Why not "isolastic" suspension like a Norton for Vibration

[birdog4549]

I once owned a Norton 750 Commando with "isolastic" suspension. They mounted the engine with rubber mounts much like a car has and it was very successful. the whole bike would shake at idle but when you gave it any throttle it quieted right out. I haven't had my XS apart but any rubber mounts may be a step in the right direction. Has anyone ever posted something like that? Maybe it would be complicated but there are threads about all kinds of complicated things that have been done.

 

[grizld1]

The Norton frame was designed with sufficient rigidity and space for rubber-damped mounts. The XS650 frame was not. Yamaha's prototype Ascot TT used rubber damping but never made it to the production line. The late Tony Hall bought the plans from Yamaha and sold a number of the Ascot frames; they're very rare, particularly on the American side of the pond.

 

[xjwmx]

I use the vibrations to help tell me how it's running. Part of it talkin to me. Not uncomfortable to me at all. I don't get it, but maybe if I was used to a car...

 

[azman857]

Get the timeing spot on, set your valves and get the carbs mixture and syc set and the vibes are minimal. I too had a Norton, an 850 Commando. Yep at idle, it'd vibrate like a paint shaker. At 2.5k and up, she was smooth as glass. Our XS's, sure they vibrate a touch, but for me (except around 2500-3250) she's pretty smooth for a ridgid mounted twin.

 

[Travis]

I think someone could probably design a rubber mount for 3 of the 5 engine mounts, but the bottom mount and bottom rear mount that bolt directly to the frame without a bracket couldn't be rubber mounted (I don't think they could easily anyway). I wonder if having 3 of 5 rubber mounted would make a difference???

 

[ReycleBill]

I think someone could probably design a rubber mount for 3 of the 5 engine mounts, but the bottom mount and bottom rear mount that bolt directly to the frame without a bracket couldn't be rubber mounted (I don't think they could easily anyway). I wonder if having 3 of 5 rubber mounted would make a difference???

I suspect that without some sort of frame enforcement, any amount of rubber mounting would be problematic and ill handling. As to reducing vibration with 3 of 5-- I donno?


PS. A Barsnake did wonders for mine.

 

[birdog4549]

I suspect that without some sort of frame enforcement, any amount of rubber mounting would be problematic and ill handling. As to reducing vibration with 3 of 5-- I donno?


PS. A Barsnake did wonders for mine.

Do you have the "buckhorn" bars on your XS and if so, did you use the liquid barsnake or the solid one. I have the stock buckhorns and I can ask them but if you have the direct experience that would be great. I put Hugh's solid riser mount on my bike and I like them because the movement of the bars didn't seem "right" for me. I like the solid mounts and it sounds like a barsnake would be a good thing. Thanks.

 

[birdog4549]

Get the timeing spot on, set your valves and get the carbs mixture and syc set and the vibes are minimal. I too had a Norton, an 850 Commando. Yep at idle, it'd vibrate like a paint shaker. At 2.5k and up, she was smooth as glass. Our XS's, sure they vibrate a touch, but for me (except around 2500-3250) she's pretty smooth for a ridgid mounted twin.

Solid stuff, thanks

 

[xjwmx]

^Right. I was thinking you were thinking about the residual vibration, after all the above had been done. Carb synch'ing is the biggest factor I think. And easiest.

 

[ReycleBill]

Do you have the "buckhorn" bars on your XS and if so, did you use the liquid barsnake or the solid one. I have the stock buckhorns and I can ask them but if you have the direct experience that would be great. I put Hugh's solid riser mount on my bike and I like them because the movement of the bars didn't seem "right" for me. I like the solid mounts and it sounds like a barsnake would be a good thing. Thanks.

Yeah, you need Hugh's risers with the buckhorns... I'm running a wide tracker style bar with the solid barsnake. That should work on the buckhorns as well. Just lube it up and don't attempt to pull it through without a helper or you'll pull your bike over on top of you. The helper holds the bike and feeds the snake into the bars.

The wider/longer the bar the more the vibration. Just make sure you plan to keep the bar 'cause the barsnake ain't coming out.

They come with very good instructions.

If the Barsnake isn't enough then you can still add bar end weights.

But like others are saying, tuning makes more difference than anything else.

You've probably noticed that certain speeds (3500 RPM on mine) create the most vibration so gearing to keep you above or below that worst range helps too.

 

[oldbiker]

hi guys,, i suppose ,,if you wanted too go anti-vibration ,,,,you could look at MACHINE TOOL ANTI-VIBRATION PADS ,,,they are used on large complicated electrical cabinets /and machines where you want toooo keep vibration to a min..regards oldbiker