Cal 20 Jumper Stays

Hi All, I was comming back in tonight and a couple were watching me and after docking and all we were talking about both of our boats, ( his is a Cape Dory )and he asked me about the jumper stays and why the mast was designed with them. I hadn't really thought about it much, and my last cal was a 2-29 and of coarse didn't have them, and I couldn't answer him. So, the question is way the jumper stays and what do they do for the rig? Thanks in Advance Chris Bowen Cal 20 #65 San Francisco Pelican #2298 Camano Island,Wa.

About half way down in this article is one man's opinion. http://www.glen-l.com/free-book/rigging-small-sailboats-3.html <http://www.glen-l.com/free-book/rigging-small-sailboats-3.html>Allen On Mon, Aug 17, 2009 at 9:07 PM, chris.bowen28 <ck… [at] wavecable.com> wrote: > > > Hi All, > > I was comming back in tonight and a couple were watching me and after > docking and all we were talking about both of our boats, ( his is a Cape > Dory )and he asked me about the jumper stays and why the mast was designed > with them. I hadn't really thought about it much, and my last cal was a 2-29 > and of coarse didn't have them, and I couldn't answer him. > So, the question is way the jumper stays and what do they do for the rig? > > Thanks in Advance > > Chris Bowen > Cal 20 #65 > San Francisco Pelican #2298 > Camano Island,Wa. > > >

Hi Chris, Jumpers are very importent in a fractional rig as is the C20's Since the forestay does not go to the top of the mast any jibstay pressure and counter pressure from the backstay will of course affect mast bend which the jumpers control. The jumpers also affect side bend and keep the mast from coming out of column. If your jumpers are tuned properly your mast will be in column with a snug jibstay and 50 to 100 pounds of backstay pressure. Since the backstay is pulling on the top of the mast and the jibstay is pulling on the mast only 7/8 of the way up, it is the jumpers task to prevent the top of the mast from overbending as jibstay pressure pulls forward and backstay pressure pulls back, Jumpers also control leech tension of the mainsail as they allow mast bend in the upper half. Jumpers are adjusted to be just taunt with no mast bend(curve) As backstay pressure is increased with increasing wind speed to flatten the sails by pulling draft out, they allow the mast to bend(curve) within limits to allow best sail shape. On Cal20's on SF Bay where 40k wind is not uncommon in the summer I have 3 marks on my backstay adjuster tackle. 1) Mast in column/no bend used up to 8k wind speed. 2)Mast bend of 3 inches as measured at mid mast/ used up to about 28k. 3) Mast bend of 5 inches 28k and above and a maximum bend limit. As the backstay pulls the top of the mast rearward the jumpers become increasingly tighter, which is good. this prevents overbend of the top section of the mast. Smooth Sailing, My Best, Mike --- On Mon, 8/17/09, chris.bowen28 <ck… [at] wavecable.com> wrote: From: chris.bowen28 <ck… [at] wavecable.com> Subject: [Cal_Boats] Cal 20 Jumper Stays To: Ca… [at] yahoogroups.com Date: Monday, August 17, 2009, 9:07 PM Hi All, I was comming back in tonight and a couple were watching me and after docking and all we were talking about both of our boats, ( his is a Cape Dory )and he asked me about the jumper stays and why the mast was designed with them. I hadn't really thought about it much, and my last cal was a 2-29 and of coarse didn't have them, and I couldn't answer him. So, the question is way the jumper stays and what do they do for the rig? Thanks in Advance Chris Bowen Cal 20 #65 San Francisco Pelican #2298 Camano Island,Wa. ------------------------------------ Yahoo! Groups Links

