Is the Knard 3x29+ fat enough?
One of the things that I like about fat-bikes is the simplicity of not "needing" any suspension for light-medium intensity trails. While a rigid 29er is just too rough for my old bones. So, is the new Knard 3x29+ tire mounted on a 50mm Rabbit Hole, fat enough to soak up the bumps?
Nothing but rave reviews for those who have ridden them.... just make sure the pressures are not too hard and they will do fine..... that latest thought though is a full fat bike with 2 sets of wheels, 4.0 Nates/Larry's/Endomorphs and then a second set of rabbit holes and knards for when the 'going' is a bit easier.
While I love my Krampus, but a fatbike, it ain't.
I find the phrases such as midfat or plumpbike, keep expectations from getting too out of hand.
+1 - it's a rigid bike with plump tires. Works great on the buzz you'd get from gravel or small debris, but it's not equivalent to any sort of quality suspension.
Originally Posted by MendonCycleSmith
I got my first and only flat so far bombing downhill on a logging road enjoying the great traction from the Knard and popping off rocks embedded in the road until I got carried away and hit a rock that was slightly too big = pinch flat.
Then I remembered I was on a rigid bike and I ought to ride it like one.
Lots of people MTB on rigid bikes so they work despite not having suspension. But as you note they can be quite a rough ride if you want to go fast and/or the trail gets bumpy.
Originally Posted by BluNosDav
The Knards would smooth out the small stuff, but anything of consequence is still going to be felt through the frame. I wouldn't ride the Krampus on my local trails as my main MTB. I can see places with smoother trails were it would be great.
I'm enjoying my Krampus mostly as a bikepacking rig. The big tires make descending at speed with camping gear less dramatic and the comfort of the big tires on gravel/dirt is noticeable at touring speeds.
BTW - as others have noted with real fat tires you kind of have to decide what you are after in terms of speed and cush with Knards. If you inflate them to be comfy at slower speeds you'll bottom out the tire on the rim if you hit anything bigger fast. Likewise if you pump them up so you can plow into stuff at speed they be bouncy when you are crawling along over chunk.
One of the downsides of not having any "suspension tuning" options besides tires psi.
In general, I find the ride on my Krampus (with White Bros 490mm Rock Solid fork) to be smoother than the ride on my Mukluk, for SW CO singletrack. The stock fork is very stiff. It's still a rigid, but a pretty forgiving one. I'm running 12-15 psi and I weigh 155. I've had one pinch flat when I tried dropping to 11 psi.
I got my first ride on a Krampus today, and it was VERY nice! Fast AND smooth.
Then I jumped on a Mukluk 3 at the same shop, and it felt like I was riding in molassas, by comparison. But, then we started talking racks . . . . .
The salesman told me that if I wanted to add a front rack & panniers, I'll need to buy another front fork. And when he placed a Topeak rack over the rear, it landed on top of the Knard tire, before the stays reached the mounting holes? (I'm starting to wonder if he grabbed a 26er sized rack by mistake?)
Since you say that your Krampus is great for bikepacking, I was wondering how your racks are set up?
I switch from a RH/Knard combo to a full fat on the front of my bike. My body (knees/ankles/wrists) hurt more after riding the RH/Knard. Don't know why. Maybe cause I'm so much faster?
Keep in mind that fat bikes are (95% of the time) rigid bikes with soft shoes.
29+ tires are harder shoes. A Krampus is a very fast bike but it is a rigid bike. I'd want mine with a suspension fork at the minimum.
29 tires are very hard shoes. I'm not that old, but I don't know how some folks do it on fully rigid bikes. I make too many handling errors.
Disclaimer: I run Regular Cycles
(as of 2016). As a profiteer of the bicycle industry, I am not to be taken very seriously.
Some people have buff trails.
Originally Posted by Drew Diller
Even on rougher trails a rigid bike is okay if you control your speed.
I prefer to ride fast and locally that means full-suspension.
If you've got full on chunk locally then I can't imagine a rigid bike even riding slowly. I was in Moab on my 6"+ travel bike riding down the Whole Enchilada wishing I had a 8" - 10" bike
Keep in mind that a rigid (non-fat) 29er will tend to be a great deal lighter and more agile than a fatbike.
Originally Posted by Drew Diller
I built a single speed Rabbit Hole wheelset for my Karate Monkey this spring. I run the 120 TPI Knard up front, and a 2.3" Nobby Nic on the rear. Normally I run standard Easton 29er single speed wheels with 2.3" Nic up front, and 2.25 Rocket Ron in the back. Theres about a 2 lbs difference in the bike in the two different configurations.
Having just ridden the same trail back-to-back in "normal" 29er mode, and then half fat/ knard/nic mode, I can't say the Knard/Rabbit hole is that much cushier than a 2.3" Nobby Nic. Why? Because that 2 extra pounds at the wheels tends to make the wheels "clunk through" obstacles when my lighter wheelset more readily "pops" over them. In fact, I find the major difference between the two setups to be traction, not necessarily cush, with the Knard having pretty awesome traction when you "lean in" heavily into turns.
The same is true for my Necro Pugs, to a certain degree. It is comfy, but it is not heads and shoulders more comfortable than my Karate Monkey in "normal mode" during the warm season. The lighter KM is more maneuverable, and has less weight/momentum, for good and for ill.
I mostly agree with you Flat Again - I do think you can tune a bigger volume tire to work better than a skinny tire vs. obstacles/bumps, but the limitation is you have to pick a speed & size of object to tune for.
