realskiers

Other Stuff => Biking and other Non-Skiing Activities => Topic started by: jim-ratliff on April 27, 2012, 09:39:59 am


Title: Mountain Bike Tires
Post by: jim-ratliff on April 27, 2012, 09:39:59 am
I don't want to revive last springs discussions about tube versus tubeless, cause I've decided it's simpler for me to just stay with tubes.

However, I have settled on the Continental X-King RaceSport mtb tire in the 2.2 size at 500 grams.  Rolls as well as the other two (see below), but the carcass feels stronger and the tread is more open and seems to shed mud pretty well. Tread pattern also seems to track better through light sand and soft dirt, and the tread wraps around to the edge of the tire more, and I can feel that in turns. Even on asphalt the tread feels grippier.

And I've become a bit of a fan of Continental tires based on my 4000S road bike tires.

The other two tires I had tried last year were;
Kenda Karma - came with the bike, 455 grams, but really light-weight feeling carcass. Lynn is still riding these, but it just felt too light for my weight.
Kenda Smallblock 8, reputation for easy rolling, 520 grams, but close packed tread plugs up.
Title: Re: Mountain Bike Tires
Post by: meput on April 28, 2012, 08:02:24 am
Hey Jim,

Thank you for highlighting the thread about tubes vs tubeless. Just went back and read it.

Took my maiden run on my new full suspension mtb. yesterday (for all of you tech hounds, a Specialized Epic comp 29'r). It came tubeless ready so I went tubeless. This was on the recommendation of both the shop guys and many mtb experienced friends. Wish me luck. Ran 29 psi front/back. No slime on the trail. Planning on 28 next ride. Stock tires: front Specialized fast trak, rear Specialized renegade control.

Now to figure out this mountain bike stuff without getting hurt . Have been avoiding it like plague over the past 10 yrs (I am too old to chance injuries especially with a fake knee, etc). So if I hurt myself  and miss any skiing next year, I will be pissed  >:(. Older mtn bike is a rigid fork/hard tail from the early 90's that was never ridden much (mostly rail trail stuff).

Did learn that there are ticks in the woods  :o. Have never gotten a tick (that I know of) in the thousand's of miles that I have logged while road biking (even spending lots of time fixing flats on the side of the road). Such is life.
Title: Re: Mountain Bike Tires
Post by: midwif on April 28, 2012, 11:50:52 am
Out of all the wonderful info in the post, what really caught my eye was the TICK.
Latest tick removal technique please?

L.
Title: Re: Mountain Bike Tires
Post by: jim-ratliff on April 28, 2012, 01:54:50 pm
Jim: I'm sure you meant "without getting hurt too bad"?  My bike still jumps out from under me every now and then.  My only advice would be to "be aware of hitting obstacles indirectly with your front tire".  That was my bad fall, I hit a root at an angle and it deflected my front tire sideways, I continued straight.
Title: Re: Mountain Bike Tires
Post by: jim-ratliff on April 28, 2012, 01:58:57 pm
Lynn-Z-Belle:
You ride way too fast for a tick to catch up.

However, if you do see one, I'm sure a loud EEEEEEEEKK would serve to scare it off. It seems to work for spiders?  :-*
Title: Re: Mountain Bike Tires
Post by: meput on April 28, 2012, 07:11:17 pm
My bike still jumps out from under me every now and then.

I like the way you put that  ;D. Took the bike out again today. Interesting how it just wanted to "jump out from under me" twice. This is where I need to learn technique when climbing. Since I was climbing, I was not going with any speed. Just had a nice role on the ground with bruised ego. No physical damage to the bike or me. No ticks today (that I found) from rolling on the ground  ???. Interesting how the tick yesterday did not involve a splat. Managed to get it just with putting a foot down when stopping.

Dropped the tire pressure to 27 psi for both front and back. Could feel the improvement of rear traction with the lower pressure (even with the 2 splats). Will prob try ~26 next time out. That should not be for a couple days. Want to get on the road tomorrow (was planning to be on the road today but the wind was cranking at ~25 mph - wind was not so much in the woods  :D).

