Over 200pounds on a 50cc Dax

Cr9ck

New Member
Sep 7, 2008
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I am wondering how fast people are going on a standard ht setup with a 50cc and weigh over 200 pounds. I would like to get 25mph if possible but my setup isn't up yet so I don't know what I will be getting.

Second I would like to know how fast people are going with mods and upgrades on a 50cc.

Thanks.
 

frenchlayer

New Member
Jul 8, 2008
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im 6'5" 250# and ride a 70cc dax. I get up to 24 on the flats with the stock gearing. This is a good speed for me as I like to ride on the sidewalks and ghost pedal.:ride2: I do plan on getting the shifter kit though, maybe this will help. If I want to go faster I hop on the whizzer.
 

Jemma Hawtrey

New Member
Dec 29, 2007
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Essex, UK
To be honest its not so much the tare weight of any particular rider and bike thats the problem when it comes to speed although it does have some effect.

Its more a function of wind resistance.

For example - if I can get 35mph with an all up weight of say 200lbs in a sat up position (which is how I have to ride) and on an unfaired bike; I might get maybe 40 or so if I put a fairing on the machine and rode underneath or in line with the fairing. All in all the tare weight of the machine would have increased but the wind resistance would have reduced and that ultimately is what limits the speed of these machines.

However this is not the end of the story because you also have rolling resistance. This is a function of all the friction surfaces on the bike and drivetrain and also the friction losses from the tyres and such.

If the bike is well maintained or new and the engine kit and such are properly adjusted these will be minimised. So to with correct tyre pressures.

I am an avid reader and I remember reading my fathers new car manuals when I was a kid - just out of curiosity really (that and he could never set up the radio right - the news tended to be read by someone who sounded like a lemming on speed for about a week until I got tired of it and set it up right)- and they always had an advisory on tyre pressures - the Renault one was usually something along the lines of a loss in tyre pressure of only 4psi (32-28) would increase fuel consumption by 5% given the same driving method. When you consider that involved a vehicle with 123hp you can see how much of an effect it would have on something so much more marginal as one of our bikes.

All in all therefore, although tare weight is a function related to the speed you will manage given a particular rider/machine combination its much less important than wind and rolling resistance (hence why all the european car makers - with limited horsepower - made aerodynamically slippery designs from the late '70s - and the US still makes vehicles that look like someone put wheels on the garage, Dodge Ram & Caravan etc I am looking at you..)

I think you should be able to manage the speed you are aiming for without too much problem - even on a tight engine.. happy riding

Jemma xx
 

Cr9ck

New Member
Sep 7, 2008
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Well thanks for your input so far. 20-25mph on this 50cc would be great. Pedaling up to 35 would be nice but I don't know if that is possible. Can't wait to have it up and running but I'm waiting on others to finish it for me at a shop so can't complain too much. Stupid rear sprocket alignment.
 

Jemma Hawtrey

New Member
Dec 29, 2007
288
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Essex, UK
Well thanks for your input so far. 20-25mph on this 50cc would be great. Pedaling up to 35 would be nice but I don't know if that is possible. Can't wait to have it up and running but I'm waiting on others to finish it for me at a shop so can't complain too much. Stupid rear sprocket alignment.
You would have to have *extremely* steep ratios to pedal assist up to 35mph and to be frank it wouldnt be at all safe as the CoG would be all over the place..

I didnt get 35mph out of mine until I fitted up a tuned pipe - which might be worth looking at

Jemma xx
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
235
63
up north now
The "cruising speed" on the china built in-frame engines seems to be from 18 to 28 mph, top being 28 to 35 on average.

My most recent one cruised at 22 mph with very little vibration or noise. 28.8 mph GPS top.