Dropout spacing confusion
#1
Senior Member
Thread Starter
Dropout spacing confusion
I converted my mid 80s road bike from 6 speed freewheel rear (126 spacing) to a 7 speed free hub rear with cassette. The hub came from a 700c road bike rear wheel of a late 80s early 90s Trek. It is a Shimano Exage hub. I measured it and it is 130 on the spacing. I cold set my rear drop outs and all is good. I just recently stumbled across some info that says 6 and 7 speed road bike rear spacing is 126 and 7 speed mtb spacing is 130. But this hub was from a road bike. What am I missing here?
#2
Senior Member
Join Date: Jul 2009
Posts: 790
Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 384 Post(s)
Likes: 0
Liked 6 Times
in
6 Posts
I converted my mid 80s road bike from 6 speed freewheel rear (126 spacing) to a 7 speed free hub rear with cassette. The hub came from a 700c road bike rear wheel of a late 80s early 90s Trek. It is a Shimano Exage hub. I measured it and it is 130 on the spacing. I cold set my rear drop outs and all is good. I just recently stumbled across some info that says 6 and 7 speed road bike rear spacing is 126 and 7 speed mtb spacing is 130. But this hub was from a road bike. What am I missing here?
There are two reasons I can think of for the difference.
One, mountain bikes used triple cranks, which require the cranks be more outboard from the frame, especially on non-ferrous frames. Moving the cassette farther outboard keeps the chainline good.
Two, mountain bike rear wheels are more likely to be subjected to lateral loads, so the wider spacing decreases dish and equalizes spoke tension side-to-side.
#3
Senior Member
Thread Starter
I just went out and remeasure the hub spacing just to make sure I wasn’t crazy and as best I can get a measurement through my spokes with my calipers it’s about 130.5 so basically a 130 spacing. I had been led to believe that when they went from the free wheel hub to the Cassette free hub the spacing jumped to 130 even though it was only a 7 speed cassette. At least I’m all set if I ever want to put another free hub body on some day and put in an 8 speed cassette LOL
#4
aka: Dr. Cannondale
Join Date: Jul 2009
Posts: 7,852
Mentioned: 234 Post(s)
Tagged: 0 Thread(s)
Quoted: 2151 Post(s)
Liked 3,380 Times
in
1,198 Posts
Also remember that late 80's-early 90's was the transitional time for spacing going from 126 to 130. It was not unusual then for manufacturers to make frames in 128 spacing so that either type of hub OLD could be used. It was also a transitional time for manufacturers, Shimano included, and sometimes a bike that was supposed to get a 126 rear freehub instead got a next-level-up 130 spaced freehub with a 4.5mm spacer to correctly space out the cassette. That may be the case here. I've certainly been surprised from time to time, especially with some 7 speed tricolor bikes that came with an 8 speed 130 hub and a spacer.
Note that there were 7 speed Shimano freehubs during that period (e.g. 105 series 1051) and even earlier there were 5 and 6 speed Shimano freehubs on 600 and Dura Ace.
Note that there were 7 speed Shimano freehubs during that period (e.g. 105 series 1051) and even earlier there were 5 and 6 speed Shimano freehubs on 600 and Dura Ace.
__________________
Hard at work in the Secret Underground Laboratory...
Hard at work in the Secret Underground Laboratory...
Last edited by rccardr; 02-13-18 at 03:14 PM.
#5
aka Tom Reingold
Join Date: Jan 2009
Location: New York, NY, and High Falls, NY, USA
Posts: 40,691
Bikes: 1962 Rudge Sports, 1971 Raleigh Super Course, 1971 Raleigh Pro Track, 1974 Raleigh International, 1975 Viscount Fixie, 1982 McLean, 1996 Lemond (Ti), 2002 Burley Zydeco tandem
Mentioned: 510 Post(s)
Tagged: 0 Thread(s)
Quoted: 7287 Post(s)
Liked 2,365 Times
in
1,382 Posts
This news might make many people feel insecure.
__________________
Tom Reingold, tom@noglider.com
New York City and High Falls, NY
Blogs: The Experienced Cyclist; noglider's ride blog
“When man invented the bicycle he reached the peak of his attainments.” — Elizabeth West, US author
Please email me rather than PM'ing me. Thanks.
Tom Reingold, tom@noglider.com
New York City and High Falls, NY
Blogs: The Experienced Cyclist; noglider's ride blog
“When man invented the bicycle he reached the peak of his attainments.” — Elizabeth West, US author
Please email me rather than PM'ing me. Thanks.
#7
working on my sandal tan
Join Date: Aug 2011
Location: CID
Posts: 22,625
Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers), All-City Space Horse (hers)
Mentioned: 98 Post(s)
Tagged: 0 Thread(s)
Quoted: 3868 Post(s)
Liked 2,560 Times
in
1,574 Posts
I converted my mid 80s road bike from 6 speed freewheel rear (126 spacing) to a 7 speed free hub rear with cassette. The hub came from a 700c road bike rear wheel of a late 80s early 90s Trek. It is a Shimano Exage hub. I measured it and it is 130 on the spacing. I cold set my rear drop outs and all is good. I just recently stumbled across some info that says 6 and 7 speed road bike rear spacing is 126 and 7 speed mtb spacing is 130. But this hub was from a road bike. What am I missing here?
