Steering stem top is hidden away (GS450)

[Guest]

Background:
I'm putting together a GS450 from bits and pieces, meaning that I purchased a project bike I did not take apart myself. I have reached the steering stem now, and have changed the bearings and bearing racers now that everything is taken apart. The racers are 100% level with the frame part, so they should be sitting in well.

Question:
The thing I'm wondering about, is that the stem top does not reach all the way up to be level with the upper fork bridge (see picture). Is that normal? I know that everything is held together fine by the upper and lower fork bridges, but still, I would expect it to be flush with the upper part.

The stem is about 8mm below the edge:
Screenshot 2020-03-30 at 22.09.01.jpg

[Gorminrider]

No, Arek. That stem should be pretty near flush. A Big Chromy bolt threads in to that stem too. I can take pictures if you need see.

[LAB3]

Compare the parts you've assembled with the instructions from a repair manual or the parts fische. Did you replace the lower bearing? That one needs to be pressed on, if it wasn't that would definitely account for your having a gap at the top.

[Guest]

No, Arek. That stem should be pretty near flush. A Big Chromy bolt threads in to that stem too. I can take pictures if you need see.

Yes, I have that chromy bolt - just wanted to show the gap. Thanks for offering the pictures though.

Compare the parts you've assembled with the instructions from a repair manual or the parts fische. Did you replace the lower bearing? That one needs to be pressed on, if it wasn't that would definitely account for your having a gap at the top.

I have followed the repair manual, but I think I know what the issue is. The lower bearing racer I hammered in with a big hammer until it was level with the edge. If that needs to be pressed in further than the edge, then this is why I have that gap. Will run out and buy one of those "race driver" tools and knock it in further :-)

Thanks to the both of you!

[Guest]

Alright - tried again. Got the lower racer pushed some mm. up, but still the image here is the best I can do. It has a gap of 4.5mm.

The question is, is it safe to drive with? Again the whole thing is being held together by the fork bridges. If yes, then I will not do more about it and continue my build.

Screenshot 2020-03-31 at 15.39.06.jpg

[LAB3]

The race can be installed properly with a hammer and drift, it's the bearing itself that needs to be pressed onto the stem. Was the lower bearing removed from the stem? That was the piece I was referring to.

As to riding it that way, I wouldn't. This is coming from a rough and tough guy who isn't afraid of getting hurt!

[Guest]

The race can be installed properly with a hammer and drift, it's the bearing itself that needs to be pressed onto the stem. Was the lower bearing removed from the stem? That was the piece I was referring to.

As to riding it that way, I wouldn't. This is coming from a rough and tough guy who isn't afraid of getting hurt!

Yes, the lower bearing has been removed, and a new one has been put on. I got it pushed on as far as I could. There might be 1 mm left down to the bottom, as I see that will not make too much of a difference at the top.

So I guess it's back to the work bench if you don't recommend riding it that way. Is there a way of doing this yourself without special tools?

[Gorminrider]

You're very close, Arek. Here's a picture. Stem needn't be perfectly flush. Sorry, it's a little blurry. I think you should be ok if the assembly has no slop- but it's hard to judge from here..Perhaps the "Chromy bolt" might pull the stem up a bit through the bearings with the clamp loose? But Don't wind it too hard. You don't want to strip threads.

stem.jpg

[LAB3]

Is there a way of doing this yourself without special tools?

The right way is to use a bearing press. Not having one the way I'd try it would be to get a piece of pipe that's ID is very close to the diameter of the stem. I'd slip that pipe over the stem making sure that it contacts the inner collar of the bearing and not the outer ring then hit it with a BFH.

Or do it right and take it to a machine shop and let them press it on, probably take them five minutes and wouldn't cost much.

[Guest]

First of all, thanks so far Gorminrider and LAB3 - you're helping me a lot, pictures including!

I actually used a pipe with a similar diameter and the old bearing on top, and have really used a lot of force, and I don't think I can do much more about it myself.

I just took a few pictures for you guys to evaluate - maybe I got the wrong parts, maybe I have overlooked something during assembly. Please let me know if it looks different on yours.

Left picture: Top assembly. To me it rises a bit too much over the edge, but then again this is first time I'm building this bike.
Right picture: Lower bearing as far as I can get it to the bottom. You see there's only missing a hair's breadth (1 milimetre or so), unless it can get further down but I can't see it?
Screenshot 2020-03-31 at 20.36.07.jpg

What's your verdict?

[LAB3]

I'm not there to look at it but by your own admission that bottom bearing still isn't where it needs to be. If you where say "close enough" and put it all back together my best is that you're not going to put enough torque on the stem bolt to make it sit where it needs to be.

Think about this: You're going down the road and the weight of the bike along with some jarring makes that bearing slip down into place. Guess what? Now your entire front end is loose. You hit a corner and experience the dredded "Death wobble" If you're lucky all you do is ruin a good pair of underwear, if you're NOT lucky you'll never have a reason to wear underwear again, if you get my drift!

This isn't a place where you want to do a "half fast" job. Do it right and be done with it.

[Guest]

I'm not there to look at it but by your own admission that bottom bearing still isn't where it needs to be. If you where say "close enough" and put it all back together my best is that you're not going to put enough torque on the stem bolt to make it sit where it needs to be.

Think about this: You're going down the road and the weight of the bike along with some jarring makes that bearing slip down into place. Guess what? Now your entire front end is loose. You hit a corner and experience the dredded "Death wobble" If you're lucky all you do is ruin a good pair of underwear, if you're NOT lucky you'll never have a reason to wear underwear again, if you get my drift!

This isn't a place where you want to do a "half fast" job. Do it right and be done with it.

Oh Christ! didn't think about it like that. I like my underwear and what's beneath it, so I get the point - get it done properly! Will find a place with a hydraulic press and have it done properly, at least so the lower bearing slips all the way down. I still expect the stem to be a few mm below the edge at the top, but accept that as long at the bottom is OK.

[Gorminrider]

The stem is supposed to be a few mm below at the top. Just not 5cm or so like your first picture of the thread. I think you're ok, myself.A millimetre is fine and you may do more damage hammering it down to capture it.

[Guest]

Hi All, an update.

Went to the local mechanic today, and they have a hydraulic press. They gave it just below 5 tonnes, and it still sits where it did before, so I reckon it is fine now.

Thanks for the help all.

Arek

[LAB3]

Excellent! Better safe than sorry on that one.