Valve stem nut on dirt bike rear wheel?

**A&R** · 16th July 2009, 00:22

Would like to know if it is best to do up the valve stem nut tight against the rim or leave loose and kept on by a valve cap?
Obviously have tube in tyre and two bolts to hold tyre in place.
If left loose why? to allow tyre to move against tube?

**barty5** · 16th July 2009, 01:30

Originally Posted by A&R

Would like to know if it is best to do up the valve stem nut tight against the rim or leave loose and kept on by a valve cap?
Obviously have tube in tyre and two bolts to hold tyre in place.
If left loose why? to allow tyre to move against tube?

leave loose cant remember the whole deal think its to do with tube movement stiops it from rippin outa the tube. sure someone elsr will amke comment.

**Brian d marge** · 16th July 2009, 03:27

Think

if the stem is stationary ..............and the tyre has any slippage

Just go through the process in your head and imagine what will happen to the various bit as or if they experience change

Stephen

**WRFracer** · 16th July 2009, 06:30

Definitely leave loose, If the tyre does move and the valve stem is locked in place it will rip the tube away from the stem resulting in a flat tyre

were as if you leave the stem loose and the tyre slips the stem will just shift in the hole and you will have a stem thats on a hardout angle but most likely you wont have a flat tyre

Then you can just deflate the tube, pop the bead and re positon the tyre so the valve stem is straight again(this can be a pain to do).
Generally to prevent slipage make sure the tyre you are fitting is clean and dry as with the rim, use some baby powder in the tyre to prevent chaff on the tube, but other than that leave it dont use bead lube generally heaps of air pressure will be enough to pop the bead.
And of course do the rim lock up tight and check it regurally as it can loosen a bit once the tyre wears in.

**Reckless** · 16th July 2009, 09:47

Mine doesn't have any nuts on the outside. When I changed the rear tyre the valve stem nut was on the inside of the rim, done up to the bottom of the stem. I suppose to keep the tube off the inside hole edge if the tube moves round? The guy I bought the bike of raced enduro events and was quite good. I thought there must be method in his madness so I left well enough alone. Never had a problem with it in sand or even on the rocky rutty rooty wires ride. I had to reposition the front as described above because the rim lock wasn't tight enough and the valve was on quite an angle and this set up all seemed to work real well.

PS The baby powder is a good idea!

**takitimu** · 16th July 2009, 09:49

Originally Posted by WRFracer

Generally to prevent slipage make sure the tyre you are fitting is clean and dry as with the rim, use some baby powder in the tyre to prevent chaff on the tube, but other than that leave it dont use bead lube generally heaps of air pressure will be enough to pop the bead.

How much pressure will you go up to before stopping ?, I generally pull the pin at 45psi figuring I've twisted the tube or some such.

**Katman** · 16th July 2009, 09:56

Originally Posted by Reckless

Mine doesn't have any nuts on the outside. When I changed the rear tyre the valve stem nut was on the inside of the rim, done up to the bottom of the stem.

Virtually all tubes come with two stem nuts. One for the inside and one for the outside.

I've gone up to 80+psi to seat the tyre with no dramas. (It depends on the state of the tube though).

**MikeJ** · 16th July 2009, 21:57

For a quicker and safer way to pop the tyre beads spray both beads with either CRC or preferably WD40 and inflate before it dries. 30-35 psi will easily do the job. WD40 is mostly a solvent and soon dries and actually helps bond the tyre to the rim once inflated. Any excess CRC/WD40 inside the tyre will help prevent corrosion of the rim.

**hayd3n** · 16th July 2009, 22:06

can always do the crc lighter trick to pop a bead might stuff the tube tho

**Buddy L** · 16th July 2009, 22:11

Originally Posted by MikeJ

For a quicker and safer way to pop the tyre beads spray both beads with either CRC or preferably WD40 and inflate before it dries. 30-35 psi will easily do the job. WD40 is mostly a solvent and soon dries and actually helps bond the tyre to the rim once inflated. Any excess CRC/WD40 inside the tyre will help prevent corrosion of the rim.

Used WD40 instead of soapy water, to put the tyres on with, and worked a treat. They almost put them selfs on.

**oldguy** · 16th July 2009, 22:14

Originally Posted by A&R

Would like to know if it is best to do up the valve stem nut tight against the rim or leave loose and kept on by a valve cap?
Obviously have tube in tyre and two bolts to hold tyre in place.
If left loose why? to allow tyre to move against tube?

I always use to do it up, I had a new tyre fitted to the DRZ at Botany Honda I asked John about the nut, he and Danny said not to do it up it allows for a little movement.
Them DRZ125 don,t have rim locks but then again they don.t have any serious torque at the rear wheel anyway.

**merv** · 16th July 2009, 22:33

Funny I thought I answered this over here http://www.kiwibiker.co.nz/forums/sh...d.php?t=103404

**camchain** · 17th July 2009, 12:52

Originally Posted by merv

Funny I thought I answered this over here http://www.kiwibiker.co.nz/forums/sh...d.php?t=103404

Heh. Always good to get plenty of angles though.

I don't run top not at all but always leave bottom nut on tube/valve stem (inside the rim) for extra wriggle room/flexibility if tweaked. I get more probs with front tire creep than rear (from braking).

You can get nifty little grommets to go over the valve stem, they help keep muddy crap from getting inside rim hole & chafing tire/tube. I think some rims have different size holes for valve stem & rim lock. I use larger hole for valve stem.

**warewolf** · 17th July 2009, 21:45

To quote one manufacturer: Valve nut

Originally Posted by Continental tyres

Only a fitting aid. Should be twisted against the valve cap after fitting the tyre.

If you get slippage, you can see the stem tilting before you get catastrophic failure of the tube, and hence can take corrective action. With the fitting aid screwed down hard against the rim, the first you'll know about the tyre slippage is the sudden and complete deflation when the stem irreparably rips out of the tube.