So not the "what tires should I get" but some questions that maybe you guys have some experience with. I have two XRs, both with 80 fronts. One was BT45s 100f/110r and the other has Sport Demons (SDs) also 100F/110R. The BT45s tend to have a lot better feel to them for me. I can ride the SDs pretty well, and they grip seemingly as a similar level to the BT45s but I have some issues with them. I am 200 lbs in gear and the suspension is sprung with cut springs front with preload spacers and heavier oil, and the rear is BBR spring on new stock shock. One issue is the profile of the tire. Now the profile of BT45s such as well pinched on those tiny rims but they seem to use more of the tire and use it better. The SDs seem a bit stiffer construction and I also tend to get more of the feeling like I'm going to ride off the edge of tire as it lean it more. I run the BT45s at 16 lbs off the track front and rear and it seems a happy enough place, I tried that on the SDs and needed to drop the pressures lower to 15 hot off track to get some heat and feel and they feel like they need to be even lower. Would less pressure allow the tire to flex more to compensate for the stiffness of the tire. Would that allow use of more of the tire profile as well? 15 lbs seems really low to me, is it safe to go lower? What pressures do minis run on 12s? on 17 slicks? Wear patterns on the BT45s look more or less like normal tires after riding on track, the SDs hardly show any wear at all compared to them.
So I have heard people say they run anywhere from 15 up to 24f/23r (cold and what I run) psi. I think the majority of this comes from rider preference on what feedback they prefer to feel from these tires. I have previously used the Sport Demons and wouldn't go back to them. I thought they were great until a fell on my face. I wouldn't receive any notice of when they would let go especially not compared to the BT45's. In my two series I would say 99% of racers use the BT45s. For my 150f I use 17" Pirelli Moto 3 slick tires. I think Pirelli recommends around 24f/22r cold. That might be off and I'm just going off of memory. I run around 22/21 personally and so do a lot of the guys I race with. Some of the kids I think drop down to 18 or so but can't really confirm that just hearsay.
I run 25 psi front and 23 rear on my XR with BT45. I am a fatass though. My bike felt too squirming when I ran lower pressure
I run about 18 hot off the track I weight about 210lbs. I'm running the 100 front and rear. I started at 24 and lowered them till they stopped chattering. The rear will still hop a little if it gets really warm.
We have to run the shock stock other than the spring, (Ohio) I have the front pretty dialed but the shock is a weak link, especially for us heavy weights.
I run ~16 for race pressure... more if Im just turning non race laps. Im 235 in leathers/gear. Mostly because the racing is so close the added traction helps. With heavy springs front & rear bike turns & rides properly. Now I just need more motor or less 100lbs less weight...lol. On Sunday our Vets class had a qualifying time of :42 on a modified 100. Heavy Hitters (over 200lbs) was a :44. Bone stock 100s with talented & light (pro) riders hit 43s.
The 110 comes in a V-rated option, whereas the 100 only comes in H rated. I have been told (but never had anyone from Bridgestone actually confirm) that the V rated tires have stiffer sidewalls and you can run lower pressures without buckling them. That said, I turned my fastest laps on 100's front and rear. 110's on the front do feel slower to turn in than a 110 rear and 100 front, but it's the type of thing that you get used to and only notice if you ride 2 different setups back to back.
I'm running 110/90 v-rated Pirelli Sport Demons on my bike but it has a XR100 rear rim laced to the front hub so I have 1.6" width wheels front/back. I've only done two track days on the bike so I'm still new; but, I ran 20 psi front/rear out here in SoCal with temps in the mid 80's. I've heard the BT-45s are the golden ticket but the Pirellis after rebate were $110 shipped so I can't complain.
