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Havocdoesbikes

Havocdoesbikes

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I was going to buy the bbr 50cc/49cc fourstroke bike engine kit on bike berry but I wasnt sure witch sprocket to get. How fast would I go on a 44 tooth? I have 26 inch tires and I weigh about 140 pounds.
 
Welcome to the forum, I haven't built a four stroke so I can't help. I have two 48cc two strokes that will run 32 flat out on a good day, you should see at least 25-28 on a four stroke. My engines are ported and tuned for performance.
 
Havocdoesbikes said:
I was going to buy the bbr 50cc/49cc fourstroke bike engine kit on bike berry but I wasnt sure witch sprocket to get. How fast would I go on a 44 tooth? I have 26 inch tires and I weigh about 140 pounds.
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The reduction box is 6:1 and drives a 10t sprocket which will drive a 44t rear sprocket. Max horse power on these engines is at 6800 rpm so then all you have to do is use my mph speed formula.

(RPM x Wheel Diameter x ⚻)÷(Total reduction x 1056)= MPH.

(6800×26×⚻)÷(6x(44÷10)×1056)=19.9 mph.
 
The engine in this kit red lines at 7500 rpm. You should get a tachometer/hour counter for the bike. You can get one on eBay and Amazon. Max torque on these engines is around 4500 rpm.

With the tachometer if you are going over 7000 rpm throttle back some. If going up a steep hill at full throttle and you aren't getting at least 4500 rpm you need to pedal assist more. This is where a multi speed bicycle has an advantage over a single speed bicycle. You can shift to a more efficient gear to pedal assist. With a single speed all you can do is increase the pedal cadence (crank rpm).

The hour counter is good for maintaining a maintenance schedule. Change the oil every 25 hours and clean the air filter every 10 hours. My 4 stroke engine has over 4000 hours use on it and is still going strong after 12 years.
 
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With a 32 sprocket at 6800 rpm you'd go 27.4 mph. You could also go to a larger drive sprocket. However you shouldn't go below a total reduction of 16:1.

With a 12t drive sprocket and a 32t rear sprocket at 6800 rpm you'll have a top speed around 33 moh.
 
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I started with the 2-stroke as my choice, I've had several motorcycles that required mixing fuel so that was no problem, some people like to pull up to a station and refuel. Comparing a 48cc two stroke to a 49cc four, the two stroke will outperform the four, the four has more internal moving parts that reduce the power output. The four with the right transmission has been proven to be reliable by some members here on the forum, the choice is up to what you want to start with.
 
Greg58 said:
There have been many members here that have bought the low end four stroke kits from ebay that the transmission failed quickly, a good quality kit that will last will cost close to twice the ebay kit.
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Along with the reputation of the company he's considering dealing with.
 
Greg58 said:
There have been many members here that have bought the low end four stroke kits from ebay that the transmission failed quickly, a good quality kit that will last will cost close to twice the ebay kit.
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Is bike berry a good and safe place to purchase these kits or is there somewhere more reputable?
 
Unless they have changed something in the transmission the website page gives a different reduction value for the transmission than their video does. The page says 6:1 where as the video says 6.83:1.

www.bikeberry.com

49cc BBR Tuning 5G Pull Start Bicycle Engine Kit- 4 Stroke

This Honda 4-stroke 49CC bike engine kit: when you want a tough, reliable engine that will go the distance with you. Shop our selection now!
www.bikeberry.com www.bikeberry.com


If you go by the video then using a 10/44 on 26" tires at 6800 rpm will give you a speed of is 17.5 mph. If you up graded to a 12/32 the speed at 6800 rpm would be 28.9 mph.
 
Sidewinder Jerry said:
Unless they have changed something in the transmission the website page gives a different reduction value for the transmission than their video does. The page says 6:1 where as the video says 6.83:1.

www.bikeberry.com

49cc BBR Tuning 5G Pull Start Bicycle Engine Kit- 4 Stroke

This Honda 4-stroke 49CC bike engine kit: when you want a tough, reliable engine that will go the distance with you. Shop our selection now!
www.bikeberry.com www.bikeberry.com


If you go by the video then using a 10/44 on 26" tires at 6800 rpm will give you a speed of is 17.5 mph. If you up graded to a 12/32 the speed at 6800 rpm would be 28.9 mph.
Click to expand...
Thank you for clarifying.
 
Norm at Venice motor bikes has said before on the forum that he likes the 7G belt drive transmission, he knows, he does this for a living. I would reach out to him if I had any questions.
 
Sidewinder Jerry said:
Unless they have changed something in the transmission the website page gives a different reduction value for the transmission than their video does. The page says 6:1 where as the video says 6.83:1.

www.bikeberry.com

49cc BBR Tuning 5G Pull Start Bicycle Engine Kit- 4 Stroke

This Honda 4-stroke 49CC bike engine kit: when you want a tough, reliable engine that will go the distance with you. Shop our selection now!
www.bikeberry.com www.bikeberry.com


If you go by the video then using a 10/44 on 26" tires at 6800 rpm will give you a speed of is 17.5 mph. If you up graded to a 12/32 the speed at 6800 rpm would be 28.9 mph.
Click to expand...
Stay away from this type of transmission, in the video, go with 7 or 8 G is the better choice.......Curt......... Gas Bike is good
 
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