Vibration

[Duccout]

Here is a talking point: vibration. I have two Mototrans singles, a 250 Strada and a 350 Forza, and both are very smooth, certainly smoother than Bologna singles. I can think of two possible reasons for this: did Mototrans use a different balance factor to Bologna? Or, is it because both my bikes use the parallel twin frame, and maybe this gives different harmonics to the standard singles frame?

The vibration frequency seems to be lower than Bologna bikes, and very similar to that of Velocette singles, with the engines being very smooth at lower revs and quite rough at higher revs, but not tingly like the Bologna bikes.

Any thoughts?


Cheers,

Colin

[Jordan]

Check the engine mounting bolts for tightness.

[IanHood]

Well, my 450 is as smooth as silk (and if you believe that...)

[Ventodue]

Jon P. might well have some good thoughts on this, he being well familiar with the products of both factories ...

[Duccout]

I suppose a good comparison would be between say, a Vento or Road and a Forza, to see if the frame makes any difference.

[Jordan]

Just for fun, loosen the engine mounting fasteners a bit, to really experience 450 vibration.

[IanHood]

My fingers (and bollocks) are tingling quite enough already thank you

[Jordan]

Once on my 450 I was riding along, when vibration rapidly became severe.
I stopped to see what might have caused it, and there it was - one of the long rear mounting bolts was sticking out by some inches, having lost its nut.
Check the simple things first.

[Duccout]

You'd pay good money for medical treatment like that! Now I know why old guys ride Duc singles - it is a treatment for impotence. As for bolts, I remember my Sebring developing excessive vibration and found the rear engine bolts loose, which is why I check them for tightness regularly. I have always wondered why Ducati never used a head steady when all the British singles did, but I am sure that if it had made a difference Ducati would have tried it.


Cheers,

Colin

[blethermaskite]

Ah Ha! I bought a sebring based race bike many years ago and guess what? it had a head steady.......removing this removed about 50% of the engine vibration so I suspect not a great mod.
Cheers George