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Old 08-14-2013, 05:38 PM   #1
CO-or-bust OP
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Eek Airing down tires for a DUAL SPORT weekend

NOTE: This question is about a DUAL SPORT weekend, NOT a strict TRAIL RIDING weekend.

Have a Pirelli MT-21 Rallycross knobby on the front and a Pirelli MT-43 trials tire on the rear of my '09 Husky TE610. I've used, and have been very happy with this combo, on 4 camp-n'-ride weekends in CT/RI, MA, PA, and NY so far this summer, with more to come .

I've been told by several ADV'ers to air 'em both down to about 10psi for these Dual Sport weekend rides of gravel, forest roads, woods trails and rocky trails and hill climbs. I'm ok with that, but here is my problem/question: Throughout the weekend we often pull out of and link up these woods/trails via winding, twisty, and often mountainous roads. My problem is that the group often ramps it up to 50+mph --------- I have yet had the guts to air it all the way down to 10psi knowing about these road sections. I've gone as low as about 14psi, but even at that my butt is puckered up pretty F'ing tight when leaning into fairly high speed turns on the road!!!

SO, THE QUESTION IS: Though these tires both may really grip the loose rocky hill climbs beautifully at 10psi (I have been VERY happy with them at 14), am I really putting myself at great risk taking these same 10/14psi tires out on winding, twisting, undulating mountain roads??? And as you all know, these group rides have absolutely NO patience for any one taking the time to air up and down between sections --- and the changes are far too frequent to be a viable option...

Yes, 10psi may be great for the many rocky trail sections, but WHAT IS REALLY THE IDEAL PSI TAKING INTO ACCOUNT BOTH THE TRAILS AND THE BRIEF, YET FAIRLY FREQUENT TARMAC SECTIONS???
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Old 08-14-2013, 05:43 PM   #2
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Quote:
Originally Posted by COorbust View Post
NOTE: This question is about a DUAL SPORT weekend, NOT a strict TRAIL RIDING weekend.

Have a Pirelli MT-21 Rallycross knobby on the front and a Pirelli MT-43 trials tire on the rear of my '09 Husky TE610. I've used, and have been very happy with this combo, on 4 camp-n'-ride weekends in CT/RI, MA, PA, and NY so far this summer, with more to come .

I've been told by several ADV'ers to air 'em both down to about 10psi for these Dual Sport weekend rides of gravel, forest roads, woods trails and rocky trails and hill climbs. I'm ok with that, but here is my problem/question: Throughout the weekend we often pull out of and link up these woods/trails via winding, twisty, and often mountainous roads. My problem is that the group often ramps it up to 50+mph --------- I have yet had the guts to air it all the way down to 10psi knowing about these road sections. I've gone as low as about 14psi, but even at that my butt is puckered up pretty F'ing tight when leaning into fairly high speed turns on the road!!!

SO, THE QUESTION IS: Though these tires both may really grip the loose rocky hill climbs beautifully at 10psi (I have been VERY happy with them at 14), am I really putting myself at great risk taking these same 10/14psi tires out on winding, twisting, undulating mountain roads??? And as you all know, these group rides have absolutely NO patience for any one taking the time to air up and down between sections --- and the changes are far too frequent to be a viable option...

Yes, 10psi may be great for the many rocky trail sections, but WHAT IS REALLY THE IDEAL PSI TAKING INTO ACCOUNT BOTH THE TRAILS AND THE BRIEF, YET FAIRLY FREQUENT TARMAC SECTIONS???
I'd go 15 - 18ish or so and leave it alone. I'm more concerned about denting a rim or a pinch flat than going on a highway for a short while. You probably don't need every ounce of traction to get anywhere a group ride goes, so why bother with the lowest possible pressure?

Edit if you DO need more traction in rocks, get the MT-43.

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Old 08-14-2013, 05:44 PM   #3
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Tires will only get you so far.. Its best to be ninja with the clutch and throttle for most of your traction concerns.

