tiger1964 

I am planning to post a WTB topic in the For Sale sub-forum, but thought I'd narrow down the request first... as in what specs I'll need.

The story. In 1974, the LBS I worked in at age 18 picked up a shipment of Zeus track frames really cheap because someone at the factory brazed in the rear "brake bridge" (!?!?) too low. Was willing to sell them for $75 with the bridge fixed, but that ruined the paint. I grabbed one and, being 18 and funds were not unlimited, stuck in a cheap "repair fork" with stamped ends. A pair of wheels and some other scrounged components later, I had a rideable bike but there's no track around here. it went into storage 45 years ago.

Fast forward to now, and I want to get the rest of my "collection" back on the road, and am planning to get several frames powder coated all at once, including the Zeus. I feel that fork has got to go! But I'm not worried about 100% originality. Again, it might never see a track, but I could use it on the rollers and possibly out on paved trails under controlled circumstances. So, this is a good time to place a WTB but what to get? I figure on a period-correct track or "nice" road fork, if it's drilled for a front brake I'll live with that and maybe even mount a brake (???) Looking at the 1974 Sutherlands guide, very little on Spanish stuff on head tube diameters, etc. It does mention Spanish stem diameter at 21.9 which seems a bit odd but as the fork is unlikely to be Spanish, who cares (right now it's sporting a cool Czech stem I got BITD, steel vertical shaft but the extension is I-beam shaped aluminum, seems almost destined for a track bike)? Head tube is about 167mm tall by my eyeball and a scale, wondering what range of steerers make sense (I guess I can cut down if needed).

Am I headed for pitfalls? Any caveats for when I post the WTB?

Stevensb 

Sounds like a good project. I have ‘70’s vintage Zeus road and track forks so if you need any measurements let me know. I bought them as colour references when I was trying to decide what colour to repaint my Zeus pro. Chose the green in the end and happy I did.

Cheers.

Brad

tiger1964 

Thanks. And that orange one looks like it would have looked right on my frame except it was white when new (I sprayed it matte black for some reason). (a) does inside diameter of the head tube mean anything? (b) I might use a Velo Orange headset unless I trip over a Zeus one of the correct threads; the stack height on the VO one is 41mm, so that means 208mm+ on the steerer, eh?

unworthy1

are either of those forks FR threaded? (Zeus often used FR threading and metric tubes, but depends on the era)

tiger1964 

Interesting to know -- IF I end up with a Zeus fork.

That said, the general question is, what specs must the fork be to fit the bike at all? Steerer length, for sure. I'm thinking English threading might be easiest for headset choices, etc. Does anything else matter?

abshipp 

I'm certainly no track bike expert, but I sure do love ogling them

Similar principles to any fork replacement effort, the key parameters are:

Axle-to-crown
Steer tube length
Steer tube threading length and type
Offset
Crown race diameter

From a lot of true track bikes I've seen, the top of the front tire is commonly very close to the bottom of the fork crown. Seems to suggest a shorter axle-to-crown measurement than a road fork, but also please take that with the first sentence in my reply at heart . Getting measurements from a comparable frame and fork can always help, and looks like you can get some!

tiger1964 

All good input, thanks. Axle-to-crown for a track bike or a fast road bike, I presume would be a bit tight and I won't be running 42mm wide 700c tires, for sure; fine, I don't mind 23's or 25's and/or maybe even tubulars, I'll be buying new wheels or at the least new rims on the hubs I have.

Steer tube threading and crown race diameter should be fine, would it not, if I buy a headset to match the new fork: English, Italian, whatever?

Offset I should think about, I don't want a touring fork, but a track fork or "fast road fork"; and I'm thinking the latter might be preferable if I'm not actually going to be on a track.

