Question Truefins

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

I was concerned about the pins rusting, so I turned it over to see what it looked like. There isn't any exposed metal, so that's good. See attached photo.

PXL_20230621_005852381.jpg
 
The documented description of yellow and green:

PXL_20230621_004649066.jpg
 
I have one piece of product feedback and maybe you guys are already working on a solution based on a blurb in the documentation. The spines are difficult to remove, more specifically, the release is difficult to press just right. I kind of had it, but didn't have a way to pull it out easily. I see on the end is a small slot, maybe add to your removal tool, the ability to hook into that slot and pull?

With that said, the first two were a pain. I got the next two out more easily. Some way to hook into that slot would have made it even easier.
Yes, it could be easier. We strengthened the glass filled nylon red spring, and we currently have it stronger than needed. We may have to back off on that tensile. We have updated the tool from what you were shipped, but in principle it is the same. The button tools in the photo below were never shipped, and the new tool has a couple buttons connected with a ribbon, shown at the online manual at truefintechniocal. If you don't have a tool, a couple blunt objects can also press the pins, but you can no longer just push the pins with one's fingers to release the spines. The surprising thing is that when the fin is flexed while kicking hard there is actually very little force on the red pins. We really don't need much shear strength at the red pins.

Perhaps the easiest way to change out spines is to make sure the red pins are fully depressed, and then use your thumb and push the end of the spine (as shown below) to eject it while you flex the fin at the same time. All you need to do is eject the spine a quarter inch or so, so the pins no longer align with the overmolded chassis shoulder holes, and then the spine is free. When reinstalling, as mentioned in the instructions, make sure the links are assembled with the hash marks III next to the hash marks III on the monprene fin rail, otherwise, for example with Green spines, you won't have a flat blade enforced during the power frog kick.

Thanks for checking this fin out. I look forward to your thoughts about your experience while kicking with Green spines. I noticed there is another thread on this forum about frog kicking, and how some users have difficulty twisting their ankle during frog kicking. If you have a chance, we would be very interested to know if you feel there is a benefit to using a Blue spine at you big toe, and a Green spine at your little toe. We have noticed a slight difference, but haven't been able to quantify it.

srt 1.jpg
 
Perhaps the easiest way to change out spines is to make sure the red pins are fully depressed, and then use your thumb and push the end of the spine (as shown below) to eject it while you flex the fin at the same time. All you need to do is eject the spine a quarter inch or so, so the pins no longer align with the overmolded chassis shoulder holes, and then the spine is free.
View attachment 788896
The first few times I tried to remove the spines, I had similar difficulty. But I quickly figured out the technique you mention above, and once I had it down didn't even need the tool for the pins. I can now change the spines fairly quickly. However, the new tool looks even better!
 
I plan to dive with them on Saturday at Blue Heron Bridge. My buddy will have his GoPro. If vis is decent, then we'll record video. If it isn't, we'll try again another day. I don't have a pool to test in, the ocean is my pool :)
 
The first few times I tried to remove the spines, I had similar difficulty. But I quickly figured out the technique you mention above, and once I had it down didn't even need the tool for the pins. I can now change the spines fairly quickly. However, the new tool looks even better!
We made a running production change from an old domed red pin top to a new chamfered red pin top (see pic below) that is 0.060 inch shorter. Depending on when the spines were installed or packaged a user could get either style. The shorter and chamfered pin top might be easier to push with ones fingers, but I need the tool for either pin style.

The red pins engage with shoulder holes at a rigid substrate, or overmolded chassis (pic below),,, so the bending moments that the spines are subjected to during a kick are directly transferred to the bottom platform of the foot pocket. The platform also has an extended rigid heel portion. This rigid platform support in combination with the appropriately sized bootie makes it relatively comfortable at the arch of the foot while kicking, and I guess also may benefit those that have plantar fasciitis. Because this fin is capable of unlimited thrust just depending on how hard you are able to kick it, we had no choice but to include a rigid overmolded chassis.

spring pin part 901.jpg

substrate 20221005_155049.jpg
 
I got my first dive in with the fins yesterday at Blue Heron Bridge. @landonnin1 was kind enough to capture video as soon as we got in the water. We had quite a large group of divers (7), 6 of which are scubaboard users. The plan was to get in the water around 12pm, and we had to arrive early for parking. This gave us hours to talk about whatever. I brought out the fins for show and tell. Everyone was curious and wanted to get an opportunity to hold a fin. I pulled the spines out a couple of times and let everyone see the spines.

