Big Block technology for the RX3

[sqwert]

Shinko now has Big Block type tires that fit RX3s with the 19-inch front wheel. Front size is 100/90-19, rear size is 130/80-17. Prices are just a tiny bit steep, or a lot less than some of the others, however you wish to look at it. Tube type, lots of other tires with similar treads are tubeless with rough insides that wear tubes when run with low pressures.

[sqwert]

Kenda has a street oriented addition to the Big Block notion to fit RX3s with 19-inch front wheels. 100/90B19 front, 130/80B17 rear. It's called "Big Block Paver" K678.

Even though the rear cross section is a bit taller than stock I expect the 19-inch front will overcome any increase in fork angle that would steepen the already touchy high speed steering.

Nice to see Kenda has 4 sets that will fit the RX3 with, ranging from 80% street to 80% dirt. A little difficult to find a matching set of tires with the 18-inch front, but Kenda has a couple choices.

K678 Big Block Paver (19-inch front);
K784 Big Block (19-inch front);
K270 (18-inch front, inch sizes)
K760 Trak Master II 80% dirt (18- and 19-inch sizes with aggressive rear tread pattern)


K761 (rear only) is a conventional adventure tire similar to the stock front. No front match.

My experiences so far are:

With K760 rear on the front, expect some odd handling on pavement or hard pack at highway speeds. Nothing scary, just a gentle speed wobble stopped by resting a hand on the bars. This was a problem with all three knobby brands fitted to the fronts of TWs. Tradeoff is sticks like rails when cornering in anything short of marbles (1/2 to 3/4 inch hail 3 inches deep close enough to marbles?).

K270 better manners at highway speeds on TWs than K760, but nowhere near as stable or sticky in any other terrain. Not a bad tire at all, but not a super aggressive 5/2/5/2 knobby like the K760. Also, on heavier bikes (KLRs) highway cornering at speed felt a bit squiggly, as if the knobs were "walking". Never felt that on TWs, but TW tires are wider, carrying 100 pounds less load, and not leaning so far over before the pegs scrape. The RX3 is somewhere in between weightwise and tire widthwise, but the pegs are even lower than a TW so I don't expect any problems unless very heavily overloaded.

K761 on the RX3 now. Stickier than the OEM tire when braking and cornering, about the same in slippery stuff when accelerating.

Haven't played with the Big Blocks, yet. Probably going with the Pavers next set, but pricing is a way high compared to shopping sales for anything else.

[fjmartin]

I've got about 5000 miles on a set of the Shinko 804/805s. They are great tires. Roll nice on the pavement and do great in the dirt.
Only word of warning is that by having the 130/80-17 rear tire which is larger than the stock AND having the progressive 465 rear shock it is VERY easy to bottom the tire out on the underside of the wheel well which is also the back side of the air box. Some have worn holes through which is obviously very bad. In my case I took some sheet metal and formed it to the shape of the wheel well and used gorilla glue to hold it in place. Works great and has lasted. I can see shine on where it hits occasionally.

Joe

[sqwert]

Sounds like the shock is too short and/or too soft.

[pyoungbl]

Joe, I'd recommend a bit more pre-load on the shock. Since your tire has a larger diameter than stock there is not much else you can do to keep the tire from hitting the fender/airbox. Your metal 'guard' is a great idea.

I have the aftermarket shock too. When I have my bike fully loaded the ride is exactly what I want, full travel and not harsh. Without the load the ride is pretty harsh. This tells me that my bike is very sensitive to load. I think I already have minimal pre-load but, frankly, I have been too lazy to make any adjustments for riding without a load because that's only a small portion of my riding time. If I had a remote pre-load adjustment I'd probably make the changes but that's not the case. As I recall, the remote pre-load was a really expensive option...something like $300 per shock!

[fjmartin]

I've added pre-load to the point where the shock is stiffer than I'd like when unloaded and still a bit stiff when loaded for camping. I won't load it up anymore as that would take away it's handling. The steel is doing the trick. I had called Progressive about the shock for the RX3 to see if they offered a version with an external adjustment...They do not. They have it for other models but not ours. Sqwert, the shock is not too short. In fact it raises the height of the bike as it's a bit longer...but also has more travel and the rubber stopper isn't long enough which is why it can bottom out on the airbox. No matter what pre-load you put on it there will always be a bump that bottoms it out. There is also a limit of how much pre-load you are allowed to put on this shock and I'm approaching that limit. I weigh 125 pounds so its not like I'm a hulk of bulk.

