Sprocket size????

Chitty

New Member
Jun 3, 2008
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Souris Manitoba Canada
We have ordered a 80 2 stroke kit for my wife, but have yet to get a bike. She wants something that is easy to get on [low]. The kit says it is for a 26" weel, so if we went with a 24" weel would we need another sproket?
 

Ilikeabikea

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Jan 27, 2008
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Using a 24" wheel will make the bike slower, unless you go to a smaller sprocket.....................................
 

HoughMade

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Apr 15, 2008
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Valparaiso, IN
If you went with a 40 tooth sprocket instead of a "standard" 44, it would compensate. A 24" is about 92% percent of a 26", and a 40 is about 92% of the 44. 40s are pretty widely available.
 

spad4me

New Member
Jan 20, 2008
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Arizona Bullhead
Re: You man need to go rack mount.

LOOK at the mounting space needed by the engine..
Quote We have ordered a 80 2 stroke kit for my wife, but have yet to get a bike. She wants something that is easy to get on [low]. The kit says it is for a 26" unquote .


Yes, a Happy time framemount chinese 2 stroke engine will fit a 18 (shoehorn needed) to 26 (very easy) MEN'S with a diamond shaped opening in the middle bicycle.
 

spad4me

New Member
Jan 20, 2008
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Arizona Bullhead
A rack mount friction drive is the only kit that I know of that the rear wheel size does not matter.
The rear wheel is only a spacer between the drive spindle and the ground. LOL

A small ish 32 cc subaru rack mount friction drive will last forever and fit everything.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
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The rear wheel size does matter...a little, a 24" wheel will have a slightly lower overall speed at any given rpm than a 26".
 

cityevader

New Member
May 11, 2008
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Santa Cruiz, CA
The rear wheel size does matter...a little, a 24" wheel will have a slightly lower overall speed at any given rpm than a 26".
Except for a friction drive, which drives the outside diameter of the wheel at a certain speed (not rpm as a sprocket drive does) which would be friction wheel RPM multiplied by it's circumference. So the tire tread tavels a certain feet per second,not revolutions per second. And since the tread is connected to the ground, it then travels at the same feet per second.
So rear tire diameter is irrelevant on friction drive.
 

Easy Rider

Santa Cruz Scooter Works
Jan 15, 2008
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Nor*Cal
The rear wheel size does matter...a little, a 24" wheel will have a slightly lower overall speed at any given rpm than a 26".
Like Big Joe said: It won't make that much of a diffrence but the up side is she'll have better low end torque.
 

Easy Rider

Santa Cruz Scooter Works
Jan 15, 2008
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Nor*Cal
My mistake. I didn't read the whole thread. I thought the discussion was about sprockets. You are correct that on friction drives, the diameter of the spindle determines the speed.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
235
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up north now
Anyhow- to the OP- A different sprocket is not required or needed, unless she is going out for a high top speed or loooong cross country cruises, then it will be a help, but still not a requirement.
 

cityevader

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May 11, 2008
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Santa Cruiz, CA
My mistake. I didn't read the whole thread. I thought the discussion was about sprockets. You are correct that on friction drives, the diameter of the spindle determines the speed.
You're right too! It started out as a sprocket question, and somehow I ping-ponged into friction drive...my fault!

HoughMade's response says it all.
But I might suggest using whatever sprocet the kit comes with, so you don't go spending money before you even know what you like. If after engine break-in, you want more torque and willing to tade off top speed, then go bigger sprocket. If torque takes a back seat to top speed, get a smaller sprocket. But base it on what like/want from experience.