Talk:Track bicycle

Bottom bracket height

"higher bottom bracket for additional cornering clearance." I've often heard this, but have never heard how much higher.

• All I can find in UCI regulations (http://www.uci.ch/imgArchive/Rules/1gene-E.pdf) is:

Technical specifications

Except where stated to the contrary, the following technical specifications shall apply to bicycles used in road, track and cyclo-cross racing.

1.3.015 The distance between the bottom bracket spindle and the ground shall be between 24 cm minimum and maximum 30 cm.

• Cannondale (http://www.cannondale.com/bikes/03/geo-40.html) lists the bottom bracket height for their track bike is 28.2 cm.

• Fuji (http://www.fujibikes.com/geometry.asp?bike_id=17) lists the bottom bracket height for their track bike is 29.2 cm.

• Others, such as Bianchi and Surly, just say "track legal".

I get the general "heigher for pedal clearance with a fixed gear", but it would seem also to depend on crank arm length. Does anyone know what the real requirement is? How would a particular bicycle at a track event be found to be legal or illegal?-AndrewDressel 00:03, 20 October 2007 (UTC)

Crank arm length affects the leverage on the gear. So if you have a long crank arm, it has to be mounted high enough to clear corners. I belive there is a mathematical formula but I do not know it. I personally use 65 size crank arms and a bottom bracket that messures 11 and 3/4" from the ground to center of allen bolt attaching crank arms. —Preceding unsigned comment added by Mrmike23 (talk • contribs) 18:12, 9 December 2007 (UTC)

We sure would like to see that formula. Anybody? -AndrewDressel (talk) 13:29, 2 May 2009 (UTC)

I'm confused by the reasoning here. Surely a track bike will lean less relative to the surface on which it is riding; the whole point in a banked track is to stay more perpendicular to a leaning bicycle than a flat surface? 86.0.203.120 (talk) 15:27, 24 August 2008 (UTC)

That a track bike leans less on a banked track is only true when the bike is following a line concentric (I suspect that is not the correct word, but I don't think parallel is correct either, and I can't find a better alternative) to the track. During turns to avoid another cyclist, or when the bike leans from side to side during a sprint, the bank of the track is not a factor, and it is important that the pedals, which are of course forced to rotate by the forward motion of the bike, not strike the track surface. The questions remains: "What exactly does 'track legal' mean?" -AndrewDressel (talk) 17:32, 25 August 2008 (UTC)

Distinct from fixed-gear

This article does not do enough to distinguish a track bike from a fixie. It should be made clear that a track bike is a sub-set of fixie. There ought also to be a section on NJS kierin track bikes.Buffalo Bill talk to me 08:26, 11 December 2007 (UTC)

Image removed

I deleted the second "track bike" image from this article. Though it shows a track frame, it looks like a street bike and fails to reflect a bike that one might see/have seen on the track. Whoever uploaded the image makes no mention of track use, only "commercial" and street use, and also makes the patently ridiculous claim that the bike has seen 900,000 miles in 13 yrs, or close to 200 mi/day. Regardless, the remaining image preceded the deleted one, and the inclusion of the latter does not seem to contribute any additional informative content. Gerta (talk) 16:00, 15 September 2008 (UTC) And who makes you king bee. I actully seen that blue bicycle in the 1996 Olympic Tryouts. And the image on this page IS NOT A TRACK BICYCLE. Wrong frame. Wrong angles. And not track legal. --ben — Preceding unsigned comment added by 74.82.64.161 (talk) 12:38, 3 October 2014 (UTC)

Off-track use of track bikes

A guy who works at my local bike shop tells me that he commutes to work using a track bike. He likes the fact that it's very light (16 lbs.?) and low-maintenance, having no gears to clean or brakes to maintain. ("I'd rather spend more effort pedaling and less cleaning.") Also, the fact that the single gear is fused to the wheel means that more of the pedaling effort is transmitted to the wheel.

I asked how he controls the bike without brakes, and he pointed out that a track bike can't coast -- the pedal spin rate is directly proportional to the speed -- so you slow down by backpedaling, i.e., preventing the pedals from spinning as fast. It would be helpful to cover this point in the article. Eclecticos (talk) 05:39, 12 January 2009 (UTC)

I've never heard before that "more of the pedaling effort is transmitted to the wheel" on a fixie. I can't think of how it could be true. In any case, the point that a track bike is a fixie is a good one, and so I've added a wikilink in the lead section to that article. -AndrewDressel (talk) 13:47, 12 January 2009 (UTC)

Geometry

I just wanted to point out that a typical track bike geometry may involve a seat tube angle of 74 degrees, which is also used on many geared road bikes and touring bikes.

Also Head tube angle does not define how a bike handles, its only one of the components that is used to determine geometric trail and wheel flop which actually do define how a two wheeled vehicle handles. A typical track bike front end geometry would be along the lines of a 74 degree head angle with 35mm of rake, this gives a geometric trail of 60mm and a wheel flop value around 16mm, numbers that are very close to rear-loaded touring bicycles. Greater geometric trail actually makes a bike more stable and less resistant to course changes.

Why is this? Because track bikes don't have to turn as much on a banked velodrome and they also need to be stable in a close pack of cyclist jostling for position. The reason a track bike will feel like it turns quicker is due to the wheel flop being moderately high which means the bike will more readily lean over into a turn. They also tend to have low pneumatic trail (read: skinny tires) which can also make their handling feel quicker. All this amounts to a bike that can be placed very precisely where the rider needs it to go but still remain stable.

Jamis Sonic track geometry: http://www.jamisbikes.com/usa/thebikes/road/sonik/09_sonik_geo.html

Mercian King of Mercia touring frame geometry: http://www.merciancycles.co.uk/frame_king_mercia.asp

Trail and flop calculator: http://yojimg.net/bike/web_tools/trailcalc.php —Preceding unsigned comment added by 72.40.132.127 (talk) 19:10, 6 April 2009 (UTC)

There is more discussion on Talk:Bicycle_and_motorcycle_geometry#Wheel_flop. -AndrewDressel (talk) 20:13, 6 April 2009 (UTC)

Come on, nothing about disk wheels?

That's the first thing an Olympics viewer notices about the bikes. And why does the London 2012 velodrome have so much black in it's color scheme? 12.196.0.56 (talk) 20:29, 3 August 2012 (UTC)

Many track bikes don't have them, especially when used on outdoor tracks. Severo^TC 07:45, 4 August 2012 (UTC)

Pedal types

It would be nice to talk about pedal types like the use of leather straps or clip less cleats like SPD's. Then talk about aerodynamic shoe covers perhaps. I have used SPD pedals but found they didn't lock on good enough for braking. And I used straps but like SPD pedals they slip off and break. For 10 years not I have been happy with atac clip in pedals. I replace the cleats yearly and my current pedals are 10 years old and not one slip-off. --ben — Preceding unsigned comment added by 86.163.223.17 (talk) 07:59, 29 December 2012 (UTC)

Please do. Just remember to provide reliable sources. -AndrewDressel (talk) 13:11, 3 October 2014 (UTC)