Hi Mike, Great explanation. When I bought all new standing rigging from Steve Seals, he told me to just adjust the jumpers to taunt with no sag, but not tight, so thats what I did. But in all the excitement I never did ask him what they were for. He also had me install the additional tang on the stern and made me an adjustable backstay. Feels great to have an all new set of standing rigging, and Ohhh she likes it. I have had several sailboats in the past that were fractional rigs, most recently ( well within the last 10 years ) the Gary Mull design Ranger 22 which didn't have them, so I am guessing the design dictates. Anyway, thanks for the explanation Chris Bowen Cal 20 #65 San Francisco Pelican #2298 Camano Island,Wa. -----Original Message----- From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com]On Behalf Of mike farrell Sent: Tuesday, August 18, 2009 5:02 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Cal 20 Jumper Stays Hi Chris, Jumpers are very importent in a fractional rig as is the C20's Since the forestay does not go to the top of the mast any jibstay pressure and counter pressure from the backstay will of course affect mast bend which the jumpers control. The jumpers also affect side bend and keep the mast from coming out of column. If your jumpers are tuned properly your mast will be in column with a snug jibstay and 50 to 100 pounds of backstay pressure. Since the backstay is pulling on the top of the mast and the jibstay is pulling on the mast only 7/8 of the way up, it is the jumpers task to prevent the top of the mast from overbending as jibstay pressure pulls forward and backstay pressure pulls back, Jumpers also control leech tension of the mainsail as they allow mast bend in the upper half. Jumpers are adjusted to be just taunt with no mast bend(curve) As backstay pressure is increased with increasing wind speed to flatten the sails by pulling draft out, they allow the mast to bend(curve) within limits to allow best sail shape. On Cal20's on SF Bay where 40k wind is not uncommon in the summer I have 3 marks on my backstay adjuster tackle. 1) Mast in column/no bend used up to 8k wind speed. 2)Mast bend of 3 inches as measured at mid mast/ used up to about 28k. 3) Mast bend of 5 inches 28k and above and a maximum bend limit. As the backstay pulls the top of the mast rearward the jumpers become increasingly tighter, which is good. this prevents overbend of the top section of the mast. Smooth Sailing, My Best, Mike --- On Mon, 8/17/09, chris.bowen28 <ck… [at] wavecable.com> wrote: From: chris.bowen28 <ck… [at] wavecable.com> Subject: [Cal_Boats] Cal 20 Jumper Stays To: Ca… [at] yahoogroups.com Date: Monday, August 17, 2009, 9:07 PM Hi All, I was comming back in tonight and a couple were watching me and after docking and all we were talking about both of our boats, ( his is a Cape Dory )and he asked me about the jumper stays and why the mast was designed with them. I hadn't really thought about it much, and my last cal was a 2-29 and of coarse didn't have them, and I couldn't answer him. So, the question is way the jumper stays and what do they do for the rig? Thanks in Advance Chris Bowen Cal 20 #65 San Francisco Pelican #2298 Camano Island,Wa. ------------------------------------ Yahoo! Groups Links

