Chain Cross over

[HLaB]

I always avoid Chain Cross over (i.e small ring at the back, small ring at the front or large,large). It's reasonable that this is a no, no with a triple, is it as much as an issue with compact double ?

 

[threefingerjoe]

Yes, that's still a no-no, even with a triple, especially the small-small combination. In that gear, you are developing a lot of power with the small chainwheel, and delivering it to very few teeth on the small rear sprocket.

 

[asterix]

..seems to me that with a triple it'd be even badder due to the slightly greater distance from the centre line of the two outer rings.

My local terrain is all hills so I have a triple and try to keep the two smallest outer cogs (9-speed) for the big ring and the 2 largest cogs for the smallest ring. When fit I don't have to use the smallest ring until the end-of-day fatigue gets me.

 

[HLaB]

Sorrry, did I phrase the original question wrong, is it a situation that should be avoided with a compact double too?

 

[Steve Austin]

yes.
Should always try to keep the chain as straight as possible.

 

[Paul_Smith SRCC]

I always avoid Chain Cross over (i.e small ring at the back, small ring at the front or large,large). It's reasonable that this is a no, no with a triple, is it as much as an issue with compact double ?

With Triple chainsets regarding ratios that you should and shouldn‘t use this may be of help, on my Campagnolo 10 speed triple set up I would generally use from my own set up shown here the following:

46 ring sprockets 1-7
36 ring sprockets 2-9 (see below)
26 ring sprockets 3-10

Although on the bike fitted and I can use all the sprockets on the middle ring, I have actually only listed the gears I actually use. Note than some bikes the chain line using middle ring smallest sprocket may be such that the chain will actually rub on the inside surface of the large ring, modern chain sets this can happen as the rings are quite close.

As I have done you need to work out what ratios you are after then try and achieve them in the relevant chain ring and sprocket locations. In my case for example I like gears of around 60”, you will see that I have got those on both middle and outer ring. I have done this essentially because this is a bike I use for two roles, solo rides of 15-20mph and touring rides of 12-15mph, to save repeated chain ring changes I can essentially use the big ring mainly for solo rides and the middle ring for more sociable rides.

It does take a bit of thought as to what you need both in terms of ratios and then equipment choices to achieve them, but it can nearly always be done. In my case for example I did invest in a high quality chainset to get the ring combinations I wanted, as for me personally I find many road specific triples to large for me and the ATB chainsets to small for what I want.


Paul_Smith
www.bikeplus.co.uk

 

[chopstick]

On a double and a 5/6 cassette not a major problem but should be avoided. On a triple with a 8/9/10 will cause problems and I consider "crossover" must be avoided.
Chopstick.