Sidewinder Jerry
Well-Known Member
What size wheels do you have?
sup people!!
- Thread starter ceedantech
- Start date
Sidewinder Jerry
Well-Known Member
Here is the specs on the OP engine:
Specifications:
45.7cc High Output Race Engine
Horsepower 4.20HP at 18,000 RPM
Torque = 2.315 lb-ft (0.32 kg-m) at 8,000 RPM
Includes fabric air filter w/ anodized aluminum protective shroud
The kit he's using has 2 roller sizes 1" and 1.25". If the stats on the engine are true at 3/4 throttle that would be 13500 rpm which would propel the bike 40 mph using 26" wheels and the 1" roller.
This seems like way to powerful of an engine for a friction drive system. Tires wearing out quickly. Potential blowouts I don't even want to think about that one at 40+ mph.
Specifications:
45.7cc High Output Race Engine
Horsepower 4.20HP at 18,000 RPM
Torque = 2.315 lb-ft (0.32 kg-m) at 8,000 RPM
Includes fabric air filter w/ anodized aluminum protective shroud
The kit he's using has 2 roller sizes 1" and 1.25". If the stats on the engine are true at 3/4 throttle that would be 13500 rpm which would propel the bike 40 mph using 26" wheels and the 1" roller.
This seems like way to powerful of an engine for a friction drive system. Tires wearing out quickly. Potential blowouts I don't even want to think about that one at 40+ mph.
Last edited:
ceedantech
New Member
I have 26" wheels, 1.25" spindle(roller) and i used kenda tire 26x1.95.
Sidewinder Jerry
Well-Known Member
Your speedometer setting for a 26" wheel is 2075. At 3/4 throttle (13500 rpm) using the 1.25 roller your speed would've been 49.7 mph. This is way too much engine for a friction drive system.
I noticed you have rim brakes and the engine is mounted in the rear. On a bicycle the majority of the weight is on the rear wheel. On hot summer days your rear tire will have an extremely high heat build up. The tire will also wear out really fast as well. You are really going to be prone to a blow out.
I'd suggest converting your engine over to a chain driven system. You may even want to do a whole new build with the engine. Then you could put a mid grade performance engine on the friction drive bike sell it to help pay for your high performance bike.
I noticed you have rim brakes and the engine is mounted in the rear. On a bicycle the majority of the weight is on the rear wheel. On hot summer days your rear tire will have an extremely high heat build up. The tire will also wear out really fast as well. You are really going to be prone to a blow out.
I'd suggest converting your engine over to a chain driven system. You may even want to do a whole new build with the engine. Then you could put a mid grade performance engine on the friction drive bike sell it to help pay for your high performance bike.
Last edited:
butre
Well-Known Member
I wouldn't put one of those on an f/d but I'd absolutely love to have one for a frame mount race bike
Sidewinder Jerry
Well-Known Member
That's the way I feel too Butterbean. A chain driven system would be the best way to go with such an engine. That much power on a friction drive setup is down right dangerous.
butre
Well-Known Member
Mine did around 34 with the stock engine and a 40 tooth sprocket. With a low compression head I could see 25 being the maximum but with the higher compression angled plug head I had no problem getting to 30+ mph, though it did take me forever to get there
Sidewinder Jerry
Well-Known Member
One does have to question what is so special about a Chun Yang engine to give it such a high performance.