Lynn, best technique to remove a tick is first of all, don't get one by not stopping  :-*. Should you get one  :o, gentle traction at the head with fine forceps/tweezers. Through out the years, I have been surprised at the number of ticks I have had to remove from the eyelid area on patients. I know, TMI  :-X.
Title: Re: Mountain Bike Tires
Post by: jim-ratliff on April 28, 2012, 08:35:25 pm
Climbing was my biggest challenge.  I was too used to pulling up on the handlebars; I would hit a root or something and the front wheel would pull clear off the ground.  Part of this was helped by slowing down the shock rebound speed to better match my weight and riding.
I also had to learn to get my weight much more forward and to stop pulling up.
On smoother surfaces lock out the front shock so your energy isn't wasted bouncing up and down.
Title: Re: Mountain Bike Tires
Post by: Svend on April 28, 2012, 11:02:42 pm
Another tip for control in climbing is light hands.  Keep your hands and arms relaxed and use a very light touch on the bars.  This lets the front wheel absorb the rough terrain and not throw you off balance and the wheel out of control.  It also forces you to keep your body balanced on the bike, and consequently you are less likely to flip over backwards.  Try it, and let me know how it works....
Title: Re: Mountain Bike Tires
Post by: bushwacka on April 29, 2012, 05:29:55 am
the conti's are really nice stuff, they are always sold out at the supplier level so I can never get them.

the easiest way to climb rough stuff on a FS bike with tubeless is just make sure bike is level when hitting it no lean and it will not bounce anywhere. If everything is setup the way it should be 95 percent of the hits will not even come close to jarring you. also the suspension should be open and working that why we have it right? If its to bouncy when open then get a new a bike.

meput just a word of caution lower than 30 psi is good just do not go to low and rim out you tires and bust your rim up.
Title: Re: Mountain Bike Tires
Post by: meput on April 29, 2012, 08:02:34 am
Thanks everyone for the climbing advice. All of it is easy to understand, the application will be the hard part  >:(.

BW, thanks for the word of caution re: going too low in  pressure with the tubeless tires/wheels. And yes, need to get the suspension components sorted out.

I am confident that all these things will come with saddle time. But as previously alluded to, hopefully without too much physical or $$$ injury  :'(.
Title: Re: Mountain Bike Tires
Post by: midwif on April 29, 2012, 09:40:48 am
I like the way you put that  ;D. Took the bike out again today. Interesting how it just wanted to "jump out from under me" twice. This is where I need to learn technique when climbing. Since I was climbing, I was not going with any speed. Just had a nice role on the ground with bruised ego. No physical damage to the bike or me. No ticks today (that I found) from rolling on the ground  ???. Interesting how the tick yesterday did not involve a splat. Managed to get it just with putting a foot down when stopping.

Dropped the tire pressure to 27 psi for both front and back. Could feel the improvement of rear traction with the lower pressure (even with the 2 splats). Will prob try ~26 next time out. That should not be for a couple days. Want to get on the road tomorrow (was planning to be on the road today but the wind was cranking at ~25 mph - wind was not so much in the woods  :D).

Lynn, best technique to remove a tick is first of all, don't get one by not stopping  :-*. Should you get one  :o, gentle traction at the head with fine forceps/tweezers. Through out the years, I have been surprised at the number of ticks I have had to remove from the eyelid area on patients. I know, TMI  :-X.

Jim2
Thanks for tick info. No brand new methods, tried and true still working. And no, not grossed out by the image of you pulling ticks off eyelids. Unless its MY eyelid! :o

Like Jim1 said, we both spent a goodly amount of time getting the hang of MTB's. And comparing bruises.
There was frequent "slippage" in the beginning. All of it slo-mo.

