Introduction and a tire psi question
 

Hi folks,

I come from a road background, trying to learn the language of mountain bikes. The back story:

I live in this old cottage:
http://bobbeasley.com/oakhaven/frontnow.png It's on 6 acres with access to another 6 for the purpose of building a bike trail. I've got a basic loop that includes grass, sand, hard packed road, and a twisty section through dense woods. I live on, what around here, is a hill but nothing you guys would respect..... Flat lands of South Louisiana.

I bought a CL bike I know nothing about. The owner, who bought it new, raced it and was very particular about components and maintenance. He is 1" shorter than I and 15 pounds lighter. I'm 5'7" 210. I mention that because I know nothing about sizing a mountain bike. He setup the rear shock and front forks for me. The specs are:

http://bobbeasley.com/bikeimages/G1.jpg

Giant Anthem X Advanced 29er
XTR including cranks
Formula Brakes
Monarch RT rear shock
Industry Nine carbon wheels with Maxxis tubless tires.

There's one spot on my trail where I get a little air and one log I hop over.

What's the range on tire pressure's? Is there anything different about airing up a tubeless tire?


Thanks!

Nice bike. Looks like it was well maintained. I race every now and then and without exception they guys I line up with keep their bikes in top condition. No one likes a DNF by their name due to mechanical failure.

On tubeless I have 2.0 Spesh fasttracks on my full suspension rig and run those typically at 30 PSI. I am 200 lbs and the trail I ride are very rocky. Lower pressure risks sidewall tears from sharp rocks. Max pressure I ride is 40 psi if I am riding on pavement for a commute to work for a change of pace.

I'm on the west coast with low humidity and high summer temps and the sealant will dry out after a couple months. You will want to check and refresh sealant once in a while.

At some point you will want to get a shock pump to experiment with the feel of different pressures and settings. They are fairly inexpensive.

Nice cottage BTW. That's a really relaxing setting. Take a couple of pics out on the trail. Love to see where everyone rides.

The cabin looks nice and cozy.

Thanks for the kind words and advice! That's my dream house for sure, 3 miles to downtown restaurants, city water, and most importantly cable high speed internet.

Old Girl's a movie star too, Season 2 episode 2 NCIS New Orleans. Oh I know the rules around here, if there's no pic it didn't happen, right?

http://bobbeasley.com/oakhaven/action.png

Okay, back to bikes. Previous owner gave me a shock pump. I've got some clipless pedals coming along with one of those Park adjustable torque wrenches. P.O. gave me a long talking to about carbon fibre and the perils of not using a torque wrench.

An old school baseline for tire pressure Is as follows :
Always carry two tubes while testing..

If riding tubed..
Rider weight INCLUDING all ride gear, helmet, shoes, fully stocked back pack, and water, divided by 7,,
plus 2 psi for the rear tire
Minus 1 psi for the front.

Tubed,,,you for example 210 pounds plus 15 pounds of gear and water...
225 pounds divided by 7 = 32.14 psi
plus 2 out back 34 psi
minus 1 up front 31 psi...
IF you can ride light/ride right and your trails are not that rocky, rooty and you do not get air drop 2 more psi at each end.
Like to get air,,,carry three spare tubes and do some testing
For you,,with a good skills bag and tubeless,, My guess would be 28 psi rear and 25 psi front.

Tubeless, several psi lower,, depending on rider skill level, trails, tire width and rim width.
Skill level,,,can you 'ride light' ?? know how to use your body to 'help' the bike or are you still hitting things seated and or stiff legged.
Too low when tubeless,, you get tire squirm and burps..

Me:
170 plus 15 pounds of gear
28 rear and 25 front tubed,,

I ride wider rims and am tubeless,, comfortable with 27 rear and 24 front as I don't like tire squirm,,but when things are wet and slippery I drop to 26 rear and 23 front.... My trails are flow trails, not much air, smoother drop In's..

"riding light", I know what it means and I'm not there yet.

I'm not saying the other guys are wrong, but I usually ride with less pressure. Like 22 PSI front and back. I weigh between 195 and 205, plus gear, usually. If I haven't ridden in a while I'll add a couple to the rear tire to accommodate the poor decisions and technique that come with being out of practice. If I go any less I get squirm. I ride in pretty rocky stuff, but put a lot of attention into riding light.

To me, riding light is focusing on an obstacle/technical section with approach and body position. If I see a short technical section coming up that I will be taking at speed (unlike a long climb), then I will get out of my saddle (I have a dropper post, so I'll usually drop it) and preload so that right as I hit the obstacles I kind of do a half-assed bunny hop to get the weight of me and my bike off the obstacles and reduce my rolling resistance. I don't jump over the obstacles, mind you, but the less weight on a tire as it makes contact with an obstacle, the less it will slow me down. I use my knees as much as I can to take up any displacement, again, for the reduced speed loss.

The opposite of this would be how I used to do it: stand up, get rigid, and just slam into everything full speed and strong-arm myself through it. Terrible for you, your body (ie crashes), and definitely your bike. Finesse makes it way more fun.

Does that make any sense at all?? Ha. If I were you I would start out around 25 PSI, more if you're conservative. If you feel too squishy or if you touch off on a rock or something, add some. If it feels to stiff, take some out. This assumes you're tubeless.

EDIT: I just realized you said you knew what riding light was. My bad, thought you said you didn't...

This makes much more sense than the "old school baseline for tire pressure" that was posted above (and that I've never heard of in all my years of riding).

195 with gear - 30/32 tubed, 20/22 tubeless, prefer chunky trails.

I weigh 200 plus gear, and I run tube tires at 25lbs... anything less than that and it feels too wobbly side to side to me.

I'm in this ballpark. Anything much less than 20-25psi and I feel like I'm going to lose the bead at higher speeds.

I usually throw 30ish in the back wheel and 25ish in the front.