qwaalodge

I recently changed the stem on my bike. I followed every step I got from youtube. Tested the bike without a single problem. Headset bearings are just right. No binding and no play.

But there is one thing I'm missing in the youtube instructions, is it okay to increase tightness of the topcap bolt AFTER I have tightened the stem bolts?? It's a little bit lose in mine and only takes little pressure with the hex wrench to remove it.

cxwrench

If it's loose then snug it down a bit. If you go too far you'll start to pull the star nut or expander out of the steerer but that's it. This shouldn't be an issue though. When you adjust the headset the top cap should be 'snug', definitely not loose.

Camilo

Once you tighten the stem bolts, the top cap serves no purpose. You can't tighten the bearings by tightening it, and the bearings won't loosen if you loosen it. You could actually remove it without any problem. It doesn't matter if it's tight. Snug it up if it works a bit loose but no need to go overboard.

CliffordK

It shouldn't make much difference. I tend to like to relieve tension a bit.

I don't know why one would tighten unless it was being used for an accessory mount, or was rattling.

70sSanO

Tightening the top cap with the stem bolts loose applies pre-load to the headset bearings. After you tighten the stem bolts, the top cap should be snug.

Since the top cap bolt is threaded onto the star nut (or expander), if you continue to tighten it, the stem isn’t going anywhere, but the star nut or expander can be pulled out if you just keep turning and tightening.

The first rule I was taught was to never try to tighten a threadless headset unless I made sure the stem bolts were loosened.

I once had a steel steerer tube that got wet and some surface rust formed on it that I didn’t see. I loosened the stem bolts to add more pre-load, but I just couldn’t set the pre-load. Eventually the star nut was at the top of the steerer tube. I should have realized the threads were going somewhere… lol!

John

qwaalodge

Thanks! I'll tighten it a bit and avoid pulling the start nut out!

cxwrench

Ok! You do that!

RiceAWay

The job of the cap bolt is to tighten the stem down so that there is no play in the headset. After you accomplish that and there is no for or aft play in the fork by putting the brakes on and wiggling the fork back and forth with no detectable play or sound, the stem is tightened, tested again and then the top cap becomes of no use,. it could pull out a little if the fork lock isn't installed properly but not if the stem has been properly tightened.

So after tightening the headset and the stem you normally just snug the top cap down so that it doesn't rattle. I use mine to install a Garmin mount under the top cap. https://content.backcountry.com/image...KEG000A/BK.jpg

icemilkcoffee 

Provided that your stem sits slightly below the top of the steerer tube, you can definitely remove the top cap and star nut after tightening the stem. I did that on quite a few of my kids' bikes with no ill effects.

qwaalodge

It does and that's good to know!