Vintage Fork Spacing
 

Was the front fork spacing on road bikes of the '60's and '70's standard? I need a front wheel for a vintage frame that I'm building up which has 90mm spacing on the fork. Can I pick up a wheel from any of the major makers of this era and expect it to fit? Since no one selling front wheels or hubs seem to mention dimensions, I'm guessing that they were standard but would like to be sure. Also, did track bikes use the same front fork spacing as road bikes?

Thanks,
Alan

I switch front wheels I bought in 2000 with wheels mad around 1980, and they fit fine. DeLong lists the spacing in the front fork as being 100mm in 1978 for all road racing bikes, measuring the gap between the fork ends. On some old forks, age, handling, or misalignment might make that gap 98mm or 102mm, but when you insert the wheel and tighten the quick release, it will "pull" back to 100mm.

Measure the gap at the very bottom end of the front dropouts. If it is a road racing frame from around 1960 or later, and the gap is only 90mm, it may be that one leg, or both legs, have gotten out of alignment. If the fork needs to be re-aligned, have a pro do it...10mm is significant.

100mm is "standard" for front axle locknut overall spacing. Rear spacing went through a number of variants prior to settling on 120mm prior to six speed freewheels. Track spacing for the front fork was also 100mm with 110 & 120 being used concurrently for a while. Cinelli for example continued to use 110 for longer than anyone else.

some older english bikes had forks spaced at ~90 mm. some really crummy japanese bikes are even narrower. bolt-on wheels usually can be respaced to fit, a QR wheel may be a bit harder. sometimes respacing the wheel can cause the spokes to brush the fork. it's generally most practical to either find a wheel with that spacing or simply spread the fork to 100 mm.

100mm was the Campagnolo standard (including track) for front hubs. It was subsequently adopted as the ISO standard. Depending on the age, level and nationality of the hubs, things can vary a bit. For instance, most of the QR/hollow axle, French hubs from the 1970s boom are 96mm. And many of the inexpensive, steel, solid axle, Japanese hubs from the same era are 93mm. You may find even narrower examples, if the hubs are very old or a proprietary design. Of course, the fork blades can always be cold set to the required width.

Thanks to all for the information. It helps.

To be a bit more specific, the frame that I’m working on is a late ‘40’s Schwinn lightweight. As Frank Schwinn’s inspiration to build lightweights is said to have come from a trip to England in the 1930’s, it makes logical sense that he may have followed the English practice on this.

Scarcity of original parts is why I’m searching for an alternative. I’ve read about cold setting frames due to changes in rear hub spacing but question whether 10mm on a 90mm fork is too much. I have no reason for this other than a gut instinct. If it makes a difference, the forks are chrome moly tubing, not the heavy, seemingly indestructible, high carbon steel commonly used later on.

I’d like to go back to daffydd’s comment that bolt on wheels can usually be made to fit. Would the process be to replace the stock lock nuts with something narrower? So, for example, if I had a bolt on Campagnolo track hub, I could hypothetically, narrow the spacing by replacing the lock nuts or some other component?

Thanks again for the help.

Alan

Typically, it's not practical to take a 100mm hub down to 90mm. That means removing 5mm from each side, which is a lot. On a Campagnolo hub (road or track), you would have to totally eliminate the locknuts and lockwashers to achieve this reduction. Seeking out narrower cones is also not practical, as you will lose access to the cone adjusting flats and could end up with an incompatible race profile that will accelerate wear.

I really think the most practical solution is to cold set the blades. Spreading them 10mm should not be a problem. Alternatively, you seek out a quality hub with narrower spacing, but that may take some time.