[sqwert]

Ran across Motoz tires today. Seems a bunch of Aussies rejected popular attitudes (yeah for them), stuck to what works (supplemented trials treads for smaller adventure bikes, an excellent choice), and hired some folks in Taiwan, now part of China, sort of, maybe, to build dream tires for us adventure, enduro, desert, and MX weirdos. Sound like home?

Anywho, they have 3 tires DOT likes in 130/80R17. They are parts of the Tractionator series.

The Tractionator GPS is the mildest looking tread, with a full diameter rib for quiet, inline stability, weight carrying capacity, and long tread life, significantly more aggressive towards the edges like other adventure tires to provide soft terrain traction and stability on oddball paved surfaces like grooves and steel spans and grates and all the other things state DOTs use to kill motorcyclists. Reviewers expect close to 15000 miles a set, and report good to excellent traction most everywhere. The tire is available in 130/80-17 for the rear, and a rear tread is available in 110/80-19 that might fit the front. Specs show 109mm width on a 2.5-inch rim.

The Tractionator Adventure is significantly more aggressive, like a modified Big Block, sort of. A 110/80-19 for the front sort of like the GPS with the center tread rail cut up in T-shaped blocks. This shape reduces the air between the blocks, adding a bit of smooth, quite, and anti-vibration. The side of the tread is similar to a double row of staggered knobs like a MX front, but closer together and bigger/stronger to carry more weight. Sort of. Again, specs show 109mm wide on a 2.5 rim.

The 130/80-17 rear tread looks similar to a hard surface knobby, more blocks and limited gaps, but lots of angles to provide more traction while cornering, and more closely spaced than typical knobbies, even DOT. Rear knobbies typically provide traction for acceleration and leaned over flat while skidding into and bouncing off berms. Really, that's all they do well. Isn't that how MX is ridden? Since typical knobbies don't work well without berms at anything other than straight line, well, pretty much explains why so many crashes where there are curves and no berms. Not a problem with these tires.

Happy now? No? You want radical traction in dirt and still DOT so you can use public roads between trails? Well, here's the Tractionator Desert Hard Terrain. It is DOT legal. It is designed for heavy adventure bikes so won't self-destruct on the pavement or when loaded with gear, like even DOT knobbies tend to do. The compromise for exceptional weight carrying, less noise, less vibration, better straight line and cornering stability on pavement, and long wear is slightly reduced air spaces between blocks, resulting in slightly less traction where surfaces don't exist, like West Coast sand dunes that blow with the wind, bottomless pits of red Georgia mud, or Mississippi River quicksand. However, this tread is host to a plethora of odd edges and sipes that should provide traction at all angles, not just stopping and going in a straight line, and not dependent on berms to go around a corner, on any surface with a bottom except maybe glare ice.

There is a 130/80-17 rear, but for the front you have a choice of 110/80-18 or 110/80-19. Even the rear tread looks like it would be a lot more stable on pavement on the front than the rear Kenda K760s I've been running on the TW. You know that's one of those tires that only has traction going in a straight line until you get it cranked over on the rails. The Motoz HT looks like it would be darn near as effective as the K760 at its extremes, and a ton more effective everywhere else.

However, measure before ordering. The specs list the width of the 110/80-18 at 130mm, and the 110/80-19 at 135mm. Must be the knobs hanging off the sides. Maybe trim to fit would be an option?

[fjmartin]

Up here in the Pacific NW the MotoZ Tractionators are hugely popular with great reviews! I'm going to give them a look for my next tire....thanks for posting!

Joe

[pete]

the motoZ tires are very good for duel sport & ADV bikes...
long lasting and have quite a stiff carcase that suits
adventure style riding...gives you the ability to run the
tyre pressure down a bit for a bigger foot print but still
keep the rim away from ground/rocks etc....
the stiff carcase is also where they fall down for all out
dirt riding... it dosn't let the tire conform to the ground
as much at lower pressures as other tires do..

when a tire starts to wear & the nobs lose there edges
that when the carcase construction comes into play...
just got to look at the FIM rated tires that can only
have nobs no higher than 13mm they work because
of the way the carcase is constructed...
big jucey nobs are great on a new tire but for
a tire to work when getting worn what the
nobs are connected to is very important aswell
maybe even more so...



