Yamaha YBR 125 07 Front End Wobble

Hello there, first post and am hoping you can help with a problem that i have that is worrying me.

Fitted a new front, rear sprocket and a new DID chain on friday at mates garage.

Since this i have noticed that from about 25mph upwards the bike has a front end wobble getting worse the faster you go (nothing on the front has been touched) yet the back end does not feel like it's wobbling.

When i got the bike home i poped it onto the center stand and just let it tick over in first and had a look at the rear wheel.

The rim it's self looks fine and i can not see any movement in it but i can see movement in the tread pattern on the tyre.

The only thing i can think of is that the first time we put the back wheel on we forgot the left hand spacer and wonded why the wheel would not spin... could this action have warped the wheel/sprocket/sprocket carrier/barings ?

Thanks in advance,