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Discussion Starter · #1 ·
So I have a 12 y/o Stumpjumper that I've taken out of storage and started to ride again. So over the last couple of rides I've noticed some things that need maintenance like brake pads...=O..., dead front fork dampers and my tires look like full depth nobs. They are the original tires.

So at the advice of my LBS, I picked up a Specialized Purgatory in 2.2 and a Storm in 2.0 for frt/rear combo.

The local conditions are pretty sloppy with lots of mud, wet roots and rocks.

Next scheduled ride is Sunday morning. Should be expecting great things from these tires? I figure since this is where the...uh...rubber meets the terrain...I'm hoping tire technology has made strides and also the fresh rubber should perform a lot better than the block of wood I have for tread on the original tires????
 

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Fortes Fortuna Iuvat
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Well I don't have experience with those particular tires, but I'll take a new set of tires over a dry rotted set any day!

Did u pick up new tubes? What kind of fork is it-RST or Rock Shox Quadra/Indy?

Congrats on un-retiring the bike!
 

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One of the biggest....

improvements in mtb tires to come in the last few years is the use of multiple rubber compounds in the tread. Usually center tread blocks are harder compounds to help dig into the dirt and shoulder tread blocks are softer to maintain good cornering grip when leaned. This is a big improvement over the old system of using the same hardness of rubber across the entire tread. Softer rubber compounds stick to the trail surface better. But the draw back is faster tread wear. Also an improvement has been tread designs for specific conditions. Many manufacturers have developed tires for specific conditions like the Storm tire. It's designed with a softer than normal tread to help the tire stick to wet roots and rocks, with widly spaced and rather spikey tread blocks that penetrate mud to find traction and clear quickly to maintain traction in the slop. It does work pretty well in wet muddy conditions.

I've never used the Purgatory so can't really give you much there. But from the looks it should perform well as a front for your conditions. But I don't know anything about mud clearing properties etc. But they look like they should bit well in the corners. You never know though.

The bottom line is you likely won't notice a HUGE increase in performance, but you will notice better traction, control, and cornering performance out of them. How much is tough to say as your specific soil conditions aren't known. Lets face it, there are some types of mud that no tire will help with. That stick like glue midwest farm mud is a perfect example. "Great things"? Maybe not great things, but you should see better performance out of the updated tires. Sounds like the LBS is at least steering you in the right direction.:thumbsup:

Good Dirt
 

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Discussion Starter · #4 ·
Well, I thought I'd report back.

Rode for 2 hrs in the sloppy, technical single track. Tires worked great. I had to fiddle around with the air pressure. Usually I like to ride them as soft as possible until I can start to feel "bottoming" of the tires. I want to say that I am quite "light" on the bike. Although I do weigh 165#s.

The Prugatory fronts are very round. It offered up very consistent feel all around. The mud shedding properties weren't quite as good as the rear Storms. But the traction level was obviously better than my old tires. Also, my old tires had squared off shoulders which could be hairy depending on my lean angles.

I did change my stem to a shorter (100mm vs 120mm) with a steeper rise. It kept me from OTB syndrome. But in some areas I got my front a little light and would push a touch. I'll just have to adjust to the new position.

The rear Storm just did a great job. I never lost the back end. And both tires combined really gave me the confidence to attack some of the obstacles like fallen trees and bad root sections. Normally I'd be clipped out waiting to walk it, but I just did my little wheelie+bunny hop combo and flew over them.

The rocks and roots definitely did not feel quite as slick as before. Not huge amounts. But noticeable. Enough to really change my confidence and attack the obstacles rather than just surviving them. If these compounds are softer and don't last as long, I'll be sure to dismount them for summer riding and run a more "dry" tire.

I have a blown Judy XC fork right now. My new Marzocchi MX Pro Lo should be coming in the mail today or tomorrow. Can't wait to try these out. 80mm vs 60mm. Real damping. Rebound adjustable to boot.
 

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Discussion Starter · #5 ·
Datalogger said:
Well I don't have experience with those particular tires, but I'll take a new set of tires over a dry rotted set any day!

Did u pick up new tubes? What kind of fork is it-RST or Rock Shox Quadra/Indy?

Congrats on un-retiring the bike!
Thanks. I think I gave some of the younger riders a surprise...good and bad.

