Smaller compact chainset

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21pavone
Posts: 10
Joined: 13 Apr 2015, 10:16pm

Smaller compact chainset

Postby 21pavone » 13 Apr 2015, 10:39pm

Is a smaller (ultra compact?) chainset with 46/30 rings available, compatible with Shimano 11-speed?

Keezx
Posts: 422
Joined: 20 Dec 2014, 10:44am
Location: The Netherlands

Re: Smaller compact chainset

Postby Keezx » 13 Apr 2015, 11:08pm

A 30 T ring will not fit on a 110 mm BCD, so a normal compact chainset can't fill your need.
Chainsets with 110/74 BCD do exist but rare, TA or Sugino may be interesting.
Any 10 Speed crankset will accept a 11 speed chain.

tim-b
Posts: 1644
Joined: 10 Oct 2009, 8:20am

Re: Smaller compact chainset

Postby tim-b » 14 Apr 2015, 6:04am

Hi
You can get 46 outer rings but the 30 inner will be a challenge for the reasons above. A triple will do the job and be more readily available provided your levers are suitable
Regards
tim-b
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Brucey
Posts: 41416
Joined: 4 Jan 2012, 6:25pm

Re: Smaller compact chainset

Postby Brucey » 14 Apr 2015, 7:55am

presumably you want a 'road' chainline? I think there are MTB chainsets that can have the ratios you want, but they will give a wider chainline, and because of the way modern BBs are designed, you can't easily adjust that.

Worth looking at Middleburn chainsets to get something that will do what you want. Also Rene Herse (Compass), Velo Orange offerings.

cheers
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pwa
Posts: 13276
Joined: 2 Oct 2011, 8:55pm

Re: Smaller compact chainset

Postby pwa » 14 Apr 2015, 9:27am

My wife uses a 700c wheeled Islabike that my son used to ride, and I replaced its "compact" chainset (something like 48/34) with a modified triple from Spa Cycles with the outer chainring replaced with a chainguard. So she now has a double with 42/28 which suits her better. A small ring of 26 would have been possible with the existing front mechanism. And interestingly, the distance between crank faces on the XD2 cranks (imagining they were both facing down at the same time) is about 15mm less than on my 2004 Shimano Deore Mtb chainset. I don't say that automatically indicates a road bike chainline, but gear changing worked well after a few careful tweaks (including slight bending of the front mech cage).

The XD2 cranks are nice to look at but cost only£20. Best buy ever! But you have to then buy the chain rings / guard (cost varies) and a suitable bottom bracket.

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NUKe
Posts: 3985
Joined: 23 Apr 2007, 11:07pm
Location: Suffolk

Re: Smaller compact chainset

Postby NUKe » 14 Apr 2015, 9:36am

An Alpine cainset perhaps we discussed it here with a few suggestions
viewtopic.php?f=5&t=94141&start=15
NUKe
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BigG
Posts: 984
Joined: 7 Jun 2010, 4:29pm
Location: Devon

Re: Smaller compact chainset

Postby BigG » 14 Apr 2015, 8:10pm

A Suntour or Shimano compact chainset from the 80s or 90s with bcds of 94/58 (5 arm) will mount on a 107mm axle and, using the outer 2 rings only, give the gears you need. The chainline is reasonable across a 130 or 135 mm rear spacing. The front rings will work with a 9/10 speed but I am not sure about 11 speed. Someone on this thread will know.

manybikes
Posts: 300
Joined: 9 Apr 2007, 10:21am

Re: Smaller compact chainset

Postby manybikes » 14 Apr 2015, 8:27pm

I second Brucey. Middleburn will do it - I have that combination, but its not inexpensive! Very good quality.

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cycleruk
Posts: 5471
Joined: 17 Jan 2009, 9:30pm
Location: Lancashire

Re: Smaller compact chainset

Postby cycleruk » 15 Apr 2015, 4:35pm

BUT do all the above suit 11 speed as the O.P. mentions?
You'll never know if you don't try it.

scottg
Posts: 845
Joined: 10 Jan 2008, 8:44pm
Location: Highland Heights Kentucky,, USA

Re: Smaller compact chainset

Postby scottg » 15 Apr 2015, 6:44pm

Sugino makes one, I use the 10s version, shifts fine, 46/30 rings and Shimano CX-70 front mech.
I am using d/t shifters, don't know about STI.

http://www.alexscycle.com/cranks/road-1 ... 11spd.html
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