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Tania
10-04-2017, 09:42 AM
I noticed this weekend that the spin-ny twisty top thing on my presta value was sticky - meaning, I had trouble opening it and then closing it once I was done adding some air. Now I can neither open it nor close it and it's stuck in a half open position and slowly leaking air. At least, I'm fairly sure that the air is coming from the valve.

Is that fixable (and if so, how?) or should I just use a new valve stem?

TwoWheelsDC
10-04-2017, 09:46 AM
Do your valves have removable cores? Replacing the core would at least be easier than having to remove the tire and replace the stem.

anomad
10-04-2017, 09:58 AM
Might try using a pair of pliers to close it. Don't get carried away applying a ton of force. But you might be able to open and close it a few times and remove the gunk. Sometimes I use a rag or gloves (or pliers) to get a better grip on those little bastards when they get gummed up with Stans. Taking the whole thing apart and cleaning it later will probably take care of it for good.

drevil
10-04-2017, 10:18 AM
Do your valves have removable cores? Replacing the core would at least be easier than having to remove the tire and replace the stem.

+1. After wrasslin' with gunked up cores and trying to clean 'em with little success, I discovered that replaceable cores are cheap and a huge time saver. Buy a bag of 10 Kenda cores for a little more than a buck a pop/each:
https://www.amazon.com/Kenda-Presta-Valve-Cores-Bag/dp/B0028N8DGU

Harry Meatmotor
10-04-2017, 04:32 PM
+1. After wrasslin' with gunked up cores and trying to clean 'em with little success, I discovered that replaceable cores are cheap and a huge time saver. Buy a bag of 10 Kenda cores for a little more than a buck a pop/each:
https://www.amazon.com/Kenda-Presta-Valve-Cores-Bag/dp/B0028N8DGU

bikeshop trick: customer has flat tire --> after replacing tube, ask customer if they want the old tube --> if no, pull the valve core (if removable) and stash in workbench drawer.

non-bikeshop trick: call bike shop --> ask if they have a stash of used presta valve cores --> profit.

other bike shop trick: no tubeless valve stem? cut up old innertube, leaving 1 cm of butyl around valve stem. Viola! tubeless!

hozn
10-04-2017, 04:59 PM
My solution to removable cores is to put red loctite on them :-). Otherwise forget using a thread-on Lezyne pump head.

(Honestly, I have never understood why people go through the hassle of putting in sealant through the valve stem.)

But in this case, certainly having a removable core might save a little bit of money. (But at $4 for a stem -- or maybe less for a tube that you cut the stem out of, this isn't a big ticket item.)

drevil
10-05-2017, 07:55 AM
bikeshop trick: customer has flat tire --> after replacing tube, ask customer if they want the old tube --> if no, pull the valve core (if removable) and stash in workbench drawer.

non-bikeshop trick: call bike shop --> ask if they have a stash of used presta valve cores --> profit.

other bike shop trick: no tubeless valve stem? cut up old innertube, leaving 1 cm of butyl around valve stem. Viola! tubeless!

Nice! I've had little success removing the cores of my old tubes, most of which are Kenda or Specialized. I have a huge stack of them that I've been meaning to patch, but at this point (a few years?), I'll just try to remove the cores and recycle them.

There was one time I was going to use a stem cut out of a tube, but the rubber base was nowhere near as thick or sturdy as a tubeless stem like the Stans, so I abandoned the idea and ponied up for a real one. I assume you've never had issues doing this though?


My solution to removable cores is to put red loctite on them :-). Otherwise forget using a thread-on Lezyne pump head.

(Honestly, I have never understood why people go through the hassle of putting in sealant through the valve stem.)

But in this case, certainly having a removable core might save a little bit of money. (But at $4 for a stem -- or maybe less for a tube that you cut the stem out of, this isn't a big ticket item.)

The pumps I carry on my mountain bikes are thread-on Lezyne or Specialized, but it's rare for the valve to get unthreaded on removal. If they do, I just screw it back in. I like the ability to be able to take them off out in the field for when I'm out in the woods. On longer rides or bikepacking trips, I'll bring at least one 2oz bottle of Stans just in case of emergency.