Some roadie joins their group ride. Can't climb. But hangs in the technical sections with blown fork and rim brakes. :p I think I was pissing off a couple of the FS guys.

I had a new tube for a spare which I mounted in the front. I didn't have a second tube, so I just re-used one for the rear and then picked up a new tube...again, originals!! I'll have to install the new tube soon.

Rock Shox Judy XC originals. New fork will be Marzocchi MX Pro Lo.
 

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traffic002 said:
Well, I thought I'd report back.

Rode for 2 hrs in the sloppy, technical single track. Tires worked great. I had to fiddle around with the air pressure. Usually I like to ride them as soft as possible until I can start to feel "bottoming" of the tires. I want to say that I am quite "light" on the bike. Although I do weigh 165#s.

The Prugatory fronts are very round. It offered up very consistent feel all around. The mud shedding properties weren't quite as good as the rear Storms. But the traction level was obviously better than my old tires. Also, my old tires had squared off shoulders which could be hairy depending on my lean angles.

I did change my stem to a shorter (100mm vs 120mm) with a steeper rise. It kept me from OTB syndrome. But in some areas I got my front a little light and would push a touch. I'll just have to adjust to the new position.

The rear Storm just did a great job. I never lost the back end. And both tires combined really gave me the confidence to attack some of the obstacles like fallen trees and bad root sections. Normally I'd be clipped out waiting to walk it, but I just did my little wheelie+bunny hop combo and flew over them.

The rocks and roots definitely did not feel quite as slick as before. Not huge amounts. But noticeable. Enough to really change my confidence and attack the obstacles rather than just surviving them. If these compounds are softer and don't last as long, I'll be sure to dismount them for summer riding and run a more "dry" tire.

I have a blown Judy XC fork right now. My new Marzocchi MX Pro Lo should be coming in the mail today or tomorrow. Can't wait to try these out. 80mm vs 60mm. Real damping. Rebound adjustable to boot.
I envy you, coming from old tech to new tech is like huffing pure oxygen. I went from probably the same Judy XC to a Tora 318, couldn't believe how far tech had come in terms of plushness and stiffnss.
 

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Traffic - you didn't say what actual tire pressures you tried, but I usually run 3-5psi lower front than rear, and it's especially helpful in slippy conditions. Since you say the front was gripping a bit less than the rear, it would be worth dropping the front pressure more if it's not pinching now.

If you deal with sticky mud a lot, you may end up needing a more mud-oriented front tire if the Purgatory keeps packing up and losing grip. Hutch Spider and Scorpion clear mud pretty well and can be found pretty cheaply too.

A better fork might improve front traction too, as far as keeping the front tire on the ground, but the taller height might move more weight backwards, and give you more washouts. You might lower your stem by moving spacers if this happens.
 

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Discussion Starter · #9 ·
Are there tire pressure gauges with presta valves? I like to pump up my tires at home before the ride, then let off air to suit the conditions. Would be nice to get a good setting and document them. If I had a little pocket gauge I can carry with me, I can keep track.

I did not run lower pressures in the front. I may look into that next time. They "felt" to be equal pressure if not a hair softer in the rear.

I'm really hoping the new forks WILL make a big difference. Since it appears to be the next highest dollar component next to the frame, I'm expecting big things.
 

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Fortes Fortuna Iuvat
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My pump has a gauge built into it, but u should be able to get a presta compatible gauge.

I too run about 3-4 psi less in the front tire as it carries less weight. This aids greatly in traction and comfort.
 

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Discussion Starter · #11 ·
Alright, I just picked up a little adapter to the presta-->shraeder.

I have an analogue gauge I use for my race car. I'll measure my pressure when I get home and see where I left it last.

Makes total sense to soften up the front since it carries less weight and it has the forks to help soften the impacts.
 

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Discussion Starter · #12 ·
FWIW, I just got home and used the adapter with my car tire gauge. 15psi front/19psi rear.

I then slapped my bike pump on there and it read pretty consistently. The car tire gauge has easier read-outs. I used the bike pump just to double check to see if I was in the right range.

So it looks like I was running a bit lower in front than in rear by empirical trial and error.

Now I'll see what the new fork will do. Just got it on my doorsteps!!!!
 
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