Awaiting delivery of my new fork to fit to my current 26er frame I was thinking/wondering about my future plans of a 29er build later this year.
I note than on one do 2 fork lengths for their carbon forks (for 29 and 26 inch wheels) with a difference of 40mm in length.
In the real world, i've seen that a 29" wheel fits in their 26" fork but would I need to get a new fork when I buy a 29" frame or will I be able to use the 26er fork?

Is a just a case of the geometry being a bit off and the front a bit low/more skittish?

New frame is likely to be an On One Inbred 29er.

My own opinion would be to buy new forks. 40mm doesn't sound like much but it'll steepen your head angle by about 2 degrees, something you'll certainly notice.

However, there's no reason why the forks won't fit and function okay ... I'd be a little wary of toe overlap though.

Thanks Stu. I'll use them for the time being anyway on my 26er and then will look to replace them when I get the new frame.
On one are doing bundles again so that'll probably be the best option anyway.