in Blue Mound (Moderator: Walt Hougas)

I'm going to try and get out to blue mound on my fatbike before the snow flies (assuming trails open up by then).  Wondering what tire pressure to run - can anyone else share what's worked for them?  Probably higher than it needs to be, but at QR and Camrock I've run 12psi in the back without issue.  I just really don't want to pinch flat.  Combined weight of me and the bike is about 180 lbs.  For reference, on my hardtail (2.4" tires also not tubeless) I've found I will pinch flat below 35 psi.

thanks in advance!

I am clocking in well above you on the scale. I typically run 8 in front, and 10 in the rear for dirt conditions when the objective is for a fun ride. I have run up to 12 psi on hard trails if the object is to go fast, but I don't like the harshness and chatter I get when running those pressures.

I have never pinch flatted on my fatty. I have certainly touched a rim before, but that is when running 3-4psi and going for max float on soft snow conditions. That being said I run the same width tire on my fully 29er, and set it at 25-27 when I ran tubes and I only recall getting a pinch flat once. Of course it was during the Pitch Black Singletrack race. Now I run 23 tubeless with no issues.

I am 215 and run 11 to 12 in dirt.  4 to 8 in snow....only pinched once at 3

Maybe Rick will see this, he rides his fat bike out there a lot. Pretty sure he doesn't change much if anything.

Edit- actually I think he runs tubeless, too.

thanks for the really useful feedback everyone! 

Sounds like I'll probably stick with 11-12 psi for riding dirt at Blue Mound.  I do at least have 120 tpi tires which I think does help soften the ride a bit even when the pressure is still kind of high.  I've tried running down to 9 on dirt but things just felt sluggish and I was constantly worried about flatting when things got rocky.  I'm pretty used to a rigid bike and don't mind the extra harshness.

I feel like I may be somewhat more likely to pinch flat than others due to riding pretty hard but not always having very good technique (ie not absorbing a big hit with my legs as much as I could).  Riding in upstate NY this summer, I even manged to get a pinch flat on the front of my hardtail when it got hung up for a split second on a big rock.  I was running ~25-30 psi in the front at the time.  I've pinch flatted a couple times in the rear as well when I was still running just over 30.

I will be at Blue Mound this afternoon.

Sorry the trail is closed again. I will speak with the ranger on duty to try and get the trail open. Unfortunately, although I've been told that they are "just waiting for" me to tell them to open, the reality is the staff will sometimes keep the trail closed even though I say conditions are OK.

FWIW, I was at Blue Mound yesterday to do some work and saw that the trails are in excellent condition. But no one was on duty, so there was nothing I could do to change the status.

I will post an update immediately if I can get a trail status change.

Walt

Walt

Thanks for trying to get the trails open Walt.  Ended up having to ride Camrock but still had a great time.  I always want to ride the expert loop that includes cliff edge but end up confused.  Does this loop still exist?  Initiation is really obvious, but I'm never quite sure where to go after that.  Definitely not a big deal, but I was also wondering if it would be a hassle to get the more updated map that's on the trail signs up on the website?  In any case the camrock trails are fantastic, and I really appreciate all the hard work that goes into them.

Sorry for the slow response. Ive got 120 tpi nates. Not tubeless. I weigh 220+ and carry lots in my camelback. I run 9-10 psi for dirt. Leave it like that for blue. Only pinch flatted once at 6 psi. For paved stuff I air up to 20. It's loud. Did the poker ride in the snow on Saturday night at 15 psi. Was very pleased with the grip/performance balance.

Just to add another data point if anyone else looks at this, but 10.5 psi (rear) was too low for me at blue mound on friday.  Even with the snow, there were lots of rocks exposed - when I realized this I probably should have added a bit more air.  In any case, I ended up with a snakebite that was serious enough that it also dented my rim (happened on overload).  After that I pumped up to 12 front, 14.5 rear trading off the harsher ride for the peace of mind that I almost certainly wouldn't flat again.

I guess I just have to accept that my riding style (ie choosing terrible lines?? :D)makes me really susceptible to pinch flats.  Next time maybe I'll try something like 11.5 front and 13 rear.

It's clear I still have a lot to learn about pressure - I rode out to the trails on the military ridge trail which had a small amount of snow on it.  Wouldn't be surprised if this is obvious to other people on here, but I felt like I was significantly faster on the way back at 14.5 psi than the 10.5 on the way out which was not what I was expecting.

If you are pinch flatting at those pressures you may be putting too much weight on your seat.  That could be riding position or style but give some thought to your weight distribution next time you're out. Most of your weight should be on your pedals while your hands and tush keep you balanced, that's oversimplified, but in general you don't want to feel like you're always 'landing' on your saddle.

Welcome to the world of fat bike tire pressures, it's a guaranteed topic of conversation among any group of fatties.

thanks for the advice Rich.  I certainly am not ruling out poor riding technique for my need to run higher pressures, but I don't have my butt on the saddle when I'm getting flats (I think that's what you're suggesting?- sorry if I misunderstood).  Every pinch flat I've ever gotten on my rear wheel including the most recent one on the fatbike has happened when I was on a moderately fast rocky descent where I was definitely standing so none of the weight would be transferred through the seat. Now how good/bad of line I was choosing and how well I was absorbing hits with my legs compared to other riders successfully running lower pressures, I have no idea.

Additionally, I certainly could move my weight further forward when descending, but this just makes me feel less stable and like I'm more at risk of going over the bars (in some cases, perhaps irrationally so).

Someone mentioned you were running tubeless, but I'd still be curious what pressure you use on your fatbike for riding dirt at Blue Mound?

Weight back but not on your seat is what you want when going downhill so it sounds like you're on the right track.  Don't rule out bad luck.