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Scoot Master
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Joined: Tue Dec 01, 2009 10:47 pm
Posts: 204
Location: Vancouver BC, Canada
scooters and mods: 2003 BWS
Haven't posted in a while, but here's a little how-to on replacing the valve stem on a Zuma wheel, without removing the wheel. Actually it's just a couple links to other how-to's and some confidence pointers from someone who's done it to their Zuma50.

It's a good idea to check your valve stems, as I quickly learned. My valve stem broke at the rubber neck around the brass. "Probably" it's breaking was my own fault for shoving a U-lock into it several times in the dark and rain. Probably, but the design of right angle valve stems places a lot of faith in the rubber's strength during inflation, and leaves little room for manufacturing flaws in a very cheap component. Mine was 2 years old, same age as the SL-26's on my wheels.

Basically this job amounts to 3 main steps:

1. Use a large C-clamp to break only one bead (get the tire off the rim on one side), in order to access to the valve stem from the inside.
2. Persuade a new valve stem into place, using ingenuity to exert a lot of force on a wiggly bit of rubber.
3. Wrap the tire in a ratcheting cargo strap in order to get the tire's bead seated again.

These two step-by-steps are the basic how-to of this job:

A. He skips the cargo strap, but the Zuma50 wheel is wide and small enough diameter that the tire won't just go back on the rim by itself.
B. Especially Step 5 which shows the cargo strap.

A few key pointers, in order:

1. You need a right-angle valve stem to fit the stock Zuma50 wheel. I picked up a $4 PVR70M valve stem from a nearby Honda motorcycle dealer. Don't bother with a straight one - it doesn't leave enough room to get an inflator head onto the valve. The hole diameter is 0.453 inches. Str8 makes a prettier valve stem that seems like it will take the beating of regular inflation and U-lock abuse.

2. You may have to push the C-clamp towards the wheel to get it around the tire. My 8-inch C-clamp was wide enough, but not deep enough, so I put a knee into the tire to squish it sideways in the C.

3. Liquid dish detergent made this easier for inserting the valve stem and re-seating the tire bead. I strongly suspect that a lubricant meant for personal use would actually be better because it would stay slippery longer.

4. Eventually, I used an allen key and a hammer to gently tap the valve stem into the wheel. The allen key was just larger than the brass tube, and pushed from the end inside. I welcome other suggestions- a C-clamp might have worked if I had one that fit the space in the wheel, for instance.

5. When inflating the tire to re-seat the bead, keep the cargo strap on only as long as needed to get the tire bead started to seat. Then take it off. If not, you could face some sudden cargo strap failure in the face, or it could just be needlessly hard to remove.

6. The sound your tire makes when the bead seats may not exactly be a "Pop". Mine was more of a strong "thup", but definite.

7. Definitely use something non-metal between the tire or wheel and the C-clamp to spread the load and prevent damage to the rim and sidewall.

I was lucky- total cost was $4 for the valve stem. I borrowed the 8-inch C-clamp, air compressor (not required, but made this a lot easier than using a bicycle tire pump ) and cargo strap. If I had to buy all those things, it would probably cost less (and take way less time) to have the scooter hauled to a dealer to have it done professionally.

2003 BWS

Mon May 06, 2013 4:57 pm

Joined: Tue Jul 18, 2017 1:49 am
Posts: 26
scooters and mods: 2003 Bugeye Zuma
Post Re: Valve Stem Replace
Funny. I just did my front almost like this w/o seeing this thread.
I didn't use the c-clamp on the rim though. Just on the beads on both sides.
I did the front but I used a straight automotive metal one for the front.
It fit fine and is not an issue to add air. It's shorter than a rubber one.
I'm waiting for a rear stem. No way was a straight one going to work there on my 2003 . Bummer.
One thing, if all you are doing is changing the stem, just push the tire off the bead where the stem is. Don't break it all the way around. Mine aired right up w/o any drama or strap . I did use dish soap.
I have a tool from my auto days to pull the new angled one through. It is a rod with notches and a pivot that screws on where the cap goes and it should make it easier for the rear.
It is similar to this but has more and deeper nothchs :
The notch rides on the rim so you can leverage the stem through the rim. On cars I've just tugged them through , using lots of lube, w/o using the rim for leverage . I'll try that first so I don't have to separate the bead more than I have to.
Can't say I've tried it on a scooter before though.
I'll let you all know how it works.
One question. Do you have to remove the muffler to get the rear wheel off ?
I just found this ... fj&vxp=mtr
Will these work in the rear ? If so, no need for tugging.

PS, I worked in a tire shop before moving up the ladder to mechanic.

Fri Jul 21, 2017 6:13 pm

Joined: Tue Jul 18, 2017 1:49 am
Posts: 26
scooters and mods: 2003 Bugeye Zuma
Post Re: Valve Stem Replace
I just ordered these ... 2749.l2649
I'll do both .
:piss2: Screw the rubber stems :piss:

Fri Jul 21, 2017 7:04 pm
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Location: portage wi
scooters and mods: 08 zuma dual headlight tmod rally kit cutom red paint koso mirros red anodized trans bolts
Post Re: Valve Stem Replace
Unless you can make the rim narrower you have to remove the exhaust

2008 zuma dual headlight mod koso mirrors liquid cooled polini corsa kit leo vince zx stage 6 variator rally kit custom red paintFUEL INJECTEDsoon to be 100cc
2008 stella olive custom ported 177 cc kit dechromed ford tear drop tail light alive and breathing and awaiting cosmtic surgery thanks to an trump cager
1985 elite 150 how long can i leave it stock

Sun Jul 23, 2017 6:57 am

Joined: Tue Jul 18, 2017 1:49 am
Posts: 26
scooters and mods: 2003 Bugeye Zuma
Post Re: Valve Stem Replace
Bummer. Oh well......

Sun Jul 23, 2017 4:48 pm
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