In other news, now that you've stretched out your bike to 130mm, there's nothing stopping you from moving up to 8-11 speed.
__________________
RUSA #7498
Originally Posted by noglider
People in this forum are not typical.
Last edited by ThermionicScott; 02-13-18 at 05:04 PM.
#8
Senior Member
Join Date: Apr 2011
Posts: 6,825
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 4260 Post(s)
Liked 1,458 Times
in
950 Posts
I have one set of 126 wheels I respaced to 130 by adding two spacers. Unless you've had the wheel since they were new...
But when 130 became common for road bikes, I imagine even the cheaper hubs in 7 were spaced that way so Trek didn't have to produce different frames for the 1000 vs the 1400, for instance. 8 speed was reserved for nicer groups in that period.
But when 130 became common for road bikes, I imagine even the cheaper hubs in 7 were spaced that way so Trek didn't have to produce different frames for the 1000 vs the 1400, for instance. 8 speed was reserved for nicer groups in that period.
#9
Senior Member
Join Date: Jan 2008
Location: Beaverton, OR
Posts: 14,787
Bikes: Yes
Mentioned: 522 Post(s)
Tagged: 0 Thread(s)
Quoted: 3228 Post(s)
Liked 3,854 Times
in
1,436 Posts
Did anyone but me ever play the old Hitchhiker's Guide to the Galaxy computer game? (If not, you still can: Hitchhikers Guide to the Galaxy 30th Anniversary) One of my favorite gags in the game was that if you consult the Guide about the Galactic Security Agency agents from the Galactic Security Agency show up, rough you up a bit, tell you there's no such thing as the Galactic Security Agency and never to consult the guide about it again, then leave. The exchange above about the Hub Spacing Police reminded me a bit of that.
__________________
My Bikes
My Bikes
#10
Senior Member
Join Date: Feb 2016
Location: Olympic Peninsula, WA
Posts: 650
Bikes: '8? Ciocc Mockba 80, '82 Ron Cooper, '84 Allez, '86 Tommasini Racing, '86? Klein Quantum, '87 Ciocc Designer 84, '95 Trek 5500, '98 Litespeed Classic, '98 S-Works Mtb
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 226 Post(s)
Liked 307 Times
in
121 Posts
I converted my mid 80s road bike from 6 speed freewheel rear (126 spacing) to a 7 speed free hub rear with cassette. The hub came from a 700c road bike rear wheel of a late 80s early 90s Trek. It is a Shimano Exage hub. I measured it and it is 130 on the spacing. I cold set my rear drop outs and all is good. I just recently stumbled across some info that says 6 and 7 speed road bike rear spacing is 126 and 7 speed mtb spacing is 130. But this hub was from a road bike. What am I missing here?
Dean
__________________
Roll Me Up and Smoke Me When I Die
Roll Me Up and Smoke Me When I Die
#11
Senior Member
Thread Starter
#13
Senior Member
Join Date: Jan 2008
Location: Beaverton, OR
Posts: 14,787
Bikes: Yes
Mentioned: 522 Post(s)
Tagged: 0 Thread(s)
Quoted: 3228 Post(s)
Liked 3,854 Times
in
1,436 Posts
According to VeloBase the Exage 500EX was available with 126, 130 or 135 spacing.
I'll also add that it's a pretty simple matter to replace the freehub body on a 7-speed Shimano hub to make it 8/9/10 speed compatible, and when doing so one would probably make the spacing 130.
I'll also add that it's a pretty simple matter to replace the freehub body on a 7-speed Shimano hub to make it 8/9/10 speed compatible, and when doing so one would probably make the spacing 130.
__________________
My Bikes
My Bikes
#14
Senior Member
Join Date: Oct 2008
Location: se michigan
Posts: 72
Bikes: fuji finest, klien pinacle
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Likes: 0
Liked 5 Times
in
3 Posts
Did anyone but me ever play the old Hitchhiker's Guide to the Galaxy computer game? (If not, you still can: Hitchhikers Guide to the Galaxy 30th Anniversary) One of my favorite gags in the game was that if you consult the Guide about the Galactic Security Agency agents from the Galactic Security Agency show up, rough you up a bit, tell you there's no such thing as the Galactic Security Agency and never to consult the guide about it again, then leave. The exchange above about the Hub Spacing Police reminded me a bit of that.
#15
working on my sandal tan
Join Date: Aug 2011
Location: CID
Posts: 22,625
Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers), All-City Space Horse (hers)
Mentioned: 98 Post(s)
Tagged: 0 Thread(s)
Quoted: 3868 Post(s)
Liked 2,560 Times
in
1,574 Posts
No such thing as a non "Ultra" 7-speed AFAIK.
