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How do you use a riller bar?

post #1 of 20
Thread Starter 
OK, I got a riller bar, but don't know how to use it.

Must I remove the existing wax prior to rilling? (I'm guessing yes, but that'll ruin all the waxing I've already done.) Can I just brush with brass instead?

Must I sand the base first to get to fresh ptex?

Do I hold the tool at a slight angle to the ski or flat?

One pass only? (I think yes, but don't know)

How much pressure?

Thanks in advance!
post #2 of 20
The objective of structuring is to impart grooves into the base material with coarse sandpaper, stiff metal/brass brush or rilling bar (or sliding in parking lots ). This removes suction that a perfectly smooth base would have, especially in wetter snows. So, wax removal is important to impart or rip/abrade/tear the base. I'd suggest starting out real easy as you can always go deeper, especially if it's cold. Less is more. It is near impossible to get an absolutely consistent pressure to leave exactly equal grooves. I wouldn't be concerned with aesthetic perfection, but functionally providing structure relative to the prevailing conditions and look at the variable structure as customizing your bases.
post #3 of 20
Thread Starter 
Thanks!

So in super cold man made snow, say -10 deg C snow temps and below, it's really not important, as suction plays no role. So I'd lose more by stripping the old wax to the base and structuring than I would if I simply were to brush and apply the wax of the day.

My guess is that above or near the melting point, proper structuring will have real importance.

Interesting note: I bought a pair of used race skis that were set up for
0 to -15 deg C. I imagine that reflects the fine structure that was grooved into he base prior to repeated waxings. A larger structure would be quite useful for warmer days, and an even larger structure for wet days.

That would explain why WC racers have more than one ski for each event.

For a one-race-ski quiver, it would only make sense to restructure a ski only when the conditions change drastically, otherwise repeated waxings are more important.

Cool!
post #4 of 20
Sounds like you got it. Additionally, I'm sure you know, once you establish your structure for the conditions, you need to free it after waxing and scraping, by brushing appropriately, or you defeat the purpose. Like you said, it's probably only something to do when the prevailing conditions change dramatically versus restructuring frequently.
post #5 of 20
post #6 of 20
Thread Starter 
Thanks doc! It's exactly what I suspected.

except those odd structure patterns. Can they actually be applied with the bar and not mar your nicely polished base edges?
post #7 of 20
Quote:
Originally Posted by BigE View Post
Thanks doc! It's exactly what I suspected.

except those odd structure patterns. Can they actually be applied with the bar and not mar your nicely polished base edges?
I've never heard of anyone doing that but me. I was having fun with old skis and it came out kinda cool. I'm not saying it was a stroke of genius and is a revolution in structuring, just saying to experiment & be creative if you have old skis to play with. I made a linear pattern, then cross over it at 45 deg lightly (so had no trouble with edges) to break up the repetition and give the water some outward channels. A "poor man's" chevron structure...
post #8 of 20
Sorry Doctor D, but I found the riller bar use info on your site to be somewhat vague and incomplete.

Here are my recommendations:
  1. There are 4 available edges to work with on the bar - 2 each for the coarse and fine structure patterns. Try to use different horizontal sections of the bar and keep track of what you used last to ensure even wear on the riller bar.
  2. Hold the riller bar across the base of the ski starting at the tip. Angle (tip) the bar forward 45 degrees and push the bar away from you towards the tail as you press the bar into the base of the ski. Try your best to not stop through the entire length of the ski - just walk forward and continue with even pressure during the entire pass.
  3. I've found that the pressure distribution on the bar is the real challenge in getting a consistent pattern. I use 2 passes - one pass with my thumbs in the middle of the bar concentrating on the center of the base and one pass with my thumbs at the sides of the bar concentrating on the sides of the base. This ensures good even coverage across the entire base of the ski.
Note that the brass metal of the riller bar is much softer than your skis edges and will not do any damage to them.

I have experimented with attempting to producing a "poor man's" crosshatch pattern by running the bar at a 45 degree angle across the base, but I've gotten mixed results and finally just quit even attempting to get a good pattern that way (I'll leave that for the stone grind machines).
post #9 of 20
Thread Starter 
Your 45 degree angle to the base is too much! If you have a 12" riller bar, you can start pulling it towards you at a slight angle, and using the left side of the tool. The angle should be so slight that when you've gone the length of the ski, the riller is using teeth from the right side to complete the job.

Then, do it the other way. Your cross-hatch won't be at 90 degrees, but who cares? It's about getting rid of suction, right?
post #10 of 20
Quote:
Originally Posted by BigE View Post
Your 45 degree angle to the base is too much!
I think Noodler means 45 degrees from vertical (orthogonal to the base of the ski).
post #11 of 20
Thread Starter 
Quote:
Originally Posted by Noodler View Post
I have experimented with attempting to producing a "poor man's" crosshatch pattern by running the bar at a 45 degree angle across the base, but I've gotten mixed results and finally just quit even attempting to get a good pattern that way (I'll leave that for the stone grind machines).
Comprex, this 45 degree angle is too much. For a ski with running surface of 10 cm, using a 30 cm riller, the angle at the ski should be about arctan(30/150) or about 11 degrees off perpendicular to the length of the ski. Imagine a billiards rake. The head is the riller, the cue is the ski. there is a 11 degree offset of the head to the cue.