Hi Chris, Thanks for the reply! Sounds like you have things under control. New rigging not only makes your Cal feel better, it gives you the confidence to sail hard when you need to without the anxiety that is always present when you are expecting a loud ping that happens when something aloft lets go. On the wind if you hear that ping, put the helm down instantly (crash tack) and you may save the rig. Off the wind, if you have a backstay failure, use the. mainsheet to keep tension by hauling it flat. Over the years I have lost 2 rigs. One on my Santa Cruz 27 when a turnbuckle let go on a aft lower, a crash tack could have saved that rig but my crew steering was not fast enough.. More dangerous was the Peterson 43 spar we lost in a midwinter race on SF Bay. We were on a tight reach from Crissy to Harding Rock when we needed to jibe. I was at the mast and I raised the spinnaker pole on the mast for the jibe. When "Trip" was called the pole would not release as there was too much load on. Three things could have saved the mast, Hold the jibe, or let out 6-10 feet of afterguy instantly, or raise the spinnaker pole on the pole lift. When the boat rolled to weather as the spinnaker took control, the pole plunged under the water and pushed the mast out of colunn where the pole was connected to the mast. No one was injured! $40,000 for the new rig. I really like to sail boats that I can afford---Cal 20!!! My Best, Mike --- On Tue, 8/18/09, Chris Bowen <ck… [at] wavecable.com> wrote: From: Chris Bowen <ck… [at] wavecable.com> Subject: RE: [Cal_Boats] Cal 20 Jumper Stays (Mike) To: Ca… [at] yahoogroups.com Date: Tuesday, August 18, 2009, 8:11 PM Hi Mike, Great explanation. When I bought all new standing rigging from Steve Seals, he told me to just adjust the jumpers to taunt with no sag, but not tight, so thats what I did. But in all the excitement I never did ask him what they were for. He also had me install the additional tang on the stern and made me an adjustable backstay. Feels great to have an all new set of standing rigging, and Ohhh she likes it. I have had several sailboats in the past that were fractional rigs, most recently ( well within the last 10 years ) the Gary Mull design Ranger 22 which didn't have them, so I am guessing the design dictates. Anyway, thanks for the explanation Chris Bowen Cal 20 #65 San Francisco Pelican #2298 Camano Island,Wa. From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com]On Behalf Of mike farrell Sent: Tuesday, August 18, 2009 5:02 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Cal 20 Jumper Stays Hi Chris, Jumpers are very importent in a fractional rig as is the C20's Since the forestay does not go to the top of the mast any jibstay pressure and counter pressure from the backstay will of course affect mast bend which the jumpers control. The jumpers also affect side bend and keep the mast from coming out of column. If your jumpers are tuned properly your mast will be in column with a snug jibstay and 50 to 100 pounds of backstay pressure. Since the backstay is pulling on the top of the mast and the jibstay is pulling on the mast only 7/8 of the way up, it is the jumpers task to prevent the top of the mast from overbending as jibstay pressure pulls forward and backstay pressure pulls back, Jumpers also control leech tension of the mainsail as they allow mast bend in the upper half. Jumpers are adjusted to be just taunt with no mast bend(curve) As backstay pressure is increased with increasing wind speed to flatten the sails by pulling draft out, they allow the mast to bend(curve) within limits to allow best sail shape. On Cal20's on SF Bay where 40k wind is not uncommon in the summer I have 3 marks on my backstay adjuster tackle. 1) Mast in column/no bend used up to 8k wind speed. 2)Mast bend of 3 inches as measured at mid mast/ used up to about 28k. 3) Mast bend of 5 inches 28k and above and a maximum bend limit. As the backstay pulls the top of the mast rearward the jumpers become increasingly tighter, which is good. this prevents overbend of the top section of the mast. Smooth Sailing, My Best, Mike --- On Mon, 8/17/09, chris.bowen28 <ckbow@wavecable. com> wrote: From: chris.bowen28 <ckbow@wavecable. com> Subject: [Cal_Boats] Cal 20 Jumper Stays To: Cal_Boats@yahoogrou ps.com Date: Monday, August 17, 2009, 9:07 PM Hi All, I was comming back in tonight and a couple were watching me and after docking and all we were talking about both of our boats, ( his is a Cape Dory )and he asked me about the jumper stays and why the mast was designed with them. I hadn't really thought about it much, and my last cal was a 2-29 and of coarse didn't have them, and I couldn't answer him. So, the question is way the jumper stays and what do they do for the rig? Thanks in Advance Chris Bowen Cal 20 #65 San Francisco Pelican #2298 Camano Island,Wa. ------------ --------- --------- ------ Yahoo! Groups Links

mike farrell wrote: > > > Hi Chris, > Thanks for the reply! Sounds like you have things under > control. New rigging not only makes your Cal feel better, it gives > you the confidence to sail hard when you need to without the anxiety > that is always present when you are expecting a loud ping that happens > when something aloft lets go.. On the wind if you hear that ping, put > the helm down instantly (crash tack) and you may save the rig. Off the > wind, if you have a backstay failure, use the. mainsheet to keep > tension by hauling it flat. > It's worth noting that the Cal 20's backstay is undersized and prone to failure. Mine started unravelling (did not fail catastrophically) and I got a new, larger-diameter one from Steve Seal that uses the right size terminals. . I didn't know about the design issue on the backstay until somebody on the list pointed it out, so I'm doing the same favor to others who might be unaware. The other standing rigging is of undetermined age, but my boat is in fresh water and the mast is unstepped for half of each year. I had a shroud start unravelling on my DN iceboat, but that rig has always looked WAY underspec'd and it's a miracle that they don't break more regularly. It's a miracle that the hulls don't disintegrate regularly, too, when you feel the forces they're subjected to on rough ice or in wind gusts. Chris Campbell > > >

