Hi-Rise 50mm Towball - 25mm Shank
Hi-Rise 50mm Towball - 25mm Shank
50mm ISO-profile towball for Thule bike racks
This hi-rise 50mm towball is designed for compatible Thule towball-mounted bike racks, including models from the Epos, EasyFold and VeloSpace ranges.
- Shank diameter: 25mm (1 inch)
- Ball diameter: 50mm
- Profile: ISO 1103 compliant
- Key feature: Flat section beneath the ball radius for suitable clamp clearance
Measure your existing towball shank or the mounting hole in your towbar tongue before ordering. Also confirm the towbar tongue thickness, available thread length and load rating.
Important fitment check
Check your towbar before ordering
This is a 50mm ISO-profile towball designed for compatible Thule towball-mounted bike racks.
The key feature is the distinct flat section underneath the ball radius, immediately before the neck begins. This shape gives the Thule rack clamp the clearance it needs to seat and lock correctly.
This model has a 22mm shank. Measure the thread diameter of your existing towball, or the mounting-hole diameter in your towbar tongue, before ordering.
How to identify an ISO-profile towball
Look underneath the 50mm ball where it meets the neck.
A suitable ISO-profile towball has a visible flat section at the bottom of the ball radius before the narrower neck begins.
If the underside curves continuously into the neck, the Thule clamping mechanism may not have enough room to seat or lock correctly.
Ball diameter alone is not enough. The profile and available clearance matter too.
Hi-Rise 50mm Towball - 25mm Shank
Frequently asked questions
Why does a Thule bike rack need an ISO-profile towball?
Thule towball-mounted racks clamp around the towball and need the correct shape and clearance underneath it. An ISO-profile towball has a distinct flat section at the bottom of the ball radius before the neck begins. This allows the rack clamp to seat and lock correctly.
How can I identify the correct towball profile?
Look underneath the ball where the rounded section transitions into the neck. There should be a visible flat section before the narrower neck begins.
If the ball curves continuously into the neck with no flat area, it may not provide enough clearance for the Thule clamping mechanism.
Does any 50mm towball work with a Thule bike rack?
No. A 50mm diameter does not automatically make a towball suitable. It must also have the correct ISO profile, including the flat section under the ball radius, and enough neck clearance for the rack clamp.
How do I choose the correct shank diameter?
Measure the mounting hole in your towbar tongue. The towball shank should closely match that hole diameter. These towballs are available with 19mm, 22mm and 25mm shanks.
Also check the towbar tongue thickness and confirm there is enough threaded shank for the washer and nut to be fitted correctly.
Will this towball fit every towbar tongue?
No. Fitment depends on the mounting-hole diameter, tongue thickness, available clearance, shank length and the rating of the towbar and towball. Confirm those measurements before ordering.
Which Thule racks commonly require this towball profile?
ISO-profile 50mm towballs are commonly required for Thule towball-mounted racks such as the Epos, EasyFold and VeloSpace ranges. Always check the fitting requirements for the exact rack model.
Do I need to check the towball download rating?
Yes. The vehicle, towbar, towball and towbar tongue must all be suitable for the combined vertical load of the bike rack and bikes. This is particularly important when carrying heavier e-bikes.
Can I install the towball myself?
Bolt-on towballs can be straightforward to replace, but the correct mounting hardware, washer arrangement, orientation and torque setting must be used. Have the installation completed or checked by a qualified towbar specialist if you are uncertain.
What should I send Stoke if I am unsure?
Send us a clear side-on photo of the towball and towbar tongue, along with the mounting-hole diameter and tongue thickness. We can help narrow down the most suitable option before you order.
