Forum menu
Hi,
I have bought a new fork (Rock Shox TK Coil, 100mm) from Merlin to replace my wife's 5 year old, slightly rusty RST fork on her rockhopper. Hopefully this will be an improvement - the current ones don't tend to move up and down that much!
Have gradually upgraded the bike over time (with new gears, disc brakes and a 2nd hand set of Mavic 717 wheels). I have not changed anything fork related before, apart from removing my own fork for service needs, so need to check the following:
steerer tubes - how much is usually required to be hacked off? Can you just fill up with spacers, or is this just lazy?
star nut - presumably a new one needs to be ordered to fit the fork - are hope head doctors worth while?
IS/Post brake mounts - do the new fangled post mounts work with brakes currently using IS adaptors? The current set have an adaptor that looks like it has two bolts lined up for Post mounts, so I was hoping to bin the current adaptor and simply be able to fit the Post Mount adaptor for the right size (they are 180mm disc Shimano M485 I think).
Steerer tube length is very important to get correct. Luckily you have an existing fork, so you could measure the length of the steerer on that, and cut the new one to match if you wife is happy with the fit. If she wants the bars to sit higher/lower you can add/remove a bit more to suit. Be careful though, one you've cut it down, there's no going back 😉
Star nut - you should get one included with the fork. If not a LBS will supply for a couple of quid. If you don't have a star nut installer, I'd advise getting the LBS to fit it for you. Some people ghetto fit them, but in my experience, if they don't go in straight they can put uneven pressure on the top bearings and you'll wear though them quicker.
Post mounts - you'll still need adaptors to fit your brake disc size. I think by default they fit 160mm with no adaptors (not 100% sure on this), but if you run bigger, then you'll need to use an adaptor to sit the caliper further out. If your fork has post mounts, you'll obviously need post mount compatible adaptors, and vice versa for IS mount.