Tube and tyre mounting

I've been having trouble with a new tyre and tube. 3.00 19 Avon Speedmaster II. I seem to be loosing about 1-1 1/2 lbs. per day and it eventually seems to go down from say 30 to 20 lbs. in about 3 weeks. Seems like too much to me, so I pull the tube, immersed it in water and can't find any leaks, did it twice. Valve is not leaking either. Is this the correct assembly, mount the washer, first nut then install the tube and the last nut on the outside? That's what the tube place and the local bike shop says to do. Just want to be sure before I do it again.



Thanks,
Dave
69S

The only tubes I ever use are the molded valve type with no internal nut. Not seen your kind in a long time. It must be sitting off the rim quite a bit. Dont see how it could affect air loss though, sorry.

DogT said:

Is this the correct assembly, mount the washer, first nut then install the tube and the last nut on the outside? That's what the tube place and the local bike shop says to do. Just want to be sure before I do it again.

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Yes.

DogT said:

I seem to be loosing about 1-1 1/2 lbs. per day and it eventually seems to go down from say 30 to 20 lbs.

Click to expand...

Let me guess, the tube is an unheard-of, far-Eastern branded item, and not a Michelin, Metzeler or Conti?

I'm sure it is not a brand name tube. Actually I tried, but no one seemed to have a good brand in 3.00 19. If anyone can source a brand name, I'll buy it, otherwise I guess I'll have to put some slime in it.

Dave
69S

check again Dave you must have a slow leek, if you haven't pinched the tube when fitting [tyre lever] then its got to be the valve.
Al

I was very careful checking the tube in water. Took my time and went over it twice, including the valve. I could do it again. I'm going to the local bike shop tomorrow and buy a new one, probably oriental also, maybe a different brand, but what choice do I have? I'd rather stay away from the Slime.

Dave
69S

Dave, to your narrow question, what you've done with the nuts is not wrong but I've found it better to omit the nut on the inside of the rim and put both - or just one - on the outside. You don't want to snug that one/those ones down too tightly, they need room to let the valve stem "cock" a little if need be, rather than ripping out of the tube.

To the broader issue, it does seem like you have a slow leak. Probably slow enough not to produce visible bubbles? I'd leave the tube out, inflate it to a known pressure, and let it sit a few days, then check it. I'm betting it'll be down a few pounds or more...

"Economy" tubes are anything but. I swear by Michelin (don't run their tires, although they're high quality, but the tubes are the best). I'd rather reuse a Michelin than put in a new tube of inferior make.

Frustrating stuff, I know - BTDT. Best of luck.

EDIT - just looked at your pic better. On yours, that rounded internal "washer" stays in and BOTH NUTS GO OUTSIDE (there are two to act as lock-nuts, although there's not much lost by using just one - especially if it helps you balance the tire more easily...), no ifs, ands, or buts. However, I don't see that as causing your leak - but it is better practice to install properly - that rounded section of the "washer" is supposed to conform to the internal curves of the hole in the rim the valve goes through.

Brian,
Thanks, when I installed the tube and even when I uninstalled it, it seemed as though there was too much 'junk' in the valve area, it just didn't seem to sit right. Rear one is the same way, but it doesn't appear to leak, but that is a quality tube, 410-19. I really don't see any issue like you say of leaving the nut off the inside and putting one or 2 on the outside, but I don't think that is my leak issue. I'm thinking the tube is bad and leaks slowly in the seams. I'm going to spend $18 tomorrow and buy a new tube and have at it again with my new pair of Motion Pro spoon irons.

I am ready to start this thing, all I need is to get the carbs on which are ready, put some clamps on the oil lines, how long can it take to put 4 - 3/8" hose clamps on and tighten up the exhaust system? Push it up into my garage (which may take a couple of strong guy plus me) and get some oil and gas in it and make a run for it.

This should be interesting.

Maybe by Friday, 'cause I can't get the tube until late Thursday. Anticipation!!

Dave
69S