I have a specialised crosstrail elite disc and wanted to fit some rigid forks so I bought some 29" forks which are adjusted in height to compensate for shock forks.
All good I thought until they arrived and unpacked them. The part where the stem meets forks is very small in diameter compared to the stock fork head and looks like they won't fit?! Here is a link to the forks and would really appreciate if someone could tell me if they will fit before I send them back.
CHARGE 29ER RIGID MOUNTAIN BIKE MTB FORK. DISC MOUNT. TANGE INFINITY. NEW. BLACK | eBay

How did you cross reference that fork to your bike?

The listing says 1 1/8",that's what your stock fork is. Note,the steerer tube doesn't slide directly into the frame's headtube,it threads through the headset.

Measure the steering tube, if it is 1 & 1/8" you are golden.

If you are concerned about the fork crown which looks narrower than the crown on a suspension fork, that isn't an issue, since the only thing that needs to touch anything is the crown race, which is just a small ring to fit the headset bearings at the base of the steering tube.

Thanks guys. Yes it's a 1 1/8 stem, that is one thing I checked along with the length of stem which I need to cut down. They should fit then which is a releif!

What year is your Crosstrail? If it's a 2013/14 it has a 60mm travel Suntour fork; that fork should have an unsagged axle-crown measurement of around 460mm. The rigid fork you've purchased is a 29er fork corrected for a 100mm travel suspension fork; it has an axle-crown measurement of 511mm.

That's a significant difference, and will seriously change the geometry of your bike by jacking up the front end. You might want to check that comparative measurement, even if your Crosstrail is slightly older.

+1)No Idea about what the appropriate Crown race seat to axle center ,

ie, blade length of the fork the frame designers made the steering geometry design around..