New owner of #129

[Carson Downing]

Hello all,

Picked up #129 last month and have been loving the boat so far. Ive made a few modifications, updated the GNAV to 16:1, I used 16mm because I had them laying around, working loads are similar to what was on it. I re-spliced the mainsheet with 1/8'' dyneema to a split tail and moved it to configuration B to clean up the stern.

I do have a few questions. The boat came with a spare carbon mast, however it looks like the upper stay connection points are 3" higher than the current mast on the boat. Class wise, would it be illegal to order different length uppers to account for this? Or do I need to move the mounts down? The boat also came with an upright rudder mount, however it looks to be a little crooked on the stern, I haven't checked it with the keel on a lift or anything yet but was just curious if they usually appear to be this crooked?

Looking forward to making it to a few of the Great Lakes events next year!

[Peter Beardsley]

Carson,

Nice splicing on the mainsheet.  You may decide you want something less stretchy on the vang over time but as long as it doesn't break, it'll work.  The 16:1 vang is otherwise legal as pictured (though if someone from the Tech Committee has another opinion, always defer to them).  Not sure what to tell you about the backup mast.  That sounds strange though.  If the rudder bracket is crooked, you can remount it to straighten it up - if you're a handy guy, using a laser sight and any similar means is ok, as long as the remounted bracket is on straight and isn't moving around.  It was an aftermarket upgrade so the potential for mounting it crooked is there. 

[Carson Downing]

The mainsheet splice was definitely one of the more difficult splices i've ever done, would probably be easier if it was done on new line. The vang is dyneema core all the way back to the cleat, so it should be good on strength and stretch, hopefully. Can someone verify the UPPER mount length for me? I have about 51-3/8" from the top of the mast to the very top of the slot. Picture included. The mast is the standard SuperSpars mast, so not sure how it would be different? The measurement on the backup mast is 48-5/8".

Thanks for the info Peter!

[Dave Nickerson]

Carson - Nice work. Couple things.

Mast measurements I have are from the base of the mast "Bottom of heel casting, w/o rectangular alignment block" to the bearing surface for the J-hook. From a bunch of masts the TC measured in 2011, that number should be about 7683mm. Please email me directly with what your actual measurements are.

Afraid your gnav purchase is too high. You have a 5:1 on the moving part (the car) on the boom times a 4:1 below the boom = 20:1. If you back the car purchase down to 4:1 and you'll be fine...

Good luck with your new boat!

Dave
TC chair

[Carson Downing]

Sent you a message with the mast measurement. I copied the top part of the Vang based on the setup on Harkens website which is 8:1. Double block to a double block with becket, 4:1 right? Or does the through block on the front of the boom count as a 5th purchase?

https://www.harken.com/DeckLayout.aspx?id=13769

[Dave Nickerson]

Thanks.
Can't vouch for Harken. For purchases you count the parts of line attached to the moving part. Bet you a beer that if you pull 5" on your upper purchase that the car will move 1"...  block thru the boom is just redirecting- adds no purchase. Then multiply by the lower purchase- in your case 4:1

[Carson Downing]

Dang, you're right! Thanks Dave.

Carson

[Garrett Johns]

Hey Carson, we had that vertical rudder bracket installed at a boat shop (Jim Betts). He laser aligned it with the keel so should be good to go.
Glad you are enjoying the boat!

[Carson Downing]

Cool, thanks Garrett!

Has anyone made a chart of target boat speeds and angles for given wind ranges? We had the boat out for a Wednesday night race in 10-20 yesterday, felt great, but hard to tell what the boat is capable of when there are no other Vipers to compare to there.

I reached out to Paul Young about the mast, he suggested leaving the current mounts in and adding new mounts at the proper measurement. That way I wouldn't have to do any carbon fiber reinforcing where the old mounts are. Even gave me a part number 👍🏼

[Peter Beardsley]

Cool, thanks Garrett!

Has anyone made a chart of target boat speeds and angles for given wind ranges? We had the boat out for a Wednesday night race in 10-20 yesterday, felt great, but hard to tell what the boat is capable of when there are no other Vipers to compare to there.

There has been a bunch of conversation on this topic over the years in old forum posts, but I can't find anything right now about it in the archives, nor do I have any polar diagrams for a Viper.  Assuming you're on a windward-leeward course (which is really the only thing that matters from a VMG standpoint), our general rule sailing downwind (which can be violated of course) is "don't try to plane unless you can plane 100% of the time."  Otherwise in puffy conditions, if you go high to plane and the puff runs out, you've lost a lot of gauge on the boats to leeward.  Generally this transitions happens at around 12-13 kts sustained, but the word "sustained" is key.  If you're not planing but you're doing more than 9.5 kts consistently, you should probably be planing 100% of the time and going 11+ kts. 

Otherwise, set the boat up to the tuning guide to make sure you're maximizing your speed potential upwind.  Hike hard and don't let the boat heel too much - if your leeward rail is in the water upwind, you're way too heeled (and likely very slow too). 