I have a few wheel/tire combos that work fine tubeless, but they're relatively difficult to initially seat because they're so loose when first mounted. Sometimes I might have to use a tube initially or use both hands to pull the tire taut while using my foot on the compressor valve. (Note, this scenario is usually with 4" or wider tires on 65mm rims or 3" tires on 40mm rims :D). Basically, it'd be very messy if I put sealant in initially.

TwoWheelsDC
10-05-2017, 08:27 AM
Basically, it'd be very messy if I put sealant in initially.

While I haven't tried it the "Hans Way", I think it would be very messy for me too. I've found that adding sealant through the valve stem is pretty clean and easy. But different strokes and all that...

Harry Meatmotor
10-05-2017, 09:04 AM
I assume you've never had issues doing this though?

It's more of a fix in a pinch, and I usually run three layers of tubeless tape, with overlap at the valve hole, so the cut up valve fits pretty snug through the hole poked in the tape.

I'll add to this discussion, too, that I tend to look at tubeless valves/valve cores as kinda dispensable - if they give me any grief due to gunky valve cores or bad seals at the base I just toss them out.

Tania
10-05-2017, 09:31 AM
I don't have a spot at my place to even deal with sealant etc so I usually let the shop handle all things tubeless-related. However, I've been thinking about getting the SO a small compressor for his garage as an xmas present. So that then I can use it.

drevil
10-05-2017, 09:39 AM
...as an xmas present. So that then I can use it.

LOL, you're not the first to do this ;)

hozn
10-05-2017, 09:46 AM
Nice! I've had little success removing the cores of my old tubes, most of which are Kenda or Specialized. I have a huge stack of them that I've been meaning to patch, but at this point (a few years?), I'll just try to remove the cores and recycle them.

There was one time I was going to use a stem cut out of a tube, but the rubber base was nowhere near as thick or sturdy as a tubeless stem like the Stans, so I abandoned the idea and ponied up for a real one. I assume you've never had issues doing this though?


I've been saying recently that I see no point in paying a premium for tubeless valve stems, but I just learned the other day that there is a meaningful difference in construction. I cut the rubber pretty close to the stem from an old tube and then continued to tighten the stem nut until eventually I pulled it through the rim bed ... That was annoying to get out! But in general, if you don't cut it too close and you don't go crazy trying to over-tighten it, using stems from inner tubes works great. The downside is that if you leave enough tube around the stem to ensure you don't pull through, it can be tricky to seat tires on narrower rims. E.g. my 18mm-internal-width rims would prefer less interference around the bead shelf, so I bought pack of 32mm valve stems to use on those rims.




The pumps I carry on my mountain bikes are thread-on Lezyne or Specialized, but it's rare for the valve to get unthreaded on removal. If they do, I just screw it back in. I like the ability to be able to take them off out in the field for when I'm out in the woods. On longer rides or bikepacking trips, I'll bring at least one 2oz bottle of Stans just in case of emergency.

I have a few wheel/tire combos that work fine tubeless, but they're relatively difficult to initially seat because they're so loose when first mounted. Sometimes I might have to use a tube initially or use both hands to pull the tire taut while using my foot on the compressor valve. (Note, this scenario is usually with 4" or wider tires on 65mm rims or 3" tires on 40mm rims :D). Basically, it'd be very messy if I put sealant in initially.

I had a hard time getting cores not to unscrew and so eventually just read the internet where people said to use Loctite. Maybe I just wasn't tightening them enough? Anyway, this method works fine for me, but I can appreciate that it is probably messier than if you're able to get the tires fully seated without sealant in them initially.


While I haven't tried it the "Hans Way", I think it would be very messy for me too. I've found that adding sealant through the valve stem is pretty clean and easy. But different strokes and all that...

Yeah, I've only done the valve core method a couple of times, but the valve got gummed up and it didn't seem to make anything easier so I stopped. But it might have been cleaner to do it that way. Certainly seating tubeless tires is a messy operation with various soaps or waxes in addition to the sealant; I do it outside. I've gotten better about not spilling sealant (that stuff's expensive!), but on hard-to-seat tires, I definitely lose some to the process.

hozn
10-05-2017, 09:49 AM
I don't have a spot at my place to even deal with sealant etc so I usually let the shop handle all things tubeless-related. However, I've been thinking about getting the SO a small compressor for his garage as an xmas present. So that then I can use it.

