- Bolt Rope Fix
Mainsail popping out of mast
The problem inevitably occurs at the junction of the aluminum track at the top of the mid section and the plastic track on the top mast.
If you think about these as two separate tracks in isolation, it is fairly easy to imagine pulling the bolt rope out of the end of either track because there is a point load, the end of the track opens, the bolt rope deforms easily, and out comes the sail. Once out it will "zip" open completely.
Put the tracks together and the point load is spread to both ends with the aluminum able to take more load before it opens than the plastic. However, because of the fairly wide size of the existing opening in the aluminum track it is not giving enough "help" at the junction.
The fix is simple and it works. Using a vice grip and some soft padding close down the opening at the very top end of the aluminum track but make sure it is over a long 6-8" taper. At the top end it should be under 1/8" but not so narrow that the headboard will not pass freely. Have the sail in the track as you do the job. Alternatively, use an 8" long piece of hardwood and, with a hammer, tap each side of the track until you have made a long smooth taper on each side.
By deforming the aluminum you greatly increase the amount of direct pull needed to open the track and this takes the load away from the end of the plastic track just above it.
The biggest load on the bolt rope is actually the water load in a main if you hold it sheeted-in while you try to pull it up from a capsize.
If your mast track has not been "narrowed down" at the factory, please do it as soon as you can.
Regards,
Ian Bruce
29er Builder
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