Ann87
Dirt Disciple
Anyone interested in helping to establish the definitive Dirt Drop handlebar history?
For the sake of technical clarity I propose adopting the language defined by this ridinggravel.com article defining "flare" and "sweep" as angles of the drops in the vertical and horizontal planes, respectively, while recognizing that in the past it seemed that many manufacturers did not differentiate and instead called all dirt-specific bar manipulation "flare." I will also be following that article's other "anatomical" definitions for simplicity sake.
I'll tentatively define Dirt Drops as ATB/MTB-specific modified drop bars.
As with most things, it seems that the basic design of flared handlebars (that allowed for both more room for wrist motion while in the drops and greater leverage while holding the extensions) was explored early on by the French/Euro Randonneur set.
However, the standard narrative is that Charlie Cunningham pioneered the use of modified Cinelli Giro D'Italia 64-42 (and/or mod 65) handlebars for MTB and cyclocross use sometime in the very early 80s, after perhaps having used unmodified drop bars as early as 1979. I can't remember reading any articles that pin down these early dates in a more definitive way but perhaps somebody has that? The modification performed was "flaring," which presumably affected both the flare and sweep. The early hand-modified Cunningham handlebars are reported to have been bent and not subsequently heat treated. I don't know if these were marketed or sold to the public at large.
When asked about drop bars on MTBs, Charlie had this to say:
"Drops have more hand positions and absorb shock better
because they’re longer but I like them mainly because their
shape is more ergonomically and aerodynamically efficient
than flat bars. The more upright position of flat bars mostly
limits leg power to the resistance of body weight. On drops,
when you stand, your hands are lower and closer to the
body so you can resist your leg muscles with your back to
get more power. This really pays off in climbing. I’m lucky
because I have pretty long arms which allow me to ride
steep, technical descents with drops by sliding off the back
of the saddle to keep my weight low over the rear wheel.
People with short arms using drops may have problems in
some offroad situations. The bummer is that my knuckles
drag in the dust when I walk."
Source: Rivendell Reader Summer 2022
Obviously, a number of racers also used standard road drop bars on MTBs through the 1980s and into the 90s, including Dave Mac who raced a Jim Merz built Team (Pink) Specialized Stumpjumper in 1984. Apparently, he had illicitly converted to road drop bar use the night before the race, which Specialized did not appreciate... yet. In any case, without FLARE, that's a different story!
Until other documents prove otherwise, Gary Klein is likely to have sold the first production MTB that came factory assembled with Dirt Drop bars in 1985. The Mountain Klein Race presumably did not sell well because there are very few (or no?) surviving original examples. The Race specification presaged (or perhaps mimicked) a lot of Charlie Cunningham design elements, including flared drops--with shifters mounted inboard of the brake levers--and the use of Harlan Meyer's lightweight hubs.
Look ma, no bar-cons!
I believe the above picture shows obvious added handlebar sweep, if not much flare. We can hope or assume that the "modified Cinelli" handlebars were heat-treated after bending, given that Klein was an established aluminum outfit. I believe that the shifters are just normal SunTour 4700 XC-Sport Power Thumb Shifters, with the only modifaction being necesary for mounting in that position being the use of a different bar clamp band.
If someone has the Mountain Bike Action Magazine review (1986?) of the Mountain Klein Race, scans would be very appreciated.
Next seems to be the 1987 Bridgestone/Nitto DirtDrop that came on the MB-1 of that year.
bikerecyclery.com "online museum" entry Nitto MB-1 DirtDrop
Bridgestone Catalog Scan (hard to read)
This handlebar is reported to have been designed by Grant Petersen. Either way, if you squint you can read that the lower grips are "flared" (swept) 12 deg for wrist clearance while climbing or sprinting. Depending on the photo angle, the (true) flare looks moderate. 12 deg of "flare" is a recurring figure in moderate dirt drop bars.
By 1987 we also have Wilderness Trail Bikes listing their own Aluminum (heatreated) Handlebars.
What is listed as a 1988 WTB catalog (but which may actually be later?) has a more expansive description of a Drop Bar that makes it clear that at this point we have reached the radically flared and swept WTB RM-2 type, in design if not in name. This is confirmed by the 5" drop, 3" reach 25 deg flare figures.
Also in 1988 the Bianchi Axis featured a Nitto DirtDrop bar. A review of the Axis gives the handlebar measurment figures of 41cm at the hoods and 46 at the ends, which pretty much lines up with the measured dimensions of the MB-1 DirtDrop listed above.
A vintage Nitto RM-014 dirt drop recently listed on ebay proves that Nitto had still other dirt drop offerings. The W520 marking on it indicates that it's too wide to be the DirtDrop offered on the Bianchi. Confusingly, Nitto now offers an updated RM-014 with a thoroughly modern 31.8 clamp dia and radical flare and sweep. I don't know about you, but I kind of wish that Nitto didn't re-use their model designations...
