Forks tube slightly too short - is it safe?

scrumpydave

I've just finished building up a frame for my mrs. Very pleased with the results.

One slight problem - forks tube length is a smidgin too short. I measured it up and thought it would be just OK but the ring that sits at the bottom (just above where the forks split) won't quite go all the way down. This doesn't seem to be a problem but I've lost some length at the top.

With the stem on there is around 1cm of space between the top cap and the fork tube. This means only one of the stem nuts is really binding and the other is not. The forks feel very secure, but I'm worried about the nut which is not gripping anything.

Should I be worried, and if so is there anything I can do about it?

nicklouse

the crown race HAS to seat on the crown if it is not you have not fitted it correctly.

if it is not a split race it is an interferance fit.

re the stem the steerer has to be above the top clamping bolt or things will come lose.

benpinnick

As per nicklouse - I would recommend finding a headset with a shorter stack height (and maybe stem too if thats still not enough), and making sure the crown race is all the way down - you CANNOT run it with a gap at the bottom! The most you can normally get away with is about 5mm at the top.

Not cheap - but this is a short a headset as you will find: http://www.chainreactioncycles.com/Mode ... elID=24984 (for a 1 1/8 standard steerer). You might find if the stem is tall that a replacement stem will be better. If you measure the stack height on the headset and also the stem height, we can figure it out from there. What bike is it going on? What type of headset does it have? If its semi-integrated with a tall top half you can save another 20mm or so.

The Rookie

Top race on crown, crown race on top?

Simon

scrumpydave

Thanks for the replies. I was under the impression that the crown race (that is what it's called isn't it?) should go all the way down but it definitely doesn't. The tube seems to get a little fatter as it gets towards the bottom. I assumed this was deliberate to ensure a tight fit. All the banging I could muster wouldn't get it any further down anyway - and it's definitely not on crooked.

Looks like a trip to the LBS to get it checked over. If I can get the crown race down all the way the problem at the stem end should go away.

nicklouse

here is a crown race being fitted with the correct tool.


when fitted it will be flush with the crown.

read the info on Parktools and book mark it.

The Rookie

As per my previous post, check you haven't used the top centreing ring as the crown race, they can sometimes look very similar.

Simon

mrmonkfinger

Sometimes the fork will need "attention" to ensure the crown race fits correctly. But they are always a very tight fit. And they must always go right down and leave no gap.

If you have a gap, its best to take the bike to a shop where they will have the correct tools to sort it.

scrumpydave

Thanks all. Definitely trip to the shop required.

Sorry Simon - I see what you were getting at now! Shouldn't be the wrong way round unless the headset was packed that way. Put it on in the order it came out of the box.

The Rookie

Depends if it was upside down in the box!

Simon