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by David Rome
December 11, 2017
Photography by David Rome
TECH NEWS BROUGHT TO YOU BY BIKEEXCHANGE
I was on a group ride in South Africa a few years ago when one of the guys got a flat. Before I had even unclipped from my pedals, the flat was fixed. He had simply put his gloved finger over the hole, taken out a tubeless plug repair kit with his other hand, and jammed a rubber plug through the hole with the kit’s needle-like tool. The hissing stopped almost instantly, and the tyre was repaired with minimal air loss.
The whole ordeal took about 20 seconds and before I knew it, he was rolling again.
As we were riding, I mentioned that while I’d seen such a thing done to a car tyre, I’d never seen it done on a bicycle. The group laughed, explaining that it’s just the common thing in the South African mountain bike scene. Thorns were such a common occurrence that nearly everyone plugged tyres, and most riders didn’t even bother carrying tubes anymore.
No removing a wheel, no removing a tyre, no installing a tube, no pumping. Just jab and go.
Fast forward a few months and I stumbled across Dynaplug, an American company with a 30-year history in the motorcycle and automotive worlds. Late in 2014, Dynaplug realised that the products it developed for motorised vehicles also worked well with tubeless mountain bike tyres, eventually expanding the range to bicycle-specific versions. Even more recently, cyclocross and gravel riders have discovered that the plugs work well in those applications, too.
I knew the product worked on wider rubber at lower pressures, but how well would it work on skinny tubeless tyres with high pressures? With that question in mind, I brought three Dynaplug bicycle plug kits in for test: the Carbon Ultralite, the Racer, and the Air.
I’ve seen firsthand how effective fresh tyre sealant can be at repairing punctures on the move, but larger cuts often see all the air and sealant hiss out together. Plugs, on the other hand, are better able to fill big gaps that might otherwise require you to install an inner tube to keep riding.
Dynaplug make their own plugs in-house with a unique bullet-like metal tip. Where most plug systems rely on a pronged tool that pierces the tyre and leaves the soft plug behind, Dynaplug’s patented design combines the piercing prong (usually made of brass) with a rubber-impregnated woven plug. The pointed brass tip is small and not actually all that sharp, and while a clumsy install may mar the inside of rim, it’ll never do any more damage than that. A small barb keeps the plug from being pulled or pushed back out of the tyre.
Multiple plugs can be used if needed for especially big punctures, but Dynaplug also offers a variant called the Megaplug (as seen below in the Racer kit). These plugs offer bigger, rounded aluminium tips and rubberised cords roughly three times the diameter of the standard versions.
All the tools tested include four spare plugs, with additional plugs available for purchase in packs of five for US$10 / AU$12.
Housed within the stainless steel shaft of a Dynaplug tool, the plugs are simply stabbed through the puncture, and then the tool is pulled out – leaving the plug behind. At this point, it’s likely you’ve fixed the puncture and you’re ready to keep riding. The exposed rubber plug can be left as is, or trimmed or folded as desired. Provided you remember to keep the kit readily accessible, you can usually plug the tyre fast enough to continue riding without having to add more air.
To test the plugs, I set up a 33c tubeless cyclocross tyre (without sealant) and inflated it to its maximum pressure of 80psi. From here, I used a thick awl to puncture through the tyre tread (and separately, the sidewall), leaving a hole far bigger than a usual framing nail.
Just one Dynaplug was needed for all but one of those holes, and the tyre remained sealed even after it was re-inflated to its maximum pressure and ridden. One of the fixes did slowly leak, but the repair was still sufficiently robust to ride. Keep in mind that this was without sealant, though; adding it created a perfect airtight repair.
Sound too good to be true? Based on my testing, Dynaplug’s kit really does work as advertised, and CyclingTips senior editor Caley Fretz has had excellent success out in the wild as well. Assuming the casing isn’t too damaged, you can leave the plugs in place indefinitely, too. There is, of course, a limit to how big a cut can be repaired, but for most circumstances, this will amply do the job.
Testing the Dynaplugs starts with creating a puncture.
Next, insert the plug and tool into the hole.
The hissing of air stopped as soon as the tool was in place. At this point, you simply pull the tool back out.
With the tool remove, the plug remains. Even though the rubber protrudes, it’s fine to ride it.
The plugs can be used on sidewalls, too.
One of the newest options in the range, the Air combines Dynaplug’s standard plug design with a CO2 inflator. It’s an extremely minimalist setup that houses just a single plug, but it’s very light as a result at just 22g without a CO2 canister.
