Pir0

Hi, I've got an old trek 400 road bike. The forks seem to jutter a whole lot, move backwards and forwards on bumps and are generally uncomfortable, I tightened the large nut around the stem at the top of the headtube, but that made the steering really stiff, and also made the forks seemmore.. a part of the bike, ie, no more juttering.

I seem to be stuck between 2 un-desirable effects.. Either my forks are free and smooth to rotate, but really juttery, or i tighten the nut and remove the jutter but my steering gets really stiff.

What would be causing this? Is it a bearing problem?

HillRider

The headset needs to be disassembled for cleaning and inspection to see if there are any broken parts, damaged balls or dried out lube. Is it still the original headset and has it ever been maintained?

Once it is known to be in good mechanical shape, you have to adjust it properly. and adjusting a loose ball headset is not just tight or loose. There is a very narrow range of adjustment where there is no play but it's not tight.

Soil_Sampler

could be indexed/brinnelled headset.

Pir0

I've just bought the bike, I honestly don't think it has been maintained as it was only ever used in winter.

The bolt that goes from the top of the stem into the steerer appears to be quite seized. I intend on upgrading the forks at some point so this is necessary anyway. How would you recommend going about dismantling the headset? Especially with that seized bolt.

Any and every bit of help is appreciated. Thanks a lot guys.

Panthers007

Here's one:

https://www.parktool.com/repair/readhowto.asp?id=127

And here's two:

https://bicycletutor.com/overhaul-threaded-headset/

Al1943

I would start by working some Liquid Wrench into the headtube, from the top down, then turn the bike over and run some from the underside down.

wrk101

Do a search on stuck stem, its been covered many times before.

You have two completely different problems, a stuck stem and a headset rebuild. For the headset rebuild, I would recommend you visit the park tool site. They have excellent instructions. But you really won't be able to do the headset until you get the stem out.

Also check the seat post. In my experience, if the stem is really stuck (and not an issue of the wedge being stuck or bolt loosening mistake), then the seat post has a good chance of being stuck. A stuck seat post is often harder to get freed up.

I am working on a bike right now that had both issues. Stem freed up with PB Blaster. Post is soaking in ammonia right now. FWIW, its a Trek 500.

une_vitesse

i think you have a quill stem, so that means the bolt on top of the stem is the expander wedge bolt. if it is seized (doesn't turn), you should probably take the front wheel out, flip the bike over and pour some penetrating liquid down the steer tube. hopefully that will free up both the threads on the bolt and the expander wedge itself from the steer tube.
once you are able to turn the bolt, if the stem is still stuck, loosen the bolt about 10 mm and then whack it on the head with a rubber mallet. that should allow you to remove the stem.
once you have the stem out, you can start working on overhauling your headset.
https://www.parktool.com/repair/readhowto.asp?id=127
good luck

Pir0

Really appreciate the advise guys. I seem to remember someone telling me about the quill stems and hitting them to free the wedge from the head tube.

Will give it a bash when I get my other one on the road so I won't be stuck It's barable for now, just don't want it getting any worse.


Again, thanks a lot for your help everyone, will bookmark those websites for further reference on other stuff Funnily enough, after never having STI shifters [just downtube shifters] I was on the park tool website last week trying to find out if i needed the lever right off to change the brake cable. Anyway, will get stuck in soon. Cheers again

Panthers007

Use a block of wood over the top - don't hit the metal directly with a hammer. And don't use a sledgehammer. If a few wraps don't do it - follow the advice from une_vitesse.

Mr. Underbridge

In general the tightness setting on the stem takes a little touch. There's a happy medium between a knocking, loose headset and a tight sticky headset. The difference between too loose and too tight can be as little as a quarter turn. So if you fixed the loose headset by cranking the heck out of it, I'd expect exactly what you saw - bars you can barely turn. Use the link in une_vitesse's post for step-by-stem instructions.

It's also a good idea to clean out the gunk from the headset as mentioned, especially if the end of your fork is open to the head tube and you ride in rain without fenders.

If you choose to replace your bearings with new loose balls, make sure to get the right size and replace *all* of them with bearings from the same lot.

Good luck!

Pir0

Cheers again everyone, will get stuck in