I wouldn't go below 15 or so.
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Old 08-14-2013, 05:46 PM   #4
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10 PSI is way too LOW.
Motocrossers run 13psi.
TE610, like any other " dual-sport " is a street bike.
Running DOT tires on a STREETBIKE, I would go no lower than 18 psi.
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Old 08-14-2013, 06:03 PM   #5
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I use 12 to 15psi on my motocross / trail bike depending on the conditions and that only weighs 220lbs. 10psi starts to feel to mushy and doesn't improve traction at all. Not to mention pinch flats....

Especially on a heavier dual sport bike I'd imagine 10psi would give you less traction than 13psi or more. A lower psi will only get you so far with traction, at some point you just need a tire that better fits the terrain you're riding in. I've never ridden a trials tire but with the DS knobbies I've ridden I didn't need to drop the psi at all for general off-road riding. Unless you feel the need for more grip.

If you've been happy going up rocky hill climbs at 14psi then I'd stick with it. At these low pressures 1psi can make a huge difference.
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Old 08-14-2013, 06:16 PM   #6
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10?

I bet those guys get lots of flats! Or they aren't riding flat worthy terrain...
On a rig loaded with camping gear, especially as big as your Husky, I would go 17-20. You can still flog the bitch over pointy rocks, and have some measure of flat protection. Just use a little more care with throttle and clutch.

I've raced mountainbikes at many levels in many disciplines for over a decade. It's less prevalent now with the popularization of the wonderful tubeless system, but I used to post much better times than a lot of really fast guys simply by running more pressure than conventional wisdom would state. I lost some.traction in corners and loose or technical climbs, but I almost never flatted.
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Old 08-14-2013, 08:51 PM   #7
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I agree with several previous posts, 10 psi is too low for even for trail riding. I'm a broke ass and run cheap Shinko 244's or K270's on my first gen KLR. With these tires 18-20 works great on the front and 20-22 in the rear for off road. They get adequate traction, and I've never had a pinch flat or bent a rim, even riding in some nasty/rocky places one should never take a 400 lb bike, and I ride spiritedly (for a KLR with suspension mods). At these pressures they still handle OK on twisty pavement, but if I'm going to ride pavement for long stretches, it only takes a couple min. to air them back up with the mtb pump I keep mounted to the bars. This is more for better fuel economy and longer tire life then handling. The handling difference on road is minimal between pressures, but very noticeable on loose dirt.

I would say definitely no lower then 16 up front and 18 in the rear, higher on the rear if carrying a load. I was running low pressure after a long weekend dirt loop/solo bike camping trip a while back, forgot to air the tire back up, and overheated the tube on the final 60 mi. stretch of slab on the way home. This resulted in a rear flat 560 miles into a 600 mile ride late on a Sunday evening, when I was due back at work early the next morning. Having to fix a rear flat on a loaded bike when I was almost home and tired, kinda sucked.
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Old 08-14-2013, 08:53 PM   #8
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Thumb Think I'll keep 'em in the 14-18 range...

Thanks to all for the input.

As I mentioned, despite many suggestions to take them down to 10psi, I've ridden four of these camp-n'-ride weekends at about 14psi. They've been great on the trails and rocks and I have NOT felt a need to take them down to the 10 range. I also have heavy duty tubes in both the front and the back to hopefully minimize pinch flats. As mentioned though, my concern and my "pucker-factor" has been shooting off onto the tarmac for 2 to 8 mile stretches and leaning into tight turns at 56mph on the road --- I just have this horrible picture of my soft low pressured tire simply rolling off the rim

So, I think I'll shoot for 18psi this weekend up in the Catskill mountains in upstate NY at The Greater Catskill area BK.RD.Run. See if that'll loosen up my sphincter when we hit those corners on the tarmac sections...

