At first glance the Birdcage looks like a fairly conventional “aero” style rim, but there is more to it than that. The first clue comes from the name; birds have hollow bones to save weight whilst retaining as much strength as possible, and the Birdcage rim has a hollow bead for the same reason. The rim’s hollow bead is still big and chunky to help reduce the chances of pinch puncturing or flat spotting the rim, but by creating a tiny hollow cavity inside it, we were able to to keep the weight down and make the Birdcage GSport's lightest rim available.
The next innovation was to adapt our cross-lacing design to the narrow inner wall of the rim. We managed to squeeze a few extra millimeters of spoke offset out of the design to help increase lateral wheel strength, and by carefully tailoring the rim’s cross-section we managed to match all the angles to the nipple so that the walls of the rim section act like the ribs inside the Ribcage rim, which helps to support the spoke nipples as much as possible.
Re‑designed Valve Core
Traditionally, the greatest flaw in “aero” rims has been the valve hole. “Aero” rims position a lot of very efficiently utilized mass in the base of the rim to support the spokes and give the rim good strength, then a huge hole is drilled through it for the valve stem and a massive weak-spot is created. With the Birdcage, we’ve offset the valve hole so that this section can retain its strength. A handy side-effect of this is that fitting a pump is now more convenient.
Easy tire installation and brake pad compatible
Aside from these original features, we spent a lot of time “sweating the small stuff”. We’ve ensured that the deep center allows for easy tire removal and fitting, and we’ve made sure that the sidewalls, while slimmed down, are still suitable for brake use.
Most high tech rim to date
The end result is one of our most high tech rims to date. With a weight of just 440g (15.5oz) it outperforms most rims weighing 20-30% more, and the weight saving from the rotational mass of the wheel feels fantastic.
Technical SpecificationsSizes: 20" only
Drillings: 36 hole
Weight: 440g / 15.5oz
U.S. Patent 7,427,112
You may return most new, unopened items within 30 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the 'Complete Orders' link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
We can ship to virtually any address in the world. Note that there are restrictions on some products, and some products cannot be shipped to international destinations.
When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.
Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.