That's where sram got it right with their DUB BB/Cranks using different spacers and chainring offset for nearly any combination of hub/frame/etc...

Guess you should be looking for a 6mm offset chainring to get a closer chain line.

 

Ah so for Shimano, I really do have to replace the chainring. I was hoping there exists a spacer for the shimano chainring to put it closer to the frame.

 

Ahhh Shimano. It's funny how they became the worst company in bike industry. Not only so they not innovate but also they do everything to make life harder.

You have 3 choices as of now
1. Try to find aftermarket DM offset chainring
2. Remove spacers from the right side of BB and place them to the left
3. Buy new cranks.

 

Ahhh Shimano. It's funny how they became the worst company in bike industry. Not only so they not innovate but also they do everything to make life harder.

You have 3 choices as of now
1. Try to find aftermarket DM offset chainring
2. Remove spacers from the right side of BB and place them to the left
3. Buy new cranks.

2.5. There are 104bcd DM spiders. A chainring with offset or bolt spacers is installed to control chain line.

 

Wait, not knowing the correct offset of your chainring makes Shimano the bad guys?

Strange flex.

 

I'm not sure if this is directed to me but I was merely asking for advice...

 

No, to silklash, sorry.
your issue is a common one, good luck!

 

What he's saying is that sram (dub) crankset works on any setup with any chainline so "why not shimano". but i'm pretty sure there's a patent story behind that. Thanksfully shimano chainrings are usually not very expensive. You can also find all sorts of spacers to make it just right, that's be the cheapest option.

I'm thinking of doing the same on a 135qr + pf30 and convert it to gxp (yeh lol) with a thread together, then put a gxp sram crankset ive laying around and non-boost chain ring.. and that's .. also going to need a buncha spacers, because gxp is what they were selling before dub

 

Why did Shimano spec their cranksets to 52mm chainline and say that it is compatible with the 135/142mm non-boost hubs? That is their narrowest chainline for their 12spd drivetrains

 

If the Deore ring mounts the same way as the XT/XTR, then Garbaruk makes an offset chainring - I think it has XTR in its name. Others have referred to it on the forum. Else, use a an old school crank and a compatible ring that’s spaced inwards with washers or spacers.

 

Ahhh Shimano. It's funny how they became the worst company in bike industry. Not only so they not innovate but also they do everything to make life harder.

You have 3 choices as of now
1. Try to find aftermarket DM offset chainring
2. Remove spacers from the right side of BB and place them to the left
3. Buy new cranks.

So then option 2, eh? There, that wasn't so hard even for an obvious SRAM fanboy. Just because they don't do it the same doesn't make it bad.

Why did Shimano spec their cranksets to 52mm chainline and say that it is compatible with the 135/142mm non-boost hubs? That is their narrowest chainline for their 12spd drivetrains

It's compatible, but perhaps not ideal if you run in the stock configuration. In most cases spacers can be moved to the non-drive side to adjust chainline as long as you have the clearance such that the crankarm doesn't hit the frame (and enough threads to hold the BB if it's threaded). Or find an aftermarket offset chainring in combination with spacer adjustment (or possibly both depending on the frame and bottom bracket).

 

@noapathy - I'm no SRAM fanboy but I do notice their contribution to moving industry forward and making things bulletproof. Also I am no fan of SRAM cranksets, cause I prefer Shimano (durability, weight and simplicity) but in case of chainline adjustments their cranks design is anti-customer.

 

Also I am no fan of SRAM cranksets, cause I prefer Shimano (durability, weight and simplicity) but in case of chainline adjustments their cranks design is anti-customer.

Sram cranks are lighter and every bit as durable. It's hard to get any simpler than 1 bolt and a preload collar but I guess that's debatable.

 

The M8100 (52 mm CL) crankset doesn't use spacers... so I suspect the M6100 is similar. The M8120 (55 mm CL) uses one spacer on each side.

I believe Garbaruk makes chain rings with alternate offsets. I know the XTR rings are different and they work on XT, not sure they also work on Deore cranks.

