My 66cc Micargi RoverGX beach cruiser

hey, this is my first bike build. I really enjoyed putting it together despite the problems that arose while doing it. All the troubleshooting was worth it now that I can ride it.

I bought a 66cc kit from Pirate Cycles in Massachusetts. I live close enough that I was able to go to the shop in person. I bought the bike there too and upgraded the wheels and got the sprocket adapter with a 40 tooth sprocket. I've spent 450 dollars total for the bike new, the engine kit, and the wheels and sprocket adapter. I don't think I will do any serious upgrades to the bike as I gave myself a budget of only 500 dollars for everything. Maybe I'll put a better spark plug, get the billet intake that pirate cycles sells, and maybe chop off the muffler, run some hose out back and put a homemade silencer at the end of it. I can't really justify spending more than 500 dollars on everything.

It runs nice stock as it is. It really doesn't bog going uphill (I weigh 155lbs) and I don't have a speedometer but it cruises somewhere in the 20's, which is fast enough I guess for a bike that only has a coaster brake.

EDIT: just borrowed a GPS to get an idea of the speed. On a couple short flats got it up to 30MPH. goes up hills nicely at 22MPH without crazy working the engine. I feel that the torque peak of the engine is around 25MPH, so maybe 2/3 to 3/4 throttle. I've got less than 50 miles on it so far so maybe it'll gain a little power after it breaks in?

EDIT 2: got about 150-200 miles on the engine and it has gotten stronger. It will hit 31-32MPH WOT on a flat, can comfortably cruise up to 28MPH and uphills it bogs slightly to 24MPH.

one more thing I forgot to mention, I was given those dampeners that go in the engine case covers. I put them in and it is pretty quiet when it idles.

if you decide to get the Rover GX a 66cc kit will not be plug and play. I had a few issues.

1) front motor mount--with the back motor mount up against the bicycle seat tube the front motor mount isn't even close to making it. I made my own front motor mount. it's ugly but very strong. here is a link describing what I did http://motorbicycling.com/showpost.php?p=487813&postcount=9

I imagine you could back the front engine studs out, put longer studs in as the stock ones didn't reach to underneath the down tube, get or make a spacer(like a hockey puck cut out the form of the downtube) and secure it that way. I did mine the way I did because I didn't want to drill into the frame and I was scared to back out the engine studs fearing I wouldn't be able to get 'em back in if I needed to, lol.


2) the gas tank won't mount stock on the top tube of the bike as is. the top tube has too much height and the pegs coming out of the bottom of the gas tank wont reach to underneath the top tube to be mounted with the given hardware. here is another link to what I did to get around that problem http://motorbicycling.com/showpost.php?p=487811&postcount=3

3) very minor problem, putting the ignition box onto the down tube of the bike couldn't be done with the bolts/mounting plate because of the width of the down tube. I bored the holes that go through the two sides of the ignition box to make them bigger and I used two of the bolts were supposed to be for the rag joint to secure it. was so snug I didn't need to bolt it.


for mounting the engine you will need to make your own front mount, or buy one. sick bike parts has a front engine mount for 12 to 14 dollars that you could buy. the gas tank will need it's own mounting solution if you want it on the top tube of the bike, or you could get one of those racks that clamps onto the seat post and secure it to that(the tank will then be in the back of you of course)


I really like the comfortable riding position of the beach cruiser. Beach cruisers look good motorized too. I felt it was worth the extra work to get it going.