Track Frame Rear Geometry?

I’ve been looking at a couple of different vintage track frames and I’ve found the variance in rear geometry to be quite surprising. I’m basing my observation on how tight the rear wheel can sit against the downtube of the frame. Some can be within a hairs breadth of touching and others may be 2 inches out (this is comparing both wheels at their min within the fork end). The difference is obviously in the lengths of the stays so can anyone suggest why they would vary so much, maybe for different types of track races? What difference would it make to the ride of the bike?

Note: to clarify a point - both framesets have minimal clearance in the front forks b/w the tyre and the crown.

Thanks in advance

Back in the day they’d race anything from smooth concrete banks to rutted dirt tracks. I have an old frame from the late 40’s and the original owner had told me the geometry was a designed little slacker with a touch more fork rake and with a slightly longer wheelbase as it was primarily used for grass track racing. Yes Grass Track … in the wet it was a handful so a longer wheelbase was much preferred.

To explain why they did this take your late 80’s short wheelbase, 76 degree headtube bike for a spin on a dirt road or on some soft sand :wink:

Also seat tube were a lot slacker back in the day because the commonly used Brooks saddle had rails that were short and thus sat more forward than is commonly found today. The seat position in relation to the pedals and bars is similar, just going about it differently.

Lastly, on older bikes tyres were commonly much wider than they are today (even tubulars). And after the silly 80’s/90’s fad of super thin tyres we are now seeing that overall (even in racing circles) tyres are going back to wider and more sensible widths. A lot of people do up older bikes with modern narrow tyres and their not experiencing handling as it was intended, skinny tyres upset the balance.

You can’t always write off an older bike because of larger clearances or a longer wheelbase by comparing them to today’s standards. They were designed and made that way for a reason. It’d be like passing up driving a Porsche 356 because it didn’t have traction control and airbags.

If your riding the bike on the street I’d much prefer the slack angled, long wheelbase bike that has clearance for wide tyres. And by wide tyres I mean good wide tyres with supple casings and light weight, not tractor casings as people commonly think. Ask around there’s plenty of interest on wide tyres recently with a few clear standouts.

For a primer …
and have a read of

A traditional Scottish racing format, still practiced by retro kooks in parts of the UK. Among other places it used to happen annually at the Maryborough Highland Gathering in central Vic, as a support event for the Maryborough Gift, along with caber tossing, haggis eating etc. Run on the footy oval IIRC. Saw it a few times as a (very) young kiddie. Now I think they just do Penny Farthing races up there?

Thanks for the great responses, grass track racing’s a new one for me. Spiritos, thanks for the tyre articles - proved to be a interesting read and I’ll be looking into some wider profile tyres henceforth. Unfortunately I think I was a little liberal in applying the term Vintage (an err drawn from ebay no doubt) I was trying to avoid people suggesting the bikes were modern fixed commuters rather than track bikes. As it is the frames in question range from late 60’s to early 80’s and funnily enough its not the earliest bike that has the looser rear. I don’t believe its a disparity drawn from tyre or wheel size as they all appear to be set up for 700’s. Any other ideas?

my coach told me he raced the grass track at maryborough one year. he said once was enough.

I’ve looked around a bit for easily available fast clinchers in wider sizes and there isn’t a lot to choose from.
Vittoria Rubino Pros go up to 28 mm but I haven’t seen them stocked in the online stores. Vittoria Diamante Pros and Evo CX, Michelin Pro3 race go up to 25 (soooo wide :slight_smile: ) and are available online.

Agree, I have a set of Pro Race2’s in 25mm that are more like 28’s. Alas, all the good wider tyres are online as nobody I know of stocks them (Commuter Cycles might have Grad Bois tyres). I have a set of Grand Bois 26mm’s Cerf’s and I like 'em a lot. Look very classic too. Might try their 28’s and 30’s soon.

I haven’t tried them but Challenge Parigi-Roubaix’s clincher’s are supposed to be the shizzle. Quoted at 27mm but run a bit wider and still only 260 grams. Also available at Velo Orange if that makes easier for ordering other stuff and making it worthwhile for shipping.

Careful though, you’ll get hooked on nice tyres and going back to a bike with Vittoria Randonneur’s, Specialized Armadillo’s or Conti Gatorskins just feels terrible with little feel and just plain sluggish. They last long and are tough but are just lifeless to ride.

who knows?

Could be a road frame with converted ends? does it have a front brake hole?

are they small frames? I’ve seen a few builders use longer stays in smaller frames because they otherwise handle like shit?

Maybe the 80’s frame was built by a less experienced builder? It takes a bit of know how and time to ensure your tight geometry isn’t too tight to be useless, so a little bit of leeway is a safer option.

anyway, it’s hard to say :?

i have never been able to get a grip on it

Right, 48 hour ban.