Dahon jetstream front fork wobbling

[cwah]

hello all,

I've been trying to install the front fork from my dahon jetstream after a long while... it's a new fork that fits now.

But I think I've lost some part and it seems there is a retainer or something that should prevent the fork to wobble. I attached the headset picture as it is, then I added the retainer then the cap.

Where can I find the right "upper head tube race" as indicated by sheldon brown?

I may also need a compression ring.

I suppose the dahon jetstream type of headset should be standard? Where can I find these parts for decent price?

Thanks

 

[cwah]

See the wobbling front:

 

[selrahc1992]

hello all,

I've been trying to install the front fork from my dahon jetstream after a long while... it's a new fork that fits now.

But I think I've lost some part and it seems there is a retainer or something that should prevent the fork to wobble. I attached the headset picture as it is, then I added the retainer then the cap.

Where can I find the right "upper head tube race" as indicated by sheldon brown?

I may also need a compression ring.

I suppose the dahon jetstream type of headset should be standard? Where can I find these parts for decent price?

Thanks

I'mjust installing a new suspnsiono fork on an old raleigh twenty - you can buy entire standard headsets on ebay for circa £6, i think yours is 1.5 inch if memory serves right? I'd be hugely surprsied if this fork headset combo isnt standard.

 

[jhruk]

See the wobbling front:

Unfortunately your video is marked as 'Private' so I can't see your headset problem.

Strangely I fitted a new headset to my Jetstream only yesterday. The headsets on Dahons are similar to standard Aheadset ones but differ due to the head-tube being of larger diameter, so you have to use a Dahon specific one.

As far as I can see there were two types fitted to the Jetstream. The normal one, where the bearings are integrated into the head-tube race, and the more expensive Fusion XP+, where the cartridge bearings are separate. The 'integrated' XP+ does seem to come with separate cups, so if you're replacing the complete headset I think you could fit either, but I'm not sure.

There also seem to be several varieties of ones using the integrated bearings. The one I removed from mine had a plastic upper ring but my replacement had a more normal metal split ring.

You can purchase complete headsets, or just the bearings, here:

C H White - Dahon Headsets

Hollandbikeshop.com – Dahon Parts


Looking at the photos in your first post my guess is you're trying to fit a different fork with a longer steerer tube. In order to tension the headset bearings you'll need to cut the tube to the correct length, or fit some spacers.

 

[Deleted member 4366]

The headset has to be in slight compression to take out the play (stop wobble). I can only guess that you have an incorrect spacer arrangement. A photo of the completely finished assembly is needed so that we can see what you've done. It will always wobble at the stage you've shown it because it's not yet clamped by the spacers.

 

[cwah]

Thank you guys. I
The link from the day on official does seem expensive especially because I'm not exactly sure which one to buy.

Could you recommend on an eBay link that would fit my dahon headset?

I think the bottom part is fine but as you can see on the picture of my fork, there is sone gap in the top tube so it needs something to hold everything in place.

Thank you

 

[Deleted member 4366]

Can we see a photo or video of what your problem is?

 

[cwah]

The photos and video are on the first post.

Video has been unlocked and photos are attached in the first post

 

[Deleted member 4366]

When you screw the cap on the top of the steerer tube, It must pull down onto a spacer, not the steerer tube, so that it compresses all the bits together. I would need to see a side view to see what you've got, but I'd say that you need an additional spacer ring.

 

[cwah]

Thanks, I tried to add an additional spacer on top but it doesn't fix the problem.

Here is the picture of the fork:

The top part:

The bottom part:

Summary of the installation:

Any idea what's the best way to proceed?

Thanks guys, really appreciated

 

[cwah]

I realised the pictures were blocked, I've updated it. Any thoughts?

 

[Deleted member 4366]

The photos aren't clear, but it looks like you have some pieces upside down. The picture of the bottom race doesn't look right at all. Shouldn't the bit on the steerer tube be under the ball race?

