Understanding GPS: A scenario.


Originally posted on 11/9/2011

GPS will no doubt be a strong reason to visit our site on a regular basis, and as we went through the whole developmental process we became aware that, used properly, GPS was a truly powerful tool. Still, like anything new, it also held the potential to be misused, abused and confused. Below is what we consider to be the “best” way to use GPS. As a time-saver and guide to an excellent layout.

If you read through the information you’ll notice that we constantly refer to GPS as a ”starting point” and a way to ”explore” the possibilities. If you will use the tool as we’ve suggested we think you’ll be very pleased with the results. If that sounds a little vague, perhaps it is. Perhaps the best way to understand how to use GPS might be a review of what I went through a few days ago with an 7’ 6” foot spinning rod. It’s a good example of a starting point followed by a little effort that led to exceptional results.

The reel was a Shimano STRADIC 4000FE. I carefully measured it (more than once) and got an A = 87.75mm, B = 77.8mm and C = 125.6mm. I charted these measurements on the permanent card I used to measure the reel and filed it for future reference.

I wanted K-Series guides and since it was a fairly stout rod I opted for KW double foots in the reduction train. GPS gave me a readout for every KW from 50mm to 5.5mm. Right away, I had plenty of ”custom” potential. Knowing I would ”like” a stripper in the 18 to 27 inch range, I looked at the 25 at 18.5 inches and the 20 at 24.9 inches. I like small guides in most cases including the reduction train so I decided to start with the 20mm at 24.9 inches. Reasonable spacing then led to a 12 at (GPS generated) 30.5 inches and a 5.5 at (GPS generated) 35.5 inches. The 5.5 seemed close to the 12 but I have a ”rule” of sorts in my head that goes something like ”no reel measurement is perfect, give yourself an inch or two forward or back on each guide in your search for perfection.” If the 12 moved back and the 5.5 moved forward, I’d be OK.

All taped and ready to go. With 3/8 oz of lead and 20lb braid I was hitting 50 to 51 yards out of the box. Not bad, but there was a bit of noise and a little vibration. I felt it could be better. I would cast and hold the rod to my ear and then cast and hold the rod up against a dark background to watch the line pass through the guides. I finally reached the conclusion that maybe this particular reel and line combo needed less ”early” choking and a little more room to breath as it fired toward the choke point.

Back to the bench where the 20 and 12 came off and the 25 and 16 went on exactly as GPS suggested at 18.5 and 28.7 inches with the 5.5 left at 35.5. I taped it, looked at it and moved the 5.5 forward one inch (see rule above).

All taped and ready to go. The same weight was now casting 55 – 56 yards consistently. The set-up was quieter and had just a whisper of vibration remaining. Picked up about 15 feet. Good, but I’ve kind of developed a feel for ”real good” and it wasn’t there yet. At this point I’m not positive it can get any better, so now I’m definitely in the experimental zone.

I had a hunch after watching the line so many times that the layout might get better with a little more height in the first couple of guides. I didn’t think I needed a bigger ring (I don’t think I’ve ever used a 30) but the height seemed like the way to go. Off came the KW and on went the KL single foots that would give me a millimeter or two more height and move guides back toward the reel a few inches. GPS told me to put the KL25 at 17.1 inches and rhe KL12 at 29.4 inches. Now I had a problem. I needed another reduction guide to get to my GPS choke point at 39 inches and KL stops at size 12! After doing some calculations myself and making a note to include KT guides in GPS, I added a KT10 at 37 inches, skipped the first runner at the choke point since the KT10 was so close and placed the first runner at 44 inches (I’ll go back later and adjust when I static load for the running guides).

All taped up and ready to go. Same weight. Smooth at cream, almost no vibration or noise with casts in the 59 – 60 yard range. This will be a great rod for 3/8 to 1/2 oz X-raps when I’m chasing fall speckled trout in the lagoons and rivers and should work good for grubs and slash baits in deep water as well.

So, is GPS for zombies who can’t think for themselves? Does it take the ”custom” out of custom rod building? Does it make everyone an expert rod builder?

GPS is a tool like so many tools used in rod building. Used properly and with reasonable expectations it can save huge amounts of time and help any builder stay on track to a final product that is as good as it can be. We hope you enjoy the journey!