EpicSki › The Barking Bear Forums › On the Snow (Skiing Forums) › Tuning, Maintenance and Repairs › edge burrs vs increasing base bevel (racing focus)
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edge burrs vs increasing base bevel (racing focus)

post #1 of 14
Thread Starter 
I have been tuning my skis for several years with more or less of the "whatever I do is better than nothing" attitude.  However, now that I am racing and have seen the benefits of a proper tune, I have become much more particular about my process.  I am fairly happy with my process as I have a noticeably sharper edge, better glide, and longer lasting wax, but I am still unsure how I should be addressing the base edge.  In the past I have always run a fine diamond stone over the edge to knock off any burrs caused from the sharpening of the side edge; however, as has been well covered on the forum, this leads to a gradual increase of the base bevel.  Since I am starting at .5, I think that doing this 3-5 times per week would relatively increase my bevel quite a bit.  On the other hand, leaving it alone leaves burrs all along the length of my ski.  In recreational tuning and speed events, I would think that the burrs are worse than the increasing base bevel because quick edge transitions are not as critical while glide proves very important.  However, in tech events (the only ones that I race) base bevels are often set between 0 and .5 so any small cleaning has the potential to drastically change the angle.  Also, since I do not have multiple pairs of skis for gatekeeping/slipping/warmup runs and the actual race, my edges have already seen 3-5 runs of non critical hard skiing.  Will these runs dull the edges enough to eliminate the negative effects of the burrs?

Any thoughts on this?
post #2 of 14

I use a stone with a base guide to take the burrs off the base edge. Ths way, the stone should hit just the burr but not affect the base edge bevel significantly.

To keep your edges as fresh for a race as possible, switch right and left skis as the inside edges take more abuse than the outside. Then switch back for the race run. For simply inspecting, when free skiing isn't permitted in the race arena, just use your recreational skis.

post #3 of 14
Thread Starter 
I tried the base bevel guide, but am finding that my skis are not as flat as they were at the beginning of the season when I set them.  Nothing substantial, but it looks like the edge and base close to the edge are slightly lower.  When I put a true bar across it, there might be a 0.1mm gap on the two sides before the edge starts which is keeping my stones from making contact with the edges.  If this is the case, maybe the additional wear caused by a free held stone will be negligible compared to natural wear after 3 days of practice and 1 race per week on each pair of skis.

I do always switch my skis for the race. 

Unfortunately since my college team has to manage our own transportation and so few people have vehicles, there is never any room for extra pairs of skis. 
post #4 of 14
Have you tried free handing a gummi for deburring along the base edge or lightly at 45°?
post #5 of 14
Quote:
Originally Posted by smoth View Post

I tried the base bevel guide, but am finding that my skis are not as flat as they were at the beginning of the season when I set them.  Nothing substantial, but it looks like the edge and base close to the edge are slightly lower.  When I put a true bar across it, there might be a 0.1mm gap on the two sides before the edge starts which is keeping my stones from making contact with the edges.  If this is the case, maybe the additional wear caused by a free held stone will be negligible compared to natural wear after 3 days of practice and 1 race per week on each pair of skis.
 

always use guides.

To even have a chance at setting base bevel right, you have to have a shop ONLY stone grind the skis and do all the other edge sharpening procedures yourself using something like the sharpie trick.  (color base edge black, file until no more color, stone polish).

You have two options:

1. get the skis ground and try again.

2. do the sharpie trick anyway. The file will cut away p-tex much more than base edge, in the end the skis might feel screwed up and need a grind anyway, but if they don't. you win. and if they do, no harm done because that p-tex was coming off anyway. 
post #6 of 14
Thread Starter 
I did set all of my own bevels from a flat ski.  I dont know if it is just the base bevel guide I have (Beast), but once it is set, I cannot grind away any more material without lowering the base or bringing the side in.  Its not like the side bevel guide in that one of its points of reference is the base edge as it rests on the base and the side edge.  Since neither of those change dramatically, I have been left with the freehand method or just leave it alone. 
post #7 of 14
You are right about not being able to adjust/correct the base edge bevel without removing base once you have removed base edge up to the p-tex. On the side edge, you may need to have your sidewalls planed. They make tools for that. It removes the part of the sidewall just above the edge that sticks out a bit to support the edge.

It is quite easy to file a ski down to a useless piece of wood, plastic, glass and steel. Once you have a bevel set, you have to either be prepared to file the ski down to a toothpick or live with slighlty off bevels as you clean up your edges. Where you have burrs and innies (Thanks for the visual on that Alpinord), you can touch up with a file, maybe, and a stone to smooth out the irregularities. Sometimes the innies are so deep you can't remove them. The best you can hope for is to soften the jaggies with a gummi. Slight variations in bevel in small sections of your edge are far better than jagged edges and burrs. Perfect edges, better yet. But the difference between slight bevel changes and perfect is miniscule, the difference between jagged/burred and perfect is huge.

