[CR] Road Path versus Path Racer

(Example: Events:Cirque du Cyclisme)

Date: Tue, 27 Oct 2009 00:35:05 +0000
From: "Norris Lockley" <nlockley73@googlemail.com>
To: <classicrendezvous@bikelist.org>
Subject: [CR] Road Path versus Path Racer


What at the outset seemed to be quite a simple matter of vocabulary has turned into quite a complicated debate, particularly in respect of the one brake or two on fixed wheel bikes.

In my attempt to describe the salient design and construction points of pure track bikes and the multi-use road-track, I forgot to mention at least one important design aspect. Jon Spangler's enquiry about the rear drop-outs reminded me.

On both these two types of fixed gear frames, the drop-outs were rearwards opening track drop-outs as standard. Essentially these were used in conjunction with wheel tensioners, simple devices that slotted over the rear axle and located aagainst the end of the drop-out. Their dual purpose was to prevent the rear wheel from moving forward in the slot when under severe pedalling forces, or sideways...and to provide a means of very fine tuning of the tension of the chain, bearing in mind that the steel chainrings of the 50s were often not truly circular nor flat. It was not uncommon on fixed geared road bikes to use one of those small twin-pronged devices that fitted around the seat tube just above the chainring that served to guide the chain onto the chainring and so prevent it coming off.

Another feature of most track frames, be they road-track or track specific models, was the use of round fork blades that were judged to withstand lateral forces better than the Imperial pattern narrow oval blades of that time. Pure track frames sometimes used plain gauge main tubes too, to provide a less whippy ride.

As for retracking the axle width spacing on these frames to allow for 120mm hubs, this is feasible, but frames that were built with the very popular "rapid taper round-to-round very stiff chainstays can be a bit challenging! If you do realign the drop out width make sure that you check your new chain-line and, if necessary fit a slightly longer bottom bracket axle to preserve as straight a chain-line as possible.

Jon asked about fixed gear frames using standard forward opening rear drop-outs. These were very plentiful and almost all builders would have such a frame in their range often under the model name of Club, or Time-Trial or as Ellis-Briggs had, an "Allrounder" model. These offered the rider the choice of using derailleur gears or fixed wheel, as fixing a derailleur gear to track-ends in those days, although certainly not impossible, was not the easiest manouevre. Generally these frames would have a 73 degree head angle linked up with a 71 -quite shallow - seat angle, and a 10.75 bracket height. Wheelbase, due to chainstays of about 17 inches and a fork rake of 2.25 inches would work out at around 41.5 to 42. These frames were the work-horses of 50s cycle riding..the frames that could do most things adequately and some things very well. Ellis-Briggs' "Allrounder" model could be a little misleading as the name could imply a frame that could serve every purpose but on the other hand it could also imply that it was designed for all manner and all distances of time-trials, being named after the BBAR - the *B*ritish *B*est *A*ll-*R*ounder -the annual time-trialling competition for riders competing for the best ALL-ROUND time in distances of 25, 50 and 100 miles, and 12 and 24 hours races.

Of course designers of cycle frame accessories such as drop-outs had already worked on dual purpose drop-outs such as the Super Champion and the Stallard models with a vertical slot for use with geared rear wheels and the long forward-opening slot for the fixed-gear wheels..for chain tensioning purposes.

I used to think that the best drop-out for a fixed wheel bike was the vertically slotted one used by many French frame builders on their touring bikes. Obviously these do not allow any tensionning of the chain - essential for sake use of a fixed sprocket. For quite a few years I used to build special hill-climb frames for those enthusiasts of this very dynamic and energy-sapping sport that is, in reality, time-trialling up very steep hills. The season for hill-climbing sets in in September or thereabouts and runs up until around Christmas. Races are very hotly disputed..and fixed geared, essentially track bikes, are used, especially by the purists. My hill-climb frames used to use the vertical drop-outs, but to provide for tensioning the chain I used to fit a tandem bracket shell with an elliptical bracket capable of being rotated to take up the slack in the chain. With careful calculation of chainring and sprocket size, this system proved very succesfull. Also, because the climbs were never very long and success depended on the rider starting quickly and sustaining a burst of speed over the length of the course, I adopted smaller wheels of 600mm and 650mm diameter for which light tubulars could be purchased.

One Lister contacting me Off-List asked about the nature of grass track racing. This wasn't an early form of off-road racing along grassy tracks, it involved racing around a circular grass track, usually a cricket pitch. All the usual types of track racing, such as sprints, pursuits, etc were catered for. It was hairy stuff..and I think that is still enjoyed in certain parts of the UK. In September at my Club's annual Cycling Festival, we applied to run grass track racing, particularly to involve younger riders, new to the sport. Unfortunately, in risk-averse Great Britain, the Local Authority insisted that we carry out a full and frank risk assessment analysis for insurance purposes. When we declared that there would certainly be a lot of thrills and that there might be a few spills too...they condemned the idea. So much for progress...Chris Boardman learnt his skills on the grass tracks around Liverpool!

Norris Lockley

Settle UK..going to fix a rear brake on my "fixie" tomorrow..but have some fear and trepidation.