I can tune my Krampus to be pretty comfy on gravel at touring speeds [say 15-20kph], but if I start bombing hills and hitting larger rocks I'll pinch flat.
I can tune for the bigger rocks at 35-40kph, but then I lose the comfiness on gravel at lower speeds.
All my bikes are rigid, I don't own any squish and I ride only off-road. Both my geared and SS 29ers are shod with 2.4 racing ralphs and they are 200% different bikes than when fitted with even a 2.25 Maxxis, the higher volume and correct pressures makes a massive difference with a fully rigid on trails.
People always say thing like "oh, hardcore", I would say with the 2.4 on the rear my bikes are smoother in the rear than most hardtails and with nothing up front I just have to pick better lines.
With everything else in place, still the single most important factor is tyre pressure, I anally check and put 20psi (will not add air if it reads 19psi but will drop some if it says 21psi) in my 29er tyres before every ride.
Trek 9.9 Superfly SL
Pivot Vault CX
BH G6 Roadie
Thanx guys, that answers the soft side of Krampus riding.
Now for the hard side of things. I went back to take a second look at the Krampus. This time I wanted to see how it would feel at higher pressure. (I commute to work on a 16-mile paved bike path.) So, I asked the salesman to pump the Knards up to their labled max of 35psi. While he was pumping, the store manager came over and asked us what we were doing. When we told him, he said that was a bad idea, because of the Rabbit-HOLE rims. He said "there's just a rubber band holding the tubes inside the rim. If you put in too much air pressure, there could be a rupture up through one of the holes." He said that you should never put more than 20-25psi in the Krampus, and made the salesman deflate the tires to 20psi, before I took my short test ride.
Is this true? Are Rabbit-Holes likely to suffer a hernia, if the Knards are inflated to the maximum 35psi listed on the tire?
Knard owners: Does the Knard leave noticeable tracks on soggy trails? I live in the Midwest and our riding season has been non-existent so far My buddies and I are planning on getting fatbikes so we can ride year round without damaging our volunteer maintained trails. Would the RabbitHole/Knard combo be as easy on the trails as a big, meaty, fat(3.8"+) tire???
No. The difference in volume between a 3" tire and a 4" tire is massive [almost double going to 4"] and the resulting lower pressure is kinder to wet terrain.
Originally Posted by DFYFZX
Keep in mind fat tires with huge knobs [ie. Nates, Bud/Lou] will chew up a wet trail more than a less agro tread [ie. Endo or Larry].
Thanks. That what I figured.
I have a pair of HDs waiting for some wheels...and a frame...and cranks...well, an entire bike
Hm, I have been wondering whether any one has calculated the air volumes of fat bike tyres? I made a very rough calculation that 4" tyre on 65 mm rim would have an air volume of about 12 liters/732 cubic inches.
Originally Posted by vikb
I get 14L for a larry 3.8/RD, and 10L for a Knard/rabbit hole, so 40% more volume for a regular fat tire.
that is a rough estimation based on a perfectly circular cross section at the measured widths.
your actual contact area has more to do with the pressure than volume though, and at the same pressure, they would have the same area on the ground, but the 29+ tire patch will be longer and narrower. Also, you cannot usually run as low a pressure, because you have approximately 1" less distance from the rim to the ground, making pinch flats more likely.
Measuring from my Krampus [RH on Flows] and my Pugs [Larry on RD] I get ~7L vs. ~13L. For a 5" BFL my estimate would be ~22L.
Sheldon has a good article about how tires support the rider.
The tire's width is what's important for determining what pressure you can run and the resulting contact patch.
Regardless of how you slice it you can operate a 4" or 5" tire at considerably lower pressures than a 3" Knard for the same rider.
But, will the Knard blow-out thru a Rabbit Hole like squeezed tick, if I pump in 35psi, to support my fat arse and gain more speed on a paved bike path?
I doubt any decent rim strip and tube will blow out through a cutout rim at 35psi. If you are worried about it, or like me, just don't like the looks of a rim strip bulging out that much through the cutouts, I would recommend some high strength high adhesive cloth backed tape for a rim strip, with something just larger than the cutouts blocking the adhesive from showing through the holes.
Some good 3M duct tape should work(3903 or the stronger 3939, or 6969 or the nuclear duct tape:8979), or if you want to get something way overkill, try some of the fiberglass backed tape with thermoset adhesive like this:Buy online 3M 365 Thermosetable Glass Cloth Tape White, 4 in x 60 yd 8.3 mil, 8 per case Bulk: 326.
but at over $200 a roll, with 8 rolls in a case, you're lookin at a $1700 box of tape, so I'd stick to the duct tape, or for a little more strength maybe some gaffer's tape.
or you could buy one of these:
Buy online 3M 5401 Traction Tape, 24 in x 36 yd, 1 per case Bulk: 72975
a $2000 roll of what looks like white duct tape.
By flat_chipmunk in forum Fat bikes
Last Post: 12-09-2014, 11:57 AM
By max-a-mill in forum 29er Bikes
Last Post: 04-22-2014, 12:13 PM
By Widget in forum Fat bikes
Last Post: 04-12-2014, 05:19 PM
By bikeny in forum 29er Bikes
Last Post: 05-17-2013, 06:15 AM
By 2002maniac in forum Singlespeed
Last Post: 03-23-2013, 10:17 PM