Thursday, September 21, 2006

18" BIRDY WHEELS ON Y-FRAME?
Is it possible to use the 18" Birdy wheels on a Y-Frame bicycle trailer?


This is trickier than it sounds, but it is possible.
The Birdy rim is 24 hole, while the Y-Frame rim is 20 hole, so it is not possible to simply lace a birdy rim to a Carry Freedom hub. The Birdy front axle is 10mm, while the Y-Frame is 12mm, so it is not possible to use a complete Birdy wheel on a Y-Frame axle. Getting hold of undrilled 18"rims is tricky and I haven't come across 20 hole drillings on the 18" rims. I also suspect it is a fiddle to get 20 hole hubs with bearings with a 12mm center hole.

Therefore the most practical way to do this is to buy complete Birdy front wheels, and then fit these with bearings with an inside diameter of 12mm. You would need to check with R&M about buying two complete front wheels, and we can source suitable bearings. At a guess the bearings would cost between 5-10GBP/unit, so a total of 20-40GBP.

I own a Birdy and use my Y-Frame with it. I do not find the differing rim sizes too much of an issue with my Birdy/Y-Frame. The tyres I use on my trailer is Schwalbe big apples, whereas I use Schwalbe Stelvios on my Birdy. The big apples are good for load bearing unsuspended vehicles like my trailer, while the stelvios are ideal for suspended fast bikes, like my Birdy. The trailer would bounce all over the place with stelvios, and big apples are heavy for a suspended Birdy, and their max pressure is too low for me. So even if the rim sizes were the same, I would not run the same tyre on bike and trailer unless really really desperate.

2 Comments:

Blogger Erik Decker said...

For my recumbent trike I bought som birdy wheels with a 12mm bolt hole in the bearings from pedalkraft.de

2:05 pm  
Blogger sri said...

The trailer needs to have a cover to keep out the sun and rain. Bike Trailer

4:18 pm  

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