#16
Señor Member
Join Date: Oct 2004
Location: Hardy, VA
Posts: 17,935
Bikes: Mostly English - predominantly Raleighs
Mentioned: 70 Post(s)
Tagged: 0 Thread(s)
Quoted: 1491 Post(s)
Liked 1,072 Times
in
634 Posts
As long as the wheel is dished properly, I doubt you'll have a problem.
__________________
In search of what to search for.
In search of what to search for.
#18
Senior Member
Join Date: Dec 2015
Location: Menomonee Falls, WI
Posts: 1,850
Bikes: 1984 Schwinn Supersport, 1988 Trek 400T, 1977 Trek TX900, 1982 Bianchi Champione del Mondo, 1978 Raleigh Supercourse, 1986 Trek 400 Elance, 1991 Waterford PDG OS Paramount, 1971 Schwinn Sports Tourer, 1985 Trek 670
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 601 Post(s)
Liked 1,054 Times
in
530 Posts
All my CV bikes are 126mm rear spacing, even the one with the 7 speed Shimano cassette. Tim
Last edited by tkamd73; 02-13-18 at 08:54 PM. Reason: Addition
#19
Senior Member
Join Date: Apr 2011
Posts: 6,825
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 4260 Post(s)
Liked 1,458 Times
in
950 Posts
120 spacing was for 5 and ultra 6 freewheels.
126 spacing was for standard 6 and ultra 7 freewheels and cassettes on road bikes. All of the 7 speed stuff was about 5.0 spacing - Shimano and Suntour.
130 was for 8 and greater speeds, but some cheaper bikes still came with 7, but in 130 spacing.
126 spacing was for standard 6 and ultra 7 freewheels and cassettes on road bikes. All of the 7 speed stuff was about 5.0 spacing - Shimano and Suntour.
130 was for 8 and greater speeds, but some cheaper bikes still came with 7, but in 130 spacing.
#20
working on my sandal tan
Join Date: Aug 2011
Location: CID
Posts: 22,625
Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers), All-City Space Horse (hers)
Mentioned: 98 Post(s)
Tagged: 0 Thread(s)
Quoted: 3868 Post(s)
Liked 2,560 Times
in
1,574 Posts
I was under the impression that all of the above had roughly 5mm center-to-center spacing (excepting SunTour Micro-Drive.) What I was trying to get at was that there wasn't a "wide" variant of 7-speed.
#21
Phyllo-buster
Join Date: Jan 2010
Location: Nova Scotia
Posts: 8,831
Bikes: roadsters, club bikes, fixed and classic
Mentioned: 133 Post(s)
Tagged: 0 Thread(s)
Quoted: 2287 Post(s)
Liked 2,031 Times
in
1,245 Posts
#22
Senior Member
Join Date: Jul 2009
Posts: 790
Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 384 Post(s)
Likes: 0
Liked 6 Times
in
6 Posts
7 speed is all narrow or "ultra" spaced, that's why it will fit in basically the same space as a standard 6. But there are a few differences between 7s.
The overall widths are about the same. Shimano/Sachs has the same spacing all the way across. Suntour's outer two spacers are thicker than the inner four though. This makes it tough to dial in the shifting across systems.
#23
No longer active
Join Date: May 2012
Posts: 1,001
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 89 Post(s)
Likes: 0
Liked 6 Times
in
6 Posts
A few years ago- having in the moment actually forgotten that I did indeed knew better (certainly a sign that I'm getting older), I made the assertion that all 126mm Shimano freehubs were UG, & incompatible with later HG systems.
Doh!!
I'd totally spaced off the fact that about 4 years before, I'd actually converted a 126mm, Shimano 105/1055 HG 7sp hub to 130mm/ 8sp, that is, to the same spec as the 105/1056.
All it took was swapping out the hub body, and swapping out the axle & spacers. Shimano's 126 & 130mm hub shells have the same dimensions (I can't remember offhand if the shell interface itself is different for UG & HG hub bodies. It's been a while; I seem to recall it's the actually same for both types).
The HG 7sp hub bodies are Bronze & slightly shorter (about the same length as a UG body) to fit the 126mm spacing; the HG 8sp are Black & about as long as 9sp body. If they have a little indelled line encircling the body, about halfway down, it's one of the UG/HG bi-compatible transition bodies. The latter also have both types of lockring threadings.
Last edited by DIMcyclist; 02-13-18 at 10:48 PM.
#24
Senior Member
Join Date: Apr 2011
Posts: 6,825
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 4260 Post(s)
Liked 1,458 Times
in
950 Posts
About.
7 speed is all narrow or "ultra" spaced, that's why it will fit in basically the same space as a standard 6. But there are a few differences between 7s.
The overall widths are about the same. Shimano/Sachs has the same spacing all the way across. Suntour's outer two spacers are thicker than the inner four though. This makes it tough to dial in the shifting across systems.
7 speed is all narrow or "ultra" spaced, that's why it will fit in basically the same space as a standard 6. But there are a few differences between 7s.
The overall widths are about the same. Shimano/Sachs has the same spacing all the way across. Suntour's outer two spacers are thicker than the inner four though. This makes it tough to dial in the shifting across systems.