..

[sqwert]

I agree about the importance of the construction of the tire body. I never drop air, not on an adventure bike, especially when loaded for a real adventure. Hey, let the air out of the tires to get more traction, pinch a tube, walk home. I run hairier knobs instead. Air down, too many risks. Run bigger tires with more aggressive treads. Size matters.

So does stiffness. (Don't go there!) 6 ply ratings suite me fine. Dunlop 606 is a toughy. I don't have to air down, gets traction in most anything, and never worry about pinched tubes. I don't mind stiff sidewalls. I have 3 tire tools, one is cut short, bent on the end opposite the spoon, and a deep notch is ground in at an angle to anchor on a spoke. Nice third hand when riding alone. Also, the bent end can be beaten with a log or rock to break a bead.


Anywho, my 53 years of motorcycling experience reveals lots of ways to do things. Motocross tires and tire sizes suck for anything else. Motocross bikes need to be light so tires need to be as light as possible, which means soft and weak. Run low air for max traction, tire life beyond the checkered flag does not matter. Motocross bikes HAVE to have berms to make time around corners or they have to be power slid. (I'm not admitting that when the berms were not to my liking or crowded with bikes I used other bike's tires and riders' feet for berms.) As much as conditions change during a race, no two power slides are alike. Very, very few riders can pull off 45 minutes of power sliding intentionally without crashing. Again. And again. Except on an especially prepped, mostly level (sometimes slightly banked), flat track. Also, 45 minutes of power sliding will usually wear the soft knobs right off a brand new MX tire. No, MX rubber is exactly wrong for most any other type of motorcycle.

You are not racing. If you crash you ruin my ride because I now have to take care of your pansy crack. My ride for the day is O-V-E-R. You suck. Sometimes, things happen. Most of the time, things happen to the same pansy cracks over and over. I don't ride with them any more. Neither do my friends when someone proves him or her self a pansy crack. Today, I'm typing about tires. Other times I can type other chapters in the Pansy Crack Prediction Book, because the vast majority have tell-tale introductory features.

To corner consistently without berms one needs STABILITY and TRACTION. In no particular order, stability is easy, run an aggressive tread and air it up to about 20 pounds off road. Use a stiffer tire body in the biggest size you can fit. Run more air if you have plenty of traction. The more air you run, to a point, the stronger and more stable the tire. If necessary, gear down to get the power band at the speeds you like. Might need to run thicker fork/shock oil and better brake pads/shoes to perform well with heavier tires.

Here is a true, extreme example. TWs have monster tires. Other than an inch of rear rim diameter, Harley used the exact same tire sizes on Electra Glides for quite some time. These days Electra Glides run the same width tires as TWs, 180 rear, 130 front. Way too much tire for a 200cc bike with 12.7 horsepower? Nope, just about perfect.

If I had a dollar for every time someone came up to me and expressed amazement that my big fat butt on a 12.7hp 200cc lumper could keep up with their KTM/KLR/BMW/Husky/etc. with 2.5 to 6 times the displacement on curvy loose muddy dirt and gravel roads I would treat us all to a nice steak dinner. Twice. You see, most of these bikes have MX-styled wheels and tires, and they just don't work without berms. Some have thinly disguised street tires (anybody else see adventure tires and think cheater slicks?) and they don't work, either.

Next requirement is tread. Gnarly, aggressive off road tread. Go look at the tire on the back of a TW. The originals had MX type knobs across the tread. Not anymore. Now, TWs come with a Bridgestone TW34. Look at the two center rows of knobs. They are wide, zig and zag, and are closely spaced. This provides a quiet, smooth ride, long wear, and tons of traction on pavement for the 99.7% of the time the bike is rolling. The tire's round cross section provides a gentle transition to the next row, pretty much conventional knobs spaced further apart. If these knobs squiggle under cornering loads the edges of the center knobs take up the slack. However, if the surface is softer than asphalt, the third and fourth rows of knobs dig in and drive, and corner, and brake. MX style knobs would just slide right out without the stiffness provided by the two center rows of "street knobs". Only the first 1/3 or so of the 5th row of knobs ever touch pavement--too many hard parts dragging--but when the surface is soft and the tire sinks in, the 5th and sixth rows come into play. You just can't spin this tire even in soft sand and mud unless you really try, and most riders need a bike with a lot more displacement. This is by far the BEST tire I've ever owned for dualsport/adventure/street and no berms. It will stop up with mud if you let it, but even the puny 12.7hp of the 200 will spin it clean without a strain. Plus, these tires have lasted 15,000+ miles under my fat butt.

