FAO - those that run or have run sealant inside innertubes... feedback req'd pls!

[TOMAS]

I operate a cycle servicing/repairs business and I'm after feedback from anyone who has or is using sealant inside of innertubes to help guard against flats. I personally have no experience of it, I do however have lots of personal experience of tubeless tyres running Stans sealant & also lots feedback from customers using tubeless tyres.

Not really after thoughts or opinions, actual experience of it is vital. I've been experimenting with injecting Stans sealant into some customer tubes who don't have the option or £ for a tubeless conversion, with their blessing as 'guinea pigs' (after all it does say it can be used inside of tubes). I know that Halfrauds have for a long time offered a 'sealant injection service' - which is an injection of 'Slime', which i'm not a huge fan of for it being too thick imo and blocks valves/causes leaky valves, it's also very heavy and causes major wheel vibrations, a lot more so than 90-100ml of Stans.

My theory is that providing the innertube doesn't have chance move freely around inside of the tyre (i.e under quite high pressures) once the foreign object has penetrated, then it ought to give the sealant a good chance to do its thing.

Cheers, Tom

 

[Suprachrgd82]

About 25 years ago I had used Slime sealant when it had a fibrous filler constituent. It worked some of the time to seal thorn punctures but fibers did not allow the Schrader pintle to seat, resulting in a very slow leak.

Just a few weeks ago I filled 4 family bike tires with the newer recipe Slime. No idea when they reformulated but Slime doesn’t seem to be the cotton swab emulsion it used to be. My daughter and I rode through a long stretch of thorn filled dirt. I patched an average of 7 holes in each of the 4 tubes and added 4 ounces of Slime per tube. It’s been about 3 weeks and all are holding pressure perfectly. Though we rarely exceed 15 mph, we have zero undesirable wheel related harmonics.

My wife’s bike has had the same factory Slime filled tubes since her bike was new in the late 90’s with no issue. I just changed her tires out and found no mess between the old tire & tube and no evidence of the Slime causing the tube to rot. I really expected to find gooey tubes, rusty spoke ends, and a righteous stink.

Aside from adding 1/2 lbs of weight to each bike, I have zero complaints. I don’t consider it a miracle product by any means but it seems to do what they promise.

 

[greencat]

Works well with limitations. I consider slime an essential for Bromptons and similar small wheeled bikes. If you've ever tried to remove the back wheel/tyre by the side of the road when it's pissing down with rain at 10pm at night, you'll likely soon agree. It won't solve everything, I once memorably had a green jet shooting out about a metre from the tyre and the bugger wouldn't seal at all. Even when it doesn't work perfectly, it can turn a fast puncture into a slow one.

It can have a tendency to block valves, but rarely happens to the extent the tyre cannot be pumped up. Removing the valve core, and using a bit of wire to clear the blockage usually does the job.

I even run sealant tubes on my mountain bike after halfords were selling them off. No problems so far. It's a good compromise between tubed and tubeless (which I've never managed to make work).

The big problem with DIY, of course, is that few presta tubes seem to come with removable valves nowadays so impossible in put sealant in - although I have heard of people using needle syringes to do so.

Lastly, it'll probably need topping up from time to time (like once every couple of years).

 

[TOMAS]

Works well with limitations. I consider slime an essential for Bromptons and similar small wheeled bikes. If you've ever tried to remove the back wheel/tyre by the side of the road when it's pissing down with rain at 10pm at night, you'll likely soon agree. It won't solve everything, I once memorably had a green jet shooting out about a metre from the tyre and the bugger wouldn't seal at all. Even when it doesn't work perfectly, it can turn a fast puncture into a slow one.

It can have a tendency to block valves, but rarely happens to the extent the tyre cannot be pumped up. Removing the valve core, and using a bit of wire to clear the blockage usually does the job.

I even run sealant tubes on my mountain bike after halfords were selling them off. No problems so far. It's a good compromise between tubed and tubeless (which I've never managed to make work).