The 1989 Nitto catalog lists RM-013 handlebars under the mountain bike section but not an RM-014. There's some disagreement about whether the RM-013 really counts as a dirt drop, although it is very slightly wept in the extensions (perhaps 7 deg).
Next in the lineup appears to be the 1989 Specialized BB-1, which was reportedly made for Specialized by WTB but is much more moderate than the WTB RM-2. These are measured at a little over 19 inches wide at the ends of the extension (the widest point) as opposed to the RM-2's approximately 24 inches.
bikerecyclery.com "online museum" entry Specialized BB-1
Then in 1990 we see the Ibis Dirt Drop, which according to most people on various forums is the same handlebar which you see stamped "Specialized RM-3", (not to be confused with the current Nitto RM-3). The "flare" is listed at 12.5 degrees, though I expect that is what we would today call sweep. Indeed it has been noted that the Ibis RM-3 has some sweep and not much flare, but instead makes room for wrists by adopting a criterium or pista-ish curve into the drops off the top section.
Bikeforums thread with pictures of the RM-3
The Radavist 1984 Salsa with RM-3 handlebar
There is an interview with Charlie Cunningham where he says that one of his favorite bicycles has RM-3 handlebars custom bent to have even more "flare", so apparently that was a thing.
In any case, by 1995 and 1996 the main remaining dirt-drop option appears to have been WTB's RM-2 (originally introduced as early as 1986) which was sometimes imported with Specialized markings and may have had subtle generational differences.
Presumably, it was the RM-2 which influenced the recent dirt drop and then gravel bar renaissance. Budget-conscience shoppers may be interested to know that the current production Nitto RM-3 is essentially a carbon copy of the WTB Specialized RM-2. However, if someone wants a dirt drop that mimics the older, less-flared-and-swept offerings, there are scant options available, outside of perhaps the Origin-8 Gary II bar or the very touring-oriented Nitto RM-13.
So, what have I missed? Weren't there some Italian-made dirt drops? Let's start filling in the gaps!
Miscellaneous commentary:
https://www.mtbr.com/threads/any-vintage-drop-bar-mtbs-out-there.85975/page-2
https://www.mtbr.com/threads/how-many-versions-of-the-wtb-drop-bar-are-there.348711/
https://www.wtb.com/blogs/wtb/16604...uJbqy37mliugu43X6Dtt9J2U12R3Xn10U_PIJlp_yT6fW
https://www.mtbr.com/threads/possible-source-for-wtb-dirt-drops.11233/
https://bikepacking.com/bikes/13-best-drop-bar-mtb/
For the sake of technical clarity I propose adopting the language defined by this ridinggravel.com article defining "flare" and "sweep" as angles of the drops in the vertical and horizontal planes, respectively, while recognizing that in the past it seemed that many manufacturers did not differentiate and instead called all dirt-specific bar manipulation "flare." I will also be following that article's other "anatomical" definitions for simplicity sake.
I'll tentatively define Dirt Drops as ATB/MTB-specific modified drop bars.
As with most things, it seems that the basic design of flared handlebars (that allowed for both more room for wrist motion while in the drops and greater leverage while holding the extensions) was explored early on by the French/Euro Randonneur set.
However, the standard narrative is that Charlie Cunningham pioneered the use of modified Cinelli Giro D'Italia 64-42 (and/or mod 65) handlebars for MTB and cyclocross use sometime in the very early 80s, after perhaps having used unmodified drop bars as early as 1979. I can't remember reading any articles that pin down these early dates in a more definitive way but perhaps somebody has that? The modification performed was "flaring," which presumably affected both the flare and sweep. The early hand-modified Cunningham handlebars are reported to have been bent and not subsequently heat treated. I don't know if these were marketed or sold to the public at large.
When asked about drop bars on MTBs, Charlie had this to say:
"Drops have more hand positions and absorb shock better
because they’re longer but I like them mainly because their
shape is more ergonomically and aerodynamically efficient
than flat bars. The more upright position of flat bars mostly
limits leg power to the resistance of body weight. On drops,
when you stand, your hands are lower and closer to the
body so you can resist your leg muscles with your back to
get more power. This really pays off in climbing. I’m lucky
because I have pretty long arms which allow me to ride
steep, technical descents with drops by sliding off the back
of the saddle to keep my weight low over the rear wheel.
People with short arms using drops may have problems in
some offroad situations. The bummer is that my knuckles
drag in the dust when I walk."
Source: Rivendell Reader Summer 2022
Obviously, a number of racers also used standard road drop bars on MTBs through the 1980s and into the 90s, including Dave Mac who raced a Jim Merz built Team (Pink) Specialized Stumpjumper in 1984. Apparently, he had illicitly converted to road drop bar use the night before the race, which Specialized did not appreciate... yet. In any case, without FLARE, that's a different story!