Thanks again!
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Old 08-14-2013, 09:04 PM   #9
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Couple of points:
I have run the trail bike at zero pressure for traction in shitty sand, I usually run at 8 in the rear, 10 in the front for clay, trees, rocks, roots and general stuff on a 450EXC that does get wound out. I don't get pinch fllats, I use HD tubes.
Dual sport I never reduce tyre pressure as the combination of road and off road makes it a pain in the arse and there are too many opportunities to wreck rims due to the weight of the bike. On the 640 Adventure I ran 20 in the front and 25 in the rear for everything, everything sounds similar to the riding you are describing, MT21 on the front, Michelin T63 on the rear.

There is a surprising amount of traction available without reducing tire pressure, as some one else suggested, clutch, throttle and commitment get you a long way. As an example, I took the R80 on an adventure ride recently on road tyres through forestry, gravel roads, fire roads, 4x4 tracks and a few stream crossings, it was reasonably dry so only a few slippery patches, the bike performed well... you don't need knobs for everything!
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Old 08-14-2013, 09:20 PM   #10
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Old 08-14-2013, 09:59 PM   #11
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Run it near road pressure that the bike mfr recommends, but a little below. Safety at 50+MPH on public roads is more important than being able to ride a non-hazardous trail a little bit easier. Lower the pressure just enough to relax the tread a bit so that it can conform a little. On something like a TE610 with typical DS tires, I'd start at around 22PSI and see if the tires are still too hard. Some tires are pretty darn stiff at 10PSI, but you'd still want to use rim locks for best safety. The tires you mentioned shouldn't be super stiff though.

If you're not running the high speeds on the road for hours at a time, you can run a little bit lower than the bike mfr specs without overheating/fatiguing the tire/tube. You'd want to air back up for more than just a few short miles though, especially in twisties. With your hand, feel the heat in your treads after a pavement ride. Imagine the stress that tire and tube were exposed to that created that kind of heat.
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Old 08-15-2013, 02:45 AM   #12
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If you run the tires flat then you will end up braking/ bending the wheels as the impact will hit the wheel were a hard tire would of taking it be for or ripping your inner tuble valve out.

When I got my 140cc pit bike I was told the same run the tires flat then fit rim lock to stop the valves ripping ect
I put my tires rock hard and never got a ripped valve or a bend wheel and got grip in the snow.
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Old 08-15-2013, 01:44 PM   #13
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Quote:
Originally Posted by Kommando View Post
Run it near road pressure that the bike mfr recommends, but a little below. Safety at 50+MPH on public roads is more important than being able to ride a non-hazardous trail a little bit easier...
Thanks Kommando! This quote pretty much sums up what my line of thinking was when I posted this question. I'm quite willing to give up a little bit o' grip on a trail I'll likely be riding in 2nd gear vs. rolling the tire off of my rim at 50+mph on a winding, twisting, downhill mountainous road.......

Quote:
Originally Posted by KOMMANDO View Post
...With your hand, feel the heat in your treads after a pavement ride. Imagine the stress that tire and tube were exposed to that created that kind of heat.
And this sounds like a good bit of advice to put to the test. I'll see if I can feel any significant heat differences between say, 18 and then 22psi.

I think my days of 14psi Dual Sport rides are over (gonna see how 18 treats me this weekend), and I'm glad that I never took the 10psi crowd's advice...
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Old 08-15-2013, 08:13 PM   #14
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Quote:
Originally Posted by COorbust View Post
Thanks Kommando! This quote pretty much sums up what my line of thinking was when I posted this question. I'm quite willing to give up a little bit o' grip on a trail I'll likely be riding in 2nd gear vs. rolling the tire off of my rim at 50+mph on a winding, twisting, downhill mountainous road.......



And this sounds like a good bit of advice to put to the test. I'll see if I can feel any significant heat differences between say, 18 and then 22psi.

I think my days of 14psi Dual Sport rides are over (gonna see how 18 treats me this weekend), and I'm glad that I never took the 10psi crowd's advice...
While the heat itself isn't great for a tire, it's not necessarily the main thing damaging the tire. The heat is merely an indicator of all the stresses the tire has experienced due to flexing as it rolls along. More flex generates more internal and even external friction, and more friction generates more heat, so the heat is a telltale sign of stress, especially on a cool day.
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