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When to grind the base.

post #1 of 21
Thread Starter 

Hi again,

 

I had my last grind done by the start of last season, this was the first and only grind done on the ski so far... After getting absorbed into the world of tuning, i decided to buy the last tool i needed and set the base bevel myself. The skis were ground to .5 / 88 back then, and the base still looks very good as i've brushed and waxed often. However, after checking with the 1 deg. bevel guide i quickly realised the base bevel had become more than 1, as the initial stroke hit the p-tex and the inner part of the edge (not the outer part). I used a 2nd cut file and made a short stroke, so i didn't really mess anything up. I'm pretty surprised that it's over 1 degree as i use a stone for deburring and don't do my edges too often. Maybe the initial grind wasn't as precise (true .5 deg) as i thought (they did have a rather old wintersteiger machine).

 

The thing is, i'll be taking some instructors course soon and i now have a newly waxed base, sharp 3 deg. side edges but an unknown base bevel. I haven't previously skied a true 1 degree base bevel, so i guess i won't feel it too much, because i'm used to the unknown bevel... 

 

Question is, i will be skiing for 9 days, do i have a shop run em over on day 1, day 5 or the last day, and then follow up with some wax cycles so they are perfect for January? What would you guys do?? I guess the snow isn't too hard at the moment, so i'm not sure how much of a difference the base bevel will make. There is no time trial on the course i'll be taking this time, so again, milliseconds doesn't matter right now......

 

Thanks!

post #2 of 21
Quote:
Originally Posted by Cowsgomooh View Post
 

Hi again,

 

I had my last grind done by the start of last season, this was the first and only grind done on the ski so far... After getting absorbed into the world of tuning, i decided to buy the last tool i needed and set the base bevel myself. The skis were ground to .5 / 88 back then, and the base still looks very good as i've brushed and waxed often. However, after checking with the 1 deg. bevel guide i quickly realised the base bevel had become more than 1, as the initial stroke hit the p-tex and the inner part of the edge (not the outer part). I used a 2nd cut file and made a short stroke, so i didn't really mess anything up. I'm pretty surprised that it's over 1 degree as i use a stone for deburring and don't do my edges too often. Maybe the initial grind wasn't as precise (true .5 deg) as i thought (they did have a rather old wintersteiger machine).

 

The thing is, i'll be taking some instructors course soon and i now have a newly waxed base, sharp 3 deg. side edges but an unknown base bevel. I haven't previously skied a true 1 degree base bevel, so i guess i won't feel it too much, because i'm used to the unknown bevel... 

 

Question is, i will be skiing for 9 days, do i have a shop run em over on day 1, day 5 or the last day, and then follow up with some wax cycles so they are perfect for January? What would you guys do?? I guess the snow isn't too hard at the moment, so i'm not sure how much of a difference the base bevel will make. There is no time trial on the course i'll be taking this time, so again, milliseconds doesn't matter right now......

 

Thanks!


10 to 1 the machine work you had done for you prior was never a .05

You might get them stone ground to include the edges to be close to flat.  Then you set the edges by hand.  That's the best way.

Good luck.

post #3 of 21
Thread Starter 
Quote:
Originally Posted by Jacques View Post
 


10 to 1 the machine work you had done for you prior was never a .05

You might get them stone ground to include the edges to be close to flat.  Then you set the edges by hand.  That's the best way.

Good luck.

 

Thanks, but do i ski them the first days now that i've waxed and sharpened them?? I could wait with the grind till the end of the week i guess... Otherwise i will have to ski a freshly ground ski without having the chance to wax it (i can't bring all my gear for this trip, limited space)!

post #4 of 21
Quote:
Originally Posted by Cowsgomooh View Post
 
Quote:
Originally Posted by Jacques View Post
 


10 to 1 the machine work you had done for you prior was never a .05

You might get them stone ground to include the edges to be close to flat.  Then you set the edges by hand.  That's the best way.

Good luck.

 

Thanks, but do i ski them the first days now that i've waxed and sharpened them?? I could wait with the grind till the end of the week i guess... Otherwise i will have to ski a freshly ground ski without having the chance to wax it (i can't bring all my gear for this trip, limited space)!


I got the impression you were worried about the base bevel.  No worries.  Go ski and have fun. 

post #5 of 21
Thread Starter 
Quote:
Originally Posted by Jacques View Post
 


I got the impression you were worried about the base bevel.  No worries.  Go ski and have fun. 

I am. Wondering if i should get it fixed in the beginning of the ski holiday or the day i leave back home, where all my wax gear is.

post #6 of 21
Quote:
Originally Posted by Cowsgomooh View Post
 
Quote:
Originally Posted by Jacques View Post
 


I got the impression you were worried about the base bevel.  No worries.  Go ski and have fun. 

I am. Wondering if i should get it fixed in the beginning of the ski holiday or the day i leave back home, where all my wax gear is.


