SRAM Long cage "WiFli" Capacity & Takeup (RamErgo)

[JEJV]

Anyone know if an SRAM Wifli rear mech will take a 34T cassette sprocket ?
With a 22T range at the front ?

SRAM's website isn't very forthcoming. I might be missing something.

Keywords: Shimergo ramergo rampagnolo srampagnolo

[Brucey]

it says 'ere

http://www.bikeradar.com/road/news/article/sea-otter-2012-sram-flatten-the-hills-with-red-and-force-wifli-derailleurs-33776/

32T is your lot.

But if that is like shimano's 32T then 34T will probably work OK on many frames

cheers

[JEJV]

32T sprocket capacity seems to be about the only information they give. I expect a 34 would be OK.

The takeup (total capacity) is clearly at least 37T. I'd like to use 44T. Wondering if anyone had tried that yet.

[Brucey]

the top pulley is slightly offset, so as the chainring gap increases, it will become progressively more difficult to use the biggest sized rear sprocket.

It'll be interesting to see if you can do it or not; an extra 7T capacity is about 2.5" of bottom pulley movement (3.5" less the increased wrapround on both pulleys).

cheers

[JEJV]

Thanks.

the top pulley is slightly offset, so as the chainring gap increases, it will become progressively more difficult to use the biggest sized rear sprocket.

You mean that when the chain is more slack, the jockey wheel will move closer to the cassette ? Or something else ?
Is that true of most rear mechs ? I don't think I really understand the difference between how Shimano & SRAM rear mechs work.

It'll be interesting to see if you can do it or not; an extra 7T capacity is about 2.5" of bottom pulley movement (3.5" less the increased wrapround on both pulleys).

Is it that much ? Is it more like 3.5"/2 = 1.75" of rearward movement ?
Certainly would not want the chain to be longer than necessary.
Larger tension wheel might help a bit.

[Brucey]

You mean that when the chain is more slack, the jockey wheel will move closer to the cassette ?

yes, that is about it. SRAM mechs for the last few years have mostly had non-offset top pulleys, but the more recent ones have had the offset pullies which Shimano have used for years, (until fairly recently with a twin pivot mech design rather than with a single pivot design).

A bigger pulley will help, if you can run it. Every extra tooth on the tension pulley gives about another 1/2T overall capacity.

cheers

[JEJV]

We have a few bikes with long cage ("SGS") Shimano mechs that regularly have different cassettes, and I leave the chain long when changing to a smaller cassette to try to improve the shifting. Because of the effect you refer to.

Just went out for a bit of shopping.
Picked up a couple of wheels, and saw one of these: http://salsacycles.com/bikes/fargo/

APEX brifters. SRAM X9 rear mech. Medium cage with a 12-36 cassette.

I see what you mean about the non-offset jockey cogs. The jockey wheel seemed almost concentric with the pivot.

This suggests 10sp X7/X9/X0/XX SRAM would work with Campy brifters.

But they might not work so well with a road cassette as WiFli, because of the lack of offset?