mtb-timeline

Mountain Bike Components

Dating Mountain Bikes by their Components

The idea here (in progress!) is to have a visual map of all mountain bike components available by type, manufacturer & year. Too often date attributions are missing, misleading, or have deliberate misinformation. Compochronology¹⁾ allows for a more confident provenance by bracketing possible dates by component manufacture dates. Component dating can disprove claims that bikes are all original and add confidence when everything seems period correct.

Similar timelines have been attempted elsewhere:

• mombat : simple text, no pics or links
• velobase : comprehensive - but too much info to make a visual timeline. mtbtimeline will rely upon velobase when it can. Velobase is very road bike centric and is missing most mountain components.
• vintage-trek : dating by code. Good idea. Many sites give serial number decoders, which is vital. Should be sed in addition to this visual component timeline.
• disraeligears : Rear derailleurs only. A nice example of how to make components visually cool.
• mombat SunTour museum: all the pics and links are dead.

Dating Rear Derailleurs

Other than dating headsets and bottom brackets (because they're harder to swap,) dating the rear derailleur is a reliable step, as they're very visible and come in a huge array of date limited shapes.

A Sachs Huret Duopar Eco on a 1981 Ritchey Everest The Ritchey Project
Available in 1981: check. Note that the velobase entry isn't an exact match and its dates are unsure. Looking at other 1981 Ritcheys shows the same or similar specs. Or, looking at other sites such as disraeligears confirms that these were available in 1981.

Chain Wrap Capacity

Mountain bikes need wide gearing to ride both up and down hill. The rear derailleur capacity limits the range of gears and the sizes of the freewheel and crankset. For example, with SunTour MounTech, the first mountain specific component group, the derailleur had a 34 tooth capacity. Pairing this with a SunTour Winner 14-32 freewheel implies that the chainrings can't exceed a 16 tooth difference, such as a 30-46 double. Try and use an older SunTour Cyclone (24T) then the bike would cease to be a mountain bike at all. Only derailleurs with wide ranges should be used and documented. Today (2021), touring derailleurs have the greatest capacity and mountain derailleurs often have less than 1980's derailleurs.

1995 Paul Powerglide bikemag

By the 1990s mountain bikes had established total dominance of the cycling world. Bike shops once sold 20 mountain bikes for each road bike that went out the door. And this dominance exposed an existential problem – mountain biking was fiercely Californian, forged in the furnace of individuality and exceptionalism that characterises that state – but the hardtail bikes of the time were astoundingly similar to each other. And without exception they were clothed in a near identical suit of Shimano components. Rockshox, Shimano Deore XT and a 7000 series aluminium frame – where’s the individuality and exceptionalism in that?

Enter the Paul Powerglide, the definitive US made bike-porn derailleur of the mid 1990s. It looked amazing: the colours, the CNC geometric shapes, the detailing around the adjustable cable outer stop and the adjustment screws – all of this was like water in the desert for mountain bike aficionados drowning in a sea of lookalike Shimano. The Guardian, 7 June, 2018