Is this headset bearing gap acceptable?

[AlexJ33]

So, I was not longer able to tighten the bearings on my threaded 1" headset, so I figured the threads were damaged on the alu headset top cap (the part that preloads the bearings) and so bought a replacement headset.

When I finally opened it all up, turns out its the steerer threads that have gone, doh, should have checked first. I don't really want to change the fork as it's a very interesting and rare paint job on the frame and forks and wouldn't look right with a replacement (see pics).

When I opened up the new headset I noticed that the new threaded headset top cap has about 10mm of threads compared to the old one's 3-4mm so I thought great, that should be enough to hold it so I tried to replace the headset. Now the problems began.

Turns out there are two "standards" of crown race ID, JIS 27mm and Euro/Professional 26.4mm. Want to guess what my Belgian Minerva frame had, JIS (why god why?) !

Unfortunately I don't have access to a lathe or a pillar drill to remove that 0.6mm of extra material, and I need that bike, its my primary means of transport around the city, I don't have a car. So I improvised, I used the old crown race and reassembled everything.

I know this is not desirable but it is possible this will do, see the gap in pic, the bearings are sitting a couple of mm higher up the race than they were previously (the white line visible is where the wear was before). It seems smooth I'm going to take it for a 10-20km ride now and see how see fairs. I was just wondering that your opinions on this gap was.

Bike is a steel Minerva Multi-cross of unknown age but presumed to be early to mid 90's and at best was mid range I believe, the frameset is a bit noddly to be honest, but looks beautiful to my eyes at least. I bought the bike then stripped everything off of it and built it up with more modern components a couple of years ago and served me well since then but getting to headset to tighten properly has always been issue which got worse and worse until I decided to do something about it.

So what are your thoughts?

 

[mdvineng]

That's not right. Have you put the cage in upside down? Stopping it from seating correctly.

 

[My_Teenage_Self]

No, that won't do.

But, why not use the entire 'old' lower assembly (crown race, bearing lower cup) and the entire 'new' upper assembly?

 

[AlexJ33]

The bearings were in upside down . Flipped them over and it seats much better now as you can see.

@My_Teenage_Self: Actually I thought to use the original lower part of the headset over lunch, it's only my second headset install so it never occurred to me that was possible before.
That would require me to remove the newly pressed in bottom race and replace it with the old one, do you think that's worth it?

 

[mk one]

No. Just fit the old bottom assembly back in as already suggested above.

 

[My_Teenage_Self]

Bearings and races are not designed to be interchangable, the balls may well be a different size. Even if it's the 100% same headset they would have worn into each other meaning you still couldn't swap them around.

use the complete lower race.

 

[Tootyred]

No. Just fit the old bottom assembly back in as already suggested above

Exactly. You cant interchange the parts as they are differing sizes. Its hard enough with either jis or iso swapping parts, but mixing the 2 standards is highly unlikely....aka fitting a ford escort door handle to your vauxhall vectra!

The cups that go in the frame are also a different size. Jis 30.0mm vs iso 30.2 you can wind a iso into a jis frame, but its often a push.

 

[AlexJ33]

Thanks for your input everyone, I will swap over the old lower cup tomorrow and go back back to the old bearings (nothing wrong with them anyway) so that at least everything is the same system, even if it is just a 0.2mm difference.

@Tootyred : Yes they were a bit of squeeze but having very little to compare it to and this being my first time using a homemade bearing press (long threaded bolt with two nuts and big washers) I didn't notice them being especially resistant, maybe they were, I just don't know, was just concentrating on getting them in straight.

Actually I have an additional question:
The new bearing cups were of different sizes one a few mm deeper than the other, there were no instructions in the box and nothing to be found online, so I tried the different cup and races with bearings and picked the pair that felt smoothest together. Is there a "standard" here ie: lower cups are generally deeper or vice versa?

Really appreciate the collective wisdom here guys, thanks for helping me rescue this old fork from the scrapper.
Regards Alex

 

[Tootyred]

If you put the bits together with the bearings in, it should become pretty clear which is the bottom and which is the top. There should be no obvious gap you can see bearing through and the should be no metal on metal contact either.

 

[AlexJ33]

So as was feared, my squeezing in the ISO cup has stretched out the headset lower.

Its not too bad, you can fit the cup most of the way in by hand now unfortunately, but it requires a firm push with my shoulder underneath it to get it 98% of the way in. I cleaned everything up, applied locktite blue to both surfaces and then re-installed the cup using the press to push it all the way home and left it for half an hour for reassembling. The old cup, the one I just reinstalled, is a couple of mm taller than the ISO one so I'm hoping that last 1-2mm and the locktite with keep it in there.

What do guys think the likelihood of it holding is, its not falling out loose after all?

P.s it was definitely the right choice to replace the old cup, there is now no gap between the cup and crown race. When you see something obvious demonstrated to you, it makes one feel pretty dumb. Thanks for the advice again.