Found this on their site about the Genesis Fortitude (a rigid specific 29er). Some interesting answers!

http://answers.evanscycles.com/answers/0924/product/ec033949/genesis-fortitude-adventure-2012-mountain-bike-questions-answers/questions.htm

Why? Some contradictory statements, but its not that bad.

What is the largest tyre size?

asked 6 months ago
Anonymous
on Genesis Fortitude Adventure 2012 Mountain Bike
1 answer
STAFF
20.5 inches, thanks

Eh?

Why? Some contradictory statements, but its not that bad.

Bike is designed to be rigid specific – suspension will ruin geo/handling and one staff member says 120mm forks will be ok.
When asked largest tyre size he quotes 20.5″ (presumably frame size).
Question about putting a 29er carbon fork on – replies that

Not really or you will have a 29inch wheel on the front and a 26inch on the back

and

As long as the dimensions add up then yes. They would have to be 1 and 1/8 tapered.

.

Other than that fine! 😯

Seem to get a real mix of people working in Evans. Have had some good advice but also a lot of ba advice in there over the years and the amount of totally contradictory advice has raised my eyebrows from time to time. The 1st answer to the question about the 29er forks is superb. Give the guy a medal 🙂

Some funny answers there.. reminds me of the yahoo Q&A.
Not the same site but check this out for a stupid advert (on the right)-

I don’t think the answers are checked as I’ve seen a few clangers as well, not practical to have someone checking every answer I guess. maybe ill suggest I do it and they’ll let me work from home!

Since I designed the Fortitude protos before I left Genesis and now work at Evans, I will ‘kick someone’s ass’ so-to-speak for those daft answers.. thank you.

Those answers are astonishingly wrong. Aside for the first one.

Rigid only and to that only really the manufacturers ones or maybe 26″ rigid forks as the factory fit ones are not suspension corrected and therefore are shorter.
1 1/8 steerer.
Not sure about tyre size but my guess is 2.25 or 2.3 depending on manufacturer.

ok answers –

fork – most 26″ rigid will be ok, ie 445/40mm rake. or 450/45mm will feel pretty similar. etc. No suspension, that was kind of the whole point of the bike, laid-back front and rigid-specific.
tyre – usual clearances so 2.3-2.4
1 1/8″ steerer only, less need for XX44+ taper on a short-fork rigid.

Have had some good advice but also a lot of ba advice in there over the years and the amount of totally contradictory advice has raised my eyebrows from time to time.

In their defence, take a selection of independants and you’ll probably get the same. It’s just people.