Talk:Step-through frame

This article really needs an image to illustrate it. Hairy Dude 18:19, 31 December 2006 (UTC)

Sorted. - Ok, I'm a relative newbie here, I'm not sure who is supposed to delete the talk page now ;) Bards 23:08, 2 January 2007 (UTC)

Removed advantage

I removed "both feet can be placed firmly on the ground when standing astride the bicycle, for instance when waiting at traffic lights" because this is also a criteria for properly sizing a standard diamond frame. -AndrewDressel 18:16, 10 March 2007 (UTC)

Diamond frames are sized, to my best knowledge, by the angle of the knee and foot in relation to the pedals, to maximise pedaling efficiency and minimise knee strain. The often results in the balls of the feet touching the ground at traffic lights, in a slightly unsteady way. My contention (I am the autho of the article) is that balance is improved when stationery because both feet can be *firmly* placed on the ground, ie. both ball and heel, as if standing up normally. I know this because I ride one, and have done about 6,000 miles on it over the last 3 years. The same could also be said of "compact frames" (ie. with a sloping top tube). Bards 20:49, 10 March 2007 (UTC)

Sorry, but that is just not true. Road bikes are sized roughly so that there is about 1 inch of clearance between them and the top tube when they are standing with both feet flat on the ground. For confirmation, check any modern bicycle owner's manual. For example, here is the Trek owner's online: http://www.bike-manual.com/brands/trek/om/road/index.html. It states at the beginning of chapter 1 "Your Trek dealer should fit you with the proper size of bicycle. Make sure there is adequate top tube clearance. There should be at least one inch (25mm) clearance between the top tube and the rider when standing over the bicycle." For mountain bikes, the suggested clearance if 3-4 inches.

The distance you mention above, between the pedals and the seat, is adjust by raising and lowering the seat with respect to the frame.

I'd add this and many more references to the article itself, but can't think of a good way to reference a sentence that shouldn't be there. The best I can do for now is remove it again and hope that you check my sources. If you can find one to the contrary, I'd be happy to read it. -AndrewDressel 22:08, 10 March 2007 (UTC)

See my answer below. I will leave it up to you. Bards 00:32, 11 March 2007 (UTC)

Removed disadvantage

I have removed "more flexible, and therefore less energy efficient. More of the rider's energy is lost in flexing the non-perfectly-elastic frame than with a stiffer frame type."

In a typical low-step frame, the remaining tubes are thickened - or in the case of a Mixte frame, the tubes are doubled up - to restore stiffness. This is the reason it is heavier. Such bicycles are often much stiffer than a diamond road or racing frame, although not as stiff as an MTB compact frame. In fact, when designing road and racing frames, a certain amount of flexibility is normally seen as an advantage, and it is designed to flex. This removes the need for small-scale suspension, and improves efficiency by evening out small bumps and textures in the road surface. Bards 21:04, 10 March 2007 (UTC)

I've put it back in and added "potentially" to both. Without test data, which I cannot find, all we have are theoretical discussions. If you do have a source that verifies that a step-through frame is as stiff as a diamond frame, that would be an excellent addition to the article.

If we are going to discuss disired vs undesired stiffness, we also need to include the direction. I have read that step-through frames lack torsional stiffness, especially when climbing out of the saddle (http://www.m-gineering.nl/buizeng.htm). I believe the desired flexibility you mention above is in the vertical plane. -AndrewDressel 22:26, 10 March 2007 (UTC)

I don't have any sources for my information, except general knowledge and a lot of personal experience of one particular step-through frame, which forms the basis of the article (initially written as a stub). I realise it needs to be referenced, which I can't do, so I won't argue :) By the sounds of the m-gineering article, they are confusing the mixte (which may be flexible, I don't know) with a normal modern step-through (the one I have is very stiff). I expect there is a trade-off, where you either get more weight, or more flexibility / less strength, because you have lost the structural triangulation (which provides extra stiffness and strength for no weight penalty).

Re. direction of flex. A diamond frame, as I understand it, flexes to create a slight bulge to one side, near the pedals, keeping the saddle and bars relatively even. I'm not aware of my step-through doing this, because the tubes are much thicker and stronger than a roadie frame; and the small triangulation near the pedals (with a pedal-height top tube) creates a very stiff joint.

Anyhow, as my experience is limited, and having explained my reasonsing, I will leave it in your hands! But I think we need sources either way, since it is an esoteric art and could easily be written wrongly, even in good faith. My main intention was to start the article with a few bold assertions, to paint a general picture. Bards 00:29, 11 March 2007 (UTC)

Safety

I notice an assertion has been questioned: "if the rider is sideswiped or blown sideways, both legs will sweep through the frame and the rider is more likely to land safely." This is based purely on personal experience. Such experience must be very rare, and probably difficult to find documented evidence. I was blown off my bike by an idiot pulling a caravan, who overtook with no clearance! The air pressure wave at the front corner of the caravan physically flung me sideways onto the verge. To my great surprise, I landed on the verge already running, my legs having been swpt through the gap in the frame. If I had been riding a diamond frame, I would no doubt have landed in deep tragedy ;) Bards 00:51, 11 March 2007 (UTC)

Misspelling of mixte

This seems to be a misspelling of the mispronounciation of the word mixte. there is already an article mixte-frame with which this topic should be merged. —Preceding unsigned comment added by Will.law (talk • contribs)

Article moved to mixte (from mixtie) to correct spelling. Mixte frame appears to be in violation of copyright; we'll therefore wait for that process before merging. jareha ^(comments) 20:25, 31 March 2006 (UTC)

Center of gravity location

Advantage: "easier for riders with a low center of gravity"

I can't tell if this is serious or not. Does it mean "short" by "low center of gravity". In that case, a properly sized diamond frame should fit a short person as well as a tall person. Step-through wouldn't be an advantage. -AndrewDressel (talk) 17:19, 7 October 2008 (UTC)

Mixte Photo

This is a poor photo... the background obscures the point of the photo: to show the frame design of the bike. Anyone have a better photo? 70.165.67.131 (talk) 14:05, 28 October 2008 (UTC)

You are welcome to provide a better one. -AndrewDressel (talk) 17:42, 28 October 2008 (UTC)

Open frame

See discussion of use of this synonym on bicycle frame talk page: Talk:Bicycle_frame#Open_frame. -AndrewDressel (talk) 16:08, 2 April 2013 (UTC)

Cross [frame]

I'd say it was misleading to call the folding Dahon bike one that has a "cross" frame. Here is what always used to be called a cross-frame bike: http://www.oldbike.eu/museum/wp-content/uploads/2012/04/1917_Raleigh_Crossframe_03.jpg Thomas Peardew (talk) 18:45, 1 April 2014 (UTC)

There's a link to a Sheldon Brown glossary that would support the Dahon description, but a quick google of the word "cross-frame" gives you far more images of the old Raleigh type than the newer Dahon (and other, typically folding) bikes. Thomas Peardew (talk) 18:50, 1 April 2014 (UTC)

Drop-Frame

It has, also, been called a drop-frame.

Nantucketnoon (talk) 03:19, 8 May 2015 (UTC)