If you’re a casual cyclist riding 10 -20 miles a week, chances are you have never considered adding tire sealant to your bike. However, if you are putting in some serious mileage, you will benefit from sealant, particularly on a mountain bike, and even more, if you are riding off-road. You might even have bought your ride with sealant in the tires, but what do you do when it’s time to top up? Can you mix MTB tire sealant?
Tire sealants have various components, and manufacturers all agree that sealants should not be mixed since no manufacturer knows for certain what is in another manufacturer’s product. Cyclists – the end users – often mix sealants (they’re reluctant to discard open bottles) with no recorded issues.
This is a particularly grey area regarding cycling and cycling accessories. From my research and after polling the riders in my group, the cyclists split into two fairly equal camps. Around half have no problem mixing, depending on certain conditions, while the rest do not mix for any reason whatsoever.
What Do The Manufacturers Say Regarding Mixing Sealants?
Every manufacturer of tire sealant says to avoid mixing brands, yet personal experience suggests that usually there is no negative issue. It is to be expected that manufacturers would prefer you to use their brand, undiluted by any outside product.
What do experienced cyclists say regarding mixing tire sealants on a mountain bike?
- Many are perfectly happy to mix sealants but warn against mixing latex-based sealants with non-latex-based products.
- Others suggest that they will only add sealant from a different brand if the existing sealant in the tire has dried, making the question moot.
Cyclists’ concerns regarding sealant
Some seriously competitive cyclists raised the point of added weight as a concern. Since the majority of sealant’s weight is in the liquid (which evaporates), you don’t have to worry about significant weight gain over time. Typically, all that remains is a thin layer of latex, which can be easily peeled out if you’re overly concerned.
When Should You Add Tire Sealant?
If your tire is not losing pressure, there is no need to change anything. However, if your tire begins to lose air slowly (say 10 PSI over 2 days), it may be time to top up. Your tire has lost the liquid carrier in your sealant due to evaporation. The remainder of the sealant is either dry or drying and can no longer travel to where it is needed.
If your tire sealant is a little low and you don’t have sealant on hand, use a little antifreeze as a temporary solution, or carry Stan’s or Orange Seal in your tote. Interestingly, once dried, Orange Seal leaves a latex coating you can easily peel off the tire if you feel the need to. Conversely, Stan’s clumps into odd little balls many proponents affectionately refer to as ‘stan-imals.’
What Causes Sealant To Dry Or Begin To Fail?
- Hot, dry weather will dry up sealant faster than the weather with more moisture in the air.
- Wear and tear is also a factor. The more you cycle and add air to the tire, the quicker the sealant tends to dry.
- Tubeless-ready tires (TLR) often lose a small amount of sealant via their sidewalls.
How To Check If Your Sealant Is Low?
On occasion, although your tire is not leaking pressure, you will want to check your sealant levels. Like a car engine uses a dipstick to show the oil level, riders can use a simple (lightweight!) zip tie to check sealant levels. This also helps ensure you don’t overfill if you do add sealant. (Around 2oz twice a year is a good guide)
Do You Even Need Sealant?
As with all things cycling, there are various opinions on this, but for the most part, cyclists vote in favor, and I’ve yet to see a cyclist happily repairing a puncture in a race or even on a family outing. We hate punctures!
Several sealants are on the market, and almost all are available online.
Here are two of my favorites:
Whether you’re an expert, a rank beginner, or someone in-between, you will love Orange’s proven ability to seal fast and even close bigger punctures (up to 1/4”) on your tubeless tires. Orange also performs well under varying altitudes and temperatures. It is supplied with an injection system, speeding the entire process up, which is great, and a 237ml bottle retails for around U$15.00.
Stan’s Tire Sealant will instantly seal small punctures in treads and sidewalls using a unique repair process that places crystals at the puncture site, sealing the hole prior to excessive air pressure loss.
- Instantly seals a puncture up to 1/2″ in both tread and sidewalls
- Performs well in temperatures as low as -20F
- Outperforms most other sealants while using less than 50% per application
- Protects wheels and tires against damage using a natural latex compound.
Regardless of what sealant you choose, here is an easy and quick way to apply the product to your MTB tire:
No tools are required other than a valve core remover which will speed up the process:
- Remove the valve cap, and drop the air pressure
- Place the core removal tool over the valve, twist counterclockwise, and remove. (Also possible with needle-nose pliers, but these are bulky and heavier to carry)
- Using a 2oz squirt bottle (or similar, as long as it has a tapered nozzle), squeeze the contents (suggest you stop at 2oz, but that’s your call) into the tube.
- Replace the valve, pump the tire, replace the valve cap, and you’re done!
- The entire process takes about six minutes from start to finish.
From my research and many years as an amateur cyclist, I suggest you stick to one brand of sealant where possible but use whatever sealant you can get your hands on as a temporary fix in an emergency. If your sealant has dried, and you have the time, remove as much as possible.
This will involve unseating – removing – the tire from the rim and is best done in a clean and dry environment, but if done every six months or so, it will never become an issue.