Two Trials Oriented Questions...

Ok i have 2 questions for the seasoned trials riders out there.

  1. How long will a luna tire last until it should be replaced…Not need to be changed, but should be changed. Ive been riding mine for around 2 months of novice trials and its starting to show quite a bit of wear. Ive rotated it every 2 weeks and i think i may need a new one.

  2. What can you do when you cant do a roll out or it will fudge the line? I ride strictly seat in trials right now because i havent become very good at sif yet. So what can i do to save my wheelset('03KH to Alex) from any real harm, if i cant roll out?(eg. 1ft drop down by 3 foot gap to 8" wide skinny parallel to the drop)

Thanks to all who reply.


I haven’t ridden a luna yet, but on my CC, i just rotate the cranks when I release that the section of tire I am hopping on has became bald and smooth, then I switch to a new spot, once my tire becomes completely smooth Ill switch to a new one.

And doing a 1 foot drop wont require a roll-out on a splined set-up, but go to and there’s a hopping video made by Kris Holm that will cover pretty much everything about hopping and roll-outs.

Well i like to roll otu becuase im 230lbs and i really cant afford to replace any parts right now:)

I know you can absorb it a lot in how you land, with your legs and back, I forgot hopw, aslo a way is to let the seat come down as you land, but im not sure how those work, i still suggest to watch the short video, the volume is kinda bad so you gotta really turn it up to hear it well.

Movie 1

Movie 2

Thanks for the linkage…Ive seen both already though:)

  1. you can ride a luna until it blows out. gerble’s luna is balder than Lex Luthor (okay, maybe the luna has a little stubble on the sides still) and he still rocks the mad trials lines on it. even when all the knobbies are gone, there’s still some rubber left on it… think of it this way, most racecars use slick tires… as long as you ride urban trials, why not use a slick yourself?

  2. you’re going to hurt yourself before you hurt your crankset doing small drops with no rollout. granted i’m only 170 lbs, but I’ve managed 2 & 3 ft drops sans roll-out on a square taper setup. the KH should handle a bit more abuse…

edit: keep your spokes tensioned and your rim should keep its shape…

So the rollout is only nessesary say for 2+ft drops then?

Pretty much, unless your on a square-tappered set-up, but your on a strong splined set-up.

I’d say 80% of your grip comes from the tire changing its shape to form around the object you are hopping to and gravity. Tire compound and tread pattern aren’t as big a deal unless you are riding offroad in soft dirt or in mud. There probably was never a time when I could legitimately say I fell or missed something because my tire was too bald (doesn’t mean I have never blamed it on that). I’d say just keep riding your current tire until you can afford a new one.

As for dropping with no roll out, it is very possible to safely drop a few feet (4 would be the max I would think about) on a splined setup. On a ST setup I would say don’t do it unless you have to. And keep it under 2 feet. As for a method:

While you are in the air stretch your body upwards as much as possible. Raise your non hopping arm high above your head. Then when you hit the ground scrunch your body downwards and bring your arm down. This is to lengthen the moment of impact as much as possible and absorb the forces being put on your uni.

if you can’t roll out, use your body like a spring. while you’re in the air, let your body extend and lengthen (it should sort of want to do this anyway) and when you hit the ground, let it bunch up again (think slinky.) that way you should be able to absorb some of the force.

as for the other question, i have no idea.

Ok Obie…thats waht ive been doing. I didnt kno it would acctually be helping though, or ai wouldnt have posted this…

As shown in this picture.

The mat, if i moved it closer, is what I practiced the frontflips on, but it was moved out of the way so I was landing in that conrete section, with the bars by it.

Jerrick Uni Air 02 Small.JPG

Ok one more question. Is it normal for me to have to increase my psi in the tire as it gets warmer? because i early April i had it around22psi and i loved it, but now im up to 31psi to get the same bounce…Is that the warmth or the tire wearing in, or is it a combination of both? And do you guys do that same with the changing of the seasons?


Yeah, I would assume it’s normal since I ride a different tire than you, and have to do the same thing.

I also have to play with the psi when it gets close to winter. But, the closer it get’s to freezing temperatures, the less I have to do this, because the knobbies and tire feel stiff…so the psi doesn’t really matter as much.

Yeah…Btween 5-10degrees i was around 22-24ish and 10-15 was around 28-29psi and any higher then 20 is 31psi+. I had no idea that weather could affect it so much!

  1. Your luna is fine until you actualy put a hole in it. Baldness really isn’t an issue if anything once you have worn it down all the way it should give even more grip because there will be more in contact with the ground.

  2. Rolling out of landings are more for really big things or to protect yourself. Since you mentioned earlier you pretty much have a fear of large heights then I doubt you will ever have a problem landing without a roll out until you start doing much bigger things. I often do 4 foot drops without any rollout (granted they are sif and i’m lighter than you) but with the proper compression I don’t even bottom out (I ride on really low pressure aswell).

Yeah…Its not even so much a fear of hieghts…I think its just that i have spent enough time on my uni at those hights. I can easily drop of a 6 foot drop onto my feat because i kno for sure that im well stablized…I think i just need more up time on my uni thats all.