

GT
Stomper Ace 20 Description
Weight:
Gender: Kids
Model Code: G54401U10
Brake Type: V-Brake
Frame Material: Aluminium
Includes Pedals: Yes
Learning to ride a bike is memorable, but it isn’t always easy. Kids have to focus on balance, pedalling, and speed... all while trying not to tumble. Up until now, kids’ bikes have basically been grown-up bikes miniaturized for smaller bodies. Designing bikes this way means proper body positioning and pedalling mechanics are compromised. Not Anymore.
LegitFit System
GT has developed the Stomper range to utilize its LegitFit system which is designed specifically for those growing shredders. The LegitFit system enables GT to build kids’ bikes that have narrower cranks, proper gearing and improved body positioning. All with the benefits of optimizing pedalling, balance, and speed right from the start. Even better is that it’s a system that works for kids of all ages... no more needing to “grow into” a bike.
Improved Geometry
GT bikes with the LegitFit system feature geometry adjustments to improve ergonomics for youth statures.
The Result: Increased stability, comfort and confidence for a wider range of riders.
Easier Pedalling
GT bikes with the LegitFit system have their pedal positions moved slightly forward.
The Result: Makes it easier to pedal.
Better Positioning
GT bikes with the LegitFit system have narrower crank and pedal positions that match the width of a child’s hips.
The Result: A stronger, more natural pedal stroke.
Easier Starting
GT bikes with the LegitFit system have fast-start gearing that also reduces top-speed.
The Result: Kids can start quicker while maintaining control and speed.
Stomper Ace 20 Specifications
Fork: GT Hi-Ten Steel
Shock: N/A
Rims: All Terra Double Wall
Hubs: Alloy, QR
Tyres: Kenda Small Block Eight, 20 x 2.10”
Seatpost: Alloy Micro Adjust
Bars: Alloy Riser Bar
Front Mech: N/A
Rear Mech: Shimano Tourney
Cassette: Shimano TZ500, 14-28
Chainset: Prowheel w/ Double Guard, 30T
Brakes: GT V-Brake
Saddle: GT MTB
Stem: Alloy Ahead
Model specifications correct at time of entry based on provided data, whilst we do our best to maintain an accurate specification it is possible that GT might have changed these specifications without notifying us as component shortages arrise.
Stomper Ace 20 Size Guide
Frame Size | Rider Height | |
---|---|---|
20" | 115 - 135cm | 3'9" - 4'5" |
24" | 130 - 145cm | 4'3" - 4'9" |
26" | 154 - 160cm | 5'1" - 5'3" |
Sizing information provided as approximate reference.
Customer Reviews & Questions

Frequently Asked Questions
Shipping and Returns
How much is shipping?
UK Mainland shipping bikes over £499 is free of charge, for orders under £499 we charge £29.95 for standard shipping.
We use DPD when shipping all our convensional bikes (i.e. not electric bikes) on an overnight service which includes full tracking and an hours timed delivery slot.
For further information please see our Shipping Policy.
When will you ship my order?
Orders placed before 12:00 on buisness days are usually shipped that same day.
Before we can ship your new bike, it needs to go into our workshop to be PDI'd (Pre-Delivery Inspected), during this inspection our mechanics will check everything is setup and ready to go - this can take a little time so on busy days or during sale periods it might take a day longer to process.
For further information please see our Shipping Policy.
How do I return an item?
If you need to return an item to us you can do so with 30 days of recieiving the item.
Simply follow the instructions on the paperwork enclosed with your order or visit our Returns Page for further information.
Returns are subject to our Refund Policy.
Is this bike in stock?
We only make available for sale products we have in stock, we do not remote warehouse products from suppliers as other stores do.
Our inventory is live except for bikes which are subject to up to a 24hr delay as our retail stores' inventory system is a bit archaic and requires a manual sync.
Have another question?
We have a Frequently Asked Questions page which also highlights our contact information should you need to contact us.
You can also contact us via Live Chat during normal office hours - the button is usually located in the bottom right of your screen.
- Choosing a selection results in a full page refresh.