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Shimano Dura Ace 7800 Hubs with non-offset spoke holes

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Shimano Dura Ace 7800 Hubs with non-offset spoke holes

Old 09-03-23, 07:54 PM
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Shimano Dura Ace 7800 Hubs with non-offset spoke holes

I recently got a deal for a bunch of 20h carbon rims, and found what I thought was a good deal on NOS 20h front and rear Dura Ace FH/HB 7800 hubs. Now that I've gone to assemble the wheels, I was wondering why the spokes were going into the nipples uneven amounts when in a 2x pattern. I realized after some closer looking that the holes on the flanges are lined up with each other, i.e. if you look at the hub from one side, you can see right through the spoke holes out the other side (sorry I'm too new to post a photo).

I have been looking all weekend for some kind of catalog page or spec sheet for these hubs but I haven't been able to find anything googling around about them or any wheel set with them. What I have seen is other Dura Ace FH/HB 7800 hubs with 24 28 or 36 holes and in their photos it is clear that the holes ARE offset from each other.

Was the 20h version meant to have non-offset holes on the flanges, or are the hubs that I bought a manufacturing defect? Is there a magic way of lacing these I'm not thinking of?

Given that these came in a 36h version, I'm debating chucking these up on a mill and drilling a second set of holes in the correct offset position as there seems to be enough meat on the hub.
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Old 09-03-23, 10:14 PM
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Originally Posted by ketiov
I recently got a deal for a bunch of 20h carbon rims, and found what I thought was a good deal on NOS 20h front and rear Dura Ace FH/HB 7800 hubs. Now that I've gone to assemble the wheels, I was wondering why the spokes were going into the nipples uneven amounts when in a 2x pattern. I realized after some closer looking that the holes on the flanges are lined up with each other, i.e. if you look at the hub from one side, you can see right through the spoke holes out the other side (sorry I'm too new to post a photo).

I have been looking all weekend for some kind of catalog page or spec sheet for these hubs but I haven't been able to find anything googling around about them or any wheel set with them. What I have seen is other Dura Ace FH/HB 7800 hubs with 24 28 or 36 holes and in their photos it is clear that the holes ARE offset from each other.

Was the 20h version meant to have non-offset holes on the flanges, or are the hubs that I bought a manufacturing defect? Is there a magic way of lacing these I'm not thinking of?

Given that these came in a 36h version, I'm debating chucking these up on a mill and drilling a second set of holes in the correct offset position as there seems to be enough meat on the hub.
they are meant to lace to "2 by 2 rims" such as Bontrager and several others... the spokes are PAIRED around the rim.... unfortunately,those rims tend to crack near the over-stressed areas containing two spokes right next to each other... which is also why you found those hubs for sale, i'd venture.....the built up wheel appears to maybe only have "ten spokes" when seen from the side, at a distance.......
i've warrned many to be careful if looking at the 20 spoke, 2 paired wheels...telling them to Inspect Carefully for cracking at the Spoke holes in the rims.
i won't buy them.
if a rider is under 150lbs or so, they tend to hold up... crit racers, CX, and stomper clydesdales like me need not apply.

