Headset gap to fork top.... too much?

martin_brown

First off sorry for the long winded post,but i hope i can explain my potential problem clearly enough.......

Im looking for reasurance that everything is ok,or that there is a problem really...... just ftted my Marzocchi sport forks to my frame which has an semi intergrated or internal headet,i have a fsa orbit z headset which is the same dimensions as the wtb inner peace headset that came wth the frame,the headset comes with a gold coloured split lower race that slides down the steere tube to the base,and the lower sealed bearing sits on this..... when the headset is not on the bike this lower race fits inside the lower bearing snugly and i think how it should be,but when sliding it down the steerer tube it sits on a wider section right at the base and as its a split design it flares out to go over the wider section and sits right at the base of the tube,so far so good,but as the ring has flared out the bearing no longer sits all the way down over this ring,and i have a gap between the head tube and the fork top,i realise that there has to be a gap of some sorts as the forks would not turn if the headtube was sitting against the forks,but is this gap too large for some reason?.... bearings have preloaded fine and it seems ok,just looks too large a gap to me,any one care to comment..... first internal bearing set up ive had .

Splasher

I see what you mean. The crown race certainly has to go all the way to the bottom of the steerer and onto the fatter part which will flare it out slightly.

Have you got the lower bearing in the right way around? That is with the internal chamfer facing down.

martin_brown

Got me all paranoid then ,so went and rechecked and yes the lower bearing inner chamfer is facing down,to match up with the chamfer on the crown race,tried both bearings top and bottom to see any variation in size and both are the same,just seems that the inner race of the lower bearing will not sit over the crown race fully...... these should be a nice smooth fit right\? should not need to be press onto the crown race should it?....... other option being the steerer tube is too big and flaring out the crown race slightly too much,therfore making it too big for the bearing to fit on........ anyone else care to venture an opinion or has had the same experience before?

Thanks for the reply

martin_brown

Anyone ever had to sand their steerer tube down to get the crown race to fit correctly? thats the only thing i can think of at the moment,steerer tube slightly too thick cusing the crown race to flare out too much so that the bearing will not seat fully down......

Splasher

No definitely never had to do that, and given that it is a machined part that is pressed into your crown, if it were the wrong size, it would have shown up during manufacture. This is the drawing for the Orbit Z. It probably isn't current, but it's the only one I have.



It shows, as you would expect, full engagement of the crown race with the bearing and a gap of 0.6mm

My next guess would be that you have the two races (top and bottom) the wrong way around. The top race is a smaller diameter than the lower since it isn't designed for use on the bulge but on the normal steerer. Swap the two split races around and assemble like the drawing and you could be OK.

martin_brown

Only have one split race,the gold coloured one shown in the pic,this sits on the steerer,then the bearing,cup,top cup,bearing solid ring spacer then top cap....... doubt the solid ring spacer that does the same job as the split crown for the top bearing will fit on the steerer tube.....

Splasher

Is the solid ring spacer (as you call it) silver and is it slightly bigger than the steerer tube?

Yahoobedoo

Shouldn't really step in here as I'm not technical at all but I've just had an FSA Orbit XLII fitted for me and it had a gold split ring at the top (I think it was called a compression ring) and the crown race, although supposedly split, actually wasn't and was just a solid ring possibly like you describe.

Here's a picture of mine:



and a picture of an FSA 1.5" headset:



both show the gold ring at the top. I know yours is a1 1/8 internal but it might be the same?

Splasher

I've had a few FSA headsets, and the top ring is always split and gold, the bottom has always been silver and some have been split, some not. The other way to tell, is the top ring (part 4) is much deeper than the bottom (part 7) (see parts drawing above).

Richard, I posted you some advice on your crown races, did you see it? It's a bugger of a job so take care.

martin_brown

Splasher wrote:

Is the solid ring spacer (as you call it) silver and is it slightly bigger than the steerer tube?

Yes its silver and fits over the steerer tube quite loose...... seems from your post and the following one they might indeed be the wrong way round,i assumed maybe wrongly that the split ring was the lower crown race as the forks that came with the bike,and the wtb headset had a gold split race as the crown race on the steerer tube base..... will have to try later today to see if the solid ring will take the place of the split ring and i have it the wrong way round.

Just looked at the parts of the wtb headset and there are two split rings with that,so plenty of oppotunity for confusion it seems for me anyways..... thanks for the replies guys,hopefully you have cracked it

Yahoobedoo

Splasher wrote:

........

Richard, I posted you some advice on your crown races, did you see it?

No hadn't seen it, you must have posted whilst I was composing my last post and then I went to bed!

Splasher wrote:

........

It's a bugger of a job so take care.

LOL, not what I was hoping to hear.

Cheers.

Splasher

martin_brown wrote:

....will have to try later today to see if the solid ring will take the place of the split ring and i have it the wrong way round.

I'm almost sure they are the wrong way round and that's why the split ring is flaring too much to fit into the bearing (because it has a smaller inner diameter designed for the top of the steerer).

However, if that's correct, it means you have a solid crown race which needs carefully drifting into place (i.e. it's a slight interference fit) so be careful.

joe boy

my orbit looks like this.

martin_brown

Well guys guess what?........ you are spot on and im a muppet :roll: swapped the races over and everything is as it should have been in the first p;ace,thanks for the pointers, glad there are those around with more knowledge than me ,bikes almost done now,heres a couple of pics

Splasher

We aim to please.