Nuts! Where to put them?

[RonXBR]

Out for a run on my CB450 and had a bit of a squeaky bum moment. Suffered a rear tyre puncture which deflated really quickly. Anyway, eventually got home, took the wheel off and removed the inner tube. Valve stem had separated from the tube, a first for me. All sorted now, new tube with shaped washer and one nut on the inside of the rim, second nut tightened down on the outside. As it was originally fitted before the puncture and on any other spoked wheel bike I've owned. Then I thought I would do some research!

https://www.kzrider.com/forum/5-chassis/611729-tube-valve-stem-nuts-tight-to-the-rim-or-not

[themoudie]

Aye Ron, pleased that you were able to control the bike, with the rapid deflation of the rear tyre.

Last time that happened to us, Kat and I were two-up on the Funduro going into a 25mph right-angled corner over a bridge, with large stone parapets on either side. Was using a Michelin tube inside a Tourance tyre. Lock to lock in the space of 30 metres and only used the rear brake to stop. Friend behind on a Z900 had kittens! The tube had failed on a moulding seam and then come out the side of the tyre, as that popped off the rim and the tube wrapped itself in the wheel spokes.

I always use Avon, Michelin or Continental inner tubes, I do not trust Chinese or other offerings.

The convex shaped area at the base of the valve stem MUST be seated in the bottom of the wheel rim, or else you run the risk of tearing the valve stem from the tube. Especially, if you are running low tyre pressures for off-road use or keeping race tyres warm on cold, wet tracks. If two nuts are supplied, either both can be threaded onto the valve stem when the tube is inserted into the tyre and around the rim, before seating the second tyre bead onto the rim, or a single nut. Once the tyre is correctly aligned with the valve stem (coloured dot on tyre wall), seated and inflated to the desired working pressure, a nut is tightened against the outer side of the rim. I do this finger tight and then a nip (some nuts are hex, others are knurled only). The second nut can either be used as a lock-nut against the first valve stem nut, or the valve cap, or omitted altogether; your choice.

In my view, any nuts threaded onto the valve stem between the rim and the tube are a potential fatal fitting error! 

Good health, Bill

[spooky]

I had the same conundrum yesterday , remove a very old tyre from the cg125, the tube came out with one nut and domed washer inside , so I put the new tube in the same .... got the front one to do tomorrow, I wonder what I will find and what I will do.. watch this space I think.

[RonXBR]

There's a familiar name on this link.

https://classicmotorcycleforum.com/index.php?topic=5701.0

Ron.

[iansoady]

Yes, and was about to echo Bill's comments here! Although as mentioned in the other thread I don't tighten the nut down to the rim as if it's left loose or run up to the valve cap you can see if the tyre has started to creep as it will cant over.

I've just realised that one advantage of the otherwise ugly XBR Comstars is their use of tubeless tyres.....

[RonXBR]

I would like to point out at this stage, down through the years I have owned a number of XBR's, which I think are very attractive bikes compared to, say, Norton's. Beauty is in the eye of the beholder.

Ron.

[mthee]

Beerholder 

[RonXBR]

Also true! 

Ron.

[iansoady]

Come on, Ron. What could be prettier than this?



But as you say, beauty, eyes, beholder.

[RonXBR]

Hello Ian, You're right of course! Late '40s and '50s bikes in the 350/500 classes have a certain charm. I see your Norton is the same age as me but a lot better preserved. Anyway, back to the original post. Are we all going to rush out to the garage and rearrange our nuts? I normally don't listen to Bill  , but I think he's right. Ignorance was bliss but potentially dangerous. So, out with the tyre levers again, skinned knuckles and shouting out words like  "DRAT" and "OH DEAR".

Ron.

[themoudie]

Aye Ron,

I normally don't listen to Bill  , but I think he's right. Ignorance was bliss but potentially dangerous. So, out with the tyre levers again, skinned knuckles and shouting out words like  "DRAT" and "OH DEAR".

Why would you?    Usually a lot of old squit!    As for the "Drat!" and "Oh dear!", yeah, pull the other one sunshine! 

When I'm disemboweling something Oriental, the Duke of Edinburgh's catch phrase is often uttered!    Italian machinery get oaths of derogatory culinary qualities!  Whilst English made motorcycles just get Anglo Saxon abuse! 

However, on most occasions a break for tea is called for, a seat in the antique Parker Knoll upright chair and a contemplation of the derided victim, followed by either a revised technique, more abuse, or tiptoeing out of the workshop and going for a walk! The latter was my reaction to a motorcycle race tyre fitters application of 85psi to a 1970's Italian cast alloy wheel, tube and tyre combination when trying to seat a Heidenau 2.75 x 18 front tyre!   Luckily, everything held and shrapnel wasn't flying around the workshop.

"Oh dear!"

Good health, Bill

[themoudie]

Aye Ian, a bonnie machine indeed, even though it has that "blacksmith" quality in appearance and operation! I love 'em and a Pussy as well, but have never owned either. My 1953 AJS 18S, was in the same mould and that served me well. But, the Italian beauty swayed my head and the AJS was flogged to make way for the old bird below that has been with me since 1976. WHY?  I dinnae ken! 

Good health, Bill

[RonXBR]

Bill, I know you're given to talking a lot of Bolognese and some underseat wiring can look like a bowl of spaghetti, but Italian bikes of that age are usually pasta best.

Ron.

[themoudie]

Ron,

Bill, I know you're given to talking a lot of Bolognese

True! 

.... some underseat wiring can look like a bowl of spaghetti

True! But the problems are the pastel shades and blackened filling! 

.... but Italian bikes of that age are usually pasta best.

Falso! Come ogni pecorino, parmigiano o vino rosso di qualità, sono migliori per l'attenta conservazione!   

Buona salute e benessere, Bill

[RonXBR]

Aye Bill, look after your bike and they'll look after you. Usually, probably, hopefully, maybe. My last Italian "stallion" was a 1959 Gilera 150 Sport, a little jewel of a bike. Handled well and sounded like a 350. Four stroke engine but looked like a two Stroke.

Ron