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Shimano 105 to GRX upgrade advice

Hi all  just after some component advice with regards changing my 105 groupset to GRX.   I ride a Trek checkpoint ALR 5 I am looking to change my crank (50/34) and cassette (11-34) to an 11 speed 1-11 set up. I have recently changed my rear mech to an Ultegra RX clutch mech. I do most of my riding  now off road.

My question is  what sized crank and cassette can I upgrade to? I have workd out that I will need to add a rear mech hanger to support  larger cassette without changing my rear mech. Any help is greatly appreciated.

Many thanks in advance.

 

 

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4 comments

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Reasty15 | 3 years ago
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Thanks very much for advice, much appreciated. 

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huntswheelers | 3 years ago
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Guess it's what you want to achieve....RX will max comfortable to 36 up back without a wolf tooth or similar..... You need to check out some gravel bike/bikepacking sites for inspiration..... I'm on a Sram Apex, 10 Speed CX bike ( Gravel spec'd ) on Panaracers with 46/34 front, 11/36 up back on a GX mech which will run to 42 ....with 46/34 and 11/36 it's 25 gear inches on inner and 36.... MTB are typically 18 gear inches for off road....this gives me 113 gear inches on road.....

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Secret_squirrel | 3 years ago
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Official Max Cassette teeth for that Mech is 34t - whether you can exceed that depends on the hanger (I presume a Road-link or similar) and your b-screw.

Its not clear what you mean by crank.  If you are changing your crank to a 1x GRX one then their 1x cranks come with a 40t chain ring. Its not clear if other chain rings are available.

https://bike.shimano.com/en-EU/product/component/grx-11-speed/FC-RX600-1...

 

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Drinfinity replied to Secret_squirrel | 3 years ago
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Daughters CX bike is running 11-42 11 speed on the back with an Ultegra mech, and no Goat link. I didn't think it was possible either!

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