Shimano XT hubs - What's the difference between....

[Peterpoddy]

......M737 and M738?

Sticker looks a bit different, but is there anything else?

Cheers!

 

[lrh]

http://www.retrobike.co.uk/forum/viewtopic.php?p=1118409

 

[FluffyChicken]

Yep one is an Aluminium axled hub designed for suspension and there where the end caps for it to fit in most for or in Rockshox forks (something like that)
the 737 being the traditional steel axle.

 

[Peterpoddy]

Ok thanks. So will a 738 work in any fork then?

 

[Peterpoddy]

Could still do with an answer on this...



It seems a 738 has a 110mm axle, which won't fit normal QR ford, am I right?[/u]

 

[Anthony]

Could still do with an answer on this...


It seems a 738 has a 110mm axle, which won't fit normal QR ford, am I right?[/u]

No, it's 100mm just the same, and it will fit any fork.

 

[one-eyed_jim]

It seems a 738 has a 110mm axle, which won't fit normal QR fork, am I right?[/u]

As Anthony rightly says, an M738 front hub has a standard 100mm OLN, and will fit any normal fork.

The M738 hub has a fat aluminium axle with separate endcaps. Shimano called the design "Parallax 110" to distinguish it from the M737 model with its 9mm steel axle. They both have a standard 100mm OLN though.

HB-M737:

http://www.chinabike.net/newbbs/UploadF ... 574960.gif

HB-M738:

http://www.chinabike.net/newbbs/UploadF ... 222182.gif

 

[hamster]

If I remember correctly the bearings use smaller balls in the aluminium-axled variety. Certainly they do in later versions which used the alu axle (M760 etc). These undersized bearings do not last well which is why long-distance tourers are now using LX / SLX hubs, which keep the steel axle and stronger bearings.

 

[one-eyed_jim]

If I remember correctly the bearings use smaller balls in the aluminium-axled variety. Certainly they do in later versions which used the alu axle (M760 etc). These undersized bearings do not last well which is why long-distance tourers are now using LX / SLX hubs, which keep the steel axle and stronger bearings.

I think nearly all Shimano front hubs use 3/16" bearings. That includes the M737 and M738 under discussion here - see the exploded diagrams I posted previously.

Some of the more recent rear hubs with aluminium axles now use 3/16" balls in place of the previous 1/4" standard:

http://www.kurbelix.com/Shimano_Technis ... -2700A.jpg

The HB-M760 is one of the rare front hubs that uses a 10mm (as opposed to the usual 9mm) steel axle:

http://www.paul-lange.de/fileadmin/paul ... 760-04.PDF

This is all getting uncomfortably modern though ...