air king

I found this photo on cyclingnews.com. Does anybody know what sort of event this is? The pace bike and the bicycle both look odd to me.

I've seen Keirin photos, but the bicycle frames here look totally different.

bostontrevor

This is motorpacing. The motorcycle is called a derny (after the long-time manufacturer of said machines) and the bike is a stayer. Stayers feature reversed forks which allow them to draft closer to the derny. Speed is the name of the game.

air king

Thanks for the quick reply.

What's with the long steerer tube?

It seems as though if speed were so crucial they might want a more aero position also.

(Not that I know a damn thing about track racing!!)

Growing up I used to watch the ESPN broadcasts from the Sunkist Velodrome. Man that was some great racing to watch. Beats the hell out of most other sports. That's about my only exposure to the sport though.

bostontrevor

Got me, I've pretty much tapped my knowledge. I could venture a guess and say that it's less important to remain aero and more important to breathe given that the derny provides a draft for the cyclist. But that's just a guess.

HigherGround

I'm not 100% certain, but I believe the reversed fork helps to improve the stability and handling at the higher speeds. Given the nature of this event, quick turns aren't nearly as important as stable handling.

Ceya

It is now a lost art. Yep it is called Motorpacing. The reason for the reverse wheel was that the rider get so close to the pacer's bike the wheel touched and it gave them better control over the bike. The bike is called a STAYER.

A lil improvement on what Boston Trevor stated earlier.

S/F,
CEYA!

P.S. Link>> https://www.e-paranoids.com/d/de/derny.html..

Derny Guide, Meaning , Facts, Information and Description
A Derny is a type of motorcycle designed and built specifically for motor-paced track cycling events (motor-paced road, 6-Day and Keirin racing). On a Derny, the driver sits close to the back of the bike in an upright position in order to block the "wind" for the cyclist drafting behind the derny. There is a "roller" mounted to the rear of the bike to prevent crashes should the bicycle come in contact with the derny.
In some events, the derny is used to bring the bicycle up to speed at which point the derny "pulls off" and the cyclist continues the race on their own. For other events, the cyclist drafts off the derny for the durration of the event. For world speed records, the bicycles generally do not have the ability to change gears and the gearing is too high to allow the cyclist to start from a stop without assistance.

The first Dernys were built by Roger Derny and Sons of Paris, France in 1938. That firm is no longer in business and the name "Derny" is now applied to all such vehicles, regardless of manufactuerer.

Bicycles built specifically for drafting behind a derny are called Stayers.

see one here at the US Cycling Hall of Fame
Right side behind the STARS and STRIPES Jersey

ink1373

the derny rider seems to have flipped knee joints to match the flipped fork...or maybe i'm just going nuts.

bostontrevor

You're going nuts.

It's just the wind blowing their snappy leather pants back.

crustedfish

hence, the "stayer lines" on a velodrome.

glowingrod

You wouldn't need an aero position at all with a wall in front of you, like drafting a bus.

ch0mb0

reminds me of "Rollerball"...but with bikes

pgringo69

is that Dieter & friends driving the Dernys?



or maybe the nihilists from Autobahn?

WorldWind

The longer head tube is to accommodate the smaller front wheel.

trekkie820

what kind of speeds do they reach?

ch0mb0

and can you flip the fork just like that on any bike?

icithecat

Running motorbikes in an enclosed velodrome must have been good on the lungs. No wonder it is a lost art.

ryan_c

https://www.bikeforums.net/singlespeed-fixed-gear/71710-ghetto-fork-cog-questions.html

velodromes

The term DERNY is not the right term for the motorbikes, which you see on this pictures.
A DERNY is more like a moped, a bicycle frame with a small motor

Those black monsters on the photo are the REAL Pacemaker-motorbikes from the beginning of the last century.
The picture is taken on the 200 m track in Dortmund/Germany during the "Big Christmas Prize", held each year at Christmas.
The motorbikes typically have a big engine (1000 ccm or more) with a fly wheel and only one or two gears and no mufflers . Power transmission by a belt. They can achieve speeds up to 130 km/h (70 mph) and were built for the long stayer-tracks of 333 and 400 m, which were so popular in the 1920 and 30ies.
Get some more impressions from this time under: https://home.t-online.de/home/Roland....n/cyclerie.htm (unfortunately only in German, but good pictures )

The motorbikes on the picture are originals from the 1920ies with copper-tanks, which are kept in shape by an enthusiastic pacemaker from Dortmund.

Unfortunately stayer races are not anymore part the UCI-World-Championship programm and therefore have been out of fashion in the last years. But there is still a good community of stayers in Europe, which organises races on a high level.

The race is actually made by the pacemaker and the rider "just has to take care", that he stays as close a possible to the "roll" in order to receive the best wind-shadow and to make riding for him easier.
The long handle bars of the pace-maker allows for fine steering and the speed is regulated by a notched grip, which allows for smooth accelleration. The overall speed can somehow also be regulated by the distance of the roll from the motorbike (shorter=more wind-shield=faster).

Note the position of the pacemakers in their normed black leather suits sitting as much as possible in the back of their bike for maximum wind-shield.
Note also the pacemakers helmet, where the "auricles" are open backwards, trying to hear the riders commands in the noise of the machine.
Basically there are just two commands possible at this kind of speed.
1) Alléz (french) = GO (faster) or
2) "OOOOOOOOH", when it has become too fast for the rider
If the rider comes "off the role" he is virtually thrown back by the wind resistance and the pacemaker must slow down considerably to pick up his rider again behind the motorbike, while the other teams pass above them and gain lap by lap.

There are plenty of clean and unclean tactics in this kind of racing and it can be really fun to watch, when two or three teams next to each other drift through the steep bends of a stayer velodrome at car speed accompanied by the ever-rising blobbing sounds of the motorbikes and a cheering chrowd.

It would be real fun to revive this discispline.

bikejack

Derny racing is still a UCI event with the smaller 50cc Moped style Derny's with no roller and normal Track bikes, the riders sit in closer to the mudguard of the bike and call out the same, they reach about 50mph.

They are still exciting races and the tactics are the same. There is no speed restriction but restriction on the riders maximum gear for the event 102" I think but don't quote me. The UCI tech regs has a full section including design of the bikes.

The style of event pictured is the type Eddy Merckx broke his back in before winning another four tours, now thats a comeback.

bostontrevor

He also killed one of his pacers. He claimed that he was never the same after. Who knows what he might have been if not for that accident.

hair07

that sounds really cool. i would love to see a race.