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Discussion Starter #1 (Edited by Moderator)
Hi,

Recently bought a used 2015 model DL650 XT with spoked tubeless wheels. Front tyre is losing air. I have already taken out valve core and cleaned. Cannot see any knocks on rim, looks all pretty good. No holes in tyre?

Any ideas where it could come from or how to find leak?
 

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Hi,

Recently bought a used 2015 model DL650 XT with spoked tubeless wheels. Front tyre is loosing air. I have already taken out valve core and cleaned. Cannot see any knocks on rim, looks all pretty good. No holes in tyre?

Any ideas where it could come from or how to find leak?
If the wheel is off the bike, submerse the wheel and tire to the level of the spoke nipples. Rotate the wheel slowly looking for air bubbles rising. Alternatively, fill a spray bottle with a soap & water solution and spray the tire in small areas, looking for telltale bubbles emanating from the leak. Locating a leak coming from the spoke nipples may be more difficult to pinpoint this way, however. But the leak is more likely to be in the tire carcass or rim-bead contact area.
 

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The DL spokes do not penetrate the rim/tire cavity. The spokes attach to a vertical fin that is part of the rim. Ruling out spokes, that leaves the tire or the valve stem.

MP is right, easiest way is to submerge the tire and rim to find the leak. Have a tire plug on hand and it's an easy fix.

If you have metal valve stems, I have found that due to the fin, the stem hole is not a flat surface which has given me an intermittent leak.
 

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Dont overlook the tire bead. I have same spoked tubeless rim on rear of my trials bike.

If any dirt worked its way between tire and rim while low PSI offroad, it will leak untill you remove and clean tire and rim.

If someone dammaged the ture bead spooning it,on,or off at one time, it may never be air tight, but you can try a bead sealer on tire and lube up goot when mounting and seating. On a 2 wheeled bike, if bead is bad, I would just replace tire.

Air it up and dunk in water, lok for bubbles. If slow, it may be 1 small bubble every 5 seconds.

Sent from my RS988 using Tapatalk
 

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There is one last thing to consider. Let's assume the wheel rim was formed from straight bar stock, bent into a hoop, and welded. (Or, maybe the rim is cast metal.) Maybe it is an imperfect weld, and air is escaping from the weld. Or if a cast rim, air leaking from a casting imperfection.

I mention this because I rebalanced my front wheel a couple days ago. As it slowly spun on the balancer jig, at a spot across the diameter from the valve stem I saw what appeared to be a slightly blemished spot, like what is left over after a grinder cleans and shapes a weld. Highly unlikely leak location, but not impossible. This weld joint, if this is what it is, should be visible on the inner face of the rim when the tire is off.

Air leak locations- valve stem and stem mounting, tire carcass, tire bead/rim seating, and the rim itself.

Steve.
 

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Soapy water.
Spray the whole thing. (Get it good and soaked)
Look for any obvious bubbles. Generally the faster the leak, the bigger the bubbles will form and the easier they are to see.
If you see nothing, wait 5 minutes.
Look again. At this point the bubbles will probably be more of a foamy pile of tiny bubbles.

If nothing, rotate the wheel 90 degrees and start over.
 

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Multi spoke, extruded. So there will be a weld joint, correct?

Steve.
 
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