Or maybe? http://road.cc/content/tech-news/230169-milkit-booster-aims-make-tubeless-tyre-inflation-easy-just-launched

Honestly, I have a Specialized Air Tool Blast (https://www.specialized.com/us/en/accessories/17pumpfloorair-tool-blast-117288/117288) but my Lezyne Dirt Drive pump can seat pretty much anything that the Blast can.

bentbike33
10-05-2017, 11:09 AM
I usually run three layers of tubeless tape...

Is three layers enough rim tape to keep the air pressure from stretching the tape into little divots over the spoke holes? In my limited experience (with narrow-ish road tubeless rims), I can only get a tubeless tire to seat with fresh rim tape.

hozn
10-05-2017, 11:30 AM
Is three layers enough rim tape to keep the air pressure from stretching the tape into little divots over the spoke holes? In my limited experience (with narrow-ish road tubeless rims), I can only get a tubeless tire to seat with fresh rim tape.

2 layers of stans yellow tape (or similar blue tape like that used by Velocity) is enough for road pressures. 1 layer is enough for MTB/Cross.

Some people "build up" the center channel on non-tubeless rims to help with seating. I've never had to do that, but maybe I've been lucky. (I don't use any rim strip in addition to the yellow tape.)

Harry Meatmotor
10-05-2017, 11:40 AM
Is three layers enough rim tape to keep the air pressure from stretching the tape into little divots over the spoke holes? In my limited experience (with narrow-ish road tubeless rims), I can only get a tubeless tire to seat with fresh rim tape.

for most of the rims I've dealt with at the shop, 2 wraps is good enough using stan's tape. At home, however, I used 3M blue packing tape you can get on amazon and according to the innernets, it's a teeny-tiny bit thinner than stan's. So at home I wrap 3 wraps. Haven't had any major issues yet between the two bikes in the house running tubeless, aside from burping in races and getting a bunch of crap in the bead because my GF corners at ludicrous speed.

hozn
10-05-2017, 02:33 PM
for most of the rims I've dealt with at the shop, 2 wraps is good enough using stan's tape. At home, however, I used 3M blue packing tape you can get on amazon and according to the innernets, it's a teeny-tiny bit thinner than stan's. So at home I wrap 3 wraps. Haven't had any major issues yet between the two bikes in the house running tubeless, aside from burping in races and getting a bunch of crap in the bead because my GF corners at ludicrous speed.

Yeah, I use Tesa 4289 (bought on ebay), since it is the same tape as Stans but a fraction of the cost. I've considered using the blue 3M too, though I had one bad experience with blue tape (I think it was either the Pacenti or Velocity tape) peeling up after a few tire changes, so I've gone back to yellow.

Tania
10-17-2017, 11:53 AM
I'm at a happy status quo* I think. The valve no longer seem to be leaking air (or not nearly as much) and I can still pump air into it when I need to (carbon rims and rocks!) and let some out when I need to (turns out those rocks are really wet and covered with wet leaves and I'm NOT going fast!).


* I haven't bothered to see if I can twist it fully open or closed. I'm good with half open and usable.

Harry Meatmotor
11-02-2017, 10:46 AM
OK - so I'm offishully done with tubeless for CX. Got taken out at Biketoberfest by a C3/Twenty-Twenty dude within 2 minutes of start, went down, and ripped the f@cking front tire off the rim. Race over.

DONE. WITH. TUBELESS.

That's 4 races so far botched due to either burping down to rim-riding, or in the last/final case, general catastrophic failure. I'm typically running 25-27psi so it's not a question of pressure.

old skool tubs, here I come.

hozn
11-02-2017, 10:58 AM
OK - so I'm offishully done with tubeless for CX. Got taken out at Biketoberfest by a C3/Twenty-Twenty dude within 2 minutes of start, went down, and ripped the f@cking front tire off the rim. Race over.

DONE. WITH. TUBELESS.

