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Reviewer/Tester
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Discussion Starter · #1 ·
We are in the middle of a hot summer here in Oz, all the trails I ride on are very dry and dusty.

I have been using Exi's front and rear on the 29'er and have been happy with their performance until yesterday.

On my last ride, I had noticed some sliding and washout from the front tire. I have attributed this to the very dry condition of the trails and the thin layer of sandy dusty mix on top of the hardpacked dirt...but i'm not sure, as this is the first time the tires have been anything short of fantastic for me.

Yesterday, I had a few very unsettling front wheel slides, one of which dumped me on my butt. I run both Exi's @ 30 psi with lightweight Salsa tubes. This is the first time the Exi's have actually let me down. Up until yesterday, they have been excellent.

The incident happened as I sprinted towards a stiff little climb. Just before the climb there is a flat section that curves to the left which is hardpack covered in a fairly thick layer of dust / sand / pebble mix and where I usually gain my momentum for the climb.

Without the run-up I can never get up to the top because of the roots and rock steps, I usually just stall out halfway up through loss of traction or get pushed offline towards a steep drop-off to the right of the trail, so I need the run-up to make it to the top.

As I was powering towards the start of the climb, and swinging to the left around the curve, the front tire just let go and down I went in a cloud of dust... :(

I re-mounted, backtracked and tried it again. The second try I got through ok, but I could feel that the front tire was on the edge of adhesion through the left curve before the climb.

The curve is not sharp, quite gentle in fact. I examined my tracks in the dirt and looked at the spot the front end let go on me, but apart from the top layer of sandy dusty junk on the hardpack, could find no real reason to account for the way the tire just dumped me.

At another section of this same trail, I barely escaped a nasty crash when the front tire let go as I was crossing a dry creekbed. I got it under control, but I was damn close to another crash.

Has anyone else who rides in dry dusty conditions experienced any front end washouts with the Exi's like me?

It seems quite suspicious that these tires just suddenly start to let go and slide around so easily even though the conditions are dry.


R.
 

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bike dork extraordinaire
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628 Posts
Rainman said:
We are in the middle of a hot summer here in Oz, all the trails I ride on are very dry and dusty.

I have been using Exi's front and rear on the 29'er and have been happy with their performance until yesterday.

On my last ride, I had noticed some sliding and washout from the front tire. I have attributed this to the very dry condition of the trails and the thin layer of sandy dusty mix on top of the hardpacked dirt...but i'm not sure, as this is the first time the tires have been anything short of fantastic for me.

Yesterday, I had a few very unsettling front wheel slides, one of which dumped me on my butt. I run both Exi's @ 30 psi with lightweight Salsa tubes. This is the first time the Exi's have actually let me down. Up until yesterday, they have been excellent.

The incident happened as I sprinted towards a stiff little climb. Just before the climb there is a flat section that curves to the left which is hardpack covered in a fairly thick layer of dust / sand / pebble mix and where I usually gain my momentum for the climb.

Without the run-up I can never get up to the top because of the roots and rock steps, I usually just stall out halfway up through loss of traction or get pushed offline towards a steep drop-off to the right of the trail, so I need the run-up to make it to the top.

As I was powering towards the start of the climb, and swinging to the left around the curve, the front tire just let go and down I went in a cloud of dust... :(

I re-mounted, backtracked and tried it again. The second try I got through ok, but I could feel that the front tire was on the edge of adhesion through the left curve before the climb.

The curve is not sharp, quite gentle in fact. I examined my tracks in the dirt and looked at the spot the front end let go on me, but apart from the top layer of sandy dusty junk on the hardpack, could find no real reason to account for the way the tire just dumped me.

At another section of this same trail, I barely escaped a nasty crash when the front tire let go as I was crossing a dry creekbed. I got it under control, but I was damn close to another crash.

Has anyone else who rides in dry dusty conditions experienced any front end washouts with the Exi's like me?

It seems quite suspicious that these tires just suddenly start to let go and slide around so easily even though the conditions are dry.

R.
I ran an Exi front Nano rear earlier this fall before the rain started and also experienced some sliding around in the dust. I remember one instance in particular where I landed a bit off balance from a small jump and the bike nearly slid out from under me. Like you, the trail was dusty loose stuff over hardpack. After that experience, I switched to a Bonty XR front, which was a bit better, although not perfect either. I just picked up a FastTrac and Ignitor and as soon as it dries up next spring I'm going to try that combo out to see if it works better.
 

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graps the nettle
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519 Posts
exi-dent?

i had the exi's on my bike in tahoe this summer for a grand total of two rides. they left a lot to be desired in the dry and dusty pumiceland up there, and, to my mind at least, the ignitor's that i was using previously (and afterwards) were superior in every way. more tractin climbing and braking, better lean angles, more predictable breakaway, much, much better rolling, and a whole lot lighter...

summer before last, i had the exi's on a 26" bike, and couldn't help but think it was one surefire way to make a ride worse. hated them, with a passion.
 

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Just Ride!
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1,281 Posts
As above, I gave my set of Exi's two outings. Both times it was dry and hard packed with tiny clay pelletized dust about and the usual midwest rock gardens. I felt very unsafe and about ate it several times. They quickly got traded to Martini for a good set of grips.

My setup could have had something to do with the results I got, not sure. I ran them with the DIY split tube and Stans sealer, which works absolutely flawless on my MotoRaptors.
http://www.geocities.com/etrexkb/no_flat.htm

If I could have the Hutchison Python Air Lite in 29" that worked so well on my 26" ss, I guess that would just be the end all for my riding and climate. :cool:
 

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i like to bicycle
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uuuuh yeah

we had a dry and dusty fall here in neb and i experienced plenty of traction from the exi. i think it is a better tire then the XR for traction. i like the XR with regard to weight tho. i can't recall either tire letting me down ever. atleast until we got icy. i run no more then 28psi. lots of folks around here swear by the exi nano combo.
 

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Premium Member
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I would not stress about it. Sounds like the conditions were just different enough to throw you off. Sandy loose over hardpack can be one of the most difficult surfaces. I suspect the trouble in the creek bed was move because you were thinking about the first slide. There are many times I slip, slide and bounce in odd directions and save it without much thought (happened 4-5-6 times yesterday).
 

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Reviewer/Tester
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Discussion Starter · #8 ·
..Update...

Hold the phone...Whoa !!

On closer examination pre-ride today.. I found a slow leak in the front tube and the tire pressure was down to 10 psi... :eek:

It seems that my front tire pressure must have been down to less than 15 psi yesterday.. :(

That explains a few things to me...like why the front end felt a bit "spongy' over the roots and rocks. I had put that down to a loss of pressure in the forks, but I checked those today and they were spot on at 60 - and 80 +.

Damn !! This will teach me to check the bike before *every* ride. :mad:

Sorry everyone for my original post, i'm blaming my stupidity on the Christmas Season.. :)

"We get too old soon, and too slow smart".

R.
 

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uh, uh...oh, i forget
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1,039 Posts
I was gonna suggest that it was a subliminal loss of concentration because you feel guilty riding today when those of us in the northeast usa, still have over 6 inches of nasty unridable crappy mushy frozen stuff all over our trails...once in the last 10 days it warmed up to slightly above freezing...makes me long for the year i lived in wagga...ok, not really...
 

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graps the nettle
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519 Posts
to each his own...

can't compare the xr to the exi, cuz i haven't ridden the xr. only able to determine between the exi and the ignitors, since that's all i've been running since august. as with anything, Your Mileage May Vary. glad they're working out for you...

mwills said:
we had a dry and dusty fall here in neb and i experienced plenty of traction from the exi. i think it is a better tire then the XR for traction. i like the XR with regard to weight tho. i can't recall either tire letting me down ever. atleast until we got icy. i run no more then 28psi. lots of folks around here swear by the exi nano combo.
 
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