Touratech-USA’s unofficial product tester, Iain Glynn, just mounted a rear Kenda Big Block dual-sport tire onto his BMW R1200GS. According to Iain, "It was harder to mount than a TKC but nothing terrible. I did it with the two Motion Pro spoons and no lube." Iain will spend Memorial Day weekend pre-running for next month’s BMW XPLOR Pacific Northwest Adventure Rally and we’re eager to see how the Kenda Big Block handles the terrain. Stay tuned for additional updates as Iain puts some miles on this tire.
Update ~ 50 miles:
Iain reports that after yesterday’s rainy commute, the wet pavment traction is not as good as the Continental TKC 80. "You can spin the tire fairly easily. The Kenda Big Block has a ‘squishy’ feeling, but it seems just like a new TKC to me, deep knobs just feel soft. I did a short loop on some urban gravel and the hookup from the tire feels very good, it does seem like it resists spinning up as quickly as the TKC. More testing will be needed."
Update ~ 3597 miles:
Since May 25th, I have been through 15 tanks of fuel, averaged 42mpg, and put 3597 miles on the rear Kenda Big Block on my R1200GS.
The miles have been split about 60/40 paved to dirt. Many scouting trips for the BMW XPLOR Pacific Northwest Adventure Rally this past June, a few scouting trips for the upcoming Shelton Valley Dual-Sport & Adventure Ride this coming October, as well as commuting to work and a rather long dual sport trip through British Columbia to an old gold rush town. Over this time I was able to thoroughly test the tire in every condition a GS rider can hope to encounter. I have put many miles on the TKC 80, this tires main competitor, on the same bike and will compare the two to better describe this tire’s strengths and
weaknesses.
As I write this, the Kenda Big Block is available for roughly 25% less than the TKC 80. By my ‘math’ the tire must then be 75% as good as the TKC 80 at everything to be considered a good value. At the rate many of us go through tires on these bikes, that can add up to a decent savings or at least a ‘free’ tire every fourth change.
Traction is the most important thing I look for in any tire. If it doesn’t stick reliably, it isn’t safe, and therefore isn’t a good tire. On dry pavement the Kenda is 90% as good as the TKC 80. The tall knobs are squirmy under hard accelerating and braking and do cause the bike to wobble if you hit uneven pavement mid corner. Additionally, the Kenda is not as good in high speed turns than the TKC is. No knobby tire is good on wet pavement, but the Kenda Big Block is not on par with the TKC here. I would say it is 60% as good on wet pavement. The tire will spin easily when pushed and does not inspire confidence. Additionally, the wet pavement traction never really changed through the whole life of the tire.
The off pavement traction of this tire on the other hand really impressed me. The tread pattern down the center of the tire has a greater number of offset blocks than the TKC, which has a big square tread block dead center in every other row. I believe that this tread design really helps give this tire a small edge over the competition in terms of off pavement performance. I felt that the off-pavement traction of the Kenda was 120% of what the TKC offered in every terrain I rode. The tire resisted spinning better than the TKC and was always predictable. In very soft sand and mud the tire was less likely to slip sideways than the TKC, which was a welcome change. The improvement in off-pavement traction alone is enough for me to recommend this tire to riders with an offroad only wheel set.
Tire wear is a hot topic for anyone thinking about running knobbies on a big bike. Riding style, terrain and surface temperatures all play a huge part in tire wear. I have had a rear TKC last anywhere from 300 miles(riding FAST in sharp shale) to 5000 miles (gentle touring). I tried to give this tire a chance to last while not taking all the fun out of riding. I rode with panniers on the bike for most of the highway miles and even about 500 of the dirt miles. The tire was regularly spun in the dirt, but generally not abused on the pavement. My highway speeds rarely exceeded 80mph and I can count the days it was over 80 degrees here in the Northwest on one hand.
The tire made it just over 3500 miles before I pulled it off. Had I not been finishing a trip, I probably would have removed it around 3k miles, but it was still fine for the highway ride home. For my riding style, this wear seems nearly the same as the TKC.
One thing I should point out is that both the Big Block and TKC 80 wear quickly through the first half of their tread depth. The next half of the tire seems to stretch on much longer. With the TKC, the last quarter of the tread depth seems to last for a very, very long time, this is a great benefit for someone who is running down a tire mid way through a trip because the tire is useable for a long time even after it ‘should’ be changed. On the other hand, the Big Block does not seem to have this final quarter that wears like iron.
There are some other comparisons I can make about the tire that are interesting but not important enough to me to be considered ‘scoring elements.’ Road noise from the Big Block was a bit quieter than the TKC 80. Neither are as quiet as a road tire, but the Big Block was a little easier on the ears. Flat repair seems to be the same for both brands.
I picked up a nail in my rear tire at Touratech’s XPLOR rally, but with a rope plug the tire held air well through the rest of it’s service. Mounting difficulty is more significant with the Big Block. It feels like a stiffer tire carcass and it was harder than the TKC 80 to get on and off the wheel. However setting the bead with the Big Block is about as easy as it gets, because the carcass holds the tire against the rim so firmly.
When you total the scoring elements, with the TKC 80 being the measuring stick at 100% and the Big Block needing to make a 75% to be a good value because of it’s cheaper buy in, it looks like this:
Pavement traction: Dry 90% Wet 60%
Off-Pavement traction: 120%
Tire Wear: 90%
The total comes to 90%, which according to my calculations means the Big Block is 90% of the tire at 75% the cost of a TKC 80. Overall, that is a good deal.
In closing, I really enjoyed trying this new tire. It isn’t a breakthrough in big bike tires, but it is a nice tire that provides bang for the buck. If you do more riding in the rain on pavement, I wouldn’t recommend this tire for you. But if you need a knobby tire for a trip where you’ll spend some time off road, or you want to try one out to see how it will fit your riding style, this is a good tire to buy.
Thanks to Kenda for providing me a tire to test and thanks to Touratech-USA for providing opportunities for me to test it.
-Iain