[Hedge72]

I'm running an older model Giant Anthem frame (horizontal shock mount) and am wanting to run a double up front. Info on the new XTR cranks are minimal to say the least and I am wondering if anyone knows whether or not the 2 ring race variety (M985) would fit on my frame. Any insight would be appreciated.

Hedge

 

[DavidR1]

The M980 (trail version) also comes in a 2 ring variety (38/24). The Trail version has a higher Q factor.

Not sure if you would run into problems with the narrow Q factor of the M985. The warn that these cranks won't fit all frames due to this.

 

[Hedge72]

Thanks for the reply and good point about the M980. :thumbsup:

So with the higher Q factor, would this mean that the ring spacing/location is also different? I noticed that the spider on the trail is different then on the race...

I'm currently running an M970 XTR drivetrain on my rig and wanted to replace my old Race Face crankset with a double. According to this thread:

http://forums.mtbr.com/showthread.php?t=646014

...the new XTR doubles will work fine with M970 shifters. All that is required is a new chain and a new front derailleur. And if I do opt for the M980 trail cranks (easier gears too boot), would I require the 2 position FD, or the 3? So many questions and so little information out there!

Thanks again

 

[DavidR1]

Lots of questions I can't answer. I will say that the XTR front shifter enables 2 or 3 positions (but a little switch). So I would guess the spacing is the same.

No doubt Shimano would say no, but you may just need to try it to find out.

 

[Hedge72]

Yeah, I hear you. I wonder if anyone knows the q factor for the new XTR cranks. All I have been able to determine is that the q factor for the race cranks is 6mm less than the trail. If the trail is the same as the M970 cranks, which I believe is 166mm, then that would put the race cranks in at 160mm, which if I measured correctly, will fit my frame...of course, this is all speculation...

 

[Hedge72]

Well, it looks as though I have found my answer!

Some further web surfing has garnered an interesting bit of info; an XTR Dyna-Sys day camp, where the test rig for the 28/40 XTR 'Race' cranks is none other than an old school Anthem!

http://www.cyclingnewsasia.com/en/tech/37-general/813-tech-shimano-dyna-sys-xtr-camp-part-2

Odd that they would use an older frame to highlight the latest in shifting technology, but this suits me just fine; I guess it is safe to say that my Anthem will indeed be able to run with the M985!

Hedge