Show and Tell:
Initial comments from the group:
What do they do?
They are heavy.
Why are they shaped that way?

I showed how the green spines don't flex one direction and explained how you can mix spines to customize flex. This concept seemed to intrigue everyone. A couple of people pulled their fins out and told stories, good and bad. I talked about how you could pull the spines out and roll the fin up for travel.

My thoughts:
Yes, they are heavy. I don't know if they are any heavier than the Hollis F1. I couldn't dive the F1's because they made me ankle heavy, so I was concerned about this going in. They were not that heavy underwater, and I'll speak more to this later. They definitely have good propulsion. The fins felt awkward at first. The medium springs fit well, maybe too well for my size 11, and my foot was hurting after about 45 minutes. I think this could be solved with a large spring. The foot pocket, otherwise, fit like a glove. The ability to adjust the spring would be nice, which is an option on the fins I normally use (Dive Rite XT). Occasionally, I had the feeling that I kicked something or someone, but I think it was the spines all engaging a limit at the same time. I had no trim problems. One annoyance with the shape of the fins, occasionally I'll get my fin caught up in my dive flag rope between my legs and it was extremely difficult to get the rope back to the other side because it would catch the shape of the fin where the spines insert. Maybe an angle adjustment would solve this. To get my foot out, I would have to roll to my back. I will try the fins again with anther colored spine, but I need to do something about the spring tension first. One of the biggest surprises was the ability to do a back kick to backup, they were very responsive.

The Video:
Landonnin1 was recording me when I was swimming out from shore and adjusting my camera, when I had no idea he was doing it. His thought was it was the best opportunity to capture my natural use of the fins. Some of the kicks were me feeling out the fins. They felt different and didn't appear to affect my buoyancy or trim. I'm uploading the videos to YouTube, when they are done, I will post the links here.

Weight and Bouyancy:
Because I'm carrying my large camera, a dive flag, and fins, I clip off the fins to my waist D-ring. Upon reaching standing depth, I removed my fins, clipped them together, and clipped them to my waist, or so I thought. I'm halfway to my truck and I realize I don't have the fins attached to me. 2 of the divers had already exited before me, but one was still geared up. We went back to the beach looking and looking. Do they float? The lifeguard said he saw some fins floating in the current, so Michael ran up the bridge to see if could see them. I snorkeled around and Matt went back underwater. There were so many people at the beach, did someone find them? I found Jenny taking pictures of something, so I swam to depth to get her looking around too. We looked for like 30 minutes and could not find them. Usually lost fins/masks are turned into a local LDS, so we gave up. We get back to the parking lot and one of our group members had found them and recognized them as the ones I was showing everyone. They said they were on the bottom, fins tips in the sand, foot pocket up in the water column.
 
I was sent two video files. They seem to be taken around the same time.

 
I was sent two video files. They seem to be taken around the same time.

Having not tried them do they feel like they wobble a little? Asking because of the independent action of each set of spines.

would also love to see a burst of flutter speed to see that action.
 
Having not tried them do they feel like they wobble a little? Asking because of the independent action of each set of spines.

would also love to see a burst of flutter speed to see that action.
No wobble. With the green spines, they were very stiff. The green spines wouldn't be the right spines to use for a flutter kick. Let me solve for the spring tension, I'll do a dive with the yellow spines next, and see if I can get another buddy to capture video of both the frog kick and flutter. I will say that when I kicked hard, they responded. I think a little flex would give me a little more power, TBD.
 
https://www.shearwater.com/products/peregrine/

Back
Top Bottom