That's 4 races so far botched due to either burping down to rim-riding, or in the last/final case, general catastrophic failure. I'm typically running 25-27psi so it's not a question of pressure.

old skool tubs, here I come.

Which rims & tires are you using? I'm not a 'cross racer, but it seems surprising you've had so many problems. Lots of folks do run tubeless, right? (I know November thinks it's "ready": https://novemberbicycles.com/blogs/blog/tubeless-cx-ready-for-prime-time)

But those are pretty low pressures for a 32/33mm tire, so maybe that just pushes the setup a little too far.

I hear of people rolling tubs off their rims too, but probably not with the frequency you've experienced.

Harry Meatmotor
11-02-2017, 11:29 AM
Which rims & tires are you using? I'm not a 'cross racer, but it seems surprising you've had so many problems. Lots of folks do run tubeless, right? (I know November thinks it's "ready": https://novemberbicycles.com/blogs/blog/tubeless-cx-ready-for-prime-time)

But those are pretty low pressures for a 32/33mm tire, so maybe that just pushes the setup a little too far.

I hear of people rolling tubs off their rims too, but probably not with the frequency you've experienced.

Spec Axis 4.0 rims, 3 wraps of 3M blue packing tape, Spec 2Bliss Terra FR and Tracer RR, Stan's sealant. 155lb rider @ 25psi FR, 26-27psi RR.

Tania
11-02-2017, 11:32 AM
I'm not a 'cross racer

Yeah, but you really should be.

hozn
11-02-2017, 11:56 AM
Spec Axis 4.0 rims, 3 wraps of 3M blue packing tape, Spec 2Bliss Terra FR and Tracer RR, Stan's sealant. 155lb rider @ 25psi FR, 26-27psi RR.

Welp, no idea re: those rims, but the tires sounds legit! (Why so much tape? [more] burping with fewer layers?) In general, I like Specialized's 2bliss tires, but haven't run anything smaller than 38mm in years now.

My money would be on the rims being the problem, but switching rims to e.g. Stans isn't such a simple option.

Harry Meatmotor
11-02-2017, 01:41 PM
Welp, no idea re: those rims, but the tires sounds legit! (Why so much tape? [more] burping with fewer layers?) In general, I like Specialized's 2bliss tires, but haven't run anything smaller than 38mm in years now.

My money would be on the rims being the problem, but switching rims to e.g. Stans isn't such a simple option.

Problem is the rims are tubeless ready, with good hooks and a flat bead shelf. And with 3 wraps of the thinner tape (thinner than Stan's by something like .05mm), I figured I'd be good to run down to ~23psi. First race on the tubeless was Dirt Crit - 30psi out back - and I burped when the rear tire came off the ground over a small whoop @22-ish mph, and landed a bit sideways. I though it was a fluke, but the same thing happened at DCCX.

Roughly half of the folks racing cross on the team who are running tubeless have had issues (like, race-ending, or at least taking them out of top-10 contention), and that's across different rims/tires. I gave it a whirl thinking the folks having issues were due to less than ideal setup/install. Just counting race fees from blown races due to tire mechanicals, the tubeless setup has cost me about $150. At least 3 people on the team have gone from tubeless to tubs in less than a season of racing on tubeless. The only setup that hasn't seen any issues is Spec 2Bliss tires on Stan's Grail. I don't think I'll ever be convinced to run Stan's rims (long story...) despite being en vogue among the dirt/gravel cognoscenti. So far rims in the "not that great" column are (and, yes, I know most of these aren't tubeless specific profiles): HED Belgium C2, Axis (Specialized) 2.0 & 4.0, Easton EA90, Velocity Aileron.

I will say, tho, I'll probably be sticking with Spec Terra and Tracer. The traction is phenomenal, especially the Terra. Its pretty insane.

hozn
11-02-2017, 02:44 PM
Ok, well Grails have been my benchmark rim, so perhaps that is why I am surprised to hear about people burping tires. Of course now I am using DT Swiss R460 rims which have been awesome, but at higher pressures for small tires or low pressure for 40mm tires.

We'll see how they fare at Iron Cross this weekend.

