Barrettscv 

What year did vertical drop-outs come into wide-spred use?

Pars 

The '73 RRA I have is the first I've seen them, but they may have been used earlier than this?

I had read that they were available around '68 or so.

Bianchigirll 

I believe most MTB builder switched to them in the very late '80s and most road bikes did likewise in the very early '90s

rhm

I'm pretty sure I've seen them on bikes as old as the 40's but I wouldn't say they were in widespread use before the 80's.

jrecoi

I think it depends on what kind of bike. If I'm not mistaken, touring bikes had them before road racing bikes and mountain bikes. The rise of vertical dropouts, or the persistence of horizontal dropouts is a mix between the prevalence of derailers, and the need to be able to limp back home on a jury rigged ghetto singlespeed.

Touring bikes were pretty much the first to have derailers, reliable rock crushers like the Cyclo Standard since the early 30s. For them vertical dropouts came early, including odd hybrids with horizontal dropouts like the Osgear, which had a separate vertical dropout placed in front of the horizontal dropout. Horizontal dropouts were used in lower end tourers, although the typical setup was to have the wheel slammed all the way back.

Mountain bikes retained horizontal dropouts for quite a while despite having used derailers since the beginning due to the tendency of derailers to catch branches and break or bend derailer hangers, forcing the mountain biker to cut chain and limp on a ghetto singlespeed back home. The switch to vertical dropouts in this case came about from the advent of replaceable derailer hangers.

Road racing bikes persisted in having horizontal dropouts at least until the combination of reliable neutral support and shorter races/race stages eliminated the need for the racer to singlespeed his bike in a manner much like the mountain biker. In addition, the racer, much interested in the speedy performance of his derailers needed a much finer control over the positioning of the cog set vs the tourer. Fads, such as steep frame angles and ultra-short-tire-rubbing-the-seattube chainstays also had a hand in extending the use of horizontal dropouts.

dbakl

They were around in the 70s, but not seen a lot. Supposedly they required a lot more precision from the frame builder than the horizontal ones.

busdriver1959

I think an additional factor was thr rise in the number of aftermarket quick releases for wheels. These started popping up in the late eighties. The point was to shave a couple of grams from the bike. Unfortunately, these products didn't grip very well. The rear axle tended to slip forward on the drive side when in low gears and high load. Rather than spec a QR that worked, the manufacturers solved the problem with vertical dropouts.

nlerner

Lots of interesting speculation on this 10-year-old rec.bicycles.tech thread, including contributions from Sheldon Brown, Jobst Brandt, and Andy Muzi:

https://groups.google.com/forum/?fro...ch/4Kw1mfZIEiY

wahoonc

My best guess would be 1990's. Most of the bikes I have are older than that and they mostly have horizontal drop outs. That being said, I have a 1989 MTB that has the horizontal, but they are plugged so the axle is fixed in place.

Aaron

john hawrylak

I remember an article on Sheldon Brown's site stating the vertical DOs were required to obtain the accuracy needed for indexed shifting.

marley mission

Hmmmm
Makes sense I guess

Bianchigirll 

I think I recall seeing something like that, maybe even here on the forums at one time.

balindamood

My understanding:

-Slotted dropouts provided some wheel adjustment which helped with setting up the rear derailleur in the days before most deraillers had a "B-screw" (the one on the knucle by the derailleur hanger). Campaganolo was a late adapter of the B-screw, and a prolific maker of dropouts which everyone else copied without much thought as to function. It also mildly adjusts the wheel base, which some (incorrectly) feel it made a diiference. Slotted DO's also are a bit more forgiving to the frame builder as they can be off a hair without fouling up the bike alignment.

-Vertical drops seems to appear in the 70's, and started more mide spread use in the 80's. Although requiring more craftmanship than slotted, they allowed for the easier removal of wheels on bikes with fenders, and generally are stronger. I belive that this is actually what encouraged the change, as very rarely have I seen a vertical dropout break.

