First time fitting Forks

For discussions about bikes and equipment.
Scudders
Posts: 11
Joined: 19 Aug 2020, 7:59pm

Re: First time fitting Forks

Postby Scudders » 23 Aug 2020, 8:59pm

Jdsk wrote:Could you add a photo of the current state of the assembly?

Jonathan


This is the current state of the assembly, it's only showing the bottom as I am happy with the top part of the assembly now.

The bearing doesn't abut to the crown race and I suspect it should.

Image shows the bottom with the crown race now tapped onto the forks
https://1drv.ms/u/s!AmE3C-rF9fUUheI2uIm ... w?e=N2NQaa

Scudders
Posts: 11
Joined: 19 Aug 2020, 7:59pm

Re: First time fitting Forks

Postby Scudders » 23 Aug 2020, 8:59pm

Jdsk wrote:Could you add a photo of the current state of the assembly?

Jonathan


This is the current state of the assembly, it's only showing the bottom as I am happy with the top part of the assembly now.

The bearing doesn't abut to the crown race and I suspect it should.

Image shows the bottom with the crown race now tapped onto the forks
https://1drv.ms/u/s!AmE3C-rF9fUUheI2uIm ... w?e=N2NQaa

User avatar
531colin
Posts: 13327
Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: First time fitting Forks

Postby 531colin » 23 Aug 2020, 9:22pm

I think thats OK....the plastic seal ring will occupy most of that gap.

gregoryoftours
Posts: 1418
Joined: 22 May 2011, 7:14pm

Re: First time fitting Folks

Postby gregoryoftours » 23 Aug 2020, 9:33pm

Scudders wrote:Any Advice on whether the crown race should fit right snug to the bearing or not?

Both of the Cassette Bearings are identical and fit really nicely to the compression ring. Should the fit be the same with the Bearing and the Crown Race?

instead the bearing seems to just sit on top of the crown race and only slightly engage/overlap. I'm hoping this is normal?

Thanks again.


Yes the crown race doesn't sit into the lower bearing as much as the compression ring does into the top one. In fact until the headset is fully assembled and pre-loaded it can feel decidedly 'wobbly'. The most important thing is for the crown race to be installed all of the way onto the stepped shoulder on your fork crown. It is supposed to be a tight interference fit unless it's a split crown race, so needs careful hammering fully into place without damaging it. The following photos show how it needs to fit (in my case the crown race is silver and alu but it's the same as your black metal one).
IMG_20200823_210656_edited.jpeg
IMG_20200823_210740_edited.jpeg

gregoryoftours
Posts: 1418
Joined: 22 May 2011, 7:14pm

Re: First time fitting Forks

Postby gregoryoftours » 23 Aug 2020, 9:50pm

Scudders wrote:
Jdsk wrote:Could you add a photo of the current state of the assembly?

Jonathan


This is the current state of the assembly, it's only showing the bottom as I am happy with the top part of the assembly now.

The bearing doesn't abut to the crown race and I suspect it should.

Image shows the bottom with the crown race now tapped onto the forks
https://1drv.ms/u/s!AmE3C-rF9fUUheI2uIm ... w?e=N2NQaa


That's absolutely correct. The plastic seal sits on the flat part but the bearing shouldn't fit far down enough to sit on the flat part or hard up against the seal. The 2 bevelled faces are the only contact point and until the whole shebang is fully assembled it feels quite unstable.
Here is the bearing sitting on the crown race from one of my bikes, the same gap is there.
IMG_20200823_214608_edited.jpeg
IMG_20200823_214650_edited.jpeg

gregoryoftours
Posts: 1418
Joined: 22 May 2011, 7:14pm

Re: First time fitting Forks

Postby gregoryoftours » 23 Aug 2020, 10:00pm

If the bearing sat fully down onto the crown race until it made contact with the flat part as well as the bevel, the manufacturing and fit tolerances would have to be perfect in order for the bearing to be held firm and central, level and with no binding, so it's not supposed to sit on the flat part. It can be quite disconcerting how 'poor' the fit can feel though, until it's all together and preload correctly applied.

Scudders
Posts: 11
Joined: 19 Aug 2020, 7:59pm

Re: First time fitting Forks

Postby Scudders » 23 Aug 2020, 10:21pm

Fantastic help gregoryoftours. I had convinced myself that at very least the inner 45 degree bevel of the bearing should abut to the bevel on the crown race to offer some kind of mechanical stability... and that I was now in some-kind of dilemma where I would have to find either a bearing with different angled bevels on the inner and the outer rings or that I would have to remove crown race and find another.

You're so right it is disconcerting how unstable it feels and it's as if the bearing is just balancing on the crown race with absolute minimum engagement.

These comments in this forum have given me the confidence to crack on with this.

I fitted a stem just to hold things together until I get a chance to come back to it and it doesn't feel loose in hand, it feels solid with just the stem. I'll firm this up once tube is cut tomorrow.
Image

Thanks again for your help and everybody else. I had visions of hauling this off to the bike shop and I didn't want to do that.

iandusud
Posts: 667
Joined: 26 Mar 2018, 1:35pm

Re: First time fitting Forks

Postby iandusud » 24 Aug 2020, 8:37am

Well done for seeking advice and persevering. Enjoy your build.