I have a set of Two Bros. CF Slip-ons on my K-8. I noticed in the literature sent with the cans that they suggest a re-pack after 3k miles. I'm guessing that they will get louder as the packing deteriorates but I'm concerned that I'll probably get used the sound increase and may not notice. My question is this: Is there a way I can tell visually that they need a re-pack and, based on the experience of others, what's an approx. number of miles I can go before a re-pack is due?