Thread: XT hubs?
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Old 10-20-11, 07:50 AM
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Originally Posted by Doug64
I did the same thing after thinking about it on my ride today (along with fixing a flat tire). I looked at Shimano's Tech pubs when I returned home and was wondering:

If a hub has more small bearings vs. fewer larger bearings, which combination results in the most load bearing contact with the hub's race at any given time? Or does it even matter? I don't have a clue.
For decades most hub manufacturers that used cup and cone bearings have used smaller diameter ball bearings in front hubs than rear, I assume that they knew something about which bearings to use for various loads.

I have also seen comments on the internet that the freehub is thinner on the newer hubs to make more room for the larger diameter aluminum axle. I don't save links of items I read on the internet, so to respond here I did a google search and came up with this example:
http://pardo.net/bike/pic/fail-001/FAIL-082.html
I assume this is a design problem.

And, I have seen comments about the freehub not being assembled property to the shell, another google search found this:
http://yacf.co.uk/forum/index.php?topic=20893.15
The freehub to shell attachment failure might be a one-off assembly problem, from the internet post it is impossible to determine if it is a design problem or not.

I have not personally had failures as described, I only cite what I have seen on the internet.

But, when I built up another tourer two years ago I decided to use the older M760 hubs which did not have the reported failures that the newer ones had. I found it interesting that at that time Surly used the M756 hub on their cargo bike (the Big Dummy) and the M770 on the LHT touring bike (source: 2010 catalog). I assumed that the cargo bike would need the heavier duty hubs, thus I concluded that I should stick with the older design.

But for my foldup bike I used the M770 for the front hub. I got a good price on the M770, that was part of the decision. I have not seen any negative comments on the newer XT front hubs and the folding bike front hub does not take heavy loads. (The rear hub on my foldup bike is not a Shimano hub.)

Surly 2011 catalog lists the Big Dummy hubs as Deore whereas the LHT is still on M770 XT hubs. Thus, if I was building up a touring bike wheel today, I would consider the Deore hub as a viable option too. I do not have any personal experience with LX.
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