Hi Chris, You are right, the backstay is undersize. In the 70's we were not allowed to adjust the back stay during a race. We had to estimate conditions and set the BS accordingly. Now we can put much more pressure on the BS. I use a backstay the same diameter as the upper shrouds. On the last boat I tuned I went up a size on the aft lowers as they bear most of the load on the rig. I was not dissapointed. I believe that I will continue to do this. I am now restoring COYOTE hull# 61 formerly CAPRICE, A gift of Dr. Bob Pavy.. She is in Coyote Point Harbor where she has been for a very long time. last haul out was 1996. She need a lot--- My Best, Mike --- On Wed, 8/19/09, Chris Campbell <cl… [at] charterinternet.com> wrote: From: Chris Campbell <cl… [at] charterinternet.com> Subject: Re: [Cal_Boats] Cal 20 Jumper Stays (Mike) To: Ca… [at] yahoogroups.com Date: Wednesday, August 19, 2009, 8:33 AM mike farrell wrote: Hi Chris, Thanks for the reply! Sounds like you have things under control. New rigging not only makes your Cal feel better, it gives you the confidence to sail hard when you need to without the anxiety that is always present when you are expecting a loud ping that happens when something aloft lets go.. On the wind if you hear that ping, put the helm down instantly (crash tack) and you may save the rig. Off the wind, if you have a backstay failure, use the. mainsheet to keep tension by hauling it flat. It's worth noting that the Cal 20's backstay is undersized and prone to failure. Mine started unravelling (did not fail catastrophically) and I got a new, larger-diameter one from Steve Seal that uses the right size terminals. . I didn't know about the design issue on the backstay until somebody on the list pointed it out, so I'm doing the same favor to others who might be unaware. The other standing rigging is of undetermined age, but my boat is in fresh water and the mast is unstepped for half of each year. I had a shroud start unravelling on my DN iceboat, but that rig has always looked WAY underspec'd and it's a miracle that they don't break more regularly. It's a miracle that the hulls don't disintegrate regularly, too, when you feel the forces they're subjected to on rough ice or in wind gusts. Chris Campbell

Hi Chris, When I bought the new rigging from Steve Seals he made the backstay the size he now supplies to everyone which is I believe the same size as the upper shrouds. I know it was definitely bigger than the old one I took off. Thanks for the heads up though........ Chris Bowen Cal 20 #65 San Francisco Pelican #2298 Camano Island,Wa. -----Original Message----- From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com]On Behalf Of mike farrell Sent: Wednesday, August 19, 2009 5:39 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Cal 20 Jumper Stays (Mike) Hi Chris, You are right, the backstay is undersize. In the 70's we were not allowed to adjust the back stay during a race. We had to estimate conditions and set the BS accordingly. Now we can put much more pressure on the BS.. I use a backstay the same diameter as the upper shrouds. On the last boat I tuned I went up a size on the aft lowers as they bear most of the load on the rig. I was not dissapointed. I believe that I will continue to do this. I am now restoring COYOTE hull# 61 formerly CAPRICE, A gift of Dr. Bob Pavy. She is in Coyote Point Harbor where she has been for a very long time. last haul out was 1996. She need a lot--- My Best, Mike --- On Wed, 8/19/09, Chris Campbell <cl… [at] charterinternet.com> wrote: From: Chris Campbell <cl… [at] charterinternet.com> Subject: Re: [Cal_Boats] Cal 20 Jumper Stays (Mike) To: Ca… [at] yahoogroups.com Date: Wednesday, August 19, 2009, 8:33 AM mike farrell wrote: Hi Chris, Thanks for the reply! Sounds like you have things under control. New rigging not only makes your Cal feel better, it gives you the confidence to sail hard when you need to without the anxiety that is always present when you are expecting a loud ping that happens when something aloft lets go... On the wind if you hear that ping, put the helm down instantly (crash tack) and you may save the rig. Off the wind, if you have a backstay failure, use the. mainsheet to keep tension by hauling it flat. It's worth noting that the Cal 20's backstay is undersized and prone to failure. Mine started unravelling (did not fail catastrophically) and I got a new, larger-diameter one from Steve Seal that uses the right size terminals. . I didn't know about the design issue on the backstay until somebody on the list pointed it out, so I'm doing the same favor to others who might be unaware. The other standing rigging is of undetermined age, but my boat is in fresh water and the mast is unstepped for half of each year. I had a shroud start unravelling on my DN iceboat, but that rig has always looked WAY underspec'd and it's a miracle that they don't break more regularly. It's a miracle that the hulls don't disintegrate regularly, too, when you feel the forces they're subjected to on rough ice or in wind gusts. Chris Campbell