I would say after because a new grind really needs a lot of work to prep. the base with wax and break in the structure of the grind.  Then, you need to get used to the new geometry as well.  You know the skis now, so that's probably best to use the way they are now.

post #7 of 21
Quote:
Originally Posted by Jacques View Post
 


10 to 1 the machine work you had done for you prior was never a .05

 

Yup.  I imagine they were put in line and sent through the machine along with every other ski.  They likely received a one degree base edge. 

post #8 of 21
They might even if you ask for .5. Was listening to some shop guys make fun of people who asked for anything other than a 1. Which is why I don't trust shops. You can never tell what guy is actually going to do the work once you turn your back, nor what details of your request they are going to decide to pay attention to. It's why I try to do most everything myself now. At least I know what I did.
post #9 of 21
Quote:
Originally Posted by Jacques View Post
 
Quote:
Originally Posted by Cowsgomooh View Post
 
Quote:
Originally Posted by Jacques View Post
 


10 to 1 the machine work you had done for you prior was never a .05

You might get them stone ground to include the edges to be close to flat.  Then you set the edges by hand.  That's the best way.

Good luck.

 

Thanks, but do i ski them the first days now that i've waxed and sharpened them?? I could wait with the grind till the end of the week i guess... Otherwise i will have to ski a freshly ground ski without having the chance to wax it (i can't bring all my gear for this trip, limited space)!


I got the impression you were worried about the base bevel.  No worries.  Go ski and have fun. 

 

On the other hand, we don't know where Cowsgo skis.  Last year in New England we had ice worse than what we usually have.  I went from a 1.0 to a 0.5 on the base bevel, the shop where I got it done is a race shop and the guy who did it actually did put a 0.5 on it.  I trust him.

 

On that ice, I noticed an immediate difference.  If Cowsgo is skiing on real snow that hasn't gone through several freeze-thaws, Jacques is right, that small base bevel difference probably won't make a difference.  Bit if he's on ice or very hard snow, it can make an appreciable difference.

post #10 of 21

Hey, don't worry, be happy.  Getting your geometry set is something you want and maybe even need to do - but you'll be fine until then.  It's more the driver than the car, unless it really has a flat.

post #11 of 21

There a lot of shops that will scoff at .5 degree base bevels.  Stop going to these shops.  If you skis are sharp - leave as is for now.  

 

Moving forward - go ahead and have the shop reset bevels to you specs.  This in INCREDIBLY hard to do with hand tools.  Once bevels are set by the machine - yes easy to maintain with hand tools.  Unless significant damage - daily maint can be done with a selection of diamond stones.  Don't forget the lube.  I use rubbing alcohol and h20 in a spray bottle.

post #12 of 21
Quote:
Originally Posted by pat View Post
 

There a lot of shops that will scoff at .5 degree base bevels.  Stop going to these shops.  If you skis are sharp - leave as is for now.  

 

Moving forward - go ahead and have the shop reset bevels to you specs.  This in INCREDIBLY hard to do with hand tools.  Once bevels are set by the machine - yes easy to maintain with hand tools.  Unless significant damage - daily maint can be done with a selection of diamond stones.  Don't forget the lube.  I use rubbing alcohol and h20 in a spray bottle.


I beg to differ on setting the edges by hand to be INCREDIBLY hard to do.  Machines do a good job to flatten a base, but don't always do the best edge work.  Even though machines have gotten better, by hand is the best.  I would trust one of the better hand held machines before I would trust a machine that one runs the ski through, 

post #13 of 21

I agree with Jacques that machines aren't necessarily to be trusted and a great hand tuner can be trusted.

 

However a great tuner, like a Mike Desantis, who constantly replaces his stones, calibrates his equipment, takes off the bindings to do a stone grind - someone like that can get a great machine tune.

 

I've never trusted stone grinds from shops with multiple employees, or no real "hot shot" tuner working the machine.

post #14 of 21
Quote:
Originally Posted by SkiMangoJazz View Post
 

I agree with Jacques that machines aren't necessarily to be trusted and a great hand tuner can be trusted.

 

However a great tuner, like a Mike Desantis, who constantly replaces his stones, calibrates his equipment, takes off the bindings to do a stone grind - someone like that can get a great machine tune.

 

I've never trusted stone grinds from shops with multiple employees, or no real "hot shot" tuner working the machine.


Yes, I was referring to edge tuning only. 

As for base grinding one still needs a competent operator, so even for a base grind one should seek out a trusted shop.

What Mango is saying here is good advice.  I also agree with him.

post #15 of 21
It's virtually impossible to set a .5 base bevel by hand. If you're using a .5 degree file guide I can almost guarantee you will be at .7-.8 when you're done and think it's a .5

I see dozens of skis every week that supposedly have .5 base bevel, and thousands every season. Last winter I had 2 pairs the whole year that actually had a .5 - they were both from Edgewise in Vermont.

I'm not sure where you're from, but judging by your use of the word "holiday" I would guess you're not from the U.S., so do your best to find a competant race shop in your area to grind the skis and set the base bevel.

There are very few people in the world that can cut a .5 by hand, and only a couple shops in the U.S. that can do it with machines. Most "Race" shops can't even do it, regardless of what they write on the sticker. The truth is though, that machines are getting better and better, and with the right machines and operator, it can be done consistently.

