Steering head seems to co.e loose

[cbertozz]

I was wondering that myself. I suspect it's the sleeve part of the nut that fits inside the top triple clamp.
Carlo is inventing some new words for us. 

yes the sleeve.

It looks like it was designed to keep the stem central which suggests that without it it would have some play but just checking

 

[Dellortoman]

Its purpose is to get clamped by the pinch bolt in the top clamp which locks it in place.

 

[Legs]

Thanks for that, obviously a different set-up to an RGS.

 

[cbertozz]

Actually Can I just realised you're referring to the very top chrome nut with sleeve, I'm talking about the one below it with the thin edge, which also has a sleeve.

Going to have to remove​ the whole front end and have a look as now even with the nut back on the stem isn't central when the top triple goes over it so can't put the top nut (also with sleeve) back on.

Looking at the front wheel - do the guards have to come off to get the wheel out? Don't have much ground clearance.

 

[Legs]

If you are going to disassemble the forks it's best to take everything off, including the wheel and calipers. With everything off you should be able to drop the fork legs and bottom triple clamp as a complete unit. Suggest you then offer up all the components (off the bike) to see how they all fit and work together. It's much simpler that way to get an understanding of what does what, plus it can be entertaining and fun (well I think so anyway)

 

[cbertozz]

Fuck those wheels are heavy!!

 

[cbertozz]

For the record here it is and I cant budge the stem in the triple so perhaps my imagination

 

[Legs]

Good start . Now, if I were you, I would get all the steering head components and assemble them to see how it all goes together but you may have sussed that all out whilst pulling it apart. Leave the top bearing in place as I bet it's an interference fit in the tube.
Give that stem a coating of grease before you put all back together to keep the rust out.

 

[piranha-bro2]

What you call the 'crush tube' is a threaded sleeve that both tightens down on the top bearing AND fills the gap between the thread on the stem and the bearing. Once it's in place there will be NO play side to side at the top, but for-aft-side-to-side play in the bottom tapered roller needs to be adjusted by turning the 'crush tube'.

BUT!! ... once you fit the top triple and tighten it to lock the assembly, the adjustment will tighten, so it needs to be checked AFTER the top nut is fully tightened. So you need to keep loosening the top nut and tightening or backing off the 'crush tube' until there is no play, but the triples rotate freely once the top nut is again clamped tight.

Hope this makes sense.

 

[tom3c75]

Carlo,

That's an unusual looking bottom fork yoke for your model year Jota.  Can't make out whether it is a Ceriani or Marzocchi unit, but it should be a Ceriani.

Attached are two pics of a correct Ceriani unit.   

Comparing the pics of your yoke with mine, it seems that the offsets differ (the distance from the stem centre line to a line joining the tube fork tube centre lines) - mine seem bigger than yours. I mention this because, if your top yoke is the original Ceriani unit, and your bottom yoke offset is not correct, then there may be an issue with the top and bottom yoke alignment.  This may result in a less than perfect clamping fit, causing your looseness.    Just a thought.   

However, it could be that your top yoke is also not quite standard, and that the upper and lower offsets do indeed match, in which case all should be well.  It may be useful to also post a pic of your top yoke.

Something else to bear in mind, is that the Ceriani steering stem for you bike was, by design, not quite parallel to the fork tubes.  So, depending on what mix of parts you have fitted, this may also have an effect.

Tom

 

[Legs]

Carlo's bottom yoke looks very much like the one on my RGS, Marzocchi.

 

[Simonr501]

There is a resemblance to my Marzocchi bottom Yoke  (Jota 120). Of course we are talking Series 2 bike.
My Marzo steering stem is quite different. I have a thin nut to tighten the steering. The top Yoke and nut just clamps the lower thin nut.
My Yoke has "Marzocchi' cast in it.

The 'ears' stop on a plate below the Yoke, the plate doubles up as an oil cooler mount.

If there is a blend of Ceriani and Marzo then that might be the source of the confusion.

One wonders if the stem is a good fit in the Yoke?

I still believe that the stem wasn't pulled right through the top bearing though.

As mentioned it would be handy if you could post a photo of your whole assembly.

 

[cbertozz]

Thanks for all the feedback guys. Forgive me not quoting everyone as it gets messy.

Here is a pic of my upper. I think from previous discussions it seemed that I had a hybrid set up.

The bottom yoke is Marzocchi I believe, the bump stop is a hybrid​ too.

It's all back in one piece and a short test ride 10km, didn't show up anything. That said still going to get my work checked by a pro.

