What's a good pressure to run tyres at Woodhill?

[oldskool]

Anyone here riding a 200 thumper with skills and has some experience on this type of terrain?

Tyre Pressure.
I'm used to hard clay tracks and I'm not finding good traction in the sand forest. Can't float the front wheel effortlessly unless bumping the seat so I'm finding muscles I forgot I had just to stay on track! The boys at cycletread pumped 30psi in when they changed my rear wheel. I was running on about 12 psi on Muriwai Bch before that. I'm thinking 16-18 psi but hesitant because I don't want to kill the rear rim on a gnarly root.

Sprockets.
I'd be curious to know what sprocket T's you're running for best traction/engine revs. I'm finding when in 2nd, revs are too high and I lose traction and in 3rd I'm fanning the clutch too much in tight. 2nd is good for engine braking tho. But the main thing is I wanna do wheelies at will without losing too much traction in the sand forest.

[Finn]

Tire pressure won't make much difference if you're not used to sand. Just keep practicing shifting your weight around and steer with your rear.

Giving it snot helps too.

[kezzafish]

Man! those are some mega pressures, i've never run more than 15psi on any terrain, they put lots of pressure in at bike shops to make sure the tyre beads the rim properly, i run 10psi in the rear and 10-12 on the front when riding in karapoti which is rocky as fuck, you could run 10 in sand before worrieing about pinching the tube on a tree root cos i blast over rocks all day with the above pressures and don't have puncture problems

[chop]

Between 12-14psi in the rear as low as 8-10 in the front

[oldskool]

Thanks Finn,
Totally agree with yah about wiggling the arse and knees about, do enough off that, but have tah disagree with yah on tyre pressure, tyre pressure makes a lot of difference on shifting ground, especially if the bike can't float the front wheel like a 35hp 2 stroker. Been there done that.

[oldskool]

@KezzaFish, Chop

Thanks for your input, I'll average both numbers and try 12psi in the rear and 10psi up the front.

To be fair to the cycletread tyre jockey, my rim is 22 years old and by the time he finished replacing the shot bearings and replacing the tyre he was covered in aluminium oxide dust and warned me that I may only have a few rides left before the spokes shot through into the innertube. So with that in mind he overpressured the wheel to protect the rim. I was thinking a compromise at 16-18ish psi.

I've picked up a newish (1996) rim and 50% tyre last night, I'll stick it in the car on standby, so will try out your suggested pressures for next family fun day at woodhill.

Most of my riding has been on 18psi as most of my riding has been on road registered 80's Enduro bikes. The old Timber Mill at Pinehill run by old man Hodges was the place to go to if you lived on the shore back then. It covered acres of pine forest and you just bashed your own tracks.

[F5 Dave]

Ha, yeah those rims delaminate, did a friend's 200 (the old rim was scary) & he painted it up a bit with some shalack stuff. I got mine etch primed.

If you are going to run low pressures, & why not esp on small light (shall we say gently powered) bike, do invest in some proper enduro tubes. They will be 2-3x the price but are far less likely to puncture & that is worth the money every time.

[oldskool]

If you are going to run low pressures, & why not esp on small light (shall we say gently powered) bike, do invest in some proper enduro tubes. They will be 2-3x the price but are far less likely to puncture & that is worth the money every time.

Thanks for the tip F5 Dave, I'll keep that in mind when I get around to swapping the new tyre on the old rim to the newish rim. Pains me to think I've got new bearings in the old rim that'll probably never get used once I've done the deed, they're not cheap at Cycletreads.

LOL had to laugh about your very diplomatic description of the rip snorting XR200! Once I have it set right for the forest conditions I'll give the noisy 125 rattlers a good hurry up! :2guns:

[oldskool]

Took the bike up to the Woodhill family fun day today and tried 12psi front and back. Have to say I had a great time, heaps of traction, no gnarly root big enough to throw me and I could wheely whenever. Occasionally the front would whump smack into a big root, when I got the timing wrong, and I'd feel a very slight kick in the bars but the front rim seems to have survived the day. However I do notice the rear tyre valve has bent 45 or so degrees. I read somewhere I could tap a few short screws into the lip of the rim to prevent the tyre from shifting around. But all in all a great day. I might try 18 psi in the rear next time and work my way slowly down from there.

[tommorth]

check your rimlocks they should be holding the tires in place pretty sure they use selftapers for drag cars but might weaken your rim

[F5 Dave]

The rimlock should be right size for the rim & tyre, some cheapo ones are a bit lame. Shouldn't need two for a 200. I'm guessing there will be none fitted.

[oldskool]

Thanks for that guys, I wanna swap the rear rim from the '86 to a '98 I picked up, so heres a good reason to do it sooner than later! ..and I'll make sure the rimlock is on proper!

[Crisis management]

A bit late getting to this thread and you've obviously now got some experience in the sand now but...... on the 200exc (100 kgs bike + 70 kgs me) I run 8 in the front and 10 in the rear and seem to cope ok.
The tubes do seem to take a bit of a beating despite rimlocks with the valve stem trying to disappear into the rim but so far I haven't had any rim damage or pinched tubes, mind you some would describe my riding as slower than a geriatric with a zimmer frame.
The sandpit's a good place to ride with enough variety of fast and technical routes and the sand surface makes you work for your traction, having to use a lot more variety of body position to get the best out of the bike.