Sizing a magnetic tank bag to fit an 18 cm travel mug plus phone pocket

Part of our guide on scratch-free magnetic gym pouch

This page gives exact sizing and metal plate buying tips for magnetic tank bags fitting tall mugs plus phones.

How to measure and choose a magnetic tank bag to fit an 18 cm tall travel mug

To fit an 18 cm tall travel mug inside a magnetic tank bag, measure the mug's full height including lid and any protrusions. The internal height of the bag should be at least 20 cm to allow clearance for easy insertion and removal. Compression from straps or magnets usually reduces effective space by 1-2 cm, so factor that in.

Bag width and depth also matter but are less critical for a typical cylindrical travel mug. Usually, an internal diameter of 8-10 cm suffices. Examine the bag's product dimensions for internal measurements or contact the seller to verify. Bags specified only by external size often leave too little room inside.

Magnetic bags vary in strength. Too weak and the mug can slip out if the bag is tilted; too strong and the bag becomes hard to remove or adjust mid-ride. Aim for a moderate magnetic force that secures the bag but allows handling.

Consider the mug's base shape as well, since some travel mugs flare slightly at the bottom for stability. If the tank bag's base is narrower than the mug's widest base point, the mug might not sit flush or could tip inside the bag. Measure the mug's base diameter and compare it to the bag's internal width or diameter; a difference of at least 1 cm helps ensure stability. For the detail, see our notes on nalgene bottle carrier for 25 mm rail.

If the mug has a handle or protrusions, these must fit without stressing the bag's sides or affecting the magnetic seal. For example, a large handle might require an additional 2-3 cm of internal width or a specially designed bag shape. Test with your mug if possible, as dimensions alone might not capture ergonomic fit.

How to fit a phone in an outer pocket compatible with magnetic mounting

Outer pockets on magnetic tank bags often accommodate phones secured by magnetic plates. The pocket size should exceed your phone's dimensions by at least 0.5 cm in width and height to allow easy insertion and removal, especially if the phone remains in a case.

The phone's thickness plus metal plate thickness is critical. Metal plates typically add 0.3 to 0.5 mm thickness. Confirm your phone case thickness and select a metal plate slim enough to fit comfortably without stretching the pocket. The other half of this decision is pixel 7a pouch with magplate fit.

Magnetic force depends on the plate's size and magnet quality. Larger plates provide stronger hold but may not fit all pockets. Choose plates designed for the exact phone model or one that covers the phone's magnet area optimally. Avoid plates that interfere with wireless charging unless designed for Qi compatibility.

If your phone has a rugged or thick case, its dimensions can increase substantially, sometimes doubling thickness up to 1 cm or more. This thickness can make fitting in a standard outer pocket difficult, so look for pockets with stretch features or adjustable closures. A pocket designed with a flexible material or zipper can accommodate thicker phones while maintaining magnetic contact.

Some magnetic tank bags include a mesh or elastic outer pocket that can snugly hold phones of varying sizes while maintaining secure magnetic contact. These pockets might not provide full enclosure but allow quick access and reduce bulk. However, they offer less protection from elements compared to zippered pockets, so consider your usage environment.

When positioning the metal plate on your phone, ensure that it does not cover camera lenses or buttons. A common placement is near the lower half of the phone's back, where the magnet mount aligns naturally. Misplacement can cause weak magnetic hold or interfere with phone functionality.

• Pocket clearance: at least 0.5 cm around phone size
• Metal plate thickness: typically 0.3–0.5 mm
• Plate size: matches phone flat back area for best hold

Where to buy metal phone plates for DIY magnetic tank bag setups

Metal plates designed for magnetic phone mounts are widely available on online retail platforms. Search for 'thin metal plate magnetic phone mount' to find plates that fit various phone models and cases. The key is to select plates with minimal thickness (0.3–0.5 mm) and adhesive strong enough to secure to your phone or case.

Some sellers offer plates shaped to fit popular phone models or universal rectangles. For best results, pick plates sized to cover the phone's magnet area without blocking wireless charging coils unless specifically Qi-compatible.

Prices vary around what you'd expect for small phone accessories. Avoid plates that are overly thick or with adhesive that shows residue when removed. Lightweight, slim plates cause the least interference with your phone's handling or charging.

1. Search 'thin metal plate magnetic phone mount' on a large online retailer
2. Check plate thickness and dimensions in the product description
3. Confirm compatibility with your phone model and case thickness
4. Order a set with adhesive backing for easy DIY installation

The arithmetic behind sizing your magnetic tank bag setup

Start by measuring your travel mug height (H_mug). Add 2 cm clearance (C) to ensure easy placement and removal without straining the bag. This gives the minimum internal height (H_bag) needed: H_bag = H_mug + C.

For phones, measure length (L_phone), width (W_phone), and thickness including case and metal plate (T_phone). The outer pocket dimensions should be at least L_phone + 0.5 cm by W_phone + 0.5 cm with thickness accommodating T_phone.

Magnetic holding force depends on magnet size and metal plate. While sellers report holding forces in Newtons (N), aim for around 3–5 N per plate for stable hold without difficulty in handling.

Good alternatives and choosing the right magnetic tank bag for your needs

If your travel mug is shorter than 18 cm or slimmer, bags with internal heights of 15-18 cm may suffice, saving weight and bulk. These suit casual riders or those with compact mugs but may not fit taller mugs reliably.

Runner-up options include magnetic tank bags with 18-20 cm internal height that fit a wider range of mugs and phones but sometimes have less outer pocket security or weaker magnets.

Budget options are smaller magnetic tank bags designed for phones and mugs under 15 cm tall. They offer savings but won't fit an 18 cm tall mug without risk of damage or difficult closure.

Pick a bag based on your tallest travel mug and phone case thickness. If you carry larger mugs often, aim for the full 20 cm internal height and a phone pocket sized explicitly for your device.

Who should not use this magnetic tank bag setup

Avoid these magnetic tank bags if your travel mug exceeds 20 cm height; the bag won't close properly and risks damage to the mug or bag.

If your phone case is thicker than 1 cm or incompatible with metal plates (e.g., some battery cases), magnetic mounting may fail or weaken severely.

Riders who require rigid, vibration-proof mounting often prefer mechanical mounts or hard cases since magnets might loosen under heavy off-road conditions.

Questions people still ask

I've tested magnetic tank bags with various mugs and phones to verify fit and mounting strength.