Either way, I would just go ski them as is, it's what you're used to at this point. Tune them when you get back.
post #16 of 21
Quote:
Originally Posted by SmoothRides View Post

It's virtually impossible to set a .5 base bevel by hand. If you're using a .5 degree file guide I can almost guarantee you will be at .7-.8 when you're done and think it's a .5

I see dozens of skis every week that supposedly have .5 base bevel, and thousands every season. Last winter I had 2 pairs the whole year that actually had a .5 - they were both from Edgewise in Vermont.

I'm not sure where you're from, but judging by your use of the word "holiday" I would guess you're not from the U.S., so do your best to find a competant race shop in your area to grind the skis and set the base bevel.

There are very few people in the world that can cut a .5 by hand, and only a couple shops in the U.S. that can do it with machines. Most "Race" shops can't even do it, regardless of what they write on the sticker. The truth is though, that machines are getting better and better, and with the right machines and operator, it can be done consistently.

Either way, I would just go ski them as is, it's what you're used to at this point. Tune them when you get back.


Given a flat ski to include the edges why do you say that it is virtually impossible to set a .5 degree base bevel?

post #17 of 21
I say that because when using a file guide the human input almost always over bevels the ski. Parents, coaches, world cup tuners alike, the base edge is almost always cut a minimum of .2-.3 more than the guide they claim to be using. So really, for a 1 degree base you should use a .7, and for a .7 use your .5, and a true .5 is so little material that even if you do cut it correctly, chances are by the time youve polished it youre overbeveled.

Add to that the fact that most shops grind structure into the base edge thats deeper than you ever cut a true .5, and as people use their files and stones to remove the structure, they are going much deeper than necessary, even with a quality guide. Structure depth on alpine skis averages .02-.04 mm, but at the inside of the edge, the bevel is virtually nothing. If you're unlucky enough to have your grind done by someone using a depth of .05+, or what many shops consider a spring or wet snow structure, youll never get it out of the edge.

Therefore, if you get a ski back from a shop that used a full width structure, and the base edge is fully polished, there's a high probability the base edge is over beveled.

I see a similar situation on the side edge, though it moves the other direction, and do to whole number jumps in guides, its not as bad. Still, usually if someone is setting their side edge with a 3 for example, their edge ends up being between 2-2.5, and so on.

The only way for most people to get a truly accurate and consistent edge is with a perfectly calibrated machine. This edge can then be maintained with diamond stones for a long time between machine services.
post #18 of 21
Quote:
Originally Posted by SmoothRides View Post

I say that because when using a file guide the human input almost always over bevels the ski. Parents, coaches, world cup tuners alike, the base edge is almost always cut a minimum of .2-.3 more than the guide they claim to be using. So really, for a 1 degree base you should use a .7, and for a .7 use your .5, and a true .5 is so little material that even if you do cut it correctly, chances are by the time youve polished it youre overbeveled.

Add to that the fact that most shops grind structure into the base edge thats deeper than you ever cut a true .5, and as people use their files and stones to remove the structure, they are going much deeper than necessary, even with a quality guide. Structure depth on alpine skis averages .02-.04 mm, but at the inside of the edge, the bevel is virtually nothing. If you're unlucky enough to have your grind done by someone using a depth of .05+, or what many shops consider a spring or wet snow structure, youll never get it out of the edge.

Therefore, if you get a ski back from a shop that used a full width structure, and the base edge is fully polished, there's a high probability the base edge is over beveled.

I see a similar situation on the side edge, though it moves the other direction, and do to whole number jumps in guides, its not as bad. Still, usually if someone is setting their side edge with a 3 for example, their edge ends up being between 2-2.5, and so on.

The only way for most people to get a truly accurate and consistent edge is with a perfectly calibrated machine. This edge can then be maintained with diamond stones for a long time between machine services.


Thanks for your explanation.  I agree that the final bevel should be achieved with the diamond or other stone.  Also we know that base bevel over time will always increase.

 

What kills me as a hand tune guy, is that I see so many skis that have had a post factory tune from a machine and the base bevels are way over cooked and the stone marks are deep as all get out from a screwed up stone.  Some skis seem to be not totally screwed over from the factory and others are.  It's a sad state of affairs.  Sad when one needs to regrind the base of a new ski just to fix the base bevel up better.

post #19 of 21
Why are we putting structure into a metal edge? Is this a byproduct of machine tuning?
post #20 of 21
Quote:
Originally Posted by sibhusky View Post

Why are we putting structure into a metal edge? Is this a byproduct of machine tuning?


Byproduct of flatting a base to include edges with a stone grinder.

post #21 of 21
Thread Starter 

Thanks everyone, ended up skiing the week out (in Hintertux) and had a stone grind done the day i went home. I of course polished every 2-3 days, but i had hit quite a few small rocks in the late season last year, so it was definitely time for a grind!

 

Found a shop with pretty new Montana machines, and got a solid stone grind. They didnt touch any of my edges, so now i have a nice and fresh ski. I am going to do 1/3 by hand and wax a ton!

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