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Cabrinha crossbow powerloss

Posted: Sun Mar 10, 2013 2:53 pm
by shawn13
I have a 2011 cabrinha crossbow 13m. I've noticed that after my last few kite trips it's had less power. I did the cabrinha bar tuning. When the center lines reached 6inch stretch I recently replaced them with 2013 lines and retuned. I still have no power. I know this because I can ride a 12 Switchblade fine and when I switch back to the 13 it feels like a 9 or 10. Can a bridle stretch? Anyone experience this before? Thanks.

Re: Cabrinha crossbow powerloss

Posted: Sun Mar 10, 2013 8:17 pm
by Hawaiis
I have noticed when the kite is new, they tend to have more power. After a while, they will not be as efficient. My reasoning is that they will stretch and loss their optimum shape, also they will pick up sand and dirt and become heavier. Maybe there are other factors too.

Re: Cabrinha crossbow powerloss

Posted: Sun Mar 10, 2013 9:18 pm
by experienced1
some thing is wrong...can't tell you what from here, but the 13m XB powerwise should be similar to the 14SB. When you installed the new center lines, did you retune the bar with all lines having equal tension with no depower strap pulled and the bar sheeted all the way in? Sound like your back/outside lines might be a bit long.
steve

Re: Cabrinha crossbow powerloss

Posted: Sun Mar 10, 2013 10:38 pm
by shawn13
experienced1 wrote:some thing is wrong...can't tell you what from here, but the 13m XB powerwise should be similar to the 14SB. When you installed the new center lines, did you retune the bar with all lines having equal tension with no depower strap pulled and the bar sheeted all the way in? Sound like your back/outside lines might be a bit long.
steve
Yes I tuned the bar. All the way in and the lines are even. I tried putting the lines closer to the kite but it only helped slightly. I can't figure it out. Can a bridle stretch? I'd hate to replace that if the kite has lost shape or something...

Re: Cabrinha crossbow powerloss

Posted: Mon Mar 11, 2013 12:31 am
by Caesar
shawn13 wrote:I have a 2011 cabrinha crossbow 13m. I've noticed that after my last few kite trips it's had less power. I did the cabrinha bar tuning. When the center lines reached 6inch stretch I recently replaced them with 2013 lines and retuned. I still have no power. I know this because I can ride a 12 Switchblade fine and when I switch back to the 13 it feels like a 9 or 10. Can a bridle stretch? Anyone experience this before? Thanks.
Hi Shawn,

I can't give you a fix for that either, but I can tell you that I noticed the same with Switchblades. After about 5 months the performance/power dropped. Not to 50% but noticeable.

Cheers
Caesar 8)

Re: Cabrinha crossbow powerloss

Posted: Mon Mar 11, 2013 12:58 am
by knotwindy
yes, bridles stretch, sometimes a lot
seems to me part of why a new kite flies "better" is the bridles are correct

Re: Cabrinha crossbow powerloss

Posted: Mon Mar 11, 2013 2:45 pm
by AlexandreBorges
Hmm...

If lines are tuned then I could give a shot! Maybe the line inside the black tube that slides through bar is broken and all that is holding your kite is the black tube itself. Also perceived by eject line tension.

It happened to me while in the middle of a long downwind. By half of it I heard something odd but could not see anything broken but I felt power difference and low power on jumps, than when I finished that day session I could see the main line broken. I had a long DW only with that black tube saving the day.

:wink:
Tell me later if that is the case.

Re: Cabrinha crossbow powerloss

Posted: Mon Mar 11, 2013 5:10 pm
by bigwave
shawn13 wrote:
experienced1 wrote:some thing is wrong...can't tell you what from here, but the 13m XB powerwise should be similar to the 14SB. When you installed the new center lines, did you retune the bar with all lines having equal tension with no depower strap pulled and the bar sheeted all the way in? Sound like your back/outside lines might be a bit long.
steve
Yes I tuned the bar. All the way in and the lines are even. I tried putting the lines closer to the kite but it only helped slightly. I can't figure it out. Can a bridle stretch? I'd hate to replace that if the kite has lost shape or something...
Hi, can you bring the kite in to Silent Sports? We can have a look at it with you. 1-800-661-7873

Thanks

Dave

Re: Cabrinha crossbow powerloss

Posted: Mon Mar 11, 2013 5:43 pm
by JS
Oversheeting is the most likely cause for loss of power (lift). Oversheeting is regularly caused or exacerbated by stretched or stretching (present only under load) lines, which normally affect the front more than rear lines. It's very difficult to detect oversheeting unless it's so severe the kite suffers total aerodynamic stall.

The only practical way to know a kite is trimmed optimally, without oversheeting, is with telltales. Ironically, competitive sailors know they don't have a chance at being competitive without telltales, and yet very few kiteboarders use them. (Interesting indication that kiteboarding - not least racing - is in its relative infancy :D )

Here's something I wrote about half a dozen years ago on the topic: http://www.kiteboardbc.com/index.php?pr=Telltales

Cheers,
James

Re: Cabrinha crossbow powerloss

Posted: Mon Mar 11, 2013 5:59 pm
by southflorida
What would be useful to understand if bridle lines are stretching is to have a factory published length for each bridle line for each model, year and size of kite. I didn't measure my Switchblade 2011 bridles when new...so maybe they have stretched a little?

Problem is, I have no reference to measure against.

(note to self - measure all bridle lines to the mm next time I buy new kite)