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Rivnut installation for hardcase battery mounting

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    Rivnut installation for hardcase battery mounting

    Let's say you want to use a hardcase battery and the pack is not going to fit within the water bottle bosses that are predrilled on the bike. What do you do?
    You need to drill out the frame with holes where you intend to mount cradle then use what are known as rivnuts. These act as both a rivet and a nut.
    Below will show you how these work, an example of installation, sources for the parts and maintenance if the rivnut ever starts coming loose.

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    While there are many styles of rivnut tools this guide will focus on the small handheld type such as sold from
    The reason for this is that this tool is practical for fitting into tight spaces. Other tools may also work though, depending on your situation.
    • Likely you want to use an aluminum m5 rivnut. Steel rivnuts will be more difficult and are not recommended with this tool, though it may work with others.
    • Remember this needs drilled as straight as possible. in theory you could use a 90" angle cordless attachment to help.
    • You want a metric drill bit so it's the best size hole. Probably m5.5 bit for an m5 rivnut.

    Quick video on what to do and not to do on a rivnut installation


    Rivnuts generally are the sort of thing where you can set it and forget it. That said, they will be more durable if you reinforce the pack to the frame as we recommend in hardcase documentation. Also if the frame cradle has space for 3 nuts this will make it more rigid and ultimately it will perform better, just make sure not to drill too close to each hole or you may overly stress the metal.

    If you do find that the nut is getting loose over time you can use the tool to tighten it back up or try the method below.

    Hi Guys

    On occasion, if you want more than 2 bolts holding your battery, or if the water bottle holes do not line up, you can install another nut.

    The tool that is required to do this task is called a Rivet Nut Gun. These can be purchased from most hardware stores

    Most local bike ships will also be able to do this installation as well if you do not have the tool
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    Step 1. Decide on what size of Rivet Nut you need. The current Rivet Nuts were M5 on my bike. These are 5mm bolts so I decided to use the same size.

    Step 2. Now you need to determine the size of the drill bit required. I decided to use a 2mm drill bit to get the hole started. The M5 Rivet Nut is 6.7mm. When reading the directions on the packing the ideal size drill bit was 0.2mm larger than the nut. I used a 7mm drill bit and the nut seems to be firm.
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    Step 3. This particular kit came with 4 sizes. You need to install the correct nose piece set and tighten firmly.

    Step 4. Now thread on the M5 Rivet Nut, This protrudes though the nose piece.

    Step 5, Push Rivet Nut into pre-drilled hole and squeeze handles firmly to compress the back side of the Rivet Nut. This will force the Rivet Nut to barrel outward and clench the frame tight.
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    Step 6. Remove the gun

    Now your installation is complete
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    Last edited by Rodney64; 05-23-2018, 04:28 PM.


      Przrząd do zrobienia


        I have used pipe clamps from Axia Alloys to mount over a dozen batteries and have found it a very secure and cosmetic mount. These clamps are used on roll cages to mount fire extinguishers and lights and come in raw, polished or painted black aluminum. They work best on round tubing but the straps are malleable enough to be used on oval tubing. Since most frame tubing has very thin walls it is best not to form the strap when mounted to the tubing but to hand form the needed curve off the tubing. If the diameter of the tubing is close, always purchase the next size larger. Then use marine grade shrink tubing to decrease the needed diameter of the strap. If the height of the battery does not allow it to be easily removed from the magnetic mount, then the two bolts that secure the mounts can be loosen and the batter rotated for ease of removal. I think this type mount looks nicer than zip ties or pipe clamps and offers a more secure mounting system than water bottle inserts.




          • ncmired
            ncmired commented
            Editing a comment
            Nice bike! A tandem with a BBSHD? How was the left side chainring cleared out around the motor - via a square taper spindle extension?
            Last edited by ncmired; 04-11-2022, 08:49 AM.

          • SilverFox
            SilverFox commented
            Editing a comment
            Thanks for the kind words. It is a new daVinci frame with a 100mm BBSHD mid drive without an extension...has only 32 test miles and is for sale. It has all the best equipment with cable-over-hydraulic disc brake on the rear and rides on 32mm tires. Mounted a 12V dc/dc converter after the 52V 21Ah battery for safety lights.