Due to rising production costs, I’ve increased the price of the SS kits by $2. Thank you for your understanding and patience! 

P.S. Messaging me asking when they will ship will not make things go any faster. 

If you are outside the USA and unable to purchase, (this link works fine for most countries but there have been issues with Denmark and possibly others)  there is another link that should work. you can find it in my other listings or search for "Upgrade Parts Kit for REP X PEPIN Dumbbells Spring Pins & Weight adj Pins ALT"

Parts are available in the following configurations so be sure to select the correct option:

1-Stainless Steel Finish

2- Black Finish

3- Nickel Finish

ALL Options come with SS Screws

Disclaimer:

The seller of this adjustable dumbbell parts kit is not affiliated with Rep Fitness, and these parts are not manufactured by Rep Fitness. This kit is custom-designed to fit Rep X Pepin Fast Series dumbbells, based on OEM parts, and has been tested for months with no issues. However, as a DIY product, installation is at your own risk. The seller is not liable for damage to dumbbells, property, or personal injury during or after installation.  If you are not confident in your ability to successfully complete the install, please have someone with more experience help you out. By purchasing, you agree to these terms.

This listing is for a parts kit to improve the functionality of the Rep X Pepin FAST series adjustable dumbbell sets (unfortunately will NOT work with the OG Pepin adjustable dumbbells since the parts are a bit different). 

You will receive modified knurled knob spring pins for the adder plates as well as modified low profile pop pin nuts and shorter bolts to go with the modified low profile nuts. The low profile weight slider adjustment parts will take approximately 5mm off each side to give a total of 10 mm extra clearance for your hand while gripping the dumbbell handle.

There are 3 options available, stainless steel, black finish, and nickel finish. Be sure to select the correct color.  I think all colors look great but the black is not a perfect match to the existing black on the dumbbells.  If this is an issue then you may want to go with stainless steel or nickel (nickel will be the closest match for the dumbbell handles).

SPRING PIN INFO

These stainless steel spring pins with knurled knobs are designed to be replacements for the new Rep X Pepin adjustable dumbbells and perfectly match the stainless steel knurled dumbbell handles. These have been custom machined specifically for this purpose. I'm not a fan of the key ring style pins and really love the look and added functionality of this alternative style. These pins also have the added function of being able to lock in place to remove the adder weights which helps lessen the risk of scratching dumbbell plates with the pin during installation and removal.

SPRING PIN INSTALLATION:

YouTube Installation Video Link: https://youtu.be/es3YO6CxmWw?si=meVIWSLcjwCENt5K

Or Search YouTube for: Upgrade Parts Kit Installation Instructions for Rep X Pepin Fast Series Dumbbells

You have two options for installing the spring pins. Test both methods without Loctite to determine which you prefer. Once decided, apply Loctite to secure the pins permanently.

OPTION 1: Flush Thread Installation (My preferred way)  Maximizes stability and hand clearance.

How: Thread the spring pin into the adder weight until the threads are flush with the adder weight surface.  

Benefits: Allows deeper pin engagement with the adder plate and provides slightly more hand clearance when gripping the dumbbell handle.  

Usage: Push each knurled knob inward each time you attach the adder weight to ensure full pin engagement. After a break-in period (generally a few weeks depending on usage frequency), the pin should slide into place easier. 

Always check for full pin engagement before use. 

Tip: 

OPTION 2: Recessed Thread Installation - slightly easier to remove adder weights

How: Thread the spring pin until the threads are 1mm below the adder weight surface.  

Benefits: Makes the knurled knob slightly easier to pull (more space to get your fingers under the knob) when removing adder plates. 

Always check for full pin engagement before use.

Tools Needed:

• 8mm wrench (or small adjustable wrench)

• Painters tape (optional, for surface protection)

• Purple (removable) Loctite (Blue/Red optional)

• Pliers, nail, small Phillips screwdriver, hammer, or screw extractor (for removal, if needed)

Steps:

1. Remove Original Spring Pin: Use an 8mm wrench to unscrew the existing spring pin. Apply painters tape to the 2.5 lb adder plate to prevent scratching the finish.

2. Install New Spring Pin: Apply a very tiny amount of Loctite (I use Purple Loctite. Blue/Red can be used but will be harder to remove if ever needed) to the new spring pin’s threads making sure it doesn't get anywhere except the threads. If Loctite gets into the moving parts of the spring pins it could make the unusable. Screw it into the adder plate until flush with the surface.

3. Finish: Wipe off excess Loctite if any got on the adder plates. Let cure per instructions (typically 24 hours).

WEIGHT ADJUSTMENT POP PIN PARTS INFO

Custom modified low profile pop pin nuts and shorter bolts to go with the modified low profile nuts. This will take approximately 4.2 mm off each side to give a total of 8.4 mm extra clearance for your hand while gripping the dumbbell handle.

WEIGHT ADJUSTMENT SLIDER POP PIN PARTS INSTALLATION:

Tools Needed:

• 8mm wrench (or small adjustable wrench)

• 4mm Allen wrench

• Purple (removable) Loctite (Blue/Red optional)

Steps:

1. Remove Original Parts: Use an 8mm wrench and 4mm Allen wrench to remove the original screw and nut (some force may be needed due to OEM thread locker).

2. Install New Parts: Apply Purple Loctite to the shorter screw’s threads (Blue/Red optional but stronger). Replace the original screw with the new screw and nut from the kit.

3. Tighten: Secure with the 8mm wrench and 4mm Allen wrench. The lower-profile nut may limit wrench access—tighten carefully.

4. Finish: Let Loctite cure per instructions (typically 24 hours).

Please message with any questions.