No top cap.

[rovers69]

Hi, I have been riding a road bike for a couple of thousand miles, though I have never had a 'top cap' in the fork steerer tube.
I am not very technical and have assumed that I am safe because the bar stem is attached to the tube using a couple of Allen key bolts.

In the absence of a top cap am I safe to carry on riding?

There isn't any play in the head.

[Vaya]

It would be fine until you loosen the stem - then when you resemble it you will not be able to remove the play from the bearings.

Personally I would rather have one.

Are the forks carbon or alloy?

[Brucey]

...Personally I would rather have one....

...me too. Quite apart from anything else, without a top cap of any kind, the edges of the parts might be 'a bit gougy' in the event of a prang.

cheers

[meic]

A selection here, though at £3-4 (p&p is free) more expensive than I thought, probably better to visit a local bike shop.

http://www.chainreactioncycles.com/head ... t=pricelow

1&1/8" is more common than 1"

[Valbrona]

Are the forks carbon or alloy?

I think the inference here being that if the steerer is metal you can do the bolts up really tight so that the stem will not move, but do them up that tight with a carbon steerer runs the risk of damaging it - damage that might not be apparent.

[cycleruk]

The top cap has no bearing on the headset assembly once the stem bolts are tightened. Leaving it off will let water down the stem and possibly make the "star nut" rusty. Water should run out of the bottom of the steerer but maybe not if it's of the "expanding stem cap" version.
It will be much easier to set the headset bearing pressure with a cap in place before clamping the stem bolts.
What is important is, If for some reason the stem comes loose, then the cap will help retain the fork in position.

[Audax67]

If your stem gets knocked out of true you'll need to loosen the assembly to true it up again. When you do, it'll be practically impossible not to have a little play in the fork afterwards. Without the cap you'll not be able to take it up very easily.

For all the things cost, best fit one and ride easy.

[Squeezebox]

http://youtu.be/ykRZbOb1c5c

Kind of says it all

[iandriver]

Top caps are cheap, or go all arty http://www.kapz.co.uk/kapz---custom---s ... -765-p.asp