What Fork Mount Adaptors do I need for my Bike?
So, you’ve decided you want to use a fork mount to transport your bike in a van or car, but how do you work out what fork mount adaptors you need for your bike?
There are a number of different fork mount brands out there, but what they pretty much all have in common is that they make use of the front fork axle to hold the bike in place.
The axle type will vary from bike to bike depending on it’s intended use (commuting, road riding, cross country, trail etc) and, most crucially the forks it has.
Now over the years, forks have evolved across all cycling disciplines so you’ll be forgiven for not knowing what axle standards are currently out there and what bikes they’re typically found on. The table below is a rough guide to the axle types most commonly in use at the moment:
| Axle type | Fastening Type | Fork Drop Out Type | Typical Bike Use |
| 5x100mm QR Spindle | Quick Release cam lever and adjuster nut | U-Shaped Drop Outs | Road Bike (Rim Brakes), Hybrid/City Bike (Rim Brakes) |
| 9x100mm QR | Quick Release cam lever and adjuster nut |
U-Shaped Drop Outs
|
Road Bike (Rim Brakes) Hybrid/City Bike (Rim Brakes) |
| 12x100mm Thru-Axle | Either Quick Release cam lever or 6mm hex head bolt | Closed Circle Drop Outs | Road Bike (Disc Brake), Gravel Bike (Disc Brake) |
| 15x100mm Thru-Axle (non-Boost) | Either Quick Release cam lever or 6mm hex head bolt | Closed Circle Drop Outs |
Mountain Bike (XC/Trail)
|
| 15x110mm Thru-Axle (Boost) | Either Quick Release cam lever or 6mm hex head bolt | Closed Circle Drop Outs (Standard or Torque Cap spot face) | Mountain Bike (XC/Trail/Enduro/All Mountain) |
| 20x110mm Thru-Axle | Either Quick Release cam lever or 6mm hex head bolt | Closed Circle Drop Outs | Jump Bike, Downhill Bike |
| 15x150mm Thru-Axle | Either Quick Release cam lever or 6mm hex head bolt | Closed Circle Drop Outs | Fat Bike |
There are a rare few fork types that sit in between the above sizes, but the above are the ones you’ll most likely come across.
If the above still leaves you scratching your head and you need to know how you measure the axle of your forks, there are a few ways to find the information you need:
You can physically measure your axle diameter and the width between the bolt head and threads, and then check the width of the fork legs by measuring the space between the dropouts, like the example below:
However, before you dash off to get the tape measure, in some instances the information on the axle type is printed on the forks themselves or you can find the axle dimensions are printed on the axle, which is handy!
In the case of the 15x110mm Boost thru-axle, what this won’t tell you is whether your forks have a standard or oversized spot face on the drop outs. To find this out, all you have to do is take a look at the inside face of lower legs of your forks. If the flat surface is only just larger than the thru-axle bolt hole then it’s a standard spot face, if it’s much larger then it’s a Torque Cap spot face
If you bought the bike brand new, you can check the bike specifications from the bike retailer or check the specification for the hub or fork manufacturer.
If you’re still not sure, the Loaded Bikes team are more than happy to help. You can get in touch using our contact form.