13" diameter and weighs 320 lbs. My calculations say it's good for 20-25hp.

Will you send me a prototype?

https://www.performancetrends.com/Calculators/Engine-Inertia-Dyno/Engine-Inertia-Dyno.php

The max speed I felt comfortable spinning the motor/dyno at was 3000rpm. You'll want around a 3-5 second minimum pull for good data. Input your flywheel size, assuming yours is a solid steel flywheel, and then keep turning up the hp untill you get to 3 seconds.

http://wotid.com/dyno/content/view/16/35/

This will show you how to calculate your Moment of Intertia(MOI) which is the most important number besides rpm of the flywheel for calculating hp and torque. every part of the dyno that spins will be calculated. Things like brake rotor and hubs, etc all add up.

Here is a nice spreadsheet that simplifies everything, including the target MOI you'll need for the required hp and speed of the flywheel.

https://docs.google.com/spreadsheets/d/1vDgb4q4uqFojHRbBL1b20Cc7vo9oAKFNGHDFP-7CYvM/edit?usp=share_link

Trailer was already built, luckily the dimensions were good enough to hack in a 400lb lump. Tongue weight becomes an issue if you can't get it centered well enough. (edited)

Sold the rig to a guy in ohio that raced minibikes with his neighbors. Not much more to it besides a hall effect vane sensor for flywheel rpm, programed arduino and car size brake. I have more pictures of the build on my facebook if you're interested.

I really thought it was a troll account at first, but I think it's just a kid that lives in the middle of nowhere and doesn't really get how the world works. Like, you see someone built a one-off custom dyno that's attached to a trailer and ask them to send you a prototype of it? What? Even if they were producing them regularly, the cost to produce one is in the thousands, prototype or not, and who is going to ship a random person online a several hundred pound piece of equipment for free? (edited)

Definite troll, like 500 posts with literally nothing constructive what so ever.

It makes too much sense honestly

Does that mean it's only a matter of time untill he has gathered all our knowledge?

^ 15.5-17.5