Let's see if it stays adjusted as required.  I greased top and bottom as well for good measure.

Given that I've never done any mechanical work before I bought the bike back, beyond changing wheels, I'm pretty pleased with the result. Mostly it's as a result of the chaps on this forum with heaps of useful advice.

 

[cbertozz]

What you call the 'crush tube' is a threaded sleeve that both tightens down on the top bearing AND fills the gap between the thread on the stem and the bearing. Once it's in place there will be NO play side to side at the top, but for-aft-side-to-side play in the bottom tapered roller needs to be adjusted by turning the 'crush tube'.

BUT!! ... once you fit the top triple and tighten it to lock the assembly, the adjustment will tighten, so it needs to be checked AFTER the top nut is fully tightened. So you need to keep loosening the top nut and tightening or backing off the 'crush tube' until there is no play, but the triples rotate freely once the top nut is again clamped tight.

Hope this makes sense.

Yes made sense, did quite a few adjustments like that.

 

[Grant]

Ceriani yokes are at a different angle to the steering head on the frame.
If you look from the side you see the forks slope differently to the angle of the steering head.
Marzocchis are parallel to the steering head.
So if you use a Marzocchi lower and a Ceriani top yoke then unless they have been modified somehow they in theory shouldn't match up.
On my bike with Ceriani forks I had the steering stem removed from the bottom yoke, the holes in the bottom and top yokes welded in and re-drilled to be parallel to the steering head angle.
A lot of work.
I would think either your top or bottom yoke has been modified, otherwise as you slide the fork stanchion up through the bottom yoke it wouldn't match up with the hole in the top yoke.

You can see how the top nut is offset in the yoke as the hole had to be drilled to allow steering stem an steering head to be parallel.

 

[cbertozz]

Ceriani yokes are at a different angle to the steering head on the frame.
If you look from the side you see the forks slope differently to the angle of the steering head.
Marzocchis are parallel to the steering head.
So if you use a Marzocchi lower and a Ceriani top yoke then unless they have been modified somehow they in theory shouldn't match up.
On my bike with Ceriani forks I had the steering stem removed from the bottom yoke, the holes in the bottom and top yokes welded in and re-drilled to be parallel to the steering head angle.
A lot of work.
I would think either your top or bottom yoke has been modified, otherwise as you slide the fork stanchion up through the bottom yoke it wouldn't match up with the hole in the top yoke.

You can see how the top nut is offset in the yoke as the hole had to be drilled to allow steering stem an steering head to be parallel.

Thanks for posting this.

What I noticed was when the nut with sleeve that holds the stem in the top yoke was backed off enough for the sleeve to clear the top bearings the stem would jump (this way the clunk I felt) to incline towards the tank, so it sat at an angle pushing on the tube (bearings).  Perhaps that would always happen with the wheel still on the ground and the nut off but perhaps suggest that the modification is less than perfect.

I can feel some replacement parts coming  o!

 

[Grant]

No, that clunk is standard, as still with wheel etc attached forces the top yoke to move once the top nut is removed.
My guess is if you do indeed have a Marzocchi bottom yoke and a Ceriani top yoke then some machining has already been done to make things fit. I really don't think they could be force fitted without machining.
Just make sure the bottom yoke is fully home before tightening the top nut, then adjust free play so the bars gently turn from side to side without flopping.

 

[cbertozz]

No, that clunk is standard, as still with wheel etc attached forces the top yoke to move once the top nut is removed.
My guess is if you do indeed have a Marzocchi bottom yoke and a Ceriani top yoke then some machining has already been done to make things fit. I really don't think they could be force fitted without machining.
Just make sure the bottom yoke is fully home before tightening the top nut, then adjust free play so the bars gently turn from side to side without flopping.

Ok great. Yes I fitted up without the wheel and forks so it was fully seated.

 

[piranha-bro2]

Holy shaez! If it were mine I'd be looking for matching top and bottom triples (yokes) asap - too much room for doubt, and judging by the probs you're having, not worth continuing to fight it! The non-parallelness of the Cerianis is going to play havoc nless the conversion is done really well (as Grant's has been).

 

[cbertozz]

Holy shaez! If it were mine I'd be looking for matching top and bottom triples (yokes) asap - too much room for doubt, and judging by the probs you're having, not worth continuing to fight it! The non-parallelness of the Cerianis is going to play havoc nless the conversion is done really well (as Grant's has been).

Might need to replace both to remove any doubt. Is anyone making these anymore?