thbirks

okay, so awhile back a purchased a roadbike frame over the internet to make into a fixed gear bike. The frame just sat around for several months until I managed to scrounge the other parts I needed. When I went to install the headset I found that a press wasn't needed. The cups went in by hand. well this didn't seem right so I examined the headtube and the front section of the bottom of the headtube looks thinner than the rest of the headtube. It looks like the headtube is ovalized.

I would like to use the frame anyway. I was able to adjust the headset just fine and the few miles that I have put on the bike reveal no problems with this ovalized headtube. So. Is it safe to use this frame? I've been told to shim the headtube with a peice of aluminum can. What do you think?

bentbaggerlen

I have used soda cans, beer cans and shim stock to "repair" oversized head tubes. Not fancy but it works. One of the bikes is ridden everyday in boston for over 5, no problems yet.

knobbymojo

JB weld might also work to repair the headtube. Ive seen the stuff hold the engine cases together on motocross bikes before, often for many years.

RegularGuy

Are you sure you have the right size headset?

If the headtube is indeed ovalized, a Chris King Steelset may be your best solution. That Chris King is one clever guy.

KleinMp99

They do help prevent ovalizing....but his is already ovalized.

WorldIRC

Wanna talk about ovalizing a headset tube. Catch this.

My boss doesn't believe in a headset press, he's old fashioned. When putting a headset in he does the following. He uses a 2x4 to protect the headset and with a mallet hammer he smashes the head set into the frame. HEHE he almost tried to pull that on my bike, I gave him so much crap.

BikerRyan

The steelset idea might be a good one. You see the steel set is actually just a headset with very deep cups on it which press further into the frame. IF the frame is indeed ovalized from a previous headset then this has probably only occured at the ends of the headtube since the old headset probably wasnt a steelset. Might be worth a shot.

-Ryan

pokey

Ya know,it really does work.So does a HS press made with washers and threaded rod.Has you boss ever screwed one up?I haven't.

RegularGuy

My thinking exactly. Only problem with the steelset is that they are mighty spendy! Beer cans are much cheaper.

WorldIRC

Yea he messed up once or twice and it cost him a couple frames. He learned his lesson. He uses the press now.

pokey

Musta really been a hamfisted klutz.

thbirks

Apparently there is a headset designed for cheap Asian bikes that has 30.0mm outside diameter cups instead of the standard size which measures 30.2mm. I think I may have gotten the wrong headset. This would explain why the cups went in by hand.

One of the Dirt Rag magazine guys was able to save his Ibis frame with an ovalized headtube by installing the King steelset. But i paid less than half of what the steelset costs for this frame.

pokey

Yeah,but that HS also comes with a 27.0 crown race instead of the standard 26.4 which would have been such a sloppy fit on the fork that it should have given you a clue. The JIS standard you refer to wasn't restricted to cheap bikes but was found on alot of better bikes that came out of the orient at one time.It still may be found on some department store bikes,but even the asian makers have pretty much abandoned the JIS standard in favor or the ISO.

thbirks

Good point, The crown race went on just as it should. So I quess i have the right headset. The frame is a Miyata 110, probably from the late '70s, if anyone's wondering.

pokey

I'm thinkin a Myita of that vintage would have had the JIS with 30.0 cups and 27.0 crownrace. On stuff ot that vintage and origin,it pays to measure.

thbirks

Yeah, I had no idea that there was a different size until I got to the bike shop to buy the headset. The mechanic, who is quite knowledgeable, felt that the frame would use the ISO and not the JIS standard, but said he couldn't know for sure without seeing the frame.

BTW, I'm guessing on the age of the frame. It has 126mm rear spacing, 27" wheels and no bosses for down-tube shifters. The serial number has been rubbed off.:confused: Anyway, I figure it's from the late '70s or early '80s but I'm no expert.

pokey

A 'knowledgeable' wrench would not be guessing in that situation.The 70s and 80s vintage stuff from the orient I have torn apart all had the JIS. Before you spend more money,or rish screwing something up,It's easy enough to take it apart,measure and eleminate the guessing.

pokey

zlj75

I just used the soda can option on a touring frame I am putting together...it seems to have worked great! I'm a bit concerned about safety this is going to be used for loaded touring...should I worry?