Aftermarket Chainrings for Dura Ace 7950 Compact Crankset??

Discuss light weight issues concerning road bikes & parts.
Kannedheat
Posts: 7
Joined: Sun Oct 18, 2009 7:50 pm
Location: Bay Area, CA

by Kannedheat

I'm in search of a source for chainrings that will fit my Dura Ace 7950 compact crankset. Due to the unique spider, and how it "blends" with the outer chainring, I'm not crossing my fingers. The bolt pattern is 110mm. Let me preface . . .

I was involved in a bad crash (bike vs. SUV) recently, and my frame, bars and wheels are toast. However, miraculously, my Di2 groupset made it through mostly unscathed. I plan to take my riding onto mixed trails (instead of on the road), and am looking to build-up a cross bike. Since I already have the groupset, I was planning to make use of the Di2. However, I'd love to put on a more traditional set of chainrings (46/36). I've noticed that some cyclocross pros in Europe are starting to use Di2, and judging from the pictures of their chainrings that I've seen, they appear to have "one-offs" made by Shimano.

http://velonews.com/photo/99009

Does anyone know of any other chainring sources for this particular crankset? I'm guessing that I could use any 110mm outer chainring, but it would obviously not mount flush with the 7950's "spider".

(I suppose I could have posted in the Cyclocross subforum, but it seems that the Road forum generates more traffic).

Thanks!!

nitropowered
Posts: 1146
Joined: Fri Jul 17, 2009 4:10 am

by nitropowered

Those rings are Prototypes and I think they are 130bcd. I asked shimano at Interbike if they were going to produce 46t rings and they said no (typical shimano response).

Any ring will work on the DA7900/7950 cranks, they just won't have that sweet blended in look.

by Weenie


Kannedheat
Posts: 7
Joined: Sun Oct 18, 2009 7:50 pm
Location: Bay Area, CA

by Kannedheat

nitropowered wrote:Those rings are Prototypes and I think they are 130bcd. I asked shimano at Interbike if they were going to produce 46t rings and they said no (typical shimano response).


Actually phoned Shimano today. The tech rep that I spoke with said that he's heard that cross-specific rings for the 7900/7950 are coming in the near future.

Kannedheat
Posts: 7
Joined: Sun Oct 18, 2009 7:50 pm
Location: Bay Area, CA

by Kannedheat

nitropowered wrote:Any ring will work on the DA7900/7950 cranks, they just won't have that sweet blended in look.


Any recommendations for a quality aftermarket ring that comes in both a 46 outer/36 inner in the 110mm bolt pattern?

musgravecycles
Posts: 157
Joined: Thu Nov 03, 2005 3:14 pm
Location: Asheville NC

by musgravecycles

There isn't an aftermarket ring out there that will cover the 'holes' in the spider.

*Pic from before Shimano made Niels some matching rings

Image

KB
Posts: 3868
Joined: Mon Jan 12, 2004 12:32 pm
Location: HULLGARIA UK

by KB

TA Squale do a chainring 110bcd that should look fine on the DA crankset as it has the 'invisible' bolts included.

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Mattias Hellöre
in the industry
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Location: Insjön, SWEDEN
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by Mattias Hellöre

If there´s a need to make something that blends nicely into a 7900 crank, let me know I may do some drawings and them send them to my water jet cutter and try it out.
Experimental Prototype

tsutaoka
Posts: 76
Joined: Thu Jul 31, 2008 6:42 am

by tsutaoka

Mattias Hellöre wrote:If there´s a need to make something that blends nicely into a 7900 crank, let me know I may do some drawings and them send them to my water jet cutter and try it out.


i'd be interested in a 46t dura ace (7950) after-market ring, if it was reasonably priced!

Vermu
Posts: 204
Joined: Wed Dec 22, 2010 6:39 am

by Vermu

Are there any issues with narrow new chain and older chainrings? Does it affect changing or anything?

Correction. I don't really mind if it doesn't fit so well in the looks department. BUT seeing FSA has dedicated chainrings
for DA79, are there any other manufacturers and does it make such a big difference in shifting?

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Kastrup
Posts: 575
Joined: Sun Dec 05, 2010 12:00 pm
Location: Aarhus, Denmark

by Kastrup

I have done a bit of research because i wanted to mount a 36 instead of the 34 that comes on the standard compact crank.

Apparently the shifting should be very poor with other chainring brands.
"Stay cool and try to survive" A. Klier to the other members of the Garmin classics squad the night before P-R.

Vermu
Posts: 204
Joined: Wed Dec 22, 2010 6:39 am

by Vermu

Damn. I've run 50/39 until now. Ordered a new bike (canyon) but after a lot of browsing and excitement I ordered one with compact cranks.
Well no probs if that lower ring could be changed to something bigger. Though I'm pondering if the difference in shifting is really that noticeable?
Think I can try with the old 10 speed and see how it goes, a bit sceptical thou.
If it becomes that hard I should really think about returning the bike and ordering a new one, the postage fees are a bit pricey but have to see.

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Kastrup
Posts: 575
Joined: Sun Dec 05, 2010 12:00 pm
Location: Aarhus, Denmark

by Kastrup

Let me know if it is possible to mount a bigger inner chainring on the compact :)
"Stay cool and try to survive" A. Klier to the other members of the Garmin classics squad the night before P-R.

RussellS
Posts: 691
Joined: Wed Feb 03, 2010 1:31 am

by RussellS

Kastrup wrote:I have done a bit of research because i wanted to mount a 36 instead of the 34 that comes on the standard compact crank.

Apparently the shifting should be very poor with other chainring brands.


Huh? How can the inner chainring affect shifting? All the inner chainring does is hold the chain. Shifting is controlled by the front derailleur and the pick-up pins on the outer chainring. I just walked to the basement and looked at my 7900 inner chainring. Its just a plain old regular normal chainring. Nothing special about it. Any other inner chainring designed for 10 speed will work just as well. Only the outer chainring on 7900 is unique.

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Kastrup
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Joined: Sun Dec 05, 2010 12:00 pm
Location: Aarhus, Denmark

by Kastrup

Clearly i didn't read my post through before posting. What i meant was that i have read stories about the shimano chains not working well with other aftermarket chainrings. My bad.
"Stay cool and try to survive" A. Klier to the other members of the Garmin classics squad the night before P-R.

by Weenie


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Getter
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Joined: Sat Nov 14, 2009 6:30 am
Location: So Cal

by Getter

Stronglight looks like they have something...but doesn't look to be available yet.

http://www.xxcycle.com/110-type-dura-ac ... er,,en.php

Inner ring
http://www.xxcycle.com/110-type-dura-ac ... er,,en.php

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