Dura ace 7400 front hub dimensions?
03-22-17, 10:04 PM
#1
Senior Member
Thread Starter
Join Date: Jun 2013
Location: Bozeman
Posts: 4,094
Bikes: 199? Landshark Roadshark, 198? Mondonico Diamond, 1987 Panasonic DX-5000, 1987 Bianchi Limited, Univega... Chrome..., 1989 Schwinn Woodlands, Motobecane USA Record, Raleigh Tokul 2
Mentioned: 25 Post(s)
Tagged: 0 Thread(s)
Quoted: 1131 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Dura ace 7400 front hub dimensions?
Going to be re-lacing a wheel with a dura ace 7400 series hubs. I've found the rear hub dimensions on THIS site, but I can't seem to find the front hub dimensions. In all honesty, I don't even know the part number for the front hub. The rear is FH-7403, but I can't find the model number for the front, even on velobase. Maybe my google foo is off.
Yes, obviously I could just measure it, but it'd be difficult with the wheel assembled. (And I don't want to disassemble the wheel until I can build it up again same day. (No downtime if possible.))
Anyway, does anybody have info on those hubs? I can't imagine it'd change much... it's a front hub, and it looks identical to many modern hubs...
These are the hubs I have. (Well, not quite, I have the hyperglide rear, not uniglide, but the hyperglide page doesn't show pics of the front hub.)
VeloBase.com - Component: Shimano FH-7402 / HB-7402, Dura-Ace 7400 (Uniglide Only)
EDIT: Oh, I need to buy spokes, hence the need for dimensions.
Yes, obviously I could just measure it, but it'd be difficult with the wheel assembled. (And I don't want to disassemble the wheel until I can build it up again same day. (No downtime if possible.))
Anyway, does anybody have info on those hubs? I can't imagine it'd change much... it's a front hub, and it looks identical to many modern hubs...
These are the hubs I have. (Well, not quite, I have the hyperglide rear, not uniglide, but the hyperglide page doesn't show pics of the front hub.)
VeloBase.com - Component: Shimano FH-7402 / HB-7402, Dura-Ace 7400 (Uniglide Only)
EDIT: Oh, I need to buy spokes, hence the need for dimensions.
Last edited by corrado33; 03-22-17 at 10:16 PM.
03-22-17, 10:13 PM
#2
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,716
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: 5786 Post(s)
Liked 2,579 Times
in
1,430 Posts
I never use published dimensions for hubs, trusting nobody but my own fingers to get this data.
However, I'm fairly certain that Shimano never altered the external dimensions of Dura Ace front hubs. Even if they did, it won't be enough to sweat. So look up any Dura Ace front hub, and you'll be fine.
BTW - as any lazy long time wheel builder will tell you, lace fronts with the same spokes as the left side rear of any matched pair of 32h 3x hubs, and you'll come out fine better than 99% of the time.
Also, if you go back to the site you referenced, they list Dura Ace fronts (all small flange).
However, I'm fairly certain that Shimano never altered the external dimensions of Dura Ace front hubs. Even if they did, it won't be enough to sweat. So look up any Dura Ace front hub, and you'll be fine.
BTW - as any lazy long time wheel builder will tell you, lace fronts with the same spokes as the left side rear of any matched pair of 32h 3x hubs, and you'll come out fine better than 99% of the time.
Also, if you go back to the site you referenced, they list Dura Ace fronts (all small flange).
__________________
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.
Last edited by FBinNY; 03-22-17 at 10:26 PM.
Likes For FBinNY:
03-22-17, 10:38 PM
#3
Really Old Senior Member
mrrabbits Spokechart calculator shows-
Spoke hole BCD 38MM
Offset 37MM
Spoke hole BCD 38MM
Offset 37MM
03-22-17, 11:02 PM
#4
Insane Bicycle Mechanic
Join Date: Mar 2008
Location: other Vancouver
Posts: 9,838
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 805 Post(s)
Liked 706 Times
in
377 Posts
VeloBase.com - Component: Shimano Dura-Ace High Flange First Gen (Black)
But FB is correct: all Shimano low-flange hubs have identical spoke circles and flange spacings. There are some tiny differences but they are inconsequential.
__________________
Jeff Wills
Comcast nuked my web page. It will return soon..
Jeff Wills
Comcast nuked my web page. It will return soon..
