B-screw mods for road bike derailleurs (CX stuff)

takai

Eats Squid
Ok, tried asking this on some road forums and they were all NFI due to it not being Durace etc

Have Shimano 105 5700 setup on CX bike, running 1x10. Dont want to shell out for 1x11 and hydros just yet. Want bigger rear cluster. Wondering if its possible to do the B-screw mod on a 105 mech, like it is on the Shadow mechs to run larger rear clusters on 1x10 on the MTB.

Considering this as i have a couple of spare 32T max rear clusters for the MTB, but no smaller NW chainrings spare.

Not anywhere near the bike at the moment, so a bit hard to check. Anyone mucked around with this?

Edit: Ugh, in wrong sub-forum. Anyone want to move it to Parts n Stuff.
 
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The Duckmeister

Has a juicy midrange
5700 got a mid-model update around 2012, which increased maximum sprocket capacity. Pre-'12 derailleurs officially have a limit of 28T, but some frames' hangers can put it a bit lower & give more clearance. 2012 model & later, post-tweak will fit a 32T out of the box. Official specs say you need the longer cage version to do it, but that's because they're assuming it'll be paired to a compact crankset with 16T chainring difference, and the total difference will push the short derailleur to its limit (but it will do it). The big cassette and tighter-range CX crankset will comfortably fit with a regular short late-model 5700 RD with no mods required.

1x of course removes the chainring difference from the equation entirely.
 

Haakon

Keeps on digging
Ok, tried asking this on some road forums and they were all NFI due to it not being Durace etc
.
Bloody roadies... I have never understood how they manage to ride with the stick so far up their arse.
 

takai

Eats Squid
If you can't do it with a huge B screw try one of these, https://www.wolftoothcomponents.com/collections/derailleur-optimization/products/roadlink

I run a 11-40t XT cassette with an Ultegra short cage 1 x 11, works a treat.
Thanks, found this https://www.amazon.com/Bicycle-Dera...=UTF8&qid=1507507243&sr=8-2&keywords=roadlink

Appears to be the same thing, just unbranded.

Also looking around it appears that i can use a 9sp MTB mech, as it has the same actuation ratio as the 10sp road shifters
 

takai

Eats Squid
probably wont ship to au, get the wolf tooth from mtbdirect, I've just put on a 11-42 x2 on friends cx works nicely no more whinging on the climbs.
Ah, thats what i have a US dropbox for ;)

Ill pick that up, but also have a play around with a XT M770 i have lying around. See if i can get a 11-36 on there. Its primarily for a lower gear so i can turn up to work somewhat less sweaty (new work is at the top of a climb), so a 36T should be enough..
 

takai

Eats Squid
To confirm, this definitely works:


Far easier than Bscrew mods, and lets me keep a good top gear as well as a broad range.
 
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