Wheel spacer advice

[Ged]

been filling my head full of stuff...

I currently have H&R 20mm spacers on the back, type that bolts into the hub then you use your own wheel bolts....

Looking at these for the front...

Are these really safe to use? and are they balanced, so no vibration at speed?

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=300723937822#ht_1293wt_1270

iv also put a wanted thread up for some other spacers in time for FCS otherwise these are being bought (unless strong advice not too)

 

[bengtt5]

would rather run the 20mm at the front and the 16mm at the back
no different to delta mics but get some better wheel bolts or studs