03-22-17, 11:05 PM
#5
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,716
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: 5786 Post(s)
Liked 2,579 Times
in
1,430 Posts
Truthfully, though, Dura-Ace large-flange hub were available in the '70's:
VeloBase.com - Component: Shimano Dura-Ace High Flange First Gen (Black)
But FB is correct: all Shimano low-flange hubs have identical spoke circles and flange spacings. There are some tiny differences but they are inconsequential.
VeloBase.com - Component: Shimano Dura-Ace High Flange First Gen (Black)
But FB is correct: all Shimano low-flange hubs have identical spoke circles and flange spacings. There are some tiny differences but they are inconsequential.
__________________
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.
03-23-17, 09:33 AM
#6
Senior Member
Thread Starter
Join Date: Jun 2013
Location: Bozeman
Posts: 4,094
Bikes: 199? Landshark Roadshark, 198? Mondonico Diamond, 1987 Panasonic DX-5000, 1987 Bianchi Limited, Univega... Chrome..., 1989 Schwinn Woodlands, Motobecane USA Record, Raleigh Tokul 2
Mentioned: 25 Post(s)
Tagged: 0 Thread(s)
Quoted: 1131 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I never use published dimensions for hubs, trusting nobody but my own fingers to get this data.
However, I'm fairly certain that Shimano never altered the external dimensions of Dura Ace front hubs. Even if they did, it won't be enough to sweat. So look up any Dura Ace front hub, and you'll be fine.
BTW - as any lazy long time wheel builder will tell you, lace fronts with the same spokes as the left side rear of any matched pair of 32h 3x hubs, and you'll come out fine better than 99% of the time.
Also, if you go back to the site you referenced, they list Dura Ace fronts (all small flange).
However, I'm fairly certain that Shimano never altered the external dimensions of Dura Ace front hubs. Even if they did, it won't be enough to sweat. So look up any Dura Ace front hub, and you'll be fine.
BTW - as any lazy long time wheel builder will tell you, lace fronts with the same spokes as the left side rear of any matched pair of 32h 3x hubs, and you'll come out fine better than 99% of the time.
Also, if you go back to the site you referenced, they list Dura Ace fronts (all small flange).
03-23-17, 09:39 AM
#7
Constant tinkerer
On the Edd calculator that I've always used, it lists the 7700 front hub at a 38mm flange diameter and 33.7mm center to left/right flange. The 7400/7700/7800 and most other Shimano small-flange front hubs are close enough to use this information.
https://leonard.io/edd/
https://leonard.io/edd/
03-23-17, 11:08 AM
#8
Senior Member
Thread Starter
Join Date: Jun 2013
Location: Bozeman
Posts: 4,094
Bikes: 199? Landshark Roadshark, 198? Mondonico Diamond, 1987 Panasonic DX-5000, 1987 Bianchi Limited, Univega... Chrome..., 1989 Schwinn Woodlands, Motobecane USA Record, Raleigh Tokul 2
Mentioned: 25 Post(s)
Tagged: 0 Thread(s)
Quoted: 1131 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
On the Edd calculator that I've always used, it lists the 7700 front hub at a 38mm flange diameter and 33.7mm center to left/right flange. The 7400/7700/7800 and most other Shimano small-flange front hubs are close enough to use this information.
https://leonard.io/edd/
https://leonard.io/edd/
All the more reason to measure it myself. Front should be easy anyway. Measure flange to flange, divide by 2.
03-23-17, 11:19 AM
#10
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,716
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: 5786 Post(s)
Liked 2,579 Times
in
1,430 Posts
To be clear, especially since the OP is considering going with ths same spokes left and right.
Fronts generally take a spoke slightly longer than the left side rear (less than 1mm). So those who, like myself use proper full length spokes come out OK. But those rounding down, may find that they've rounded down too far for the front.
I was very surprised that the OP came out only 1mm different left and right. Every build I've done on modern hubs needs 2mm difference. A rough guide is 1mm difference for every 10mm difference in CTF distance.
Fronts generally take a spoke slightly longer than the left side rear (less than 1mm). So those who, like myself use proper full length spokes come out OK. But those rounding down, may find that they've rounded down too far for the front.
I was very surprised that the OP came out only 1mm different left and right. Every build I've done on modern hubs needs 2mm difference. A rough guide is 1mm difference for every 10mm difference in CTF 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.