So, bigger is better. MORE! MORE! Sure MX knobbies only have 5 rows of tread. The TW tire has 10. More is better, too.

On the other hand, the stock TW front tire sucks. Unless it is brand new. Then it wears out in about 6000 miles. The long, skinny center knobs closely spaced in two rows wear off kilter terribly fast, causing all manner of vibration and noise. The middle rows themselves seem to squiggle cornering on pavement, not support at all for the adjacent rows, two on each side. Too bad Bridgestone didn't do a smaller version of the rear tire for the front. That's okay, though, there are all manner of tires from cheater slick to 5/3 MX style that will fit. Most are intended for the rears of bigger bikes, so tough and aggressive tires can be had.

I wish my RX3 could fit the 180/80-14 TW tire on the back, with something like the Dunlop D908RR in 140/80-18 for the front. STIFF enough tires for STABILITY when dragging pegs, tons of TRACTION on any surface short of glare ice or spilled oil, TOUGH enough punctures will be very rare (nothing a little RideOn wouldn't fix), probably LAST 15-20,000 miles per set, STRONG enough to carry any load an RX3 will pull. Not cheap, but nothing better. That's the way to go.

[pete]

I don't like the wider tires on a ADV bike... they sit on the top
of gravel and become very skittery where the narrower tyre cuts
though easyer into the hard base where the grip is and throttle steering
is far more controled... but the XT660R will brake any tire lose if yer get to
heavy handed....
i use Shinko 700 on it... ok on lose ground / gravel & great on the road as the
side blocks are bridged to help stop flex...

my dirt/enduro bike I run tubliss in it... so pinch flats are not a issue
even at 6psi....



.

[sqwert]

A loaded RX3 weighs close to 450+ pounds easy. It will plant any tire as long there is not too much air pressure. Over-inflation does messy things, any surface. Not enough air and things loose stability.

Anywho, gravel over hardpack is a problem for everyone. Seen a GIXXER with track tires loose it in a slow speed turn with a few pieces of gravel on concrete. Messed up a pretty bike. Bigger tires with low inflation wrap over gravel and stick to hardpack, and skinny tires just skid.

Softpack requires aggressive tread so rocks fit between knobs. Knobs still reach over and around, gripping the softpack, often gripping the rocks and forcing them down into the soft pack for extra traction. Lots of racket when gaining speed with a front knobby packed with rocks wedged between the knobs. Typical fronts are not aggressive enough to do that, no matter the size. Knobs are too small and too short. I run the TrakMaster rear on the front of the TWs. Like rails on any terrain, 28psi on pavement, 23psi on dirt. Just an annoying wobble at high speed, but does not affect handling. Not much of my riding is gravel over soft stuff. Maybe if I had a lot of the same as you I'd feel different. I remember a lot of gravel over soft (sand) in Australia, though, but bike was heavily loaded, the wide tires did not sink as badly (only 4 of 8 riders who did not go over the bars at least once had fat tires, 4 with 21s all went over at least once, all bikes were TWs), and the gravel in the tread did provide the ability to turn. Turning was difficult in spots without gravel because the front just washed out, controlled with a little counterweighting. Better than the 21s, which had a habit of starting to wash, then when the riders counterweighted, digging and stopping the bikes really short. Flying Ws are worrisome when so far from help as we were, and years before cell phones. Egads! We did some stupid things.

Those who change heavier bikes to wider tires generally play a few minutes, then pull up beside me at speed and grab a handfull of front brake. Then they giggle like little girls. That much difference. Most folks I know with 650s and such keep the stock 21 front for day rides with no loads, and a 110 or 120 on an 18 or 19 for longer trips with heavy loads. There is a difference, and the right wheel and tire makes a good day better. Time and place for everything under the sun.

By the way, most folks I know who have tried both on the same bike use a much more aggressive tread on the 21, so the comparison is not valid. Could different treads have affected the outcomes of your experiences?