What is the diameter of the handle bar on a mid 1980s Trek 520?
10-15-17, 07:39 AM
#2
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,725
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Mentioned: 140 Post(s)
Tagged: 1 Thread(s)
Quoted: 5792 Post(s)
Liked 2,582 Times
in
1,432 Posts
Assuming you have original aluminum drop bars, then odds are it's 26.0mm which was the standard for road bars until fairly recently.
However, there's a small possibility that it 25.4mm (1").
The difference is big enough that you can make a gauge by carefully cutting a 1" slot into a piece of card stock, then seeing if it will slip over the fat section near the stem.
However, there's a small possibility that it 25.4mm (1").
The difference is big enough that you can make a gauge by carefully cutting a 1" slot into a piece of card stock, then seeing if it will slip over the fat section near the stem.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
10-16-17, 02:03 AM
#3
Banned
Assuming you have original aluminum drop bars, then odds are it's 26.0mm which was the standard for road bars until fairly recently.
However, there's a small possibility that it 25.4mm (1").
The difference is big enough that you can make a gauge by carefully cutting a 1" slot into a piece of card stock, then seeing if it will slip over the fat section near the stem.
However, there's a small possibility that it 25.4mm (1").
The difference is big enough that you can make a gauge by carefully cutting a 1" slot into a piece of card stock, then seeing if it will slip over the fat section near the stem.
10-16-17, 04:04 AM
#4
Senior Member
25.4 is most likely. 26.0 is common on European bikes esp. Italian bikes.
https://www.sheldonbrown.com/cribsheet-handlebars.html
https://www.sheldonbrown.com/cribsheet-handlebars.html
10-16-17, 10:02 AM
#6
multimodal commuter
Join Date: Nov 2006
Location: NJ, NYC, LI
Posts: 19,808
Bikes: 1940s Fothergill, 1959 Allegro Special, 1963? Claud Butler Olympic Sprint, Lambert 'Clubman', 1974 Fuji "the Ace", 1976 Holdsworth 650b conversion rando bike, 1983 Trek 720 tourer, 1984 Counterpoint Opus II, 1993 Basso Gap, 2010 Downtube 8h, and...
Mentioned: 584 Post(s)
Tagged: 0 Thread(s)
Quoted: 1908 Post(s)
Liked 574 Times
in
339 Posts
The clamp, as discussed above, is either 25.4 or 26.0.
The handlebar itself is probably 23.8 mm assuming it's an aluminum drop bar. If it's a steel bar, the diameter may be 22.2 mm.
The handlebar itself is probably 23.8 mm assuming it's an aluminum drop bar. If it's a steel bar, the diameter may be 22.2 mm.
__________________
www.rhmsaddles.com.
www.rhmsaddles.com.
10-16-17, 01:22 PM
#8
Keepin it Wheel
Join Date: Aug 2011
Location: San Diego
Posts: 10,245
Bikes: Surly CrossCheck, Krampus
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 26 Post(s)
Liked 3,433 Times
in
2,540 Posts
Assuming you have original aluminum drop bars, then odds are it's 26.0mm which was the standard for road bars until fairly recently.
However, there's a small possibility that it 25.4mm (1").
The difference is big enough that you can make a gauge by carefully cutting a 1" slot into a piece of card stock, then seeing if it will slip over the fat section near the stem.
However, there's a small possibility that it 25.4mm (1").
The difference is big enough that you can make a gauge by carefully cutting a 1" slot into a piece of card stock, then seeing if it will slip over the fat section near the stem.
10-16-17, 01:29 PM
#9
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,725
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Mentioned: 140 Post(s)
Tagged: 1 Thread(s)
Quoted: 5792 Post(s)
Liked 2,582 Times
in
1,432 Posts
If it's 0.3mm thick. I believe that's more than the bypical can, so no.
OTOH - I once bailed out a friend with a paper shim made by winding paper coated with glue around the bar to reach the right diameter. I assembled and clamped it wet for good adhesion between the layers, and my friend rode it for much longer than we had originally planned, no problems.
FWIW, I'm a big fan of paper laminate shims and have enjoyed great success using them in all sorts of applications. I greatly prefer them to reliance on beer cans.
OTOH - I once bailed out a friend with a paper shim made by winding paper coated with glue around the bar to reach the right diameter. I assembled and clamped it wet for good adhesion between the layers, and my friend rode it for much longer than we had originally planned, no problems.
FWIW, I'm a big fan of paper laminate shims and have enjoyed great success using them in all sorts of applications. I greatly prefer them to reliance on beer cans.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
10-16-17, 01:44 PM
#10
Keepin it Wheel
Join Date: Aug 2011
Location: San Diego
Posts: 10,245
Bikes: Surly CrossCheck, Krampus
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 26 Post(s)
Liked 3,433 Times
in
2,540 Posts
My dad as a hobby makes recurve bows out of laminate pre-paper. (Only one or two have assploded in people's hands)