I do not agree with the "required for indexed shifting" statement above as early Suntour versions required some movement for and aft of the rear axle to get Accushift to fully work correctly. They were kind enough to go bankrupt, so now it does not matter since Campagnolo was able to figure out how to make SIS work decently about the same time.

I do suspect that the actual casting of vertical drops is easier than horizonal ones. Because manuafturing precision and accuracy have progressed, it is an easier change to make, and thus desireable. I will also note that big-box bikes still largely come with slotted drops, which are stamped, not cast.

Jeff Wills

Depends on what you mean by "wide spread use"...

I'd say late '80's, early '90's. Mountain bikes first, then road bikes switched over. Indexed shifting did drive manufacturers to tighter tolerances in manufacturing, which (in turn) made it easier to implement vertical drops.

lee kenney

MTB , Trailmaster had a nice fabricated VD {1980 ** , Joe Breeze had a nice VD casting , Ritchey also

Jeff Wills

Campagnolo No. 15 catalog shows vertical dropouts in 1967.
https://www.campyonly.com/history/cat...catalog_15.pdf (page 31)

T-Mar

I firmly believe that the widespread adoption of vertical dropouts was driven by the need to ensure optimum performance of indexed shifting sysyems. Horizontal dropouts allow ignorant owners to inadvertently change the chain gap, which is critical to indexed shifting. Vertical dropouts are a step in mistakeproofing indexed shifting for owners and mechanics.

CrankyFranky

I specified a sport tourer in early 1981 from a small English builder when I first moved there. It wasn't much of a discussion point - loaded or unloaded, the perception I got from the shop owner was that verticals are just better and have no unarguable drawbacks, even if I wasn't set on touring. Since my plan was to do more cycletouring (tent and the works, but light) and since I had found removal of a rear wheel from a loaded bike can be challenging without deflating the tire, I went with the recommendation. Never regretted it, however conservative I am.

Andrew Muzi in the above-referenced Google Group said "Bob Jackson, Jack Taylor and other small builders were offering them on touring machines in the sixties." It's clear that individuals who had small- to medium-sized frame businesses had made the switch two decades before it became somewhat more common. (as an aside, the other points from that discussion that surprised me were that: a. the chainstay bridge was devised merely to stop wheels from jamming and not for structural rigidity and b. the forward load on the rear axle can surpass normal downward loads).

When the question is put this way "when did the big corporations change over to verticals", the answers only illustrate the point that large businesses tended to be very conservative w.r.t. design until the mountain bike movement shook the design paradigms to the core. Building bicycles was a narrow - margin business. Don't forget that many larger marques were simply disappearing, only the names being sold.

Ask the question "why was Trek still building their 1980s frames with horizontals?" of the original Trek guys and you'll probably get a number of different answers, some of which may come close. I can't imagine that the decision was to decrease a few rejections at QC. I think it was simply blind tradition - not wishing to get a critical style detail wrong and sink the company.

frantik

uh, i have 3 mtbs, all from the 80s, and all have vertical drop outs without replaceable derailleur hangers. the earliest one was manufactured in 1985

balindamood

I have seen a number of mid-level Centurions from '82-84 that had vertical drops...just to confuse the data.

well biked

My '83 Centurion Pro Tour (their top-line touring bike) has Suntour vertical dropouts as well.

Bikedued

Go figure, but I have a seemingly low end Vista Elite from the early 80's, but it was spec'd with Shimano 600 Arabesque, and made from Araya "631" tubing. Yes it has turquoise/greenish lettering on the 631, on a black label. The paint scheme is a ripoff of a mid seventies Motobecane. black with red head tube, and two red seat tube bands. Even the head badge looks oddly Moto-esque? The weirdest part? It has vertical dropouts? Strange bike!

I have seen verticals on a few Nishiki models, too. Early eighties..?

Catnap 

Vertical drops go back to the 1930's as noted above. Here are two examples of the Osgear type:

fietsbob

The Index shifting made them, a requirement for most people.. axle always in same spot .

Catnap 

looking at those Osgear drops, I'm wondering why bike evolution moved away from the long guide rail in front of the drop and instead moved the guide to the rear.

like so: