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Discussion Starter · #1 ·
My front tire, a hutch python 2.0 tubeless, is losing air over a ride, probably due to a dodgy seal. I've noticed that when it gets down to about 20psi (ie, far from flat), the handling of the bikes front end is atrocious. Rolling rocky drop offs were the front tire goes down first, plenty of weight on it (I'm a clyde), becomes very difficult, bike is all over the place. Now, obviously I'm going to fix my tire, but I had a few thoughts.

Should it be possible to roll down drop-offs at low front tire pressures, and I just need to work on my technique? How does clyde handle a descent of rocky "stairs"?

Don't DHers run quite low tire pressures? Guys I know tell me they run "the lowest pressure they can get away with" :confused: on the DH. There has to be times when a boat-load of weight goes onto the front end, what happens here?
 

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get DH treads

JBone said:
My front tire, a hutch python 2.0 tubeless, is losing air over a ride, probably due to a dodgy seal. I've noticed that when it gets down to about 20psi (ie, far from flat), the handling of the bikes front end is atrocious. Rolling rocky drop offs were the front tire goes down first, plenty of weight on it (I'm a clyde), becomes very difficult, bike is all over the place. Now, obviously I'm going to fix my tire, but I had a few thoughts.

Should it be possible to roll down drop-offs at low front tire pressures, and I just need to work on my technique? How does clyde handle a descent of rocky "stairs"?

Don't DHers run quite low tire pressures? Guys I know tell me they run "the lowest pressure they can get away with" :confused: on the DH. There has to be times when a boat-load of weight goes onto the front end, what happens here?
Dh ridders use heavyduty DH tires, 2.3-3.0 size, and they weigh 1000-1600 or so grams PER TIRE. They also use heavyer DH TUBES. I haven't had tubeless tires but I prefer DH tires on my Monocog, cause it is like suspension at 17or so psi front on a nokian nbx 2.5 and 20-22 in the rear 2.3 nbx, and this is on a full rigid set up w/regular tubes, I'm about 180#. If you want to play with low presser you should pay for full DH treads, pay for the tires, pay for the added rolling weight,pay for a tougher climb up that hill, but it will pay back dividends, in reliable low pressure comfort , traction and control.
 

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First things first...

JBone said:
My front tire, a hutch python 2.0 tubeless, is losing air over a ride, probably due to a dodgy seal. I've noticed that when it gets down to about 20psi (ie, far from flat), the handling of the bikes front end is atrocious. Rolling rocky drop offs were the front tire goes down first, plenty of weight on it (I'm a clyde), becomes very difficult, bike is all over the place. Now, obviously I'm going to fix my tire, but I had a few thoughts.

Should it be possible to roll down drop-offs at low front tire pressures, and I just need to work on my technique? How does clyde handle a descent of rocky "stairs"?

Don't DHers run quite low tire pressures? Guys I know tell me they run "the lowest pressure they can get away with" :confused: on the DH. There has to be times when a boat-load of weight goes onto the front end, what happens here?
Get rid of the 2.0 and get a 2.3 or 2.4. There's no reason in the world why a clyde should be riding skinny tires. 20 pounds is not enough pressure to keep the bead on the rim, in my experience. Lighter riders can and do ride with pressures this low but my experience has been that we just create too much torque on the tire and we wind up twisting it, thus losing traction.

It's not your technique. It's the small (relative to being a clyde) tire and the low (relative to being a clyde) pressure. For reference, I have a set of 2.4 tubeless Hutchinson Octopi that I run between 30-35 psi.

Ken
 

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Those tires are too wimpy for a clyde. I run those or WTB Epicwolf tires for racing, but wouldn't trust them for day to day riding. Even at race time I find that 35-40psi is required to keep the thinner tires on the rim.

There is a lot of misconception on tubeless systems. There is this whole cult that promotes tubeless as a way to run lower pressures. Most manufacturers and tire gurus (like shiggy mtbtires.com) will say the oposite and recommend slightly higher pressure.

I have tried the low pressure/rigid bike. At 230lb it is not a good idea unless you are a mellow rider. I corner hard and ride aggressive. The only setup that was stable was a heavy dh tube/tire combo. By that time there was so much rotational mass that I found the benefit of added suspension minimized.

One last comment. I highly recommend using a tubeless sealant like stan's even if you run a UST tire and rim. The sealant will help seal up the bead so less air can get out even when the tire burps a little. Added benefit is that it also seals up thorn and other small punctures.
 

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Discussion Starter · #5 ·
Thanks for the advice re the front tyre size, just bought a conti vertical 2.3 so we'll see how that does. I'm out of the loop with tyre choices, I thought 2.0 was quite big!
 

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More thoughts....

JBone said:
Thanks for the advice re the front tyre size, just bought a conti vertical 2.3 so we'll see how that does. I'm out of the loop with tyre choices, I thought 2.0 was quite big!
When you tear the sidewall or flat for the 2nd or 3rd time, try a Hutchinson Octipus. It hooks up just as well as the Conti but much more durable. Don't misunderstand, the Conti's hook up really well but they're not too durable and they're a little undersized compared with other tires.

Ken
 

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mtbr Buckeye...in Austin
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JBone said:
Thanks for the advice re the front tyre size, just bought a conti vertical 2.3 so we'll see how that does. I'm out of the loop with tyre choices, I thought 2.0 was quite big!
I like my vert protection rear. 2.3 one :)

Not as fearful on the sharp-ass baby-heads we have in Austin.

I'm not tubeless, but at 260 I have to run 55+ psi in order not to get pinch flats.
Not fun, but I got real good at chaning tubes..
 

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The reason you are getting the....

JBone said:
My front tire, a hutch python 2.0 tubeless, is losing air over a ride, probably due to a dodgy seal. I've noticed that when it gets down to about 20psi (ie, far from flat), the handling of the bikes front end is atrocious. Rolling rocky drop offs were the front tire goes down first, plenty of weight on it (I'm a clyde), becomes very difficult, bike is all over the place. Now, obviously I'm going to fix my tire, but I had a few thoughts.

Should it be possible to roll down drop-offs at low front tire pressures, and I just need to work on my technique? How does clyde handle a descent of rocky "stairs"?

Don't DHers run quite low tire pressures? Guys I know tell me they run "the lowest pressure they can get away with" :confused: on the DH. There has to be times when a boat-load of weight goes onto the front end, what happens here?
unpredictable handling is the low pressure. At 20 psi you loose a significant amount of sidewall stiffness, XC tires with folding sidewalls have notoriously thin sidewalls even in UST models. The sidewalls flex too much under load at low pressures. The tread plants on the ground and the rim is dancing around side to side over the top as the sidewall flexes. Also in turns because of the sidewall flex you are probably flexing the side wall enough to actually pull the inside edge of the tread patch off the ground. This would result in loss of traction and poor handling as well. DH tires have significantly heavier side walls that help prevent this, and is one of the reasons that DH tires are so much heavier. Sidewall thickness varies widely among manufacturers so you have to experiment to find what works for a given tire. Anyway, as one of the other posters said, 20 psi is not enough in most instances to keep the tire on the rim. A stouter tire would definately be recommended at your weight and from the way it sounds like you ride.

Good Dirt
 
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