TFL Tundercat Soft Growler Review
I’m riding the XR growler soft Thundercat. I have about 200 trail miles on the tire. I have ridden Hoosier treaded and smooth, pint stock Unilli, XR stock, original BTG, X-rad, Feiben 10x6-6. This is my first “Enduro” type tire.
Traction is great. It is strongest on hard pack dirt and weakest on deep, loose pack, large gravel and mud. Where it is strong, it is super strong. I’ve had it pull me up short single track climbs, where I need to lift the nose 12 degrees to clear. Because of the terrain I have to hit it at low speed, high torque. I was astounded that the tire can handle that much torque without slipping. These are sections I always carry the board up.
I think the tread pattern is really interesting. It uses sipes, which are common in dirt cart racing. I think these are really effective. The soft compound makes a big difference on the size of the contact patch. It makes low speed, difficult maneuvers much easier. If you want a ride that is easier to balance, soft compound will definitely help you. I found pulling this maneuver to be much easier on the Thundercat. [https://www.reddit.com/r/onewheel/comments/12iojm6/me\_getting\_super\_dizzy\_testing\_turn\_boost\_for/](https://www.reddit.com/r/onewheel/comments/12iojm6/me_getting_super_dizzy_testing_turn_boost_for/)
Tire shape is agreeable to me, but I prefer something with a rounder profile. The softer sidewall compound makes the profile feel rounder than a harder compound tire with an equivalent geometry, like the Pint stock Unilli. I did some measurements at different pressures and found these tires to be quite similar in terms of sidewall height vs. inflated diameter.
The soft sidewall has the negative side effect of making the tire less responsive to roll changes. This is similar to a car with tight suspension having better handling than a car with loose suspension. Loose suspension is better for off-roading but you lose some ability to corner and control accurately. At times, I will feel a sensation I call “wonky,” where the board will bounce back and forth between the sidewalls seemingly on its own, just from the energy of the sidewall flex. This happens more often on narrow single track. I think it is something I will just get used to.
The ride is extremely smooth. The absorption of the compound allows for a faster ride with better traction in rough conditions. The downside is bonks are relatively weak because of the absorption of the compound, even at higher pressures. I see this as a necessary trade off to gain the suspension capability. Since I have added suspension springs to my board, this is not an issue because I can “pre-compress” the springs before the bonk to regain some of the bounce lost by the tire.
My biggest concern is durability. About 100 miles in, I had a sidewall hole that would not seal. It was directly where the vent spur was located. I figured it was an air bubble that got caught in the vent spur, which would be a manufacturing defect. Brandon at TFL said it’s too hard to tell with these soft compounds. It could just as easily be a rock scrap. I got my warranty replacement anyway because TFL is great. As an experiment, I used a standard tiring plug kit to fix the damaged tire. It was more difficult to use the plug kit than on a car tire because of how soft the tire compound is. The plug itself is very sticky and it did not want to release from the tool onto the tire. I was able to get it done with some unusual techniques. It has held well for 100 miles. No slow leakage. This makes me feel better about durability and field repair.
It was directly where the vent spur was located. I figured it was an air bubble that got caught in the vent spur, which would be a manufacturing defect. Brandon at TFL said it’s too hard to tell with these soft compounds. It could just as easily be a rock scrap. I got my warranty replacement anyway because TFL is great. As an experiment, I used a standard tire plug kit to fix the damaged tire.
It was more difficult to use the plug kit than on a car tire because of how soft the tire compound is. The plug itself is very sticky and it did not want to release from the tool onto the tire. I was able to get it done with some unusual techniques. It has held well for 100 miles. No slow leakage. This makes me feel better about durability and field repair.
The pressure range of this tire is incredible. I consider high pressure 15-20, mid pressure 10-15, and low pressure <10 psig. At 150lb and I see 5-20 psig as the operable range. I prefer mid pressure 10-12 psig because the tire still maintains its round profile, but you still get a good amount of suspension. I found low pressure feels a bit too square to me, and the tire can feel more wonky.
I would like to compare this quickly to the Feiben 10x6-6 [https://www.alibaba.com/product-detail/FB6002-FEIBEN-Electric-Scooter-Specific-Wide\_1601574664682.html](https://www.alibaba.com/product-detail/FB6002-FEIBEN-Electric-Scooter-Specific-Wide_1601574664682.html) which is a favorite of mine. This tire is a hard compound with an aggressive, knobby tread pattern, and a very round profile. I think this tire contrasts really well with the Thundercat. To me, the Feiben is the more fun tire but less capable in extreme situations. The hard compound and smaller contact patch makes it more reactive to roll and yaw. This allows for snappier, looser carving. The rounder profile allows for deeper carving. The harder compound bonks higher, but it does not have the same suspension ability. Without this suspension ability, this tire gets worse traction on rugged downhills. Because of the smaller contact patch and harder compound the Feiben tire does not have the traction of the Thundercat despite the knobs, except in cases where there is mud or deep gravel. In these cases, the knobs seem to penetrate the terrain a bit better.
I see room in my quiver for both these tires. The Feiben for more fun carving and hitting bonks. The Tundercat for pushing steeper, more difficult downhill terrain. I'm looking forward to the 5" version.