The CO2 inflator works like most other threaded inflators: thread on the head completely to pierce and seal the cartridge, then back it out slightly to release the gas. The CO2 is expelled through two small holes in the Dynaplug shaft, behind the plug. It’s a quality inflator, and Dynaplug claim they test every single one with a 12g canisters prior to it leaving the building.
Because of that hole in the shaft, though, you need to jam the tool 30mm deep into the tyre; otherwise, you’re be releasing CO2 into the open air, not inside the tyre casing. It’s an awkwardly long insertion depth for a 33c cyclocross tyre, and jamming it straight down into the casing sees the brass tip bottom out on the rim, which can scratch the rim tape.
According to Dynaplug, a shorter, road-specific version of this tool is on the way to better suit lower-volume tyres. In the meantime, I would recommend going in at a diagonal angle.
Dynaplug is also working on an accessory for 2018 which will allow the CO2 inflator to attach directly to the valve, in case you just want to add pressure and don’t need to use the plug. It’s worth noting, too, that the plug can be used without the CO2.
Like any non-insulated metal CO2 inflator, care must be taken during use as the attached canister gets extremely cold. Gloves or some other kind of cover are strongly recommended.
This dual-sided tool is great in that it offers two different sized plugs that are ready to use and fully protected from the elements. Impressively light at just 24g (including two plugs), the anodised aluminium construction and smooth edges makes this one the most suitable for use in a jersey pocket, or just strapped somewhere on your bike within easy reach.
It’s minimalist in that it doesn’t offer storage for spare plugs, but that’s also what makes it so light, compact, and efficient. My only complaint is that there are no external markings on the caps to show which plug is hiding underneath. It’s not a big deal most of the time, but that bit of fumbling could waste precious seconds in a race situation. It would be great to see Dynaplug colour-code the end caps, or you can do a similar thing yourself with tape or shrink wrap.
This is the simplest, cheapest, and bulkiest Dynaplug option I tested. The hollow glass-filled nylon body keeps the total weight in check at just 32g, but there’s still enough space inside for three spare plugs. As a result, it’s a great lightweight option for extended trips or rides where multiple punctures may be a reality. I did find the spare plugs had a tendency to stick together or rattle, but wrapping them in wax paper kept things tidy.
This model is slower to use than the other two as there is some basic assembly required before the tool is ready to use. But despite this version taking more time to use, the spare plugs add some peace of mind for any ride where the clock isn’t running.
One Dynaplug version I did not test is the Micro Pro. This is perhaps the best-known and most common kit from Dynaplug, which perhaps shouldn’t be a surprise given that it was the company’s original launch product into the mountain bike market. The Micro Pro features a pill-shaped aluminium housing; inside hides the insertion tube on one side, and a handful of spare plugs in the other.
This model remains a staple in the range – it earned a spot on Caley Fretz’s list of favorite products in 2017 – but where it arguably lacks compared to the three models tested here is in its 48g weight. That’s still an impressive figure, but it’s nonetheless heavier than the three models above.
It isn’t often that a product completely fulfills its marketing promises, but based on our collective experience, Dynaplug’s tubeless plug kits live up to the hype. They’re extremely easy to use, and assuming you have relatively fresh tyre sealant in your tyres, dependable long-term, too.
These are highly recommended for anyone using tubeless tyres, and of all the plug-type repair kits currently available, Dynaplug is the most refined option going. It really is in a class of its own, although the price typically reflects that.
You can’t go wrong with any of the options reviewed above in terms of function, so it’s really more a matter of choosing the one that best fits your needs. If you’re seeking a low-cost option and aren’t overly concerned with your finish time, then the Ultralite Carbon would probably make the most sense with its multiple plugs. And if you want the multiple spare plugs, but are willing to spend more, look to the machined aluminium options, such as the Micro Pro.
However, if you’re the type to ride with a single tube and one CO2 canister, then you’ll love both the Racer and the Air. The Racer is best for mountain bike or gravel racers where large holes are more likely; the Air is more of a one-shot fix, and something that arguably could be your only spare required in a short race, assuming you can swallow that price tag for such a small item.
www.Dynaplug.com / KWT Imports (Australian Distributor)
Genuine Innovations’ low-cost plug kit (top) gets the job done, but it isn’t nearly as convenient to carry on the bike as the Dynaplug Racer. It’s certainly slower to use, too.