Noob to Knobs

[pbbeck]

I'll be taking the GS out for a dirt-riding clinic this weekend, so I had a pair of Conti TKC80s installed today. Since the last set of knobbies I rode on was on my Schwinn BMX bike when I was 12,

Initial impressions (based on my 10-mile ride home from the dealer):

 

1) Much smoother than I expected on the road at speed > 20mph.

2) Definitely can feel the knobbies < 20mph.

3) More turn in effort required, probably because of the more squared profile of these tires as compared to the Anakees.

4) Traction seems great on the road. Can't wait to try 'em in the dirt on Saturday

5) They look bitchin'!

 

Questions...

 

1) What pressure do people run on the them?

 

2) Theoretical question... My intuitive understanding is that because I'm now riding on knobbies, my contact patch is reduced somewhat, which therefore means less traction in similar conditions than with non-knobbied tires. Is this an accurate assessment? Please... no brand loyalties/preferences. Just wondering from a theoretical perspective.

[johnlt]

The TKC 80s are much better on the road than real off-road knobbies. Yes, ultimately they have less traction on the road than road tires but normally, they will perform better than the rider is capable of. I used them on a recent CC trip on my GSPD (now sold) and they worked great. They are good on the dirt but not as good as "real" knobbies. An excellent compromise. Only downside is they wear out fast.

[TMH]

When I bought my KTM 950 it had the OEM Pirelli Scorpion "dual sport" tires on it. These were actually great on the road, but I found traction (especially in the rear) VERY lacking off road. So I installed some TKC80's, and boy what a difference!

 

CAUTION: They feel pretty good on the road so far, but don't get overconfident. They do grip pretty well while cornering but they have reduced your stopping abilities significantly. Please be careful while riding on the street with them, and give yourself some extra room from the car in front of you!

 

Regarding pressures, my KTM 950 is reasonably close to the weight of a GS, and I'm no featherweight at 260# (not including gear). I had read on some of the KTM sites that guys were using 25 psi, and I wanted to make sure that I was getting the most off-road grip out of the tires so that is what I ran. Now this won't be an issue for you (tubeless) GS guys, but here is the result of my first off-road adventures with TKCs at 25 psi:

There were multiple bad parts to this story:

1) That was not a patchable hole;

2) My spare tubes were back at camp;

3) Camp was 50 miles away.

 

But there was also a good part: Our ride was about to get into this stuff:

Now the main track in the photo (we call that "the sidewinder") was made by a GS, while the straight and true track on the right was made by my KTM 950 with a flat front tire which beautifully floated over the surface of the sand. Couldn't have asked for any better performance! The hard and/or paved portions of the ride back to camp were less enjoyable needing to keep the speed down to about 20 mph so as not to overheat and destroy the tire. But eventually I made it back, and after riding 50 miles on a deflated tire, the sidewalls sure had softened up to make it easy to change the tube!

 

Needless to say I ran higher pressures the next day: 32 f/34 r. After thinking things through a little more, it was pretty stupid of me to run a heavy bike + passenger combo at 25 psi unless it was exclusively on dirt or sand. And I didn't need to maximize my grip by running ultra-low pressures - The knobby TKC's were providing so much more grip than any "dual sport" tire that I could have run them at 40+psi and still benefitted.

 

So I'm not going to run my TKC's at anything below 32 psi in the future, unless I happen to be on one of the Mauritanian Dune stages of the Dakar someday. And I'll be carrying a spare tube for now on.

 

Have fun with your "new ride". The TKC's really do look great on bikes like the KTMs and GS's, and they transform their off-road handling. Here's a shot of my bike the next morning after the tube change, and ready for the day's action:

 

Tom

[pbbeck]

Thanks for the info and for your story. You bike looks great. I can't wait to go out and get dirty. I'll be sure to post pics in the Ride Reports forum.