Please help.

GoldenMotor.com

jquintinjr

New Member
May 14, 2011
5
0
0
United States
i have a 2004 or 2005 model of a specialized hard rock 15'' frame.
heres a link for a referrence. (click the geometry tab for 15'' frame specs)
Specialized Bicycle Components : Hardrock Sport

i want to put an engine on this for under $300. i just am at a loss as to what engine will work. its my understanding that common engines that would fit a v frame bike will not fit my bike due to a lack of engine height clearance.

so i was thinking of getting a 49cc 4 stroke rear mount friction drive engine hoping it will fit.

im not looking to spend more than $300. and the 4 stroke 49cc rear friction drive from 4 Stroke Rear Mount Kit - $285.00 : Zen Cart!, The Art of E-commerce looks promising.

although im not sure if its a 49cc or a 31cc cuz it says both.

if this engine will fit my bike what would a reasonable top speed be being that i weigh 170lb and on a flat stretch
 

jquintinjr

New Member
May 14, 2011
5
0
0
United States
i have a 2004 or 2005 model of a specialized hard rock 15'' frame.
heres a link for a referrence. (click the geometry tab for 15'' frame specs)
Specialized Bicycle Components : Hardrock Sport

i want to put an engine on this for under $300. i just am at a loss as to what engine will work. its my understanding that common engines that would fit a v frame bike will not fit my bike due to a lack of engine height clearance.

so i was thinking of getting a 49cc 4 stroke rear mount friction drive engine hoping it will fit.

im not looking to spend more than $300. and the 4 stroke 49cc rear friction drive from 4 Stroke Rear Mount Kit - $285.00 : Zen Cart!, The Art of E-commerce looks promising.

although im not sure if its a 49cc or a 31cc cuz it says both.

if this engine will fit my bike what would a reasonable top speed be being that i weigh 170lb and on a flat stretch
bike i have is identical to this
 

LS614

Active Member
Dec 22, 2009
1,236
3
36
CT and MA
I'll tell you upfront that I GREATLY dislike aluminum frames because it is much harder to know if the aluminum alloy can handle an engine. I think the downtube on that bike might be too big for the stock grubee mounts so you'd need bigger mounts like those at Sick Bike Parts. As for your first question about the rear friction, I think it's a GREAT idea. 4 stroke is reliable and so is friction. I can tell just by looking at that link that the engine is a clone of the honda gx31 so it is a 31cc, yes. If it were a 49cc clone, the tank would be on the top. One other thing, the claim of 40mph on that kit is bogus, you'll get 23-27mph if you are lucky. I still think that is a good idea. Peace :)
-LS
 

jquintinjr

New Member
May 14, 2011
5
0
0
United States
I'll tell you upfront that I GREATLY dislike aluminum frames because it is much harder to know if the aluminum alloy can handle an engine. I think the downtube on that bike might be too big for the stock grubee mounts so you'd need bigger mounts like those at Sick Bike Parts. As for your first question about the rear friction, I think it's a GREAT idea. 4 stroke is reliable and so is friction. I can tell just by looking at that link that the engine is a clone of the honda gx31 so it is a 31cc, yes. If it were a 49cc clone, the tank would be on the top. One other thing, the claim of 40mph on that kit is bogus, you'll get 23-27mph if you are lucky. I still think that is a good idea. Peace :)
-LS
thanks man! so 27mph tops? :( was hoping for more...u no of any cheap walmart bikes thatl take a 49cc grubee? not cruiser style...
 

LS614

Active Member
Dec 22, 2009
1,236
3
36
CT and MA
When I shop for a bike to motorize I look for several things
1) as few cables as possible where the engine and gas tank mount
2) a steel frame
3) if you can, a frame with small tubes
Nowadays you probably will NOT find a small tubed bike, but steel will help make it sturdier. You can get a welder to weld some mounts to a steel bike, or you can just get the front mount from SBP, just make sure your downtube is round and not square. I can't stress the importance of a steel bike. Also, if you want to save money but want a strong, fast, quality engine out of the box, get a 66cc Raw engine or an SD Stinger engine. Both are quite good, and I've personally had a VERY good experience with the stinger. :)
 

jquintinjr

New Member
May 14, 2011
5
0
0
United States
When I shop for a bike to motorize I look for several things
1) as few cables as possible where the engine and gas tank mount
2) a steel frame
3) if you can, a frame with small tubes
Nowadays you probably will NOT find a small tubed bike, but steel will help make it sturdier. You can get a welder to weld some mounts to a steel bike, or you can just get the front mount from SBP, just make sure your downtube is round and not square. I can't stress the importance of a steel bike. Also, if you want to save money but want a strong, fast, quality engine out of the box, get a 66cc Raw engine or an SD Stinger engine. Both are quite good, and I've personally had a VERY good experience with the stinger. :)
would a raw or grubee fit on this bike? http://www.walmart.com/ip/NEXT-Parowan-26-Men-s-Mountain-Bike/16318857 or this one Walmart.com: Roadmaster Granite Peak 26" Men's Mountain Bike: Bikes & Riding Toys
 

MotorBicycleRacing

Well-Known Member
Jul 28, 2010
5,844
109
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SoCal Baby!!!
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so i was thinking of getting a 49cc 4 stroke rear mount friction drive engine hoping it will fit.

im not looking to spend more than $300. and the 4 stroke 49cc rear friction drive from 4 Stroke Rear Mount Kit - $285.00 : Zen Cart!, The Art of E-commerce looks promising.

although im not sure if its a 49cc or a 31cc cuz it says both.
WARNING: Do not buy anything from motorbicycle.org
He has been taking money and not sending product then not
answering phone or email.
EZ Motorbike dropped him as a dealer.

motorbicycle.org is just a drop shipper anyway.