Deontologist

I used to be able to downshift 5 cogs at once and upshift 3 cogs on my Mirage-equipped bike.

The other day I was messing around with my bike and managed to throw the entire rear derailleur out of whack. It was only after watching several YouTube videos about adjusting the RD did I manage to get it back. Now everything shifts cleanly. No missed shifts and no multiple shifts at once.

However, I noticed today that I can throw the thumb lever down way, way further than before. In effect, I can go through the entire 9 speed cassette at once.

What could I have done? Is this a common occurrence? I don't mind being able to downshift 8 cogs at once ... it might even be a selling point if I sell my bike! Shifting is otherwise perfect. No skipped cogs or anything. And yes my limit screws are set properly. The chain has not fallen off even after several rides and the levers distinctly stop when I try shifting past the biggest or smallest cogs.

FastJake

I'm assuming this is a drop-bar brifter, yes? What make/model and approximate age? I have some Campy 10 speed brifters that will downshift (bigger cog) two or three cogs at once with the paddle and upshift (smaller cog) five or six cogs at once if the thumb button is pressed far enough. I don't use that feature too often but sometimes it's nice to have.

On the other hand, a downtube/bar-end shifter will dump the entire cassette in either direction at will.

ThermionicScott 

The more cogs you have, the nicer that feature is. Especially if there is a wide jump between chainrings.

FastJake

I apologize since this is off topic, but since you mentioned chainrings... Do you thing there's a front derailer out there that will shift a 28/42/52 Biopace? It will be on my touring bike shifted by a down-tube lever so quick shifting is not needed. It has an abused adjustable bottom bracket that might die soon and I'm considering new crank options.

fietsbob

Yellow Jersey shop in your town can help . the Biopace design is early 80s they had a FD that worked then, in the OEM Builds .

ThermionicScott 

That's an intriguing setup, certainly not one intended by Shimano. Since the chainrings have a smaller radius at the widest part where they'd come closest to the FD cage plates, I'd probably just try a regular Deore FD from the BioPace era and see if that works. As long as the 42 and 28 are kept in-phase (and I have no idea why one wouldn't), the upshift shouldn't be any worse than between a plain 42 and 28, but you'd still need some patience, I think.

The "half-step plus granny" Deore FD is a possibility, too, but I'm trying to imagine whether it would actually be better or worse for your setup.

Andrew R Stewart 

Many/most front ders will have enough movement range to cover a triple ring set up. Most triple specific ft ders will have a cage shape which will shift from the inner to middle better then double specific ders (and back down to the small ring). Some (no current that I know of) ft ders are half step specific and have a cage shape which is less effective at shifting the ring steps stated. Some ft ders have a cage which has so "deep" an inner plate that the lower edge of the inner plate can rub on the teeth of the middle ring when shifting up onto the large ring.

The BioPace aspect can actually help the shifting sometimes because the chain is raising and lowering it's position within the cage (and therefore runs past the shapes that a modern ft der has on it's cage). But predicting ft der efficiency is a hard thing to do. Those who seek certain shifting efficiency and play with ring counts and sizes often end up with a few ft ders as they try different combos to get the best performance.

So do your best with the ft der's claimed specs as a first step but then the actual mounting and adjusting will give the feedback that is needed to say which works good enough. Andy.

Deontologist

Yes, drop-bar brifters. Mirage, ~2005. I know that according to Campy it can dump 5 cogs at once or upshift 3 at once. I'm just curious as to how I manged to "hack" it to dump the entire freaking cassette, which is pretty cool (although now I wish my thumbs were longer to really pound that thumb lever down).

Drew Eckhardt 

Pointy-hood ergo levers have enough travel in the thumb button to reach the smallest (8th or 9th) cog. I have long thumbs and could do that riding on the hoods, although it'd be too awkward riding in the drops.

Ultrashift levers are limited to five.

I skipped over rounded-hood ergo levers.

That said you're unlikely to want more than five. Riding 50-34 x 13-14-15-16-17-18-19-21-23 eschewing the fully cross-chained combinations the next easier gear after 50x21 was 34x15 just five cogs away. 53-39 and wider cassettes missing 18 and/or 16 cog take fewer.

52-36 or 50-34 x 14-23 10 cogs would call for a 6 cog move following big x 22 with small x 16.