Cruzer Posted September 1, 2008 Share I hope I have used the correct terminology here! My bike shop say that it is normal that my chain rubs whenever I say use 39 / 22,23,24,25 or 53 20/22/23/24/25. They say I am crossing the chain over and that I should rather be shifting Blades up fron rather than using the entire casette at the back on just one Blade. Any Ideas or comments? Link to comment Share on other sites More sharing options...
KDEE Posted September 1, 2008 Share My short answer.....Indeed they are correct as regards using the whole cassette with one front blade... Was taught way back when....... Top half of the cassette with small chainring and bottom half with the big chainring... A very simple explanation and Im sure others will give more eloquent answers, but you get the idea.. Link to comment Share on other sites More sharing options...
Willehond Posted September 1, 2008 Share Modern cassettes and derailleurs (which they did not use way back when) should be able to handle cross chaining. Stay in the big blade as long as your ego allows you! Link to comment Share on other sites More sharing options...
Johan Bornman Posted September 1, 2008 Share You don't say where your chain rubs. But in general, KDEE is right and eloquent with ". Top half of the cassette with small chainring and bottom half with the big chainring... " Cross chaining has nothing to do with derailers - they can all handle (i.e. do it) it. It has to do with misaligning the loaded surfaces on the sprockets and chain internals. Instead of pulling across the entire facing surface of the sprocket, the chain now pulls only on the one side, placing a disproportionate load on that side. The same happens inside the chain. Rapid wear is the only side effect. If you can live with that, then you can live with cross-chaining. However, top-end components such as Campag's upper end stuff (perhaps Shimano as well, I don't know) can "trim". This means you can fine-tune the front and rear derailer with micro-adjustments that eliminates any rubbing noises. Once you've used such a shifter you wont go back to ordinary one-position-fits-all components. Link to comment Share on other sites More sharing options...
Rich Posted September 3, 2008 Share Is this true for MTB - is cross chaining (I think this means big blade, big cassette?) more likely to lead to derailer damage? Link to comment Share on other sites More sharing options...
NotSoBigBen Posted September 3, 2008 Share I don't think derailleur damage, probably more related to premature wear to chain/cluster/chainrings ........ If the chainlength is correct of course! Link to comment Share on other sites More sharing options...
Matchstix Posted September 10, 2008 Share I agree with mr Bornman. If you front derailluer is setup correcly you should be able to use all the gears. My trim feature on my bike works only while upshifting to bigblade. If you time to waste you can take the no of teeth on your front chainrings devide that by the teeth on your cog/cluster. this will give you a number. Use the gears where to where the nubers start to overlap. for example 53/20=2.65; 39/15=2.6 Link to comment Share on other sites More sharing options...
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