U20 Class Member's Forum
General Category => U20 General Discussion => Topic started by: U20 Site Moderator on June 28, 2021, 04:46:09 AM
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The class will be hosting regular webinars. We hope you find these useful and informative. Feel free to suggest topics for future sessions.
For your convenience, here are the forums which are also listed below in context of the conversation:
1: Shapes of Speed Upwind - Steve Shaw: https://www.youtube.com/watch?v=d45FVv8fyCE
2: Shapes of Speed Downwind - Steve Shaw: https://u20classforum.org/webinar/2021_Webinar-2.mp4
3: Jim Antrim - U20, U24, A27 Architect: http://u20classforum.org/webinar/2022_Webinar-1.mp4
4: Maintenance: http://u20classforum.org/webinar/2022-Webinar-2.mp4
5: Shapes of Speed Aluminum and Carbon Mast Tuning - Steve Shaw - https://www.u20classforum.org/webinar/2023_Webinar-1.mp4
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Many thanks to Steve Shaw for putting this one together. It was an informative evening.
Recording can be found here: https://www.youtube.com/watch?v=d45FVv8fyCE
Link to load test video Steve referenced (minute 4:45) : https://www.youtube.com/watch?v=TWxzURQd1fU
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Wow, that was great. Thanks!
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Nicely done. Thank you. It was breezy (around 15) here on Lake Mendota last weekend Sunday. Per your suggestion, we watched the jib leach more carefully than usual. I have these observations, but no answers yet. First, the leach fluttered on port tack but not on Stbd. We corrected that easily by adding a bit of tension to the leach cord. Our blocks were in the same position. Any thoughts on what contributes to this variation?
We had just the beginnings of overbend wrinkles in these conditions. Uppers 390 lb, Lowers 315 lb. Crew wt. about 300 lib. We were a bit light, I think.
We race PHRF against some very fast J24's. We were fast upwind until I had to de-power main in the big puffs. Whether I did it with traveler or mainsheet the effect was the same. Jib stalled and we'd slow down. I guess that's to be expected since we're closing the slot with the fuller main. Pinching up in those big puffs didn't seem to kill the jib as much.
What's your experience in getting through these big puffs upwind?
Thanks in advance for your opinions, stories, etc.
Don
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Your mast is most likely not centered.
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Don,
On my older sails I have seen the same with the leech which in my novice opinion has to do with how the sail roles on the roller furling. My new sails don't do it but my older ones do.
I seem to do well in the heavier air and I almost never use the mainsheet to depower. I set the mainsheet tension to get the right shape and appropriate forestay tension. The lowers need to be tight enough to not let the mast bend much (rough conversion is your lowers were 24-25 on the black gauge) in order to get the forestay tension. I will drop the traveler and feather (pinch up) the boat to try and keep a constant heel angle. When you use the mainsheet that means you have to pull the vang on. That pushes the mast forward bending the rig which lowers the hounds and adds forestay sag.
What sails are you using? You will need a little more mast bend with the Doyle sails than the Ullman sails.
Nicely done. Thank you. It was breezy (around 15) here on Lake Mendota last weekend Sunday. Per your suggestion, we watched the jib leach more carefully than usual. I have these observations, but no answers yet. First, the leach fluttered on port tack but not on Stbd. We corrected that easily by adding a bit of tension to the leach cord. Our blocks were in the same position. Any thoughts on what contributes to this variation?
We had just the beginnings of overbend wrinkles in these conditions. Uppers 390 lb, Lowers 315 lb. Crew wt. about 300 lib. We were a bit light, I think.
We race PHRF against some very fast J24's. We were fast upwind until I had to de-power main in the big puffs. Whether I did it with traveler or mainsheet the effect was the same. Jib stalled and we'd slow down. I guess that's to be expected since we're closing the slot with the fuller main. Pinching up in those big puffs didn't seem to kill the jib as much.
What's your experience in getting through these big puffs upwind?
Thanks in advance for your opinions, stories, etc.
Don
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Thanks to Steve Shaw for another outstanding presentation! 8)
If you missed it you can view it here:
https://u20classforum.org/webinar/2021_Webinar-2.mp4
Youtube: https://youtu.be/TXMJFVmzj1M
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I find these webinars very interesting and helpful. What a great opportunity to share thoughts and experiences. Especially for me because I have not been able to join any of the class races. I was quite impressed with the knowledge and experience in the group. Thanks to everyone for putting this on and participating.
Last evenings webinar on maintenance was no exception. Naturally, I thought of more questions after it was over. e.g How do you fix a crack under the floorboards between the flange and the inner side of the hull? There used to be hardware that would allow you to adjust the turnbuckles on the stays without additional tools. Is that still available? ...
I hope you will continue these in the future. One topic might be boat modifications or variations that people have implemented, such as lifeline straps, turnbuckle adjustment, main sheet and boom vang rigging. As someone who does a lot of single-handed sailing, I am always looking for new ideas to have more control and fun on the water. I would also be interested in a webinar based on the carbon mast. e.g., what it takes to convert, costs (including conversion of stays, sails, etc) how to go about doing it, advantages, disadvantages. Is everyone happy they made the change? I would also be curious if anyone has done roller furling on the boom with this, and if so, how well did it work?
The U20 has been a great boat for me. The class, this forum, and these webinars make it even better. Thanks again for all of your work to make these possible.
Allen Townsend
U20 #7