[hatake]

I know there are tons of 1x10 questions using 3x cranks and in general it seem to work just fine. But when you say "fine" does your extreme opposite selections work just like your middle gears? Or is it "it's rough at both ends but it works ok" type of fine?

Here is my situation: I built my new (to me) Rip9 as 1x10 using my beloved XTR chopped m960 cranks with 3-year old pre-bust HBC rings still in an excellent condition. I went for somewhat rocky ride and it didn't drop chain (I even forgot to engage XT clutch LOL), so it looks like this set up is working. I used road chain (Shimano 105 CN-5701 10 sp chain - it was lighter than SLX chain) with SLX 10sp cluster.

I initial had a spacer on drive side as usual. It was immediately clear that it wouldn't work. So I removed the spacer from drive side to non-drive side. The chain line was still pretty bad in granny gear, which would get 50% of trail time… Crank rotation requires significantly more effort, and you can hear chains getting bent and grinds. Small gear is pretty much silent strangely, even though it's getting similar bend.

Stability in granny is more important for me, so I need ring moved inward. I dug up chain ring spacers from ancient square cranks (they used to come with a whole bunch of spacers), measured 6 mm in height. Now, it moved the chain line by about 2 gears, so the 3rd gear gets the best chain line. Granny is silent. Small gear is sort of rough but I doubt I use that gear that much.

Is this what you would expect with 3x cranks? It can't be a Niner thing, can it? I also encountered more pedal strikes today compared to my ss 29er that I usually ride… Ride itself is a confidence inspiring, smooth handling, decent climber. So I'm a little puzzled. Can you share your inputs?

 

[AlexRandall]

Well, a 1x crank can be exactly the same as a 3x. It matters not what number of rings the crank was originally designed for, but the position of the ring you decide to use up front.
And given that this position will fall somewhere between the extremes of the high and low gears at the back you can quite easily guess that there will be angle on the chain in both extremes.
You can either spend a lot of time and effort trying to tweak the ring so there is perhaps less angle in the extreme you more regularly use, or you can just ride the bike and accept that chain angle is a part of every geared bike - and indeed would have been exactly the same angles when you were running middle chainring in your 3x setup.

And it looks like your chain is too short.

 

[hatake]

Maybe after a while I won’t even think about it. The width of the cassette is the same between 9sp, so yes I do understand it’s just like running middle ring for all gears. So you guys just set it up and just go? I even thought that the road chain has less side-to-side tolerance (I don’t know, I never had road equipment).

I used something like this (6mm), do you guys use the same thing to move the ring inward? Any other (cleaner looking) way?

 

[JMac47]

Not exactly sure what your question is that you want input on.

And I don't know if you originally had the ring mounted to the spot where the "big" ring would have been, but l can't recall seeing anyone using that size spacers.

 

[hatake]

I guess my question really was - anyone using 3x cranks have any issue with granny? Did you try to remedy it (with extra spacers between ring and crank arms)? Is 1x crank made to do things differently? I should just stop wondering how this set up maybe hard on equipment and just ride it and replace ring/chain at some point. M960 arms act as spider, so I removed the largest portion. What's on there is a middel ring. Thanks.

 

[AlexRandall]

As said before, with only 1 ring upfront there is only the relative position of that 1 ring in relation to the spread out back. If you've biased it toward the gears you are most likely to use then you'll be in the best position to have the straightest chainline for the most time possible.

Go out and ride and enjoy!!!

(and hope for no chain drop!)

 

[hatake]

Yup, RIP is a wonderful platform for rocky CO trails. Thanks guys.