View Single Post
Old 02-20-2010, 11:37 PM
exavid exavid is offline
Motorized Bicycle Elite Member
Join Date: Dec 2009
Location: Medford, OR
Posts: 163
Default Re: Reducing Vibrations at High Speeds.

Vibration is an interesting problem. I have two 49cc motor bikes. One is a two cycle on a Schwinn mountain bike, the other is a four cycle on a Schwinn Cruiser. The two cycle is pretty smooth, I have a pull back bar on the bike and don't feel much vibration at any speed in the bars or seat. On the cruiser I get a pretty strong buzz in both seat and bars. I have a 44 tooth on the two stroke and a 50 on the four. I've ordered a 44 for the four stroke which should here Monday. I'm hoping that the lower rpms at cruising speed will reduce the vibes a bit. At least it will slow the engine a bit which sounds like it's really churning. It's hard to be sure since fan cooled engines always sound like they're running faster than non fan equipped ones. So far I have about 100 miles on the two stroke and 20 on the four stroke. Both are running well, I like the centrifugal clutch and pull cord on the four stroke but find the lighter two stroke bike a bit more fun to ride. One change I'm planning on the four stroke is to build a better engine mount I plan on bolting two pieces of aluminum angle (can't weld it the frame is aluminum) side by side with the flanges outward to the bike frame. A couple of holes in the sides of the frame at that point won't affect the strength much since lateral holes in that area are really in a neutral stress point. If that isn't enough my next plan will be rubber shock mounts. One way or another I'm going to make the four stroke smoother and quieter.
Goldwing 1500, Silverwing 600, Schwinn 49
Reply With Quote