Svend, yes, thanks for the reminder about hands. That was the biggest difference initially. How you handled the front of the bike is quite different between road bikes/mountain bikes. NO PULLING UP on hills with MB's! Or an unwelcome wheelie is in store!  :'(

L.

C'mon Jim, admit it, that spider was pretty substantial looking. Like maybe a teenage brown spider. Not one of those
wuss house spiders. Those I relocate outside.  :-*
Title: Re: Mountain Bike Tires
Post by: jim-ratliff on April 29, 2012, 10:19:22 am
As you wish, Buttercup.
Title: Re: Mountain Bike Tires
Post by: Svend on May 11, 2012, 05:57:46 pm
Svend, yes, thanks for the reminder about hands. That was the biggest difference initially. How you handled the front of the bike is quite different between road bikes/mountain bikes. NO PULLING UP on hills with MB's! Or an unwelcome wheelie is in store!  :'(

L.

Lynn, when climbing, you want to have light hands so that the front wheel can deflect a little bit and "flex" with rough terrain -- up/down and side to side (a little bit).  If you keep your arms, wrists, shoulders rigid, then the wheel will tend to bounce off of rock/roots/ruts and you will have a tough time of it.  And tire yourself out in the process.  Relax, go with the flow, adjust steering and path as needed, but with finesse, not brute force.  And by all means keep your weight over the front.  Or put another way, keep your C-O-G vertically over the crank or slightly ahead.  No wheelies!  Fore-aft balance is key.

Despite your full suspension rig, you still have to use your body as a shock absorber and let the bike move underneath you to flow over the terrain.  Elbows, shoulders especially, but also knees and hips -- always keep 'em loose and moving to absorb bumps and depressions, etc.  Get yer butt off the seat too, when the terrain demands it -- ie. super bumpy, steep descents -- and give the rear wheel some more freedom to move up and down and smooth out the trail if needed, and get your C-O-G back when going downhill.

Have you and Jim played with the suspension settings on your forks and shocks? Rebound adjust? Air pressures? Travel adjust? I assume so, knowing Jim's attention to technical details.  But if not, this is well worth tinkering with, and can really improve your steering control on rough trails.

Hope this helps....

Svend
Title: Re: Mountain Bike Tires
Post by: jim-ratliff on May 11, 2012, 06:21:13 pm
Yep, Jim has.


But I do have a question. There was a rubber O-ring around the rear shock. That is what you used to see how much the shock was sagging (getting compressed). The guideline was that static compression just from body weight was about 25% of the travel.  That rubber ring is gone from Lynn's bike.  Do I need to get it replaced?  Does it serve any other function, such as cleaning the piston before the dir would get dragged into the seals?
Title: Re: Mountain Bike Tires
Post by: Svend on May 11, 2012, 06:22:14 pm
Back to the topic of tires....I have a couple of questions for the MTB gurus here...

In some of last year's posts, I think Liam and Josh recommended using a wider tire on the front, and perhaps one with a more aggressive tread pattern.  Why is this? I don't recall ever finding out why.  Wouldn't it be best to run the same tires front and back -- same width, same tread?

And as followup to that question, should you match the tire profile shape front and rear to keep cornering and handling smooth and predictable? In other words, if the rear tire has a round profile, I would guess that putting a more square profile tire on the front would be bad for handling(?)

The reason for my question is that, while I am really liking the Slant Six's that I put on my 29er last fall (they work great in my local terrain), but about the only thing I am missing from the change-over is the more cush ride that the old Bontragers gave me.  Otherwise, they are better in every way.  So, I am thinking of swapping out the front for a wider 2.2 width, and one with larger tread lugs for a better ride.  Just wanted to check with you guys to see if this is advisable, and if so, do I keep the profile consistent with the round shape of the Slant Six?


Edit:  I am going to cross-post (re-post?) these questions into my own, older thread about tires, so as not to hijack Jim's here.

Title: Re: Mountain Bike Tires
Post by: Svend on May 11, 2012, 06:33:22 pm
Yep, Jim has.