10-20 knots of wind is a huge range for wind speeds - makes sense for a lake, but if you're in those conditions, you're changing gears a lot and if the wind isn't going below 10 knots, you can set the boat up for the puffs instead of setting up for the lulls - you'll still be fully powered in 10 knots of wind (as opposed to the much tougher condition of 5-15 kts where you want to set up for the lulls).  Usually we are at full power and are starting to depower aggressively at 10 knots (i.e., 3.25" of mast blocks, upper shrouds at 34-35), and if that is our setup, we want to be going 5.7-6.0 knots upwind all of the time (which is possible if you're sailing with at least 540 lbs of crew weight - pretty hard to do if you're sailing lighter than that in those conditions - heavier teams will be able to do 6.1-6.4 upwind depending on sea state - pretty hard to go more than 6.4 kts upwind in a Viper on a true close hauled course in flat water and no current unless you're overstood, which doesn't count, and if you are able to do that, try taking a bit more height and make that weather jib telltale lift a bit more).  At a certain point (usually around 13-14 knots, more pressure upwind doesn't make the boat go any faster - you just heel more, so you can take some more height and pinch/feather to compensate and still try to go the same speed (again, assuming flat water).  Downwind...10 knots of wind you can go 7.5-8 kts and in 20 knots of wind you can go 14.5-16 kts...so find those puffs and keep the boat under the mast.

[Matt Rowlinson]

Hi Peter--following up something you said in FB thread--wondering about how much chock you use. It seems you vary from 2.5" in the light to 3.25" over 10 knots (that's more than we've ever dared/been able to wedge in there). Any thoughts welcome--thanks for all all your contributions.

[Peter Beardsley]

The number of mast chocks you're able to wedge in will be directly related to your mast butt position and your headstay length.  We have our boat set up to the North tuning guide (which is probably not all that different from Brad's Doyle tuning numbers, though I haven't seen Brad's latest numbers), which involves having the headstay at max length and the mast butt in the aft most position.  If you do that, suddenly you'll see that you have room for A LOT of blocks.  We can get 2.75" of blocks in fairly easily (i.e., singlehanded).  From there, it's often a two person job, where we have one person pull aft on the mast (with feet braced on the coaming, all weight on the mast), and the other person ready to add mast blocks.  Depending on the position of your "mast block hardware" (i.e., block and cleat), you may need to file away the sides of the aft most block.  Our boat did not come supplied with a Harken block on the deck since it serves no purpose (i.e., our mast line goes from the eyestrap, around the mast a couple of times and through the eyestrap a couple of times, to the cleat - pics attached) and we told Rondar they could save themselves $20 and 5 minutes of labor, and our clam cleat as supplied on the newest boat was mounted a couple of centimeters outboard to eliminate play between the mast blocks and the cleat, so that helps a bit.  Getting the last bit of blocks in takes some effort.  We have the retaining line over the top of the blocks, NOT through the blocks - the orange line in the pics is just to keep the blocks from getting lost.  We also put a trapeze handle on the end of the retaining line so that in light air when we're trying to pull the mast forward to induce headstay sag / in general just to keep that line tight and keep the blocks from popping up, we're able to do so.  There are some other people who have taken a different approach given the relatively small range of adjustment of mast blocks and permanently mounted the forward mast blocks to the front of the coaming with a bolt, have drilled a tiny hole in the bottom of the aft most mast block (i.e., the curved block) and tied it down to the front of the mast step so that it doesn't ride up, and only adjust a few of the middle blocks.  That's pretty slick too if you want to do it - we've meant to try it but honestly it's one of those projects that is lower priority for us.  Final note is that the attached photos actually show us with 3.125" of mast blocks in - we have one additional 1/8" block that we use in 16+ kts that we call the "turn it to 11" block (and a quarter incher is out in these photos as you can see).  I cannot endorse this approach unless you are 100% confident in your Viper tuning ability - if you have too little upper shroud tension (i.e., less than 35), you WILL invert your mast with this setting (I once tried 3.5" of mast blocks and inverted my mast in the parking lot - not a good look).  That said, I think headstay sag control is the most important control to get right in a Viper if you want to be fast upwind in hiking conditions.  Teams that get it wrong have jibs that are too full, are overpowered, and have to ease a lot more to compensate, and they just go slower and sideways while hiking more and more with little improvement in performance.  I'll post an example of that in a second.

There's a lot going on in the photos.  Ignore the green/white line - that is a tow line / bow line.  Ignore the white line - that is a spin halyard.  Retaining line is dark blue.  We also don't deal with tiny mast blocks mostly - we use big adjustments in quarter-inch increments except for the Turn It to 11 block. 

[Matt Rowlinson]

Huge thanks Peter! lots to digest here--Matt (also--last I heard from Brad, Doyle also recommends max headstay and step max aft. They recommend shortening the headstay in big breeze, which seems to me less effective than adding chocks.)

