Wheel/ Tyre Valve

[il_cacciatore]

Hi All.

 

My old rear tyre was a Bridgestone BT020 that had caught a nail. Instead of having it plugged (I was told it couldn't be) I had slime put in it. The slime never worked properly as it didn't stop the tyre loosing pressure allbeit ever so slowly. After several months and thousand miles later I was ready to get a brand new tyre after the endless hassles of having to inflate the tyre every weekend that I chose to take it a run. So I bought a Metzeler Z6 Roadtec.

 

Got the tyre fitted to the wheel and installed it back on the bike. The weather was crap so I tucked it away in the garage with the intension of taking it out a run when the weather improved. Woke up to a real nice sunny day, opened the garage door and... FLAT TYRE!

 

Feck I thought, must have caught a nail again but after a close inspection there was no nail. Next culprit was the valve. Put some washing up liquid on it and found that my suspicions were correct. Ok, so why didn't the garage that fitted the new tyre not check or indeed replace that as a matter of course when fitting the new tyre? That would be normal practice for car tyres.

 

Phoned them up and was told that they don't check valves but could rectify the problem... at a cost of 5 quid plus labour! After spending over a hundred quid on new rubber thought that was a bit off.

 

I had went into the local quik fit and the guy gave me a car valve. I thought it would be a simple case of just taking the core out and installing the new valve but it didn't fit.

 

My question, are motorcycle tubeless tyre valves a different size to car tyres?

 

My next question is, has anyone fitted a 'turret' valve to their Guzzi as the standard one is difficult to get at with a compressor attachment and a L shaped valve would result in more convenient re pressurization of the tyre. If so, do you know what diameter the valve hole is on a Guzzi wheel?

 

Many Thanks

[Greg Field]

I use right-angle valve stems. Orient them to point to the right so they're easy to access with the bike on the sidestand.

[Skeeve]

Next culprit was the valve. Put some washing up liquid on it and found that my suspicions were correct. Ok, so why didn't the garage that fitted the new tyre not check or indeed replace that as a matter of course when fitting the new tyre? That would be normal practice for car tyres.

 

Yes, it is, and so is mounting the tire free with purchase, but I don't know of any motorcycle shops who do this! Glaringly faulty valve stems don't even elicit a courtesy "Hey, you really should replace that thing while we're doing the tire, it'll only cost you another $5*..."

 

There are angled valve stems (45deg & 90deg) out there, and these should come stock on motorcycles but (mostly) don't, so you as the owner should be prepared to automatically replace the stockers the 1st time you change the tires: either type will radically improve the user experience when checking air pressure [which as conscientious motorcyclists, we should be doing at least once a month, right? ]

 

BTW, Slime should only be used with innertubes, not with tubeless tires on alloy rims! That stuff will corrode your rim over time, plus it doesn't work as well as a tire plug: any shop who told you that a plug was inappropriate for your tire but proceeded to use Slime as a solution needs to be avoided...

 

 

Ride on!

 

* Highway robbery for a cheap rubber stem, about right for a proper metal valve stem that likely won't ever need replacing again...

[belfastguzzi]

You'd be well advised to change both valves if you still have the originals. It's most likely not the valve core that is faulty – it's the valve stem. They are made out of cheese and they split around the circumference. It's not obvious – until your tyre goes flat. Change them to stainless steel.

 

There have been a number of threads on this before, so it's a common occurrence. As well as the valve stem splitting, I also had a retaining nut split. That resulted in the valve dropping into the tyre and the tyre deflating on the move.

 

Maybe the problem is worse in areas that get a lot of salt on the roads.

[il_cacciatore]

Hi

 

I believe that it could be the core but it might possibly be the stem as you suggest - I'm not sure if they are originals. I'm going to try and change the core first and if it still looses air then I'll have it changed in with an angled valve stem. My front tyre will be needing changed soon and I'll ensure that is changed in entirety when I fit new rubber. In Scotland they pile salt onto the roads most of the year.

 

The slime 'solution' came about subsequent to visiting another different anon motorcycle shop who proceeded to claim that motorcycle tyres couldn't be plugged and that by doing so I would be not only risking my life but everyone elses life around me! Obviously I didn't believe that story, it eventually ended up with a different motorcycle shop telling me that the nail that was in the tyre was too far toward the edge of the tyre and was in at too great an angle to be plugged. I didn't realize that Slime was a corrosive substance! I'll know not to use that again. Don't fancy spending a ton of money buying a new rim.

 

I have a feeling that most motorcycle shops around my area talk nonsense as a matter of course to get you to spend as much money as possible.

 

Many Thanks

 

[gstallons]

Install about 3 bar. air pressure, mix a dishwater and water solution and spray on the valve stem. The air bubbles will show up.

[Skeeve]

The slime 'solution' came about subsequent to visiting another different anon motorcycle shop who proceeded to claim that motorcycle tyres couldn't be plugged and that by doing so I would be not only risking my life but everyone elses life around me! Obviously I didn't believe that story, it eventually ended up with a different motorcycle shop telling me that the nail that was in the tyre was too far toward the edge of the tyre and was in at too great an angle to be plugged.

 

Well, plugs are more certain than Slime, so if it wasn't suitable for plugging, neither was it suited to Sliming... scoundrels!

 

General rule: plugs in the center 1/3 of tread are fine, and you just decrease the speed rating of the tire by one level; by the 3rd plug, you're generally running out of room for adequate highway speed [we all know bikers regard the posted limits as merely suggestions, right? ] and need to pop for a new tire.

 

Plugs in the outer 1/3 of tread are generally considered as allowable to get you somewhere to change the tire, but I'll confess to using a tire w/ a plug in the outer 1/3rd for a couple thousand miles on my daily commute [never exceeding 80mph, on a tire rated to 150+mph...] before I figured I'd gotten enough wear out of it to merit replacement.

 

Plugs in sidewalls are right out, altho' I could see being stuck in the middle of the desert and doing it just to get myself down the road to the next major city where I could replace the tire, but I'd be limping along at 35mph on the verge...

[GuzziMoto]

I agree that plugging is riskier closer to the edge of the tire and that I would not want to do it but probably would in a pinch.

On the Slime issue, I have used Slime and not had an issue, but my tire guys hate that foam flat repair stuff and say to avoid it if you can and if I use it, be sure to let them know ahead of time.