But I do have a question. There was a rubber O-ring around the rear shock. That is what you used to see how much the shock was sagging (getting compressed). The guideline was that static compression just from body weight was about 25% of the travel.  That rubber ring is gone from Lynn's bike.  Do I need to get it replaced?  Does it serve any other function, such as cleaning the piston before the dir would get dragged into the seals?

Kinda figured you'd played with the settings.  Sorry for questioning a perhaps obvious thing.  Have you found some good settings yet that are working for you?

As for the rubber ring, I don't think that it serves any cleaning function, as the business end of the piston (that which sees all the travel) is going to get dirt on it no matter what.  The ring will never be in that zone -- as soon as you start pedaling it will move further and further away from the shock seals.  But it is useful for checking sag, as you say.  You can check sag two ways:  using this ring and the length of it's deflection from unweighted to weighted; or by measuring the entire length of the shock when weighted and unweighted, and comparing the two values.  The latter, however, requires a second person to wield the tape whilst you sit astride the bike.  Whereas the ring allows you to do this solo.  Quick and easy replacement for the ring:  a medium size zip tie, snugged up tight to the piston, free end trimmed.  Works on front forks too.
Title: Re: Mountain Bike Tires
Post by: jim-ratliff on May 11, 2012, 07:37:10 pm
Thanks Svend. That does make sense. Yes, since the middle of last year it feels like they are working well.  I read somewhere that rebound should be as slow as possible as long as you aren't hitting bumps so frequently aht you wind up compressing the front shock.  Since I subsribe to LivingProof's theory of moderation in all things, we are probably at about 8 clicks out of 11 towards the soft end. And same on the rear shock.


Our biggest learning curve was pulling up on the handlebars to climb - and that coupled with shocks that were rebounding too quickly back then made pulling the front wheel off the ground way too easy.  I've ridden some of those same trails since then and they are actually pretty easy (with the weight forward, the shocks slower, and hands softer, and pedaling less hard in the low gears). I guess that was another difference, the torque that we could generate in the lower gears is day and night from low gears on a road bike.
Title: Re: Mountain Bike Tires
Post by: Svend on May 11, 2012, 08:00:11 pm
I keep forgetting that you're coming from years of road riding.  Must be tough to unlearn all those habits and techniques in the transition to singletrack.  I have never done any road cycling, except as a kid through the neighbourhood on my old 10 speed.  All of my riding in the past 30 years has been on a mountain bike.  What I am "learning" now, is not actually new, but just the relearning of stuff that I already knew years ago, before taking a 15 year break from the sport (read:  kids, house, small business to run....).

In that context, riding on the new bikes is a piece of cake -- lighter weight, suspension, better geometry, better tires, shifters, the works.  All of the skills that Terryl and I learned 30 years ago were on rigid, steel frame bikes.  Tire selection was minimal -- Specialized Ground Control and Panaracer Smoke and Dart...that's about it.  The bike's suspension was our knees and elbows.  But we still ripped up the trails, and got pretty darn good at it, too.  We rode just about any trail we could find, except the rockiest and gnarliest.  But shallow river crossings, steep descents, deep mud were candy to us.

Ah, but what a fun sport it is.  We love it.  Next best thing to skiing, in my books.  Great to hear that you and Lynn are enjoying it so much.  Keep smiling!

Title: Re: Mountain Bike Tires
Post by: bushwacka on May 11, 2012, 08:54:54 pm
Yep, Jim has.


But I do have a question. There was a rubber O-ring around the rear shock. That is what you used to see how much the shock was sagging (getting compressed). The guideline was that static compression just from body weight was about 25% of the travel.  That rubber ring is gone from Lynn's bike.  Do I need to get it replaced?  Does it serve any other function, such as cleaning the piston before the dir would get dragged into the seals?

doesnt do anything except set sag. Also keep in mind every person is different and most shocks valving is not correct for most people. For true nirvanna PUSH industries can do some really good things for shock tuning.