Leaking Spoke

[Phang]

alpina recommends RASSINT - PTFE from LOCHIM (what is that?)

note that the o-rings are NBR type, so the lubricant compatibility may potentially turn this discussion into a micro oil thread :lol:

 

[Louis]

Hi Stelvisti

I went back to tubeless and put new tires on, but a few spokes were still leaking.
Turned off the nipple and found that the O-ring was damaged, a little piece was missing gggrrr.
Put new O-ring in and it is OK now. Bought 100 O-rings and will probably change them all in winter.

Still have to make some test-rides to see if they are staying leak-free.

StelvioGreetz from Holland........Louis

 

[DanPez]

Phang,
Thanks for the info.
Knowing the o-ring material I was able to find this:

Good resistance to:
Aliphatic hydrocarbons like propane, butane, gasoline (petrol) and mineral oils and fats.
Hydraulic fluids not easily flammable belonging to the HCF group.
Silicone-based oils and fats.
Water (some types can withstand up to 100°C.)
Many diluted acids, bases and saline solutions at room temperature

I figured machine oil is good
So I added a drop on the inside rim and let it soak for a few minutes.
I didn't disassembled the nipples at all,
I used a 1/4" hand torque screwdriver with a 7mm socket.
Set it at 4N-m (+/-30 in-lb) ....... Found a reference point on the rim (Valve stem) and tighten the spokes for one side first then the opposite side spokes.
Found 5 loose. (Rear rim only)

 

[Phang]

I checked mine when it was 10,000km on the odometer. Only 1 rear spoke sang a key lower than others when I tapped them with a spoke wrench.

It took about ¼ turn to bring it back to the same tune.

 

[DanPez]

When I first removed the tire, the resonance when flicking the fork, was greater than with the tire on.
Takes a good ear to tune a fork (which I'm loosing slowly) hearing that is .......so I did it the scientific way .....by torque. :silly:

 

[Mark111]

Reviving this old thread, anyone know where I can get the correct O rings for my Alpina spoke nipples.
Need some to fix a couple of leaks at my wheel rims.

Mark

 

[GTM®]

Alpina direct. My friend is the importer here in the US if you hit a dead end.

 

[Paul_Tim]

I don't recomend Slime or similar if you have angled valve stems, previous owner did this to mine and the slime got into the valve mechanism itself and prevented me adding air to the tyres where it went solid where it rested rather than dripping back into the tyre. Pain in the proverbial to sort out.

I've replaced O rings (add some silicone gasket as a belt and braces fix) but had one spoke that wouldn't fix and continued to loose air (about 4psi a day). I cut and glued a small piece of inner tube to the inside of the rim over the end of the spoke, that fixed it. Should probably get it fixed properly one day but it wont fail suddenly so it can wait until all the other vehicles are behaving themselves

 

[Rafael]

My buddy's Griso rim was leaking about 2 psi per day. He didn't want to deal with the dealer, so asked me to check it out since we were changing tires anyway. We found that about a third of the spokes leaked - confirmed with blow bubble fluid for kiddies. I had thought of using chain wax to seal the air path from the inside and RTV if that didn't work. But at the car parts store I spotted Flowable silicone. Abandoned the chain wax and used the flowable stuff on all spokes for even weight distribution. Placed the goo in the nipple dipple of the rim. Did about 6 spoke at a time and allowed time for the goo to set. It flowed right into place and popped any bubbles and they rose. Worked perfectly - about .5 oz total was used. Pressure was checked a week later and found to be 1.5 psi down. Considering the temperature difference of inflation times, that's probably the best you can get.

I didn't consider tightening spokes to stop the leak. My thought is that the o rings are not affected by the tension. The tightening only affects trueness. Am I wrong about that? Should he take the bike it to have the rim checked - still under factory warranty.

I'm going to check mine for leaks at the next tire change.

 

[WayneOrwig]

My thinking is that a retorque might seat an o-ring that is a little loose.
Or it might damage one more if there is a burr on the metal.
You never know.

But a spoked wheel should be inspected and retorqued occasionally no matter what.

 

[John Warner]

I know the stuff (Slime) they sell in the US will eat away an aluminum rim over time, it also stays liquidified until a hole is present, only then does it become hard to stop the leak......so that wouldn't work.

It's worked on my Rear Wheel, that has three leaking spokes.
Was losing approx 2-3psi every couple of days, until I stuck a bottle of sealant in it.
Turned it over at varying speeds by hand for 3 or 4 mins to ensure the sealant got onto the relevant areas.

Once my Griso Wheels are on, I'll strip the current Wheels down (front is losing 2psi/week) and seal the Spokes properly.

Tightening the Nipples is unlikely to do anything, the O-Rings are sitting in a parallel bore in the rim.

 

[senyacap]

Gentlemen,
Noticed a same symptom recently - air is leaking around one of the spokes on Stelvio rear wheel (checked with soapy water sprayed all over the wheel). I've ordered a new spoke nipple with O-ring and took the wheel to the local tyre shop, they have replaced the nipple and reassembled the wheel by that did not help a bit.

More careful inspection revealed a tiny hairline crack on the rim originating at the nipple hole, about 2mm long. That's not good.

So now I have a disassembled wheel and a tough question on repair strategy. Options are:
1. TIG Weld. Pro: stropng and reliable. Con: heat stress, need to refinish, need to re-bore the hole to properly seat O-ring
2. Drill the crack end and seal with some adhesive. Pro: doable, cheap, reliable if done properly. Con: can fail if adhesive is chosen or applied incorrectly, weakened hole

I'm more in favor of option 2 currently and I'll appreciate advice on the adhesive that would properly bond to aluminium rim and would withstand normal riding conditions. Acrylic? Epoxy? Polyurethane?

 

[John Warner]

Not sure I'd go for either option to be honest.
How about getting it machined out to remove the crack (concentric with the Spoke Hole), then get an insert machined up to 're-make' the Hole.
The insert and the Hole it's going into would need to be tapered so there's no chance of it pulling through, but once bonded in, and with the tension of the Spoke on it, it should last.

The other options would be to get a replacement Rim laced to the Hub, or find a second-hand complete Wheel.
Wheels from any of the CARC models will go straight on.

 

[senyacap]

Thanks John, I did not think of machined inserts, this seems to be a best option so far. I think about 1:4 taper and Loctite 638 to set the insert in permanently and airtight.

Is it possible to order a new rear rim separately? Guzzi parts catalogue suggests either wheel as a whole or just spare spokes/nipples.

 

[John Warner]

Doubt they'd list the Rim separately, would probably be cheaper to buy a S/H Wheel anyway.
Mind you, a S/H Wheel could be in the same state, or could fail in the same way after a short time.

Looking at the Pic of the Nipple in Phang's post above, you could probably use them in a standard replacement Rim.

Just noticed your location, you should be able to find somewhere to do the Machining option there.

Here, you'd be looking at around £180 for a Rim, + around £60 for the Build (with your Hub and Spokes).

Try TLM in the Netherlands for S/H Spares.
http://www.tlm.nl/webshop/en/used-parts/wiel-velg-naaf-as?limit=100http://www.tlm.nl/webshop/en/used-parts/wiel-velg-naaf-as?limit=100

The Cast Wheels tend to be much cheaper than the Spoked ones, so that's another option.