Tubeless Woes

[Doomanic]

I changed my front tyre last week and it seemed to go well, however it was just killing me into a false sense of security. I went to check tyre pressures today, ready for Malvern tomorrow, and the tyre was flatter than an anorexic supermodel. All I did when I changed the tyre was that; change a tyre. It was already set up tubeless. Closer inspection revealed that it was leaking from the valve. So I tightened it up. Now it’s leaking from the spokes! What the fudge is going on? I did don’t disturb the valve or tape when I changed the tyre.

 

[ccrdave]

Ok then my guess is tape not wide enough

 

[ccrdave]

If you dont have wide enough tape stick small tube in then dplit the tube open all round the centreline, fold it back over the rim mount the tyre and blow it up then carefully trim the excess tube off that sticking out where the tyre seats is called getto tubless

 

[Donnie797]

I wouldn't do big experiments with it, you had enough trouble already. Just get the right tape and be a happy tubeless man

 

[Doomanic]

There’s nowhere local to get tape.

Anyway, my day just got a whole lot worse...

That’s the leaking spoke, complete with what looks to be a hairline crack.
?????

 

[Gary]

That's warrantyable.
Asuming the bike is less than a year old and they're the OEM wheels and not tweaked/tightened by yourself.

What rim is it?

Mavics used to do that a lot, Yours is due to the Aluminium being overly brittle and having no eyelets to spread the load.

 

[Doomanic]

It's a SunRigle Duroc 40. OEM wheel, not touched by my fair hands; I don't mess with wheels.

I've emailed the supplying dealer and Trek.

 

[Gary]

Many Sunringle rims definitley used to be some of the stiffest (which can also mean brittle) made.
I've no experience of the Duroc series rims though. Just inferno, MTX, Single/doublewide MAG series and ryno lites.
Rim material stiffness (and softness) is a big deal when riding DH and I'm a total geek for that sort of thing. Eg. a softer rim will dent easier but allow you not to puncture when it pinches. While it won't be as strong. it's a compromise. When racing DH rims are considered by many (me included) as disposible items.

 

[eabmex]

The tire bead MUST sit on the tape to ensure a proper seal, of course if it does not it will be hit or miss. If you replace the tape I suggest ordering one a couple milimeters wider than the rim so that when it is properly installed and follows the rim contour it covers from J bead to J bead, also, do not forget to add tension when fitting the tape.
Hope this helps

 

[Giff]

When mine have failed it’s always been at the valve. I now put a very small pilot hole through the tape (with a pin) and then thread the valve in through the tape. It seems to make a better seal. G.

 

[Frankenbetty]

it’s always the rim tape when I’ve had this problem. I’ve been tubeless for years on my non E-bikes but on my new E-bike I’ve just stuck some Stans fluid in the tubes in a diy Slime tubes way. Reckoned the weight wasn’t such a big deal on an E-bike and just wanted the extra puncture protection without the faff.
when I was using tubeless properly an airshot tubeless pump was one of the best purchases I ever made as I found my compressor was a bit brutal and could damage the tape when I popped the tyre on

 

[KennyB]

it’s always the rim tape when I’ve had this problem. I’ve been tubeless for years on my non E-bikes but on my new E-bike I’ve just stuck some Stans fluid in the tubes in a diy Slime tubes way. Reckoned the weight wasn’t such a big deal on an E-bike and just wanted the extra puncture protection without the faff.
when I was using tubeless properly an airshot tubeless pump was one of the best purchases I ever made as I found my compressor was a bit brutal and could damage the tape when I popped the tyre on

I tried this fluid in the tube once and it didn't work. All I got was sealent all over the inside of the tyre and a flat. Apparently the sealant spraying out of the puncture and reacting with the air is what causes the seal.

 

[Giff]

You can buy tubes pre-filled with Slime.

 

[eabmex]

You can buy tubes pre-filled with Slime.

Yes, Specialized sells them, they are a great option to have as a spare tube. The only downside is that they are heavey and bulkier when folded compared to a regular tube.

 

[HORSPWR]

had my tyres “tubelessed “ a week ago, was advised to expect some leakage until everything settles but after 50 miles they still lose all pressure overnight . Rims are tubeless ready. No obvious sign of leakage....should I expect this to improve ?? Am reluctant to venture too far from a good pump until I can be sure they will survive the ride.
Bike shop advised it will sort itself out after a couple of rides but its now more than a couple.
Any thoughts?
Have fun.

Yes, take it back and get them to do it again, it's not that hard!

 

[HORSPWR]

Hi Doomanic

Highly unlikely you will cure the problem with sealant alone, a good tubeless install should be capable of holding pressure without any sealant at all, the sealant should be for sealing puncture's in the tires. I always leave the fluid out and then test with air alone and if it's still holding air after 30 mins I remove the core and inject the fluid in through the valve.

100% a rim tape issue, not sure what wheels you have but try covering the the spoke holes with a narrow duct tape, start 100mm one side of the valve and finish 100mm the other side, then use a normal full width tape or rim strip over that. use a scalpel to carefully core out around the valve hole so that it seats properly.

Worth the effort and will make future tire changes a lot easier.

I've found that cutting a perfect circle in the rim tape for the valve can cause leaks, I've had more success with cutting a small cross into the centre of the hole and then pushing the valve through. This makes the rim tape come through the hole a bit and seals better against the rim preventing air getting in underneath. Just my 2c what works best for me.

 

[speedkills]

I'm running cushcores and have noticed what I believe is a pattern of the spokes leaking at first, then sealing up really well almost immediately if instead of putting the sealant in the tire carcass, I push it in through the valve stem. I think it keeps it close to the spokes and then the air immediately tries to escape there and pushes the sealant into the spokes.

 

[Matt van]

if you let a tubeless go flat you can just pump it back up and if your lucky it'll stay pumped up but more than likely will need to put fresh tape and sealant in it, but if you use it enough and it doesn't go flat it should last for a couple of years. I check the tyre pressure before each ride as I use 20 and 25psi which is low and add sealant every 6 months and this works for me