The wrap for a 1x Yankeebird is whatever the spread is for the cassette alone, since there's no other ring there's no additional difference to account for.
As for clearing the 42t cog, the only thing that matters is that the RD can clear it alright. The "how" that is done, well there are endless creative ways to do that with endless RD's ! With extenders you would be able to use a road RD. I know back in the 70's there was a bike shop in Missoula, MT that made custom extenders and freewheel cogs using Campy racing RD's I believe. They were really loooong ! You'll be fine with most off the shelf things you can buy today. On Saturday, May 7, 2022 at 12:39:17 PM UTC-4 Yankeebird wrote: > What about a 1x? > How do I calculate wrap for that? > I have two older bikes with the old trad 7spds cassette I’d like to > replace with 13-42. The Altus has a max rear cog size of 36 but if I only > do a 1x does it matter? Can I use the old derailleur, even? > > On Wednesday, May 4, 2022 at 8:00:26 PM UTC-4 Garth wrote: > >> As long as you're within the total capacity of the RD it could work with >> one of those Wolf Tooth derailleur hanger extensions, called a Roadlink I >> think. Others make them, but Wolfies and Wheels Mfg I know for sure use a >> stainless steel bolt, while the other use aluminum. The Wolfie helps to >> clear the largest cog only, it doesn't add any capacity, that's for the >> RD. A 13-42 , at 29 teeth, doesn't leave much room for a triple with much >> spread. 45t is what most mtb RD are ? That leaves 16t spread for the rings. >> I for one never use certain combos of course so these "formulas" are >> theoretical, actual use, if you know what you're doing, can go beyond all >> that. "Know what you're doing" ... meaning .... not running say a 26t small >> cog and the last 3 cogs, and likewise, not using the big ring in at least >> the 2 largest cogs, it really depends on the crank chainline and how much >> you heed or ignore the horrible sound of cross angling of the chain. >> >> A half step triple would work, like a 44/40/28 for example. The numbers >> are off the top of my head, not a suggestion. Having the half step would >> help split some of the large jumps in the cassette. >> >> On Wednesday, May 4, 2022 at 7:11:11 PM