History of Development & Innovations
SICgrip Innovations
Lightweight training grips made from extruded aluminum
User replaceable and variable friction grip surface (pressure sensitive adhesive StikGrip)
Logarithmic spiral grip shape featuring a variable radii sloper surface that changes difficulty by rotating the grip (Gstrings)
4-point grip suspension to stabilize a portable hanging grip (Gstrings, Pocket Rocks, and gBar)
The ability to vary grip angle (X, Y, and Z axis) for comfort, grip type, and degree of difficulty (3D-Sling; and 3D-Slider)
X-sling with Prusik hang loop allowing 3D adjustments (Gstring Classics)
An elliptical crimper that changes surface contact area as it rotates and changes angle making it harder or easier
Adjustable crimp depth through the use of shims so that difficulty can be incrementally increased as the user gains strength (Pocket Rocks)
RipCord Quick Release: a simple adjustment system for easily releasing and adjusting grip angle and position without having to take grip down from anchor (Gstring PROs)
Portable training grips that are small enough to fit in your pocket (Pocket Rocks) and allow training virtually anywhere they can be hung
Magic Pocket: a multi-use negative space (tunnel through the grip) which yields 4+ different grip types and positions depending upon it’s orientation (Pocket Rocks)
The use of finger “dimples” (indentations) to easily position hand by placing middle fingertip into a small depression. This allows one to easily and consistently place hand back to the same position on a sloper. 
An adjustable crack board (Crack Rack and forth coming DYI SqueezeBox) that will mount normal climbing holds or a medium sized hangboard and as an adjustable crack - from thin hands through OW and can vary from flared, straight, or in-cut. 
Using wooden dowels of various diameters cut on a slight diagonal to yield increasing difficulty over their length (the Continuum Board).
Half round wooden dowels on a board (gBar Hangboard) with an adjustable angle four-point suspension that allows the user to change the finger contact area. This allows it to range from positive to slopey/crimpy (depending upon size of the dowel). This also yields a more user friend grip than a flat edge.
Pockets and edges diagonally cut into a surface (curved or flat) to yield different grip depths by flipping/rotating the grip (Pocket Rocks)
Knot pocket - a place to hid and secure the knotted ends of the cord which makes it aesthetic instead of having unsightly knots exposed on the sling. (Pocket Rocks and Gstrings)
Foldable and adjustable doorway hanging mount for grips or a hangboard mount (Gstring Gallows)
Gstring Development
We’ve been experimenting with ideas based on a logarithmic spiral shaped grip and a four point adjustable sling arrangement since the mid-90s. The goal has always been a versatile training product for climbers that offers as many grip positions as possible, but in a small form factor. A couple different ideas/versions were even shopped around to several well-known companies but never resulted in a commercial product for climbers. Here’s some of that process shown through photos, though not necessarily in chronological order.


Final prototype
After finalizing the adjustable four-point sling and significant testing of the last prototype above, we felt like we were close enough to what we envisioned for a marketable product that we decided to go ahead with a final pre-production version using the target material - aluminum. By moving to aluminum we were able to create the exact size and shape since there were no material constraints like there were with some of the other materials. A final modification included the elliptical crimper which can be changed from easy to hard just by its orientation. 
Two climbing friends, Brian and Alex, provided the expertise we needed to create the aluminum prototype. Brian is a mechanical engineer who took my notes and rough computer drawings and put them into SolidWorks CAD software and turned it into a virtual model. He used the virtual model for testing to make sure the Gstrings would be strong enough to endure the actual stresses that it might be subject to during use. This was followed by actual physical tests, to confirm the CAD modeling. 
Alex, a machinist and consultant in relation to all things metal, took Brian’s Sold Works specifications and input them into an EDM (Electrical Discharge Machining) to cut the actual prototype. The prototypes were cut from a 40 lb. solid block of 6061-T6 aluminum! Here are some photos from that process and the end result. The EDM machine is an incredible piece of equipment!
Production version
After stress tests and and several months of user feedback, we made final adjustments to the SolidWorks specs. This included thinning non-critical structural walls to reduce weight and over-all size slightly, and adding an ergonomic curve to the flat edge for more comfort while also making it more joint and tendon friendly. We then sent the specs to a extrusion manufacturer to machine a die and extrude 8’ lengths of the “G” tubing to be used in the production of the end product. Lastly, various jigs were created to make chopping, slicing, drilling, and various aspects of assembly more accurate and efficient.
It’s been a long but rewarding process to see this project through from a felt need, to an idea, a design, various prototypes, and finally into small scale production.
We're now in the process of applying for a patent on both spiral grips and the 4-point adjustable suspension in various forms, which have wider application than this specific product. Look for new offerings in the future!

Pocket Rocks
Our second product was developed using some of the ideas and designs proven through the Gstrings. However, we wanted a design that could be: even more portable; would be easier to mass produce (more reasonably priced); and offers a few new features (adjustable crimp depth, Magic Pocket; 1/2/3 finger pocket; finger dimples, 3D-Slider adjustment). They will replace the Gstring Classics. Gstring PROs will continue to be out top-of-the-line product, and while there’s some overlap between the two products, they each have unique features and applications. Pocket Rocks will offer the same unique 3D adjustability for comfort and angle exemplified by both models of Gstrings. However, the new 3D-Slider system is an improvement over Gstring Classics. Grip angle/orientation is changed by simply sliding the cord through one side of the grip. Grip position is held in place by the weight of the user hanging on the grips and the friction generated by the cord inside the grip and the acute cord angles..

< Original Pocket Rock prototype borrowing the adjustment system of the original Gstring Classics. Notice the optional shims to be used to reduce the crimper size in gradual increments as user gains strength.
> Final production prototype: solid Beech wood with the new simplified 3D-Slider adjustment.

A few examples of the 10+ prototypes developed to explore different sizes, subtleties of shapes, different materials and processes. From left to right: hand made laminated Poplar wood; foam master for making silicone mold for urethane; urethane grip; CAD machined rubberwood in two-halves then glued together; CAD machined solid Beech. Each prototype underwent extensive testing to determine positive features and what needed to be changed - both from end user and production perspectives. In the end, with a grip this size, everything tends to be a compromise. However, we feel confident that we have the equivalent functionality of some of the best hangboards on the market - and Pocket Rocks will do things hangboards can’t do, PLUS...it’s portable and and will be more reasonably priced! See our rationale for using wood instead of urethane here.

                 printout of CAD file from SolidWorks                               Pocket Rocks product/business card