bark_eater 

I'm replacing the headset on a 1989 Centurion Sports DLX. I put a 1000 miles on the original and it was always notchy or loose. I rode it loose for a while and then got spooked about ovalizing the head tube and tightened it up. I got good at steering with my body weight. So its time to replace it and I discover that its a 30/27 mm JIS headset. I ordered a Tange replacement and figured I'd have a bike shop face and ream the head tube, as the original build skipped that. As it turns out no one with in an hours drive has the 30/27 JIS cutters.

So... I'm going to build it back up as is. Any suggestions that will extend the life of the new headset? I'm going to start off with loose balls and was going to scrape the paint off of the mating surfaces. Any thing else I can try? Thanks, Woody

Andrew R Stewart 

"Any suggestions that will extend the life of the new headset?"
- Learn how to make a proper slightly preloaded but not too tight bearing adjustment. IME many will over load a new headset and not know it as the ball tracks are so smooth still.
- Keep grit and grime from getting inside, often carried in by either road spray off the fr tire or carrying the bike on the car in the rain. If the bike does see rain consider overhauling the headset soo after. The first time you will learn how well sealed the headset is and thus whether you might be repairing this service more or less often in the future.
- On the install insure that the cups and races are square to the axis, that they lay flat on properly prepared surfaces.

"I'm going to start off with loose balls and was going to scrape the paint off of the mating surfaces"
- I sure hope that your replacement headset wasn't painted on the ball tracks by the factory. A good sign of a bad factory. Now there might be a finish coating of some colored oxide (gun bluing is one) but the better headsets should have bare steel surfaces and ground if the unit is a better grade one.
- The classic best way to deal with first time use and the initial break in of the contacting parts is to do a follow up overhaul after some short period, like a month or 300 miles (as examples). Andy

squirtdad

just curious how did your determine it was not faced and reamed? the original head set fit and it most likely would have been a factory build, not a bare frame? I thought factory builds had this done, albeit at various degrees of quality. I could be wrong of course

bark_eater 

The head tube machining is very rough and painted over. I'm assuming any reaming or facing of the head tube was done before it was brazed together. The bright metal "facing" is where I scraped the high spot paint off with a razor blade. The bare metal on the inside is where I stuck a Dremel brush inside. The reamed surface is scored from dull tooling.

ericoseveins

Personally I think I would ream the head tube to 30.1mm with the normal facer and use a 27.1mm facer on the crown race. Maybe I'm missing something here though.

bark_eater 

I have an Zeus ISO reamer and was proceeding, but couldn't get the tool in the head tube. I thought it was the seam in the head tube it the burs from the large lug vents. I filed and Dremeled for a bit before I thought to check the original headset. I already have the JIS headset, and I still can't get my tooling into the head tube to do the cutting.

Andrew R Stewart 

Pretty typical high production factory reaming. I very much doubt this was done prior to the brazing as it's that heat and it's warping/distorting nature that is some of what a reamer is correcting for. Additionally note that the end face, of the headtube, has a slight countersink/bevel. That's another fairly common production aspect. The rough reaming is, as mentioned, likely from worn cutters and/or to much feed while reaming.

As to your ISO cutters not working- Some headtube reamers have a short lead in beveling to the blades to better allow entry into the hole. Do yours? Some have a pressure spring to provide the feed rate, does yours? The photo shows no obvious marks from a cutter being tried. I assume you have measured the cutters and compared to the cups (the cutter should be about .1mm smaller than the cup skirts). I wish I was there as something about the cutters not working sounds a bit off. Andy

bark_eater 

On my Zeus tool just before the cutter the shaft of the tool is of a diameter that will not fit into the head tube. I'm pretty sure its hanging up on the tubing seam and some other burs. I'm sure I could figure out how to ream the head tube to allow the iso cutters to cut, but success would necessitate buying another headset.

ericoseveins

Okay, so the only goal then is to make the headset go as far as possible? If the reamer won't go then I think the main thing would be to face the head tube and the crown race so that the cups wear as evenly as possible. The shops you contacted should be able do that but the cost might be pretty much equivalent to the cost of the headset.

bark_eater 

I'll bite. What tool would they have that faces a head tube with out reaming it for the cups also?

Andrew R Stewart 

There have been some facing tools that use a non cutting pilot shaft ti fit the HT ID. The ones I have seen are industrial intended and electrically powered. But, again, for a lugged bike I have not seen a pre brazing reaming/facing done by anyone who knows about this stuff. The ends of the lug are often not either flat or square to the HT axis often enough.

I am unsure exactly what the problem is with your cutter, It almost sounds like the tool's parts are in the wrong order. Post #8 makes it sound like the tool has a bigger than the cutter's size ring or spacer on the starting end of the cutter. Is this the first time you've used this tool? Andy

bark_eater 

Here's the tool I have. I've used it before, but there is to much going on inside the head tube with the tube seam and large vent hole burrs to insert it. I'm sure I could ream or hone out the head tube to get this tool to work, but I have the JIS head set on hand so I'm going to use that. Thanks for the reassurance that the original reaming and facing was done after brazing. If the new JIS head set blows up, I will recut to ISO.

bark_eater 

It looks like this tool can be used the same way. The issue with this tool and this bike is incompatible tolerances. The pilot on this tool is not going to work on this bikes head tube with out more work. The park tool version may have different tolerances. Dont know. Trying to get one of my local bike shops to help with a work around would involve way to much time, driving, money and a reiteration of this conversation with 20 year old mechanics.

Andrew R Stewart 

Most of the head tube reamer/facers I've used have a cone at the not being cut end to center the shaft, thus don't use a pilot that wants a tight fit to the HT ID. I had thought the Zeus tool was much the same as the Campy which uses a centering cone. Andy

bark_eater 

There's a centering cone on the other end. The only other bike I've needed this for was a higher end British 531 bike and it went fine.

JohnDThompson 

If there's a centering cone on the other end, perhaps you could remove the problematic sleeve and just use the cone? That's how most other head tube facer/reamers work, e.g. Campagnolo, Bicycle Research, etc.