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Gearing question.
 

[Closed] Gearing question.

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[#12166838]

Morning, so I currently have a 48/36 Ultegra chainset and a 11-32 cassette on a Ultegra medium cage rear mech. Is there any reason why I can't fit a 48/31 GRX chainset to give me more chance of getting up stinking steep hills? Thanks, Stuart.


 
Posted : 26/12/2021 10:29 am
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What front mech? Check Shimano.si for tech Doc's etc


 
Posted : 26/12/2021 10:38 am
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GRX chainline is slightly different to Ultegra so your front mech might struggle.

Another option would be a wider-range cassette. An Ultegra rear mech will handle it, despite what Shimano document.


 
Posted : 26/12/2021 12:08 pm
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Another option would be a wider-range cassette.

I believe the Ultegra will handle up to 40T perfectly well with a roadlink. As for the front end, instead of a whole new crankset how about some Absolute Black 46/30 oval chainrings? 30x40 sounds like my kind of gearing!


 
Posted : 26/12/2021 1:18 pm
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I believe the Ultra will handle up to 40T perfectly well with a roadlink.

I have 50/34 and 11-40 without a Roadlink. Can't guarantee that'll work on all frames though.


 
Posted : 26/12/2021 1:20 pm
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Some tips here https://singletrackworld.com/forum/topic/ultegra-6800-smallest-chainrings/


 
Posted : 26/12/2021 1:31 pm
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Have a play with different ring sizes and cassette options in a gear inch calculator such as https://www.sheldonbrown.com/gear-calc.html

New inner ring and 11-34 cassette would set you back ~£80 going on Merlin prices.

https://www.probikekit.co.uk/bicycle-cranksets-and-chainrings/shimano-grx-rx600-double-11-speed-chainset/12649530.html isn't a bad price for a 30/46 chainset, if you don't mind 175mm cranks.


 
Posted : 26/12/2021 1:32 pm
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I have 50/34 and 11-40 without a Roadlink. Can’t guarantee that’ll work on all frames though

This is the way to go if you're happy to experiment.


 
Posted : 26/12/2021 1:38 pm
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What 40t rear cassette are people using with the ultegra rear mech?


 
Posted : 26/12/2021 2:58 pm
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As ever, thanks everybody.


 
Posted : 26/12/2021 4:00 pm
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Ian, XT 11-40 on mine.


 
Posted : 26/12/2021 5:04 pm
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Ian, Sunrace on mine


 
Posted : 26/12/2021 5:07 pm
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Although TBF I switched one mech to 105.


 
Posted : 26/12/2021 5:08 pm
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Thanks all. So a mtb cassette will just work fine on 11sp ultegra with a road rear mech? (Obviously within limit of chain capacity of cage). Has this always been the case? I thought Shimano cassettes were mtb or road.....

Ian


 
Posted : 27/12/2021 5:25 pm
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That's what I'm using on the Amazon.

105 5800 shifters

105 5800 50/34 chainset

105 5800 front mech

Ultegra RX800 rear mech (I wanted RX for the clutch as I take the Amazon off-road most of the time)

XT M8000 11-40T cassette.

The only "non-standard" thing I've had to do is extend the 116 link chain by two links. I can fully cross-chain.

If I remember correctly, depending on your hub, you may need a 1mm spacer behind the cassette.


 
Posted : 27/12/2021 6:00 pm
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Not only that, Deore 591 9speed derailleur is a great cheap alternative if you're struggling to wind up the extra chain, it works with 10 and 11 speed, not sure about 12sp though.


 
Posted : 27/12/2021 6:16 pm
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Guys, thats awesome. Thanks!

Ian


 
Posted : 27/12/2021 6:52 pm