You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more
Reading the one up article on the front page, and it's something Ive seen on threads here a few times.
maybe I'm missing something, but the idea of having clicks left over when setting up gears to work like this is a bit odd. The idea of having a flappy bit of slack cable doesn't make sense.
from the article:
'and that the system leaves three clicks on the shifter when you’re in the eleven tooth on the cassette.'
why would you set it up like that?
surely, you set up the mech limit screws accordingly, then set the cable tension normally, so for the rear mech, set cable tension initially when you're in the 11t. The mech stop prevents the mech from going further than the 6/7 sprockets you have and mean you don't have access to the other clicks.
same goes for the front mech with a 3x shifter.set the limit screw in the smaller chainring, take up cable slack, shift to large ring, adjust limit screw and fine tune cable tension. no longer able to access number 3 on the shifter as the limit screw stops the cable pulling further.
am I actually missing something fundamental here? I've never set up my hybrid botched systems with excess cable slack and they worked damn well.
I've got no idea what that article is, or why you'd want a shortened cassette, but I agree, you don't want slack cables.
However, one thing I've heard mentioned is that it might not be good for the shifters to be pushing against dérailleur limit screws if they're mid-way through their index/ratchet. I can't say I've noticed a problem myself, though I can only refer to running a triple shifter with double chainset, and not mismatching shifter/cassette numbers at the back.
I assume it saying you can have more pull to cope with the greater chain angle with three clicks
My 2 x 9 has a three speed shifter [ and mech] and its set up so it can only do one click
Agree with you OP - I'd set up the smallest sprocket as usual, but then limit the travel on the mech so you never get the largest 3. However, with a narrower cassette you'd need a (far) longer stop screw, which is perhaps part of the reason - by doing it with cable tension you negate the need for that.
Always done the same using doubles too.
Have i missed the bit where the OP references the article?
Anyway, some mechs struggle to limit the mech on shortened cassettes so you have to limit the shifter (my sram X9 mech wouldnt limit to 6 sprockets, a longer screw did not work as it missed the stop but also hit another bit of the mech meaning you couldnt get it down to the 11T either).
OK, that makes sense, the limit screw on some mechs not being long enough.
Which brings another point possibly, if you were designing a large flanged spacer, like the oneup, and knew about the potential limit screw issue, would you not design it as a 2 piece so the remaining 6/7 sprockets were spaced mid way on the cassette rather than at the end?
Thereby either a. making both limit screws useless (;-))or b. making both limits screws useful and also maintaining a favourable chainline for most middle positioned chainrings?
^^ without redesigning the freehub body you wouldn't be able to move the sprockets inboard whilst retaining the 11t sprocket as it sits over the end of the freehub.
Regardless of this, I just don't get why you'd restrict yourself to 6 or 7 gears anyway? The reason given appears to be that it gives you closely spaced gears, in which case why not just use a 10sp 11-25 or 11-28 road cassette?
Is it just a dh fashion thing?
same goes for the front mech with a 3x shifter.set the limit screw in the smaller chainring, take up cable slack, shift to large ring, adjust limit screw and fine tune cable tension. no longer able to access number 3 on the shifter as the limit screw stops the cable pulling further.
The cable pull for 1->2 on a 3x shifter is different from 2->3. So if you're using a 2x front mech, you want to use 2->3.
(Yes, I'm sure you can bodge it with 1->2, but the cable pull will be wrong)
Jim, I wasn't aware of that. Figured it was as close as, and not had any problems with it.
That said, my 2x was either small to mid position, say 28/40, or middleburn duo, so it'd be shifting part way through the mechs stroke or at the closer to the frame part of it, I guess.
DjTom, you're right, couldnt do the 11, would need to use a 12. :-/