Quieter bike engine kit (don't need speed)

[Neon]

I'm a big fan of electric so i would say electric is the way to go as well. The Walmart bikes are not a bad way to start out. With a few improvements they can be made into much better e-bikes. But those improvements cast extra money and adds to the price of the bike. As far as being quiet, they're not really that quiet because of the gear reduction. Starting off they sound like a car with a standard transmission backing up. At speed there is a very loud whine that i can't compare to anything. But they have enough power to climb hills very well. Even with a soggy 200 lb rider aboard.

 

[AussieSteve]

Just want to point out that not all electrics are noisy. My (presumably non-geared) hub motor makes virtually no noise.

 

[Neon]

I know not all motors are noisy Steve. I was simple mentioning the cheap walmart bikes with the Currie electric 450 watt motors. All that i've heard sound the same. I would love to nab a hub motor. Could come closer to having the ultimate stealth bike.

 

[AussieSteve]

It [/i]is[/i] good for stealth - even when they see it many people don't realise it's electric and ask what the box, (battery), is for.
I'd love 450W, though. I've considered an upgrade, but then range would suffer unless I also upgrade to a 14Ah or bigger battery, so I stuck with the 200W motor.
From the noise point-of-view, on shared pedestrian/bicycle cycleways, I have to ring the bell when I approach people from behind to avoid panicked leaps out of the way. The only sound is the clicking of the pawls in the rear freewheel.

Another less often mentioned advantage of electrics is that they're virtually maintenance-free compared to the ICE bikes. Aside from charging the battery after rides, the maintenance is the same as a normal bicycle.

 

[mlcorson]

HappyValley:
Mini 4 stroke engines.
You said:

I've had good luck with adding 12" of common automotive 1/2" heater hose, found at most hardware or car parts stores, at the muffler end to dampen the exhaust note even further. You barely hear them at idle.

No chance this can damage the motor? Could the added pressure possibly burn the exhaust valve? Is the heater hose an 1/2" ID?

see this comment:

A 4 stroke engine is not hurt by the exhaust system but a clogged one (unlikely) can cause overheating which can burn your exhaust valve.

http://www.motoredbikes.com/showthread.php?p=130126&highlight=burn+valve#post130126

 

[Happy Valley]

HappyValley:
No chance this can damage the motor? Could the added pressure possibly burn the exhaust valve? Is the heater hose an 1/2" ID?

Could it? I think like many things it depends on how it's done and care that goes into it. Yes, 1/2" ID and I buy the hose by the foot so 12" is just right, a straight shot with no radical bends, also I've been remiss not to mention I remove the chintzy "spark arrester" screens, my thought being it's removal balances any added restriction of the hose.

Many miles later, so far so good and it really knocks down a lot of noise.

 

[mlcorson]

Happy:
I will give it a try.
Thanks
-Mike