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Old 09-04-23, 09:37 AM
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Originally Posted by maddog34
they are meant to lace to "2 by 2 rims" such as Bontrager and several others... the spokes are PAIRED around the rim.... unfortunately,those rims tend to crack near the over-stressed areas containing two spokes right next to each other... which is also why you found those hubs for sale, i'd venture.....the built up wheel appears to maybe only have "ten spokes" when seen from the side, at a distance.......
i've warrned many to be careful if looking at the 20 spoke, 2 paired wheels...telling them to Inspect Carefully for cracking at the Spoke holes in the rims.
i won't buy them.
if a rider is under 150lbs or so, they tend to hold up... crit racers, CX, and stomper clydesdales like me need not apply.
I read about there being rims like this, but I wasn't able to find any record of Shimano's version of it. Not sure if its worth putting these hubs up for sale, they weren't crazy expensive (100/set) and if I drill the extra holes I need I can sell it as weight savings for the weigh weenies
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Old 09-07-23, 10:42 AM
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Originally Posted by ketiov
I read about there being rims like this, but I wasn't able to find any record of Shimano's version of it. Not sure if its worth putting these hubs up for sale, they weren't crazy expensive (100/set) and if I drill the extra holes I need I can sell it as weight savings for the weigh weenies
If you havenít already, Iíd play around with using them with traditional rims. Might be an interesting experiment.
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Old 09-07-23, 11:11 AM
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Originally Posted by GLBorchert
If you havenít already, Iíd play around with using them with traditional rims. Might be an interesting experiment.
I have! I laced it up all the way around. It sucked! 1/4 of the spokes worked alright, 1/2 had 5-8 threads showing outside the nipple, and 1/4 screwed in so far that they went past the threads in the nipple.

There may be a way to lace them up with 4 different lengths of spokes, but I don't have an arsenal of them available to me. I also don't know how a wheel with different length spokes, although at similar tensions, would work.

Another option would be double sided spoke nipples larger than 12mm (maybe a 16 or 20mm even) as well as extending out the other end towards the rim tape 10mm or so.
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Old 09-07-23, 11:43 AM
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Originally Posted by ketiov
I have! I laced it up all the way around. It sucked! 1/4 of the spokes worked alright, 1/2 had 5-8 threads showing outside the nipple, and 1/4 screwed in so far that they went past the threads in the nipple.

There may be a way to lace them up with 4 different lengths of spokes, but I don't have an arsenal of them available to me. I also don't know how a wheel with different length spokes, although at similar tensions, would work.

Another option would be double sided spoke nipples larger than 12mm (maybe a 16 or 20mm even) as well as extending out the other end towards the rim tape 10mm or so.
Well, you tried! Thanks for sharing the outcome. I figured that spoke lengths would be the challenge.
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Old 11-23-23, 05:45 PM
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Just wanted to update this thread. Originally I started with 270mm spokes all around. I made the wheel work with 5x 270mm spokes and 5x 264mm spokes on the drive side and 5x264mm and 5x274mm spokes on the non-drive side. Spoke tension is balanced per side (non-drive side is lower tension than the drive side), and the wheel is perfectly centered. So it is doable!
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Old 11-29-23, 05:14 PM
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Originally Posted by maddog34
they are meant to lace to "2 by 2 rims" such as Bontrager and several others... the spokes are PAIRED around the rim.... unfortunately,those rims tend to crack near the over
There paired spoke pattern of those Bontrager wheels was asymmetrical, meaning there was a small stagger between spoke pairs. But, yeah, it did not make for a very strong wheel. I've seen the non-staggered Shimano wheels. I remember truing up some Giant wheels like this, too, from maybe 20 years ago. You'll have to knock yourself out trying to drill a hole pattern in the hub to work with a 28, 32, or 36 spoke rim. I wouldn't bother.
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Old 12-02-23, 11:05 AM
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Originally Posted by oldbobcat
There paired spoke pattern of those Bontrager wheels was asymmetrical, meaning there was a small stagger between spoke pairs. But, yeah, it did not make for a very strong wheel. I've seen the non-staggered Shimano wheels. I remember truing up some Giant wheels like this, too, from maybe 20 years ago. You'll have to knock yourself out trying to drill a hole pattern in the hub to work with a 28, 32, or 36 spoke rim. I wouldn't bother.
I was going to potentially drill one side to 40 holes (20 extra) for the correct offset of spoke holes. Seemed like enough meat on there and quick work on a CNC mill but I like the mismatched spoke length solution better.
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Old 12-02-23, 11:27 AM
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Originally Posted by ketiov
I was going to potentially drill one side to 40 holes (20 extra) for the correct offset of spoke holes. Seemed like enough meat on there and quick work on a CNC mill but I like the mismatched spoke length solution better.
Good luck.
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