[Peter Beardsley]

Brad and I have talked about the shortening headstay route - I plan to try it in 15+ kts at some point but haven't had a good opportunity yet.  I don't know that Brad is doing it in lieu of blocks - I think he is doing it to change the helm, but I'll let Brad chime in on his rationale at some point. I will say that when he did it on a day in Sarasota when he was overpowered (18-20 kts and not enough crew weight) he was able to hang upwind and we (even more overpowered at 490 lbs) were not even close.  So I'm curious.

Photo attached of what good and bad headstay sags look like.  Granted, this photo is slightly unfair in that teams are rounding a weather mark, vangs are eased, etc., but a few things are obvious.

1. 269 has very little headstay sag - very straight, flat entry on the jib luff.  This was in around 13 knots of wind.  We had 3.25" of blocks in and the uppers were around 35.

2. 159 has a moderate amount of sag.  Not as fast, but hey, they're rounding the windward mark in front of us, so I shouldn't be a hater.  I'm not sure this is why they were ahead though.

3. 222 has an in between amount of sag, but you can see they're a little overpowered.  Also, this was a short beat (0.6 nm - YRALIS Saturday racing - we got in 4 races in 2 hours and the teams are all pretty close to each other).  The bigger point is that it is clear visually when there is too much headstay sag.  For people who aren't as good at sighting the rig, our baseline is that if all crew are hiking reasonably hard, we should have all blocks in.  You're allowed to change blocks mid-race, so if you're wrong, it's easy to deal with (relatively - we do it downwind typically - that's it's own post about good technique for making this happen when you realize on the first beat that you're set up incorrectly, and what philosophy you should have pre-start when you're not 100% sure about where the rig should be with upper shroud tension and mast blocks).

[Carson Downing]

Cool, thanks Garrett!

Has anyone made a chart of target boat speeds and angles for given wind ranges? We had the boat out for a Wednesday night race in 10-20 yesterday, felt great, but hard to tell what the boat is capable of when there are no other Vipers to compare to there.

There has been a bunch of conversation on this topic over the years in old forum posts, but I can't find anything right now about it in the archives, nor do I have any polar diagrams for a Viper.  Assuming you're on a windward-leeward course (which is really the only thing that matters from a VMG standpoint), our general rule sailing downwind (which can be violated of course) is "don't try to plane unless you can plane 100% of the time."  Otherwise in puffy conditions, if you go high to plane and the puff runs out, you've lost a lot of gauge on the boats to leeward.  Generally this transitions happens at around 12-13 kts sustained, but the word "sustained" is key.  If you're not planing but you're doing more than 9.5 kts consistently, you should probably be planing 100% of the time and going 11+ kts. 

Otherwise, set the boat up to the tuning guide to make sure you're maximizing your speed potential upwind.  Hike hard and don't let the boat heel too much - if your leeward rail is in the water upwind, you're way too heeled (and likely very slow too). 

10-20 knots of wind is a huge range for wind speeds - makes sense for a lake, but if you're in those conditions, you're changing gears a lot and if the wind isn't going below 10 knots, you can set the boat up for the puffs instead of setting up for the lulls - you'll still be fully powered in 10 knots of wind (as opposed to the much tougher condition of 5-15 kts where you want to set up for the lulls).  Usually we are at full power and are starting to depower aggressively at 10 knots (i.e., 3.25" of mast blocks, upper shrouds at 34-35), and if that is our setup, we want to be going 5.7-6.0 knots upwind all of the time (which is possible if you're sailing with at least 540 lbs of crew weight - pretty hard to do if you're sailing lighter than that in those conditions - heavier teams will be able to do 6.1-6.4 upwind depending on sea state - pretty hard to go more than 6.4 kts upwind in a Viper on a true close hauled course in flat water and no current unless you're overstood, which doesn't count, and if you are able to do that, try taking a bit more height and make that weather jib telltale lift a bit more).  At a certain point (usually around 13-14 knots, more pressure upwind doesn't make the boat go any faster - you just heel more, so you can take some more height and pinch/feather to compensate and still try to go the same speed (again, assuming flat water).  Downwind...10 knots of wind you can go 7.5-8 kts and in 20 knots of wind you can go 14.5-16 kts...so find those puffs and keep the boat under the mast.

Awesome info, We weren't too far off then. 550lbs on the rail, we were able to be around 5.8-6.3 upwind. Downwind our top speed was 13.7, consistently over 10 knots though.

I'm also liking the Configuration B mainsheet setup, with the split tail at the center of the boat. Mostly because I can swing the tiller extension back and not worry about the sheet at the stern. Was nice to be able to twist the main more, and I was able to get sufficient leech tension with the Gnav, which allowed me to ease the sheet when the breeze picked up. I need to get numbers on the Gnav for consistent trim. How far are you guys able to get that car to move forward? I got the car to about where the block runs into the forward stop and felt like I shouldn't wail on it anymore, had the boom bending pretty good. Of course this was 16:1 so I didn't want to break anything 😜

I'm definitely interested in how you change blocks on the course, I had a hell of a time fitting all the blocks in on the trailer.