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Discussion Starter · #1 · (Edited)
I read in one post that giant recommends a 50mm chainline and that raceface suggested a 48mm chainline when using their crankset.

I called giant today and get conflicting info. I have a 2006 trance and my buddy has a 2005 reign that I just built up for him. I just measured from the center of the middle ring to the center of the shock eye with the bike upside down. I get 50mm chainline for both bikes! Both have a 118mm wide cartridge bb and shimano octalink II cranks. Before installing the 118mm bb in my trance I tried the 113mm taken from my nrs and the granny was very close to the frame.

What gets me is that giant says that the 2005 reign 3 came with a 113mm wide bb and my 2006 trance 4 came with a 118mm wide truvative isis cartridge bb. Other trance and reign models use the newer adjustable crankset/bb combo, so I am just going by the older cartridge bb info.

The problem that we are facing with the reign build up was that I did a rush job on the rear derailleur setting and it was not going into the smallest cog, but the rest shifted perfectly. My buddy ended up dropping a chain to the outside on 2 hill climbs and had to take it easy on climbs on that maiden voyage. Has anyone heard of dropping a chain to the outside if the rear derailleur was not set correctly? I have since done a perfect adjustment by following the park manual. Prior to that I just eyed the idler wheel to set the high and low end points. I would ride the bike again to test it, but the wrong fork was sent and it is being swapped with the correct model by the end of the week. My buddy just ordered a new shorter 113mm bb to replace the 118 that I installed. I am serioiusly thinking that giant is wrong, it can't be a 113mm wide bb in the reign.

Please help out ASAP by measuring your trance and reign drivelines as mentioned above. Thanks for your help!
 

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You should have gone with a 115mm/68 BB instead of the 113mm one, therby getting a roughly 47mm chainline - which is pretty close to what I run on my Trance, using a HT2 XT crankset. Roughly 47.5mm chainline with how I have it setup.
 

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Discussion Starter · #4 ·
LyNx said:
You should have gone with a 115mm/68 BB instead of the 113mm one, therby getting a roughly 47mm chainline - which is pretty close to what I run on my Trance, using a HT2 XT crankset. Roughly 47.5mm chainline with how I have it setup.
The older shimano xt octalink crankset uses a cartridge bb that is available in 113mm or 118mm wide only. Since my trance 4 came with a 118mm truvativ, I tried my 113mm bb from the nrs and it looked like it would be too close to the linkage. So to play it safe I ordered a 118mm bb. Bike shifts fine and I gave it no additional thought. Started the build for cyfers reign and told him to order a 118mm bb as well. Installed it, only to find that he was dropping the chain to the outside instead of off the granny. A local bike shop told him that the chainline was probably not the cause, it was the pawls in the rear hub that needed to be adjusted to keep the chain from slacken up as much. This sounds weird to me, but the guy said it was the cause with another bike once and that cured it. I now have the rear derailleur adusted perfectly on the reign and just installed a new 113mm bb that arrived today. With the heim 3 ring chain guide installed, the 1mm stainless steel plate added to the 113mm bb is giving the reign a 47.5 or 48mm chainline (very close to tell by eye).

I'll wait until next week or so, but I may change the bb in my trance to a 113mm bb to make for a straighter driveline. Currently I measure 50mm.
 

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48-50mm is a workable difference. All current Shimano cranksets use a 50mm chainline. Race Face X-Type cranksets use small spacers that allow a fine tuning of the chainline from around 48-50mm. Did your friend drop the chain off the small cog on the rear or off the large chainring - kinda hard to tell from your post. Either way it is a limit screw adjutment issue on the front or rear derailleur.
 

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Discussion Starter · #6 ·
Dogboy said:
Did your friend drop the chain off the small cog on the rear or off the large chainring - kinda hard to tell from your post. Either way it is a limit screw adjutment issue on the front or rear derailleur.
It was not the typical drop off the granny to inside of frame, but from the middle ring if i recall. It was dropped the opposite way, towards the outside. All the bike parts arrived on a friday and I built it up that night and then finished it on saturday before a ride. The rear derailleur was having difficulty going into cog 1, but was fine going from 2-9. I have since done a proper adjustment and not eyeballed like before. That could have been the problem, or th ehub adjustment as the lbs thinks it is. Now we are waiting for a new fork to arrive. Shop sent a 130 mm fixed all mountain fork instead of 130/150mm tas as shown on website. Turned out the dealer was given wrong info and now we are getting the marzocchi all mountain 1 with eta/tas and 130/150mm travel.
 

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Dogboy said:
48-50mm is a workable difference. All current Shimano cranksets use a 50mm chainline. Race Face X-Type cranksets use small spacers that allow a fine tuning of the chainline from around 48-50mm. Did your friend drop the chain off the small cog on the rear or off the large chainring - kinda hard to tell from your post. Either way it is a limit screw adjutment issue on the front or rear derailleur.
From the granny ring the chain was tangled to the outside of the Chainstay. Kinda weird if you ask me but we both thought it was either a Chian Length issue or derailuer adjustment needed. When we got back to Mavrim's house we noticed allot of play in the chain while the bike was shifted in to small cog and granny gear combo. Normally there should be slack but not as much as we saw. Since then a Heim guide was installed and the derailuer was fine tuned too. When I inquired at a LBS to find out exactly what spindel length was needed on this bike, since Giant couldn't give me an answer to this on three seperate phone calls. I described the problem to the head mechanic there and he said it sound like the bike needed a Freehub adjustment was needed. Not too sure, we're gonna go for round two this weekend with the chain guide, newly fine tuned derailuer and a 113 Bottom Bracket too, along with a few links more removed form the chain. Hopefully the bike is running perfect then. :rolleyes:
 

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The spindle length is dictated by the crank being used. You can't just say spindle length X works with X frame.
 
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