Bear in mind that WC techs may wear out a pair of skis in less than a season maintaining them the way they have to be kept. Skis can go from FIS legal to FIS illegal through the tuning process alone.

Using guides doesn't guarantee you get the bevel your guide is designed for. I've had a tech tell a friend that he ruined his skis' bevels simply by stoning them with guides.
post #8 of 14
This brings up a question that I've been thinking about for a while. Is there any downside to not taking down the entire base edge when setting your base angle at say 1 degree?  My approach has been to set the base angle so that it leaves about 1/4 of the edge untouched next to the p-tex base.  These leaves room to take it down further as needed before a base grind is necessary.  I don't race but I love the feel of sharp edges on hard packed/icy groomers.
post #9 of 14
*bump*

I too am interested in the answer to this last post from figurado.
post #10 of 14
much of the edge angle change is relative to the courseness of the tool.  a very fine Diamond file or better yet a high 600+ ceramic will with proper lubrication and touch have much less impact on your set angles.
post #11 of 14
Racing skis have very narrow edges, barely over 1 mm wide, so they would be very difficult to bevel only part of the way across the base edge.

Recreational edges are typically wider, approaching 3 mm. If a bevel covered the entire base edge, the angle (between base and side edges) of a 3 mm wide edge would be higher off the snow relative to the angle of a 1mm wide edge with the same amount of bevel. It would seem this difference in height would be insignificant given a 1 or 2 degree bevel over 1 to 3 mm.
post #12 of 14
Yeah, intuitively if the edge is 3mm wide and you bevel only the first 2mm of that width the edges will have less clearance, so the skis would react/bite that bit more quickly.  Something akin to a 0.75 degree bevel compared with a 1 degree bevel, but not the same I'm thinking.  Seems a fair compromise if you get the base ground flat and ask the shop to leave the base bevel flat for home tuning - you'd get that extra 1mm to play with before having to grind again.  Mind you, I'm certainly not the voice of experience here, having only just bought tuning gear.
post #13 of 14
i BELIEVE YOU ARE CORRECT., BUT THE PROPER MEASUREMENT OF A BASE EDGE BEVEL IS WITH A TRUE BAR AT 60MM ACROSS THE SKI. 1MM GAP AT 60MM ACROSS THE SKI IS 1 DEGREE WHEN THE TRUE BAR IS MATCHED ANGLE OF THE EDGE. AND I BELIEVE IT WOULD THEN MAKE NO DIFFERENCE WHAT WIDTH THE EDGE IS.

Quote:
Originally Posted by MastersRacer View Post

Racing skis have very narrow edges, barely over 1 mm wide, so they would be very difficult to bevel only part of the way across the base edge.

Recreational edges are typically wider, approaching 3 mm. If a bevel covered the entire base edge, the angle (between base and side edges) of a 3 mm wide edge would be higher off the snow relative to the angle of a 1mm wide edge with the same amount of bevel. It would seem this difference in height would be insignificant given a 1 or 2 degree bevel over 1 to 3 mm.

 
post #14 of 14
Ok Terry brace yourself!

To properly remove the hanging burr created by side edge work, you should have the skis up on it's side, base away from you. You absolutely do not need a bevel guide to do this, period!

You also should not be using a diamnd stone or abrasive stone or file.  A gummi stone is too soft, a diamond stone is too abrasive.

The ideal tools is an Arkansas Stone or a Transluscent Surgical stone or true hard stone.

After your final pass with your last stone used on your side edge. you take your hard stone and place it flat against the base edge with about 1/4 to 1/3 of the stone sticking up above the side edge. Using your thunb on our side wall (On top of the ski in this orientation) with medium pressure (and I go from right to left, with my sk in the vise  on my right side) simply pass the stone in a semi up and back motion making sure the hard stone is in constant contact and in the same relative postion with the base edge.(easier to do then expalin!) there is no risk of goofing up your base bevel angle unless you completely roll the stone up and over the side edge. (No one here can be that uncoordinated) make a couple of passes. Remeber this is not an abrasive stone. You will be able to hear the edge smoothing out as the burr is removed. The burr is simply a microscopic curl of steel that is created on the side edge but hangs down into the snow if not removed and will play absolute havoc with your ski performance as it stikcs down into the snow and wmakes you skis complelety unpredictable.

I then use a very fine gummi stone at a 45 degree angle to the actual edge with ABSOLUTLEY NO PRESSURE!!!!!. to completely finish the edge.

I also use this same type of stone as my last "Honing" stone as the last step in polishing my side edge BEFORE the deburring process have described.above.
Edited by Atomicman - 5/3/10 at 9:26am
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EpicSki › The Barking Bear Forums › On the Snow (Skiing Forums) › Tuning, Maintenance and Repairs › edge burrs vs increasing base bevel (racing focus)