on a bowden system yes, but just ever so slightly. not any more than you could fix with retraction and other settings, and prolly only nylon and other flexible ones you should be doing in a direct dirve anyway would be affected.

and even if it were worn down that much it wouldn’t cause any problem as the entire tube is made of the same slippery stuff, it’s not a coating.

light speed = gravity speed

lead’s bad for you, sure, but when some of the other metals on this scale’s red might literally explode your tongue/face/head depending on sample size and saliva accumulation, i’d say yellow fits it pretty well.

i use revolution (selamectin) from the vet and it’s like a fucking flea nuke. if you’re getting it soon i wouldn’t worry about fleas getting in the house because once you use this stuff it’ll clear all of them out of the area in literally hours. fantastic stuff.

also, don’t trust any over the counter flea sprays or treatments at stores, they all use neurotoxins that they claim is safe for cats, but some cats are more sensitive and it might cause neurological damage or even death.