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.
03-23-17, 11:24 AM
#11
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,716
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: 5786 Post(s)
Liked 2,579 Times
in
1,430 Posts
You sure there's not a typo there? The Mr. rabbit spreadsheet (which lists the 7400 front explicitly) says the 7700 front hub is 38mm flange and 37mm center to flange. (Those numbers are identical to the 7400 front) and very similar to the 7710, 7800, and 7900 +- a mm. 33.7 seems a bit small. I checked the Edd calculator (that's where I had originally found the rear info) and it is indeed 33.7mm.
All the more reason to measure it myself. Front should be easy anyway. Measure flange to flange, divide by 2.
All the more reason to measure it myself. Front should be easy anyway. Measure flange to flange, divide by 2.
The differences don't translate directly to changes in spoke length.
spoke length changes 1mm for every 100 of CTF, and on 32h 3x, by about 15% of the change in flange diameter.
__________________
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.
03-23-17, 01:23 PM
#13
Senior Member
Thread Starter
Join Date: Jun 2013
Location: Bozeman
Posts: 4,094
Bikes: 199? Landshark Roadshark, 198? Mondonico Diamond, 1987 Panasonic DX-5000, 1987 Bianchi Limited, Univega... Chrome..., 1989 Schwinn Woodlands, Motobecane USA Record, Raleigh Tokul 2
Mentioned: 25 Post(s)
Tagged: 0 Thread(s)
Quoted: 1131 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
To be clear, especially since the OP is considering going with ths same spokes left and right.
Fronts generally take a spoke slightly longer than the left side rear (less than 1mm). So those who, like myself use proper full length spokes come out OK. But those rounding down, may find that they've rounded down too far for the front.
I was very surprised that the OP came out only 1mm different left and right. Every build I've done on modern hubs needs 2mm difference. A rough guide is 1mm difference for every 10mm difference in CTF distance.
Fronts generally take a spoke slightly longer than the left side rear (less than 1mm). So those who, like myself use proper full length spokes come out OK. But those rounding down, may find that they've rounded down too far for the front.
I was very surprised that the OP came out only 1mm different left and right. Every build I've done on modern hubs needs 2mm difference. A rough guide is 1mm difference for every 10mm difference in CTF distance.
Using other calculators, it seems like the qpb calculator is rounding the longer one down by .3mm and the shorter one up by .4mm. So technically, the distance is very near to 2mm difference. I know the rule of thumb is to round UP, but in all honesty I don't think it matters over such short distances. Heck, spokes aren't even offered in all lengths and some people are forced to use a spoke a mm short or too long.
(EDIT: And I'm in the DTSwiss camp (for now). I've actually never used wheelsmith, but I've built up a half dozen or so wheels with DT and they've done well by me. Some have well over a few thousand miles and are still perfectly true. Besides, DT spokes come with nipples and wheelsmith I have to order separate. Actually, now that I think about it... it may be advantageous to order them separately...)
Yeah yeah yeah I'm getting to it.
I'm a novice wheelbuilder so I still like to refer to the people more experienced than me before and after I do anything...
Last edited by corrado33; 03-23-17 at 01:31 PM.
03-23-17, 01:30 PM
#14
Banned
I read books before the internet, My LBS has had a paper chart that DT published,
My friend & the guy who keeps the door open & the lights on , we figured out the respoking of the front rim with a Dynohub.
My friend & the guy who keeps the door open & the lights on , we figured out the respoking of the front rim with a Dynohub.
03-23-17, 03:54 PM
#15
Constant tinkerer
When I ran the flange width discrepancy (discussed above) in Edd, I got a difference of 0.4mm.
However, it is always good to do a sanity check measurement before buying spokes if possible. I ALWAYS measure rim ERD myself on EVERY rim I build up. Small variation there really can cause spokes to fit or not fit, and rims don't necessarily match manufacturer published data.
03-23-17, 07:31 PM
#16
Senior Member
Join Date: Jan 2013
Posts: 2,679
Bikes: too many sparkly Italians, some sweet Americans and a couple interesting Japanese
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 569 Post(s)
Liked 582 Times
in
409 Posts
I always measure mine and just built a lovely 7410 set and notes show FH measured 34mm as per FastJake.
