Knobbyknife

This sure looks like a nifty little tool. Have any of you fine people pulled the trigger on one? http://www.knobbyknife.com/index.html

Hmmmmm.

Welp I'm OK with admitting that I'm too damn lazy to spend the time necessary to slice all the knobs on my tires. Looks like a novel idea, and I'd love to see some REAL data on tire life extension and increased tire bite. But until I see more substantive data to prove the claims (other than the "compelling" testimonials)... I will remain a skeptical curmudgeon.

Looks like that would work for allot of people that race. Being a backyard trail runner I just run my tire into the ground and put on a new one. BTW, I am running the Michelin Desert and it is a great tire but $$$$. Knobs are short but are a good compound and very predictable on all types of terra.

yeah flip it over,get another few rides out of it, change it for new for race day and you are amazed at the new grip levels.

..and repeat

no so fast...

I wouldn't be so quick to call this a novelty item. Man, this has to be faster than removing the wheel, removing the tire, reinstalling the tire, then reinstalling the wheel and adjusting/aligning the chain. I'd say this tool would pay for itself if you did the whole "turn around" procedure once. I bet if I were trimming knobbies with it, it would be hard for anyone to "turn around" a tire faster than I could trim the knobs. Plus, you could do this a few times before the tire is actually ready to change. It doesn't take long to roll the edges of knobbies on a 450-4t. Actually, my new Michellins lasted about 2 good rides on all this NC clay before they were rolled pretty darn good, and 2 rides is a long way from the knobbies being worn out. That sharp edge really does give the tire lots of bite. It allows the tire to cut into a harder packed surface instead of skimming on top. There are 2 aspects that make knobbies important on a tire. 1.) Reduced surface area to the ground. This reduced surface area concentrates weight in a smaller area, which increases pressure, which in turn, causes the knob to sink into the terrain and bite, giving you traction. 2.) The sharp edge on the knob increases it's ability to cut into the terrain and help it sink in. At this point, the knob is in the ground and biting.

Having an edge on the knob is every bit as important as having the knob on the tire in the first place. The more densly the terrain is packed, the more difficult it will be for the knob to bite-in and work properly. If it worked better with big rounded edges, wouldn't it come new from the manufacturer with big rounded eges instead of sharp edges? Taking the edge off the knobby reduces it's ability to function properly. When you ride pretty hard every time you go out, it's easy to tell a difference between a fresh, sharp set of knobbies and a dull-rounded set of knobs. When you push the bike hard regulary, you want the tires to perform at optimal levels every time you ride. If you're trailriding and/or dual sporting, you aren't going to notice a difference.

I wouldn't call this novelty at all. I'd say it's a definite solution to a problem lots of folks have been struggling through for a while-just like the hair dryer replaced 20 minutes worth of towel drying for ladies with long hair-and does a better job.

I'd say go for it. You can keep a $100 tire running like a brand-new one long before it's worn out. If you do it after every couple of rides, this means you get a $100 tire that actually rides like a new $100 tire every time you use it for maybe 10 rides instead of 2. If you're not riding hard, you probably don't need it, but a sharp edge on a knobby makes a HUGE difference when pushing hard. I can see where this tool could keep a new tire running like a new tire for an extended length of time and if I can make my new tire run like a new tire for 10 rides instead of 2, it's like I got myself $500 worth of new tires for $160. If you do it regularly and just take off enough each time to keep the knobs sharp, you got new-tire traction until the knob is just too worn down to use anymore (which will likely happen before you cut too much off of it to use anymore).

Get one of these things and practice on an old tire first. I bet you'll be quicker at doing it than you are at cleaning an air filter or even changing the oil. It will definitely be quicker than turning the tire around. The only reason I could see someone not falling in love with this thing once they've used it a few times is if they are only casually riding thier bikes when they ride. This would definitely be a useful tool for those who are constantly ripping it up.

I have to go along with MX1 and that is the reason I posted the link. I have turned tires around and it does help one time. Actually I switch the rears on my WR and 450, which turns the tires the other way. After about two rides the tires are rounded again. Even without pushing hard a big difference is noticed in the slick slime that we encounter on Or. Coast Range rides.
Funny thing is that on Monday my riding buddy and I were having lunch at the staging area where we ride and a discussion regarding the cutting tires came up. How in the old days the racers would trim there tires for the track conditions and how it was a lost art and a part of what it took to be fast.
Anyway when I got home there was a link for the Knobbyknife in my mail box.
I have some ideas on how to make one that may even work a little better with interchangeable knives of different sizes,

I'm still too lazy, but it'd be interesting to see some forum members try it and give a good assessment.

I could always make my son do it in exchange for me continuing to finance his racing escapades!

Well I ordered one 3 days ago and will report back. It seems like a good idea and I wish I had thought of it. And, I described it to a friend as a soldering iron with razor knife on the end that gets to 500 degrees and makes it easy to cut. I think it could be pretty useful but only time will tell. I figure even if I only use it once per set of tires, it's bound to get me more life out of that set. I don't know how it will work on Motoz(natural rubber though).

BTW, they're selling lots of them. They contacted me and let me know they usually ship the next day but due to high demand they can't ship until 6/13 but will be shipped priority 2 or 3 days. I'm in no hurry, but it does seem useful so I'm looking forward to it.

Here is a picture of an attachment I made, that goes on in place of the tip on my soldering iron.

I am pretty happy with the way it works for trimming tires.

Very nice looking.

Similar to a tire grooving tool, which can come in handy to tune tires for conditions (changing a soft terrain knobby to a grippier hard terrain knobby ect.)or making a dualsport tire more mud worthy by opening up the channels between knobs.
It's been done for years in the four wheeled racing world

I have spent a lot of time cutting sharp edges on knobbies because I hate to watse a tire with plenty of knobs left. i use a Sawzall-takes about 20 minutes/tire. This looks like a better idea so I bought one. I have three dirtbikes and a few 4 wheelers so I'd rather do this than change tires!
no novelty- great idea-iunless yer flush w/cash and someone else changes yer tires