> Graham Motzing Wrote:

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

> my 'moped butt dyno' = about 15 years of comparing peoples posted dyno

> results from the forum and the speeds those bikes actually run- compared

> with seeing some of the builds in person, compared with other shit i

> know from motorcycle tuning:

>

> single speed:

>

> 30 mph- 1.5 hp

>

> 35 mph- 2 + hp

>

> 40 mph - 3 hp

>

> 45 mph - 3.5 hp

>

> 50 mph - 4 hp

>

> 60 mph- 6 hp

>

> 70 mph 8-9 hp

>

> 70+ 11+ hp

>

> Data is very limited as few mopeds break 70 mph and i've only seen a

> handful dyno'd- metrakit 80 and gillardoni puch E-50's but the jump

> from 70 to say 75 requires a ton more power. Thats where air drag

> really goes off a cliff and it starts to take a ton of power to

> overcome.

>

> obviously this is very much an educated guess, tons of people post all

> kinds of questionable crap over the years but enough people have posted

> good accurate data over the years that you can kinda guesstimate the

> rough amount of power it takes to push a moped at a given speed.

>

> A well-built DR 43 runs low 50's on a single speed vespa transmission.

> By my math, i'd say 4-5 hp. More than enough for the shitty kinetic

> frame you'll be riding.

>

> It will be interesting to see what you guys come up with.

Just to throw it in there, I've had my bike dyno'd twice. Once by a home made dyno and another by dynojet. Home made dyno had me at around 12.5hp @ ~12k rpms. Dynojet had me at 10ish hp and then around 11hp with MRX02 fuel @ same rpms.

Top speed recorded was 68mph on 50cc with more to pull (I ran out of street). So I think your chart is about accurate as it can get by eyeball.

I think we forget dyno's are unreliable with numbers especially on really small motors.