Hello all! I need some help!

keysertomasi · #1 08-15-2009, 10:43 PM

Hi everyone,

I've wanted to put together (and ride) a motorized bike since I was 11... about 16 years ago. Well, I've finally gotten to the point where I can.

I currently have and ride a 2007 KHS Urban Xpress, and I'd like to motorize it, but am not sure as to what, if any motor kit will properly fit it. I don't want to cannibalize the bike as it is currently my main mode of transportation. I'm not sure as to the size of the frame, but can easily measure whatever dimension is necessary. If anyone has an ideas on what kit would work, what I should measure, etc. please let me know.

Can anyone help? Thanks in advance!

BAMFinCali · #2 08-16-2009, 12:05 AM

what type are you looking for,2 or 4 stroke? in-frame or rear mounted on a rack?

**Dave31** · #3 08-16-2009, 04:09 AM

Welcome keysertomasi,

For the in frame two-stroke...
Most 24" or 26" bicycle with diamond frame and horizontal top tube should have sufficient space to mount motor.

At least 12.5 inches running along the seat tube from the top of the bottom bracket to the bottom of the top tube.Tubing size from 1-1.5inches on the both the seat and down tube. Plus or minus 70deg. above the bottom bracket between the down tube and the seat tube. Inner distance between pedals needs to be greater than 4.5 inches in width to clear the 4.5inch wide motor.

http://motorbicycling.com/f3/what-ki...mmend-510.html

**BarelyAWake** · #4 08-16-2009, 04:37 AM

Got any pictures of your bike?

About the only thing I can add is little details like obviously twist grip shifters are a problem if you have them as you will need to replace the right one w/a throttle. It's not a huge deal as you can replace it - but that brings up another aspect, upgrading components.

Should you wish disk brakes or w/e, oftentimes these various modifications can exceed the value of the bike itself - if there are too many, such as front suspension etc., you could be better off looking for a bike specifically for this project including the features you would want.

Another way to look at it (and what I did) is to view this first MB as a "prototype" and build it to learn what you like, don't like, didn't think of the first time. I erred by modifying a motor mount, so now my engine wont fit in another. Not a huge problem as these kits are inexpensive - but it's something to keep in mind.

BTW - awesome! Welcome to the family, yer gonna love it!

keysertomasi · #5 08-16-2009, 02:01 PM

Hi everyone,

thank you all so much for your quick and comprehensive replies. Let me try to answer each of your questions in turn:

BAMFinCali - I am looking for a two-stroke, in-frame motor. I'm in a state where the motor size must be less than 50cc, so one of the 48-49cc kits would be best for me.

fairracing31 - Yes, I've heard about 24" - 26" frames.... the only thing I don't understand, is what dimension of the frame is 24" to 26"? In response to your mention of the various lengths, the lenght of the seat tube inside the frame, from the inside (or bottom) of the top tube, to above where it meets the inside of the other tube is a but more than 13". All three tubes in the triangle part of the fram have diameters between 1-1/8" to 1-1/4". The angle between the seat tube and down tube is something I can not measure right now without a protractor or other proper tool. The width between the pedals at the narrowest point is about 4-3/8".

BarelyAWake - The forum won't let me post photos until I am an active member otherwise. They are available on photobucket, I can send you the links via email or some other way if you prefer.

Thanks again, and please let me know your thoughts.

Cabinfever1977 · #6 08-16-2009, 02:05 PM

24 and 26" is the wheel and bike size not the frame size. anything over 12 1/2" for the bike frame tube should be fine.(thats the part from the top of peddal/crank area to the bottom of top tube)

keysertomasi · #7 08-16-2009, 05:36 PM

Hello, although I can't post pictures yet, I made my avatar the picture I had planned to upload. Small, I know, but perhaps useful. Thanks.

keysertomasi · #8 08-16-2009, 10:22 PM

I am looking for a two-stroke, in-frame motor. I'm in a state where the motor size must be less than 50cc, so one of the 48-49cc kits would be best for me.

keysertomasi · #9 08-16-2009, 10:22 PM

Yes, I've heard about 24" - 26" frames.... the only thing I don't understand, is what dimension of the frame is 24" to 26"? In response to your mention of the various lengths, the lenght of the seat tube inside the frame, from the inside (or bottom) of the top tube, to above where it meets the inside of the other tube is a but more than 13". All three tubes in the triangle part of the fram have diameters between 1-1/8" to 1-1/4". The angle between the seat tube and down tube is something I can not measure right now without a protractor or other proper tool. The width between the pedals at the narrowest point is about 4-3/8".

keysertomasi · #10 08-16-2009, 10:24 PM

The forum won't let me post photos until I am an active member otherwise. They are available on photobucket, I can send you the links via email or some other way if you prefer.

Although I can't post pictures yet, I made my avatar the picture I had planned to upload. Small, I know, but perhaps useful. Thanks.