Anyone try these yet for their bike?

Titanium Front Fork Axle Sliders Protector Honda CBR600 F4 F4i 99 00 01 07 | eBay

Also has anyone try putting spools through the rear axle? I'm thinking about giving it a try.

 

Not those specifically and not on a F4i. Had fork sliders and offset spools on my s1000rr during a lowside. Front sliders had to be replaced. Unfortunately the exhaust acted as a rear slider though.

The front sliders are definitely worth it. But if you're looking to protect the rear, you have to remember the right side has a big ole can that needs protection too. Look for exhaust sliders too

 

Good idea about the exhaust slider!