TwoWheelsDC
11-02-2017, 02:59 PM
Problem is the rims are tubeless ready, with good hooks and a flat bead shelf. And with 3 wraps of the thinner tape (thinner than Stan's by something like .05mm), I figured I'd be good to run down to ~23psi.

Genuine question...if the rims are tubeless ready, why the tape? Does the tape somehow allow you to run lower pressures?

hozn
11-02-2017, 03:11 PM
Tubeless ready just means the shape of the rim is designed for tubeless (mounting, not burping, etc.). There are generally still holes for the spokes in rim bed.

There are also UST rims (or other tubeless rims) that don't have holes in rim bed.

TwoWheelsDC
11-02-2017, 03:23 PM
Tubeless ready just means the shape of the rim is designed for tubeless (mounting, not burping, etc.). There are generally still holes for the spokes in rim bed.

There are also UST rims (or other tubeless rims) that don't have holes in rim bed.

Aha...I just assumed anything labeled "tubeless ready" would not have the holes. But now I know!

Harry Meatmotor
11-02-2017, 04:16 PM
Aha...I just assumed anything labeled "tubeless ready" would not have the holes. But now I know!

There are a handful of manufacturers making tubeless carbon rims where the rim bed isn't drilled for spoke holes, but the spoke bed is drilled for normal spoke nipples. To lace the wheels, you need to drop the spoke nipple into the rim through the valve stem hole, then finagle it into position. Just a tiny bit tedious. But no need for sealing tape.

Tania
11-06-2017, 06:00 AM
The tubeless valves that came with my eThirteen wheels have a core remover built into the top cap.

15688

mstone
11-06-2017, 10:32 AM
There are a handful of manufacturers making tubeless carbon rims where the rim bed isn't drilled for spoke holes, but the spoke bed is drilled for normal spoke nipples. To lace the wheels, you need to drop the spoke nipple into the rim through the valve stem hole, then finagle it into position. Just a tiny bit tedious. But no need for sealing tape.

I wonder what the average number of installed spokes is before someone throws the whole thing out a window.

hozn
11-06-2017, 10:49 AM
I wonder what the average number of installed spokes is before someone throws the whole thing out a window.

This is exactly why I've never even considered building one of these :) I think for me it would be 1, maybe 2.

(Tape is so easy to install and adds negligible weight, so I'll always choose that option rather than a wheel that is a pain to build or, heaven forbid, repair.)

drevil
11-06-2017, 11:00 AM
This is exactly why I've never even considered building one of these :) I think for me it would be 1, maybe 2.

(Tape is so easy to install and adds negligible weight, so I'll always choose that option rather than a wheel that is a pain to build or, heaven forbid, repair.)

I wonder if you could do the same thing as in this video (at 2:46):

https://youtu.be/rAw7ihWIgAk?t=2m46s

hozn
11-06-2017, 11:06 AM
I wonder if you could do the same thing as in this video (at 2:46):

https://youtu.be/rAw7ihWIgAk?t=2m46sI think you can, yeah. That video does make it look easy. Probably the second time I accidentally lost the nipple in there after removing the magnet I'd be kicking myself, though.

Raymo853
11-11-2017, 05:37 AM
Otherwise forget using a thread-on Lezyne pump head.

(Honestly, I have never understood why people go through the hassle of putting in sealant through the valve stem.)


Lezyne has a new design hose that no longer backs out valves. It is compatability with all the older pumps.

I put sealant through valve stems every month in every tire. Why? Some tires are so hard to seat and sealant dries up in a few weeks.



Sent from my SM-G900V using Tapatalk

hozn
11-11-2017, 07:16 AM
Lezyne has a new design hose that no longer backs out valves. It is compatability with all the older pumps.

I put sealant through valve stems every month in every tire. Why? Some tires are so hard to seat and sealant dries up in a few weeks.

On their portable/hand pumps? I've tried a few Lezyne heads on floor pumps; the more traditional double-barelled head actually works well, but their other push on or "half-twist" heads worked terribly for me.

I use the Silca push-on head on my Lezyne dirt drive now.

For me sealant lasts closer to a few months, though it probably depends on a number of factors (?)