Single chainring advice needed

Discuss light weight issues concerning road bikes & parts.
urbanspaceman
Posts: 15
Joined: Thu May 25, 2017 7:05 pm

by urbanspaceman

Hi there.

I have been using an Aerocoach Arc 54t chainring on a Rotor 3D24 (110 BCD) chainset, all good.

However I have a few early-season hilly TTs and want to run a 50t instead.

Am I okay to use any brand of chainring so long as it's outer? (Eg http://www.chainreactioncycles.com/fsa- ... prod129956)

Then is it just a case of using single chain ring bolts (Eg https://www.amazon.co.uk/Alloy-Chainrin ... B004CSTWQO)?

Thanks in advance :)

by Weenie


Marin
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Location: Vienna Austria

by Marin

You want a narrow / wide chainring like SRAM or Wolftooth. An outer with shift ramps will drop your chain.

And yes on the bolts, however I prefer regular chainring bolts with washers because they offer more thread overlap.

darnellrm
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Location: NC, USA

by darnellrm

Marin wrote:
Mon Feb 12, 2018 9:59 pm
You want a narrow / wide chainring like SRAM or Wolftooth. An outer with shift ramps will drop your chain.
That's pure baloney. The shift ramps never come into play if you aren't shifting from a small ring.

Kurets
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Joined: Thu Feb 25, 2016 9:55 pm

by Kurets

darnellrm wrote: That's pure baloney. The shift ramps never come into play if you aren't shifting from a small ring.
Sounds like you don't understand why the teeth on outer rings are shaped in the way which they are. To aid both down and upshifting the teeth on double and triple chainrings are shaped in order to allow the chain to derail or climb up on the teeth. This is the opposite of what you want for a 1X setup where you want maximum chain retention.

darnellrm
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Location: NC, USA

by darnellrm

Kurets wrote:
Mon Feb 12, 2018 10:28 pm
darnellrm wrote: That's pure baloney. The shift ramps never come into play if you aren't shifting from a small ring.
Sounds like you don't understand why the teeth on outer rings are shaped in the way which they are. To aid both down and upshifting the teeth on double and triple chainrings are shaped in order to allow the chain to derail or climb up on the teeth. This is the opposite of what you want for a 1X setup where you want maximum chain retention.
I do know that it's not going to shift anywhere without a front derailleur forcing the chain if you set up the chainline properly. No need for the wide-narrow ring. Those are only good to induce lots of chain friction. They were designed for off road use where there is lots of chain bounce.

urbanspaceman
Posts: 15
Joined: Thu May 25, 2017 7:05 pm

by urbanspaceman

Thanks for the replies. Would I be right in thinking that a Sram Rival 1 X-Sync would do the job (https://www.ribblecycles.co.uk/sram-riv ... #pid=33933)?

commendatore
Posts: 176
Joined: Mon Dec 30, 2013 1:51 am

by commendatore

darnellrm wrote:
Kurets wrote:
Mon Feb 12, 2018 10:28 pm
darnellrm wrote: That's pure baloney. The shift ramps never come into play if you aren't shifting from a small ring.
Sounds like you don't understand why the teeth on outer rings are shaped in the way which they are. To aid both down and upshifting the teeth on double and triple chainrings are shaped in order to allow the chain to derail or climb up on the teeth. This is the opposite of what you want for a 1X setup where you want maximum chain retention.
I do know that it's not going to shift anywhere without a front derailleur forcing the chain if you set up the chainline properly. No need for the wide-narrow ring. Those are only good to induce lots of chain friction. They were designed for off road use where there is lots of chain bounce.

Chains bounce and drop on the road too. You may be able to get away without it most of the time, but unless a dropped chain is acceptable in your TT, go with a narrow wide ring.

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wheelbuilder
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Joined: Wed Feb 08, 2017 2:10 am

by wheelbuilder

Narrow-Wide for single ring use. No exceptions. You will drop a chain if not used. Maybe not right away or in the middle of your cassette on a glass smooth road, but otherwise it will happen.

Marin
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Location: Vienna Austria

by Marin

darnellrm wrote:
Mon Feb 12, 2018 10:05 pm
That's pure baloney. The shift ramps never come into play if you aren't shifting from a small ring.
It's not and I have the scars to prove it.

A narrow/wide or 1x-specific chainring is an absolute necessity, while a clutch type derailleur isn't.

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Frankie - B
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by Frankie - B

David millar in the tdf prologue in 2003 anyone?

He dropped his chain on a regular chainring used as 1x.
'Tape was made to wrap your GF's gifts, NOT hold a freakin tire on.'

Grill
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Location: Oop North

by Grill

wheelbuilder wrote:
Tue Feb 13, 2018 4:24 am
Narrow-Wide for single ring use. No exceptions. You will drop a chain if not used. Maybe not right away or in the middle of your cassette on a glass smooth road, but otherwise it will happen.
Two seasons racing on an ARC and still never dropped a chain. I think what you mean is to use a ring specifically designed for single-ring use, as opposed to a narrow-wide.

Marin
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Location: Vienna Austria

by Marin

Grill wrote:
Tue Feb 13, 2018 5:06 pm
Two seasons racing on an ARC and still never dropped a chain. I think what you mean is to use a ring specifically designed for single-ring use, as opposed to a narrow-wide.
"The ARC has ... custom long teeth to retain the chain"

Yes

bm0p700f
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by bm0p700f

A nother narrow wide chasing user here and it is essential. Mines a garbaruk oval ring.

darnellrm
Posts: 202
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Location: NC, USA

by darnellrm

bm0p700f wrote:
Tue Feb 13, 2018 5:33 pm
A nother narrow wide chasing user here and it is essential. Mines a garbaruk oval ring.
Did you actually try the single ring setup with a normal ring?

by Weenie


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IrrelevantD
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by IrrelevantD

darnellrm wrote:
Mon Feb 12, 2018 10:05 pm
Marin wrote:
Mon Feb 12, 2018 9:59 pm
You want a narrow / wide chainring like SRAM or Wolftooth. An outer with shift ramps will drop your chain.
That's pure baloney. The shift ramps never come into play if you aren't shifting from a small ring.
I'm going to have to disagree with you on this one as well. I've never run a 2x ring 1x, but I've had my chain drop from my big ring to my little ring. So YMMV, and you may be able to get away with it, but at the very least, there's going to be an increased likelihood of dropping the chain.
* There is a 70% chance that what you have just read has a peppering of cynicism or sarcasm and generally should not be taken seriously.
I'll leave it up to you to figure out the other 30%. If you are in any way offended, that's on you.

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