I like Shimano cranks, but SRAM offers more options and chain ring options from 3rd party sources.

 

The M8100 (52 mm CL) crankset doesn't use spacers... so I suspect the M6100 is similar. The M8120 (55 mm CL) uses one spacer on each side.

They are the same in that respect and you're correct. The 6120 spindle is 6mm longer than the 6100 and it includes the two 3mm spacers that go onto the spindle. I was thinking of the BB spacers, not the spindle spacers. If OP has a BSA or 89.5 pressfit BB, it's possible to move a spacer from the drive side to non-drive side as long as nothing hits the frame. Alternatively, if that's not possible or the m6100 chainline doesn't work well enough for OP a new ring for the old 2x crank would be another inexpensive option.

I’m wondering on what basis you’ve come to associate ‘SRAM’ with ‘bulletproof’?

Bulletproof marketing? 🐂

 

new ring territory, imo.

I'm a fan of oneup and wolftooth's DM spider solution. Buy the spider with the offset you want, and any of their rings fits it. If you need a new offset, then you can buy a new spider, but still use the same rings. I swear I remember seeing Shimano DM version of OneUp's Switch, but I don't see it on their page now. The WT CAMO is out of stock and has a number of limitations, too.

I've been using Race Face Turbine cranks for awhile now, though, because they have more chainline and q-factor flexibility than anybody else at this point.

 

For what it's worth, I am kinda in the same boat using an FC-8120 crankset (55mm chainline) on a Supercaliber with a boost rear. Past experience with the regular FC-M[X]100 cranks with the 52mm chainline was that the chainring would either not clear, or have paper thin / sketch clearance (it varies by frame), so I just got the wider crank, but on this particular bike the ring could be 3mm closer with good clearance for the better 52mm chainline. However, I sitll want the wider crank arms so my shoes don't rub on the stays, and there's room for a crank arm power meter if I ever want one.

tl;dr, I have also been looking into 6mm offset chainrings for Shimano direct mount. Seems to be 3 options out there. Pass Quest from AliExpress (cheapest), Alugear from Poland, and Garbaruk from Poland. I have an Alugear on my fat bike that has been great, can't decide between that or the $50 one from AliExpress that also seems to be good.

As for why Shimano went this route with 3 different crank spindle widths, I can see pros and cons to this solution vs. a universal one. MTB frames are far from standardized for clearances.

 

Spider adapter and a 104BCD chainring, plus chainring shims.

deckaschainrings.com/decaks-chainring-spider-adapter-for-shimano-direct-mount-to-104bcd-m6100-m7100-m8100-m9100-xtr-slx/

 

The Shimano XTR direct mount cannot be altered for chain line. But the direct mount XT can be modified. Just remove the bolts that hold the chainring to the spider and mount it to the other side. You would need to buy a security torex bit and a metric tap to change the blind hole to a thru hole. It works on my 135mm x qr rear wheel. The chain line works out to 46mm.

 

Even with "optimal" chain line there will be power loss and wear in first gear with 11 and 12 speed. Ironically, when you need the most efficiency. See "Say Nein to Twelve". CUES has 11-46 9 speed which is narrower than hyperglide. 10 speed comes in 11-48. Another trick with a 2x crank is chainring spacers. I run narrow wide, perfectly centered, and tuck in a 24 to shift with SRAM GX derailleur, or by hand. This allows a larger than normal NW ring, like 34 or 36, while still having access to very low gearing with a nearly straight chain.

 

Do you do you have any pictures of how to did this or what it looks like once done?

 

My solution. Plain old 64 BCD 2x chainring and a chain guide. Run whatever tooth count you desire from 22-30T, for peanuts. Cheapo AliExpress 24mm spindle 2x crankset. Machine off the 104 BCD mounts. Machine the 64 BCD mounts to make the chainline whatever your heart desires Yeah, you need access to a Lathe, or be friends with someone who does I do a little bit of machining in my day job