Thumper Club Forum

Technical => Bike Problems/Questions => Topic started by: guest288 on May 10, 2008, 11:05:41 AM

Title: My forks are bobbling!
Post by: guest288 on May 10, 2008, 11:05:41 AM

Dropped the forks by 36mm through the yokes on the cougar to aid turning in.
Took the bike out for a cracking ride this morning, made a great difference to the little bike but now I've noticed that above 40mph or so I seem to have a repetative bobble through the bars. The tyre and rim still seem true, it seems as though its in time with the tacho gubbins but I'm not sure.
Any ideas guys?

Title: Re: My forks are bobbling!
Post by: johnr on May 13, 2008, 09:33:17 AM

is the wheel ballanced? tyres usually have a small coloured spot on one of the sidewalls, this is to be put opposite the tyre valve to help with ballance.
is it an up down bobble, or a side to side one?

Title: Re: My forks are bobbling!
Post by: guest146 on May 13, 2008, 03:39:12 PM

By lowering the bike on the forks it removes a little  of the bikes self centering and its want to go in a straight line, hence the quick turning, but my guess would be it now shows up even a small out of balance that would not have been noticed before. Maybe a steering damper would help

Ken

Title: Re: My forks are bobbling!
Post by: OMEGAMAN on May 13, 2008, 04:57:08 PM

 :-\  I know it sounds a bit strange, but check the REAR wheel balance as this can upset the front (forks).