# Rohloff and Shimano 1x Boost Crankset - Anybody Tried?



## randomrouleur (Oct 24, 2017)

I am spec'ing up a new 135mm solid-axle Rohloff / Karate Monkey build. I'm looking at potential cranksets for it to achieve the 'magical' 54mm chainline. I've seen that the new Boost versions of Shimano cranksets, for example the Shimano SLX M7000 Boost Single 11sp Crankset, offer a 153.4mm chainline, which is obviously incredibly close and ought to be fine in the real world. Has anybody tried running this combo? It seems like potentially an elegant solution. I would be looking to replace the standard chainring with a more hard-wearing 8 or 9-speed chainring such as the Surly SS ones. Will this alter things again? I've seen that the chainrings appear to curve inboard, so I worry that a replacement straight chainring will actually put the chainline further out.

If not, what are people's preferred options? I have Middleburn RS-8 Rohloff cranks on another build, which are great, but I'm looking for a cheaper option this time round. Am I best off sticking to a triple crankset, such as the Shimano SLX M7000 Triple?


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## ladljon (Nov 30, 2011)

don't know what a boost crankset is.......I run White Industries ENO with Phil Woods Ti BB on both my Rohloffs


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## MrBadger (Apr 4, 2010)

I'm running a boost chainline with my Rohloff, albeit with Hope cranks and a spiderless chain ring but, boost is boost I guess. Works perfectly for me. I think it's 1mm out of line so just a knicker whisker off.


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## randomrouleur (Oct 24, 2017)

Thanks MrBadger - that's useful to hear! I'm interested to see what people are tending to use now that the 104BCD Shimano cranks seems to be being phased out. I've gone with a Deore M590 Triple (with a Middleburn chainring) to play it safe, but it seems that all the new cranks are tending towards 96BCD - perhaps someone will make solid quality 96BCD rings suitable for 8-speed chains? Anybody know of any already available?


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## randomrouleur (Oct 24, 2017)

Perhaps not news to some, but just discovered that with the new splined sprocket carrier for the Rohloff (which comes with new hubs), the chainline is pushed out to 57mm! Back to the drawing board...


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## fokof (Apr 24, 2006)

Headsup on that subject:

Spliner carrier #8540 = chainline 57mm
Spliner carrier #8540s = chainline 55mm


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## MrBadger (Apr 4, 2010)

fokof said:


> Headsup on that subject:
> 
> Spliner carrier #8540 = chainline 57mm
> Spliner carrier #8540s = chainline 55mm


Why? Does 2mm make such a difference? I've always just got mine somewhere near by sight. Always runs fine and I don't seem to go through a pile of running gear.


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## randomrouleur (Oct 24, 2017)

Yeah, interesting to know at what offset you actually start to see a difference in chain/sprocket wear etc.
But, with Rohloffs, that are often being used for touring, it's not unreasonable to be talking about a scenario where, over a six month tour, you might conservatively make 3-4 million revs of the pedals (60-70rpm x 60mins x 6hrs x 28days x 5 months actual riding). Very small offsets could make profound differences in how much you get out of components and this could be very relevant when you are touring in places where it's hard to get replacement parts. Admittedly, this is a rare scenario, but it's mine next year!


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## Rob_E (Nov 22, 2010)

I just a longer spindle length to get a wider chainline when I was using that kind of bottom bracket. Now I'm using an external bottom bracket, and I find I can do a fair amount with the spacers. 

As for the small variations adding up to failure down the road, I never worried about that. Most people tour with a cassette, meaning that even if one or two gear combinations are perfectly aligned, most gear combinations are not, and yet they survive without catastrophic failures. If you're worried, monitor your chainrings for wear and start looking for replacements at the first sign of wear. But I suspect that small variations in chainline will have less of an effect than good, old-fashioned chain stretch will as you rack on the miles.


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