Cube Nature Pro - changing the fork.

robtom

My 2013 cube Nature Pro came equipped with a Suntour NCX-D LO selectable suspension fork. As I only use the bike for on-road touring, I want to replace the fork with a carbon one that is disc compatible and has eyes for mudguards. There would appear to a number of such forks available, however, can anyone tell me whether the head tube on the Cube Aluminium Superlite Trekking Cross frame requires a tapered steerer tube or which specific fork type would fit it?. I have the 54 cm frame which has a stated head tube length of 140mm.

I've not done a fork change before thus any other advice or warnings of potential difficulties welcome.

bikaholic

It's unlikely to be a tapered head tube since the SR Suntour NCX-D Lo hybrid suspension forks were never offered with that steerer tube option, even on OEM models.

However, in order be 100% sure, you will need to remove the forks from the frame and take a gander.

You will need to take the following measurements:

1) Steerer tube length - the steerer tube on the replacement forks should be atleast this length;
2) Steerer tube diameter;
3) The outer diameter of the lower part of the head tube - carbon forks are commonly offered with 44mm and 50mm crown (fork shoulder) diameters for that streamlined, integrated look. Obviously, if you bought a fat crown fork for your skinny head tubed frame, then it would look wrong;
4) Axle-to-crown height - if the A2C on the replacement forks is significantly either higher or lower then the ride and steering characteristic of the bike will be adversely affected due to the altered centre of gravity of the bike.

If it's too low (lets say lower than the A2C of the Suntour fork minus the suspension travel) then steering will become very direct and there might be a risk of pedal strikes against the ground.

If it's too high then steering will feel very wallowy and you will tend to wheelie when you ride uphill.

5) Rake - if the rake (or dropout offset) is significantly lower than the Suntour's then you may experience toe overlap with the front wheel (although, a low A2C is also a contributing factor to this condition).


Mounting mudguards is best done the traditional way: by fixing to the hole under the crown and securing to the eyelets next to the dropouts.

In many cases, the mudguard stays will need to be bent in order to accommodate the bulge of the front brake caliper.

The Rookie

Bearing in mind you can get adaptors to fit a straight steerer fork into a tapered headset anyway.

You'll almost certainly need something designed for MTB's to get the right A2C, have a look at the Mosso aluminium forks, they are pretty much as light as carbon but have what you need to mount mudguards. My Mosso weigh in at 616g.

robtom

Many thanks for two very useful responses. I shall do some dismantling and measuring and bear in mind your comments on the Axle to crown height and "rake" matters. Any resulting questions, then I'll be posting some more queries.....!