Poor mans cross-hatch like this:

1) Ski is upside down, clamped.

2) set RHS of riller bar across the contact point on the tip of the LHS of ski (you are the frame of reference). Set up a 10 degree angle from the perpendicular to the ski. 0 degrees being straight across the ski. The face of the riller bar should point across the ski, not away.

While pulling riller towards you, without changing the angle, the riller should track so that at the end of the pull, the LHS of the riller bar is on the RHS of the ski.

3) set LHS of riller bar on RHS of ski, across the shovels contact point at a 10 degree angle so that the face of the riller points across the base to the other side of the ski.

While pulling riller towards you, without changing the angle, the riller should track so that at the end of the pull, the RHS of the riller bar is on the LHS of the tail.

I'll have to try that on an older pair of skis. I'll report my results.

Apparently, it is sufficient to hot-scrape and brush to remove the existing wax, so I will not worry about sanding. I have noticed that shop tunes come with linear rilling. I think this is can be a problem for beginner and intermediates, since it makes the ski run straighter, and harder to turn.
post #12 of 20
BigE - I totally understand what you're saying, but getting good results from that method would be tough. It all comes down to pressure distribution across the bar - having the pressure start on one side of the bar and gradually shift to the other side as you go down the ski would definitely be tough to manage, but not impossible. I just don't think the pattern will be as consistent as a straight vertical one.

Comprex - you're right, I'm tipping the bar at a 45 degree angle, but I also did mention holding the bar itself at a 45 degree angle laterally across the base (which I don't do any more) which BigE has pointed out being too much angle to achieve a crosshatch pattern manually.
post #13 of 20
Thread Starter 
Maybe it would be better to clamp the riller and move the ski?
post #14 of 20
Right, I understand the offsets.

What I don't understand is how you guys are devising these crosshatch angles, from

intuitive symmetry
limitations of the rillers you have
some model of the entry of new snow/departure of old snow paths?

and, if the latter, why not reference the crosshatch to the edge and sidecut rather than the midline of the ski?
post #15 of 20
Comprex - honestly, if someone can devise a great way to impart a more complex structure on a ski manually (and cheaply) then I'm all for it. The devices used by nordic tuners are really expensive and they're not wide enough for alpine skis. I've never seen any structuring devices for alpine that impart the complex patterns that a good stone grind can produce.
post #16 of 20

You got the pricey part right.

Quote:
Originally Posted by Noodler View Post
I've never seen any structuring devices for alpine that impart the complex patterns that a good stone grind can produce.
UP Racer first showed me this, my jaw dropped:

http://www.holmenkol.us/cartproducts...+Tools&ref=285
post #17 of 20
Noodler & comprex thanks for the insights & corrections, I appreciate it. Oh, and if my stuff ever seems vague and incomplete it's because it reflects the limit to my knowledge; so you made an accurate assessment

And yes 45 deg would not be correct, if you want to be precise, I guess the main idea was that if you are trying to put some coarse structure in for warm/wet conditions, it makes no sense to run a linear pattern straight down the base, and that it should be broken up somehow.

I must say I got a kick out of the coining of the new phrase "poor man's cross-hatch".
post #18 of 20
Thread Starter 
Quote:
Originally Posted by comprex View Post
some model of the entry of new snow/departure of old snow paths?

and, if the latter, why not reference the crosshatch to the edge and sidecut rather than the midline of the ski?
I can't see that ridiculously expensive holmenkol press implementing a model of entry/exit paths either.

Why not just use a brass or nylon brush and scrape the cross-hatch into the wax, why is pressing it in any better?
post #19 of 20
BigE - my experience is that brushes are great for "freshening" a structure, but not all that great for imparting one onto the ski base. I even have a stiff steel brush that doesn't do much to my bases. I like to be able to see the structure with a naked eye - although these brushes may be doing something at a more microscopic level, it's still not like using a structure tool or getting a good stone grind.

I also have the SkiVisions structure tool. This tool actually cuts structure into the base whereas the riller bar presses in the structure (mostly, there is some very light cutting though). I gave up on the SkiVisions tool because it was really easy to screw up your bases if you weren't careful. However, it was able to manage the pressure better and you could apply multiple passes at different angles to the base (for the poor man's cross-hatch).
post #20 of 20
Quote:
Originally Posted by comprex View Post
UP Racer first showed me this, my jaw dropped:
Mine did too -- when I saw the price! :
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