The single front rings from the Olympics

Discuss light weight issues concerning mountain bikes & parts.

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kingkongsfinger
Posts: 252
Joined: Mon May 07, 2007 1:06 pm
Location: UK

by kingkongsfinger

that dont need a front chain guide, where can you get them from/are they available?

How do they work????

Will they fit the new XTR chainset?
"I could have done this job myself in five minutes, but as things turned out I had to spend two days trying to find out why it had taken someone else three weeks to do it wrong."

thisisnotaspoon
Posts: 95
Joined: Thu Aug 30, 2012 8:42 pm

by thisisnotaspoon

SRAM XX1 ?

It had alternating thick/thin teeth so that the chain wasn't able to flex as much so in principal it can't twist enough to de-rail itself. So far I've only seen it announced for the XX1 cranks which use a new BCD (presumambly to allow for <32t chainrings).

by Weenie


colinmack
Posts: 47
Joined: Sun Nov 26, 2006 8:59 pm
Location: UK

by colinmack

I don't think the chain ring is any different, it's that the rear mech is. Shimano and SRAM have new rear mech's that have a locking clutch system that stops the cage moving forward, which holds the chain under more tension and stops the chain being dropped off of the chain ring. I may be wrong but I think that's the theory.

crohnsy
Posts: 439
Joined: Mon Aug 16, 2010 6:43 pm
Location: Canada

by crohnsy

Colimack, you are wrong.. Sorry mate. The rear dérailleur is also different but the clutch is the same being used in 10spd derailleurs as well. The new XX1 derailleur has a straight paralleogram rather than a slanted one required for multi-chainringed bikes. The whole idea around XX1s ring is their new chainring is profiled to match their chain with alternating wide and narrow teeth.

Much like how the XX1 rear derailleur originally began as a product for the DH world, the group's X-Sync chain rings also have roots in another realm: touring. The story goes that a unorthodox chain ring was developed for cycle touring that employed radically shaped teeth designed to hold the chain onto the ring as the bike was being ridden over rough roads, thereby keeping the casual cyclist from having to get themselves covered in grease when reinstalling the chain. Although XX1 uses the same concept, the idea has been taken to the next level. The design uses alternating tooth profiles; one with a thicker and heavily stepped shape, followed by a more standard looking tooth. When viewed from above, the alternating teeth match the inner profile of the male and female chain links. The radical teeth work with the XX1-specific chain to limit the chance of it lifting up and off of the ring. Size options will include 28, 30, 32, 34, and 36 tooth rings, although odd tooth ring sizes will not be available due to the alternating pattern of the X-Sync design.


http://www.pinkbike.com/news/sram-xx1-ride-11-speed-2013.html

limba
Posts: 956
Joined: Tue Dec 16, 2003 4:24 am

by limba

Yup, it's a whole new thing. It doesn't need a chain guide. Nino used it, maybe Sabine Spitz too.

It's Italian. Google can translate or you can just look at the pictures if you don't understand.

http://www.light-bikes.it/forum/index.php?topic=25914.0" onclick="window.open(this.href);return false;

Here's more in English.

http://www.cyclingnews.com/features/gal ... ide-review

colinmack
Posts: 47
Joined: Sun Nov 26, 2006 8:59 pm
Location: UK

by colinmack

I stand corrected, well sitting down really.

Snicks
Posts: 57
Joined: Sat Nov 12, 2011 8:33 am

by Snicks

They do however recommend a guide for anything really gnarly don't they?

thisisnotaspoon
Posts: 95
Joined: Thu Aug 30, 2012 8:42 pm

by thisisnotaspoon

They do however recommend a guide for anything really gnarly don't they?


Seems to be a marketing thing. They had it on their sponsored enduro (of the gravity kind, not 24/12) riders bikes for the press jollies. Then the same riders stuck chain devices on for the races. Seems the answer is it's much better than a single ring, but not quite good enough for what they're marketing it at. I've got a silentguide on my 'enduro/AM/mini-DH' bike
and can't see myself upgrading even if a 3rd party makes them for other chainsets. The cassette and mech are tempting but I'm not sure I'd ever go back to SRAM, their mechs fold in two if you just look at them the wrong way!

TheRookie
Posts: 910
Joined: Wed Jan 18, 2012 4:23 pm
Location: Midlands, United Kingdom

by TheRookie

Is there a chance though that with the right ring design it would work on a 1x10 with a dampered (aka clutch, although it's not actually a clutch but a friction damper) rear mech? Although XXI is all new, the only parts that seem to eliminate the need for a chain guide are the dampered mech and the chainring, in which case no need for SRAM just use a Shadow plus rear mech.
Impoverished weight weenie wanna-be!
Budget 26" HT build viewtopic.php?f=10&t=110956

HillRPete
Posts: 2292
Joined: Tue Apr 12, 2011 8:08 am
Location: Pedal Square

by HillRPete

Rookie, good question. The chainring design will probably be taken up by third party manufacturers pretty quickly, at which point it will be easy to find out. Anyway the chainguard yes/no is not a sharp line, is it, more like what works for you.

knutte18
Posts: 21
Joined: Fri Sep 14, 2012 7:27 am
Location: Finspång, Sweden

by knutte18

It seems that some WC-riders like Alexandra Engen is running a XX1-crank/ring with a X0 Type 2 RD, XX or X0-cassette and XX/X0 shifter. Don't know if it is a 10 spd or 11 spd chain though.

Look at Engen's WC-Eliminator bike and setup here.

TheRookie
Posts: 910
Joined: Wed Jan 18, 2012 4:23 pm
Location: Midlands, United Kingdom

by TheRookie

I think I count 10 sprockets in that pic......
Impoverished weight weenie wanna-be!
Budget 26" HT build viewtopic.php?f=10&t=110956

thisisnotaspoon
Posts: 95
Joined: Thu Aug 30, 2012 8:42 pm

by thisisnotaspoon

Although XXI is all new, the only parts that seem to eliminate the need for a chain guide are the dampered mech and the chainring


Depends what you want to achieve, I like my current chain device setup for it's reliability and it protects the chainring through rocky sections. I see the appeal for XC weight weenieism though. I'd like the mech and cassette design through to give a wider range and eliminate ghost shifts.

grover
Posts: 1108
Joined: Mon Jul 26, 2004 1:06 pm

by grover

The reason you see the XX1 crank with a 10 speed xo or xx shifter/derailleur/cassette is the riders wheel choice. The XX1 cassette requires a different freehub which is only available from SRAM and DT Swiss at the moment. Many other companies have announced that they will be making one but they're not available yet.

The extra spring tension in the rear derailleur and the new chainring is what negates the need for a chainguide. The spring tension in the XX1 derailleur and the XO type 2 derailleur are similar. The different parallelogram (and offset upper jockey wheel) of the XX1 derailleur is primarily to make it function with the wide spread 10-42 cassette. It may contribute extra protection from dropping a chain but it's not the primary reason for the design.

tompho
Posts: 67
Joined: Tue Mar 13, 2012 8:37 am

by tompho

XX1 is the future. Extralite will have a freehub soon.

by Weenie


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