Until other documents prove otherwise, Gary Klein is likely to have sold the first production MTB that came factory assembled with Dirt Drop bars in 1985. The Mountain Klein Race presumably did not sell well because there are very few (or no?) surviving original examples. The Race specification presaged (or perhaps mimicked) a lot of Charlie Cunningham design elements, including flared drops--with shifters mounted inboard of the brake levers--and the use of Harlan Meyer's lightweight hubs.
Look ma, no bar-cons!
I believe the above picture shows obvious added handlebar sweep, if not much flare. We can hope or assume that the "modified Cinelli" handlebars were heat-treated after bending, given that Klein was an established aluminum outfit. I believe that the shifters are just normal SunTour 4700 XC-Sport Power Thumb Shifters, with the only modifaction being necesary for mounting in that position being the use of a different bar clamp band.
If someone has the Mountain Bike Action Magazine review (1986?) of the Mountain Klein Race, scans would be very appreciated.
Next seems to be the 1987 Bridgestone/Nitto DirtDrop that came on the MB-1 of that year.
bikerecyclery.com "online museum" entry Nitto MB-1 DirtDrop
Bridgestone Catalog Scan (hard to read)
This handlebar is reported to have been designed by Grant Petersen. Either way, if you squint you can read that the lower grips are "flared" (swept) 12 deg for wrist clearance while climbing or sprinting. Depending on the photo angle, the (true) flare looks moderate. 12 deg of "flare" is a recurring figure in moderate dirt drop bars.
By 1987 we also have Wilderness Trail Bikes listing their own Aluminum (heatreated) Handlebars.
What is listed as a 1988 WTB catalog (but which may actually be later?) has a more expansive description of a Drop Bar that makes it clear that at this point we have reached the radically flared and swept WTB RM-2 type, in design if not in name. This is confirmed by the 5" drop, 3" reach 25 deg flare figures.
Also in 1988 the Bianchi Axis featured a Nitto DirtDrop bar. A review of the Axis gives the handlebar measurment figures of 41cm at the hoods and 46 at the ends, which pretty much lines up with the measured dimensions of the MB-1 DirtDrop listed above.
A vintage Nitto RM-014 dirt drop recently listed on ebay proves that Nitto had still other dirt drop offerings. The W520 marking on it indicates that it's too wide to be the DirtDrop offered on the Bianchi. Confusingly, Nitto now offers an updated RM-014 with a thoroughly modern 31.8 clamp dia and radical flare and sweep. I don't know about you, but I kind of wish that Nitto didn't re-use their model designations...
The 1989 Nitto catalog lists RM-013 handlebars under the mountain bike section but not an RM-014. There's some disagreement about whether the RM-013 really counts as a dirt drop, although it is very slightly wept in the extensions (perhaps 7 deg).
Next in the lineup appears to be the 1989 Specialized BB-1, which was reportedly made for Specialized by WTB but is much more moderate than the WTB RM-2. These are measured at a little over 19 inches wide at the ends of the extension (the widest point) as opposed to the RM-2's approximately 24 inches.
bikerecyclery.com "online museum" entry Specialized BB-1
Then in 1990 we see the Ibis Dirt Drop, which according to most people on various forums is the same handlebar which you see stamped "Specialized RM-3", (not to be confused with the current Nitto RM-3). The "flare" is listed at 12.5 degrees, though I expect that is what we would today call sweep. Indeed it has been noted that the Ibis RM-3 has some sweep and not much flare, but instead makes room for wrists by adopting a criterium or pista-ish curve into the drops off the top section.
Bikeforums thread with pictures of the RM-3
The Radavist 1984 Salsa with RM-3 handlebar
There is an interview with Charlie Cunningham where he says that one of his favorite bicycles has RM-3 handlebars custom bent to have even more "flare", so apparently that was a thing.
In any case, by 1995 and 1996 the main remaining dirt-drop option appears to have been WTB's RM-2 (originally introduced as early as 1986) which was sometimes imported with Specialized markings and may have had subtle generational differences.
Presumably, it was the RM-2 which influenced the recent dirt drop and then gravel bar renaissance. Budget-conscience shoppers may be interested to know that the current production Nitto RM-3 is essentially a carbon copy of the WTB Specialized RM-2. However, if someone wants a dirt drop that mimics the older, less-flared-and-swept offerings, there are scant options available, outside of perhaps the Origin-8 Gary II bar or the very touring-oriented Nitto RM-13.
So, what have I missed? Weren't there some Italian-made dirt drops? Let's start filling in the gaps!
Miscellaneous commentary:
https://www.mtbr.com/threads/any-vintage-drop-bar-mtbs-out-there.85975/page-2
https://www.mtbr.com/threads/how-many-versions-of-the-wtb-drop-bar-are-there.348711/
https://www.wtb.com/blogs/wtb/16604...uJbqy37mliugu43X6Dtt9J2U12R3Xn10U_PIJlp_yT6fW
https://www.mtbr.com/threads/possible-source-for-wtb-dirt-drops.11233/
https://bikepacking.com/bikes/13-best-drop-bar-mtb/
Last edited:
When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
