You Madazz Trike or upgrade axle will be supplied with Nyloc Wheel nuts, this is so they dont come off!
Please do not tighten these wheel nuts too tight. If you do you will put pressure on your bearings and cause them premature failure and your wheels wont run free.
A good guide is too only tighten them enough so that there is no more sideways play in your wheel. Any tighter is not necessary and will slow you down!
*TIP - If you can turn the spacers with you fingers but not feel sideways play, this is perfect.