 

[cwah]

just tell me if you need more pictures and i will share

 

[Nealh]

Good spot, d8veh is right Cwah on the bottom of the fork the crown race is above the bearing race, you need to reverse those 2 parts. As your pic of the bottom shows the bearing race isn't sitting in the bottom bearing cup its just resting on the underside of the crown race doing very little no wonder you have wobble. The crown race when fitted will be tight and will need a gentle tap down to seat properly on the bottom of the steerer tube then the bearing race just sits nicely in to the concaved seat and in turn these sit up in to the underside of the head tubes bearing cup , whilst you are at it a smear of grease won't go a miss on the bearing.
Can you show a pic of the head tube seat area from the top and bottom, hopefully you haven't damaged the bottom one.

 

[jhruk]

Yes d8veh is correct, those two parts are the wrong way round.

It looks as though you may have dismantled the integrated bearings, although you should still only have two ball races - not three! Firstly try and put the bearings back together. The outer case is pressed into each end of the steerer tube with the race and inner part retained by the thin shiny ring. They look like this when complete - there's no need to remove them from the tube if they're ok. Once assembled check them for wear – the inner part should rotate freely and without any play.

 

[cwah]

Thanks guys.

Yes you've shed some lights on my mistake, I've reversed the crown race and the bearing!!

Here is what my tube looks like:

Close up on the bottom part:
-Front:

- Back:

It looks like there is a little mark to properly sit the crown race on the bottom? Do I need a specific one for this fork???

The bearing were completely damaged while I removed them from my original fork and I don't have access to them anymore

The bearing you're seeing are ones I've been purchasing there and there hoping it would fit the fork:
http://www.amazon.co.uk/dp/B007V2LUFO/ref=pe_385721_37986871_TE_item

I can buy new ones if needed.

Thanks

 

[Deleted member 4366]

First, you put the bottom race on the fork. It's the bit above the balls in your previous photo. It goes the other way up though. It needs to go all the way to the bottom, so you have to find a way of tapping it down without damaging it. I use a large screwdriver tapping one side at a time, but yiu have to be careful with that mathod. It will be a tight fit on that swollen bit on the bottom of your steerer tube. Next, goes the caged ball-race. The third part should be jammed in the bottom of the steering head tube on your frame. Normally, it's matched to the other two parts and you can't always mix parts from other sets. It's always best to get a complete new set.

For a new set, the first thing you have to do is remove the two pieces from the top and bottom of the steering head tube with a big screwdriver. I use a specially filed one, which fits better. You'll see what I mean when you try and knock them out. Then, you bang in the two new ones using a block of wood and making sure that you get them the right way round if they're different. After that, bang on the lower race onto your fork steerer tube, put the greased lower ball race on and insert the fork steerer up through the steering head, drop the greased upper ball race on, then the upper race. There is often a wedge-shaped spacer next and, finally, a dust cover or shroud.

It's all shown in the picture in your first post except that the star nut is already in your steering head and you screw on the cap after you've added enough spacers to keep the cap clear of the steerer tube. Don't screw the cap too tight. Screw up the cap before clamping the stem.

 

[jhruk]

That would explain it – I thought those caged bearings looked too big.

I've just dismantled one of my old dahon bearings and it's full of loose small balls – they look to be around 3mm. Like this:

You could try and rebuild the old bearing, using new balls, but I'd suggest a complete new headset and starting again. You'll need to knock out what's left of the old bearings and press in new ones.

 

[cwah]

OK makes sense. Time to get a new headset.

What should I buy to make it work?

This new headset?
http://m.ebay.co.uk/itm/151374800355?_mwBanner=1

Do I need specific tool to make my life easier? I prefer not to use hammer and make noise but if I have to I will

Thanks guys

 

[jhruk]

OK makes sense. Time to get a new headset.

What should I buy to make it work?

This new headset?
http://m.ebay.co.uk/itm/151374800355?_mwBanner=1

Do I need specific tool to make my life easier? I prefer not to use hammer and make noise but if I have to I will

Thanks guys

No, as explained earlier the Dahon has a larger than normal diameter head-tube, so you need a Dahon specific one. I gave you links in the earlier post.

To press in the new bearings I used this contraption (purists look away now!)