I guess what still has me apprehensive is, once I get a fork and a headset... will it attach to the head tube OK? Again, back to my 1974 Sutherland's Guide, they only mention outside diameters on head tubes: English & Italian (and I presume Japanese and higher-quality American?) at 31.75mm, and French at 32mm. Unless different wall thickness, that suggests a different inside diameter to the head tube as well. So, the most worrisome mis-match would be if the 1974 Zeus is indeed "French", and using an English (for example) headset to get the fork threading right, means the races to fit into the head tube are 1/4mm too small... a problem?

fietsbob

Uh, Planning street use ? get a fork with a mount for a brake..

You notice for banked track velodromes the fork blades are round , for road they are oval..







..

tiger1964 

UPDATE: Nothing like direct observation! So, I dragged the bike out from the murky corner of the basement and pulled the bar/stem, and dropped the fork out and tapped out the lower race. My digital micrometer is accurate to .01mm, you can guess the user somewhat less so. Outside diameter if head tube is very close to 31.75mm (31.8 to 31.82 actual, but there's paint) and the inside diameter is as close to 30mm as I can get a clear reading. Do y'all think it's safe to procure an English or Italian fork, as long as steer length, offset, and axle-to-crown make sense?

Never did before , but that was the mid-70's and I was an immortal teenager. If I get a road fork, fine, if I get a track fork and one of those $$$ up-through-the-steer adapters might fit, that's fine too.

By the way, When I first got the bike running I was out on it, and decided to cut through the campus of the University of Maryland campus on a weekday afternoon. On a long grade running between buildings I went to slow down and I clearly had not tightened the sprocket's lockring enough, it backed off and the sprocket too. No way to stop, I simply yelled GANGWAY and students scattered in both directions, no one hurt. Not sure how I made it home, at least it was uphill the whole way which must have helped. Well, maybe I do need a brake...

fietsbob

I think Japan for NJS Keirin racers they have a front brake adapter for their competition bikes..

maybe they motor-paced train on the roads..

JohnDThompson 

Since you're replacing the fork, you may as well go with English thread to have maximum flexibility in choosing a headset. AFAIK, Zeus headset cups were all standard 30.2mm ID, regardless of thread spec. Zeus track bikes used a pretty short rake on their forks.

tiger1964 

So, it sounds like I should be able to source an English-spec fork (or Italian), and be OK. Time to place aWRTB ad, thanks.

tiger1964 

UPDATE: I'm just getting started, but the 1st three responses on my WTB came up short... literally, the steerer tube not long enough.

(a) 4th guy might come through! I hope. Waiting on dimensions.

(b) eBay asking prices are astronomical, I presume many of you have bought entire bikes, fine ones for what they want for a fork.

(c) For a second time, a friend is offering to donate to me his 1974 Legnano, as he has "gone carbon" and is not looking back. Unsure of model, but all-Campy except Universal centerpulls. 25" frame, taller than I usually ride, but I betcha the steerer tube is long! A shame to break up the F&F, someone might want it some day.

(d) Doh! Last year, I got that nice Masi from a For Sale ad here and moved all the parts over from my Palo Alto. And then i occurs to me the Palo Alto F&F are in the basement. Wow, probably because the top tube is so short, the head tube is long and the steerer is over 220mm! Again, I'd hate to break top a set, but I have a fallback. Pretty sure the entire fork is chrome under the red paint.

(e) Tell your friends! Perhaps someone has an orphan fork laying around?

unworthy1

So you are looking for an all-chrome plated ISO or ITAL threaded road fork (drilled for a brake) with 208mm min. steerer? Any other details: does the crown style matter, forged ends of a certain make? If the crown is engraved with some other logo is it a deal-killer? Care if it's Reynolds, Columbus or Tange blades? Want to trade for something or pay $$

tiger1964 

Saw your post on my WTB. All chrome or at least part chrome, at least the tips! Drilled or undrilled OK. Logo on crown is fine unless It's C.Itoh or something else horrid. I'm kinda flexible on a "fun bike". Hadn't really thought about crown race diameter, hence this topic to nail down specs.

Not sure I really have anything to trade, so... $

unworthy1

I will PM you as soon as I get pix of the Tange chrome fork I have, it's pretty nice and I think size is right