The big problem with DIY, of course, is that few presta tubes seem to come with removable valves nowadays so impossible in put sealant in - although I have heard of people using needle syringes to do so.

Lastly, it'll probably need topping up from time to time (like once every couple of years).

Cheers guys, in patricular im looking to inject Stans sealant into tubes...

I've mastered the art of injecting into non-removable core presta tubes by way of large syringe under pressure and tight hose over the open valve, big of jiggling the brass tip in the hose helps whilst under pressure.

I think my method will be patricularly useful for us Retro riders. Having suffered very few punctures on my modern mtbs since I first went tubeless a decade ago, the thought of flats on the retros is offputting.

I find that Stans dries out after 9-12 months in tubeless situation and would assume samd for a tubed application.

 

[jimo746]

I've used Stans in conventional tubes in the past without any major issues, some minor problems with it blocking the valve, but that's the same with any tubeless system, a removable valve core can help with that.

But I found I used my retro mtbs infrequently, didn't check the sealant as I should, and so it dried up & didn't work as intended, and made a trailside puncture repair messy and difficult

I now use regular inner tubes, without sealant. For me it wasn't worth the extra hassle, cost, time etc on my retro Mtbs.
On my modern Mtb sealant works great in a tubeless setup, but on my retro mtbs that see limited use, and fewer miles, on more sedate terrain , and rarely puncture with regular tubes I'd rather use regular tubes without sealant.

Maybe see if a few customers would trial it? I can see for commuting & everyday use it may have benefits , time saving etc.

 

[TOMAS]

I've used Stans in conventional tubes in the past without any major issues, some minor problems with it blocking the valve, but that's the same with any tubeless system, a removable valve core can help with that.

But I found I used my retro mtbs infrequently, didn't check the sealant as I should, and so it dried up & didn't work as intended, and made a trailside puncture repair messy and difficult

I now use regular inner tubes, without sealant. For me it wasn't worth the extra hassle, cost, time etc on my retro Mtbs.
On my modern Mtb sealant works great in a tubeless setup, but on my retro mtbs that see limited use, and fewer miles, on more sedate terrain , and rarely puncture with regular tubes I'd rather use regular tubes without sealant.

Maybe see if a few customers would trial it? I can see for commuting & everyday use it may have benefits , time saving etc.

Yup agree with all the above. I've got a few customers with teenage kids who get flats from thorns like every week or so on their more budget bikes such as B-Twins and Carreras, tbh I'm doing myself out of work but going to trial it on some on them to see what results I get. I think it would work very well on the 700C 35-43C wired tyre commuters best, these are under decent pressure to avoid the thorn moving about loads in the tyre/tube.

Had a 'Slimed' MTB suffering slow flats in a couple of weeks ago, pulled the tube out to discover around 7 large thorns through the tyre! It only went down after like 2-3 days, which is pretty good going tbf.

 

[scant]

I have run stans sealant in normal tubes without issue. the only real downside being after a year you'll need to replace the tube & start again as the sealant will have dried up.

 

[TOMAS]

I have run stans sealant in normal tubes without issue. the only real downside being after a year you'll need to replace the tube & start again as the sealant will have dried up.

Why would you need to 'start again' and bin the tube after its dried up? Why not just top it up, as you do in tubeless tyres? I don't spend hours piggling or scrubbing off the dried up stuff on tubeless tyres, just add some fresh sealant and its good to go in my eyes.

 

[scant]

yeh you could do if you dont mind the added weight, roughly 2ounces a time. but also old sealant can form a big plug & all the sealant gets sucked to that point, so any new sealant gets drawn to that point & isnt effective in preventing future punctures.

I dont get 6months out of a tyre (I ride a lot), so scrubbing out old sealant for tubeless is never a concern.

 

[greencat]

I've mastered the art of injecting into non-removable core presta tubes by way of large syringe under pressure and tight hose over the open valve, big of jiggling the brass tip in the hose helps whilst under pressure.

Great to see some pics/video of this approach if possible.