First Motor Bike ride today

Discussion in 'Motorized Bicycle General Discussion' started by MikeSSS, Aug 19, 2014.

  1. MikeSSS

    MikeSSS New Member

    Joined:
    May 15, 2012
    Messages:
    16
    Likes Received:
    0
    Bike is a Trek 920, no suspension mtn bike, 9 speeds in rear, 3 speeds in front. Tires are from Performance, Gotham 26x1.75 puncture resistant. Tubes are the thick puncture resistant, with lots of slime.

    This bike rides very well but the tire/tube/slime combo has a lot of rolling resistance.

    Motor is Subaru Robin EH035, a 33.5 cc four cycle, overhead valve, pushrod engine, with centrifugal clutch.

    Mount is a Straton friction drive. Roller diameter measures 1.161".

    The motor and kit performed perfectly, average speed was 16.2 mph for 18.88 miles. Gas used was 520ml or 0.137gal for 137 mpg. 14 to 17 mph is a very nice cruise speed, slower is quieter. Idle when going slow or stopped was 100% reliable.

    Conditions were not ideal, there was a strong head wind for half the ride. I wore a sun brim on the helmet and this acted as a aero brake when riding to windward. Finally removed it and riding was much more pleasant.

    All things considered, this motor and drive work extremely well.

    Happy trails,

    Mike
     
  2. wheelbender6

    wheelbender6 Active Member

    Joined:
    Sep 4, 2008
    Messages:
    3,825
    Likes Received:
    12
    Those head winds really make you appreciate the Subaru engine. I used the Gotham tires for a while from Performance and was very happy with them.
     
  3. 2door

    2door Moderator
    Staff Member

    Joined:
    Sep 15, 2008
    Messages:
    16,308
    Likes Received:
    30
    Congratulations, Mike.
    Those first rides are always good ones. Especially when they go as well as yours apparently did. Sounds like you did a good job on the install and now you're reaping the rewards.
    Thanks for sharing your good fortune. Have fun and please, ride safe.

    Tom
     
  4. Mike B

    Mike B New Member

    Joined:
    Mar 23, 2011
    Messages:
    2,256
    Likes Received:
    2
    Have fun!

    I am a big fan of friction drives, have 2 Statons, one with the same motor you have and one with a 33cc Tanaka. Love them both. They do not suffer the vibration issues of happy time motors and can easily be lifted off the tire for a zero drag pedal bike. And they go plenty fast enough.
     
  5. KCvale

    KCvale Well-Known Member

    Joined:
    Feb 28, 2010
    Messages:
    3,942
    Likes Received:
    29
    It is sure nice to see someone come in with a good experience on a first run for a change.
    Well done Mike ;-}
     
  6. MikeSSS

    MikeSSS New Member

    Joined:
    May 15, 2012
    Messages:
    16
    Likes Received:
    0
    This instillation has the motor tilted slightly front down. For this reason, the gas tank on the motor will not fill completely. I do have the larger tank that installs on top of the motor mount and may install it.

    I have a tendency to speed up going to windward, because the engine noise is harder to hear and use to gauge speed. On this ride I used a gps to measure speed, distance and time, it worked well but needs to be mounted on the handlebars.

    Calculated rpm is 4250 at 14 mph and a bit under 5500 at 18 mph. This Trek 920 feels very nice at speeds up to 20 mph, I didn't go faster but calculations yield about 7300 rpm at 24 mph, the calculations used 5% slippage.

    I did use pedaling assist at times, especially climbing or to windward. Pedaling is very easy, especially compared to after the motor ran out of gas and there were climbs on the way home.
     
  7. Davezilla

    Davezilla New Member

    Joined:
    Mar 15, 2014
    Messages:
    2,708
    Likes Received:
    3
    Glad to hear you got yours running so nicely for the first ride, sounds like your rpms and speed are about right for that size engine, and yes, any wind resistance you can cut down on will make a difference.
    Since you're in San Antonio maybe we can go for a ride on one of these weekends when I'm not so busy at the shop. Mine is good to go but I need to finish a few welds on my pipe and put it back on, I put a different front end on mine and it was hitting the pipe I made so i had to take it off and make a few small changes to keep the front tire from contacting it when turning.
    My shop is located at 2011 Quintana road if you want to pay me a visit sometime and I'm open from 8:30 am to 5:30 pm or so during the week and I open up at 9 on saturdays and stay open as long as I got work to do. I also tinker with motorcycles and motorized bicycles when business slows down or after hours.
     
  8. Ronzworld

    Ronzworld Member

    Joined:
    Feb 21, 2014
    Messages:
    118
    Likes Received:
    1
    Yes nice ta hear "success" stories isn't it ? Great stuff ... enjoy !
     
  9. KCvale

    KCvale Well-Known Member

    Joined:
    Feb 28, 2010
    Messages:
    3,942
    Likes Received:
    29
    Well, you have to figure that people that build and post lots of their builds pics were easy 'success' stories, in fact we build so many bikes here that a problem is a strange occurrence, but it is nice to not have most every 'nOOb' post being the same old common problems for a change.
     
  10. MikeSSS

    MikeSSS New Member

    Joined:
    May 15, 2012
    Messages:
    16
    Likes Received:
    0
    Dave,

    I'll contact you when I get the chance, been looking after some medical problems for a few days.

    The Straton friction drive unit seems to be very problem free. It took about an hour to mount on the bike, later the throttle was mounted in a few minutes. I chose the Straton friction drive and Robin engine because I'm too lazy to tinker with things to make them work.
     

Share This Page