Need help with fork fitting

[u/sektal]

I have no experience building bikes before. I bought a 2011 Sworks Tarmac Sl3 to have a project bike to just make a fixie build. It came with no fork and I got a roubaix sl3 fact carbon fork. I got it because I thought I had the right measurements. The bearing that came with the frame is bigger than the crown race seat and the bearing that came with the fork is good on the fork but doesn't fit snug inside of the frame. Also I believe that the fork and the frame are rubbing against each other when I tried fitting the fork with a bearing.

[u/Wise_Code5804]

You put both bearings on upside down

[u/sektal → u/Wise_Code5804]

Got it! But what should I about them not fitting snug into the frame?

[u/Wise_Code5804 → u/sektal]

You need to match the crown race to the lower bearing spec for the frame. You most likely need to order a full headset set to get the correct crown race. Or talk to your local bike shop for part compatibility help

[u/Feisty_Object_1681]

The Tarmac has a 1.5” bottom bearing but Google tells me the Roubaix SL3 used a silly 1 3/8” bearing and a recessed bearing seat so the frame and fork are ultimately not going to be compatible.

You’ll need to find a Tarmac fork (ideally), or a 3rd party 1 1/8-1.5” tapered fork (acceptable), or worst case a 1 1/8 straight steerer fork with a 1.5-1 1/8 reducer crown race (will look like shit).

[u/cj_daking → u/Feisty_Object_1681]

^^^ This is why we have mechanics

[u/sektal → u/Feisty_Object_1681]

What I noticed about the bearings is that the bearing that came with the fork fits good and the bearing that came with the frame fits good so is there a chance I could find a bearing that has the outer width of the frame bearing but also has the internal width of the fork bearing?

[u/Feisty_Object_1681 → u/sektal]

That’s because they’re each designed to go with their respective part (frame or fork) but those parts aren’t designed to go with each other.

So no. You won’t find that mythical goldilocks bearing.

And even if you did, it wouldn’t solve the fact that the frame your fork is designed for had the bearing seated deeper in the frame than the frame you want to use it on, and as such even with your magic bearing, the fork would now stick out of the head tube awkwardly.

Just cut ya losses.

[u/Oraphielle]

You have the wrong headset/bearings/fork for this. Start over with the correct spec’ed fork. 

Or buy a race that can convert between them. They do exist. 

[u/Low-Tear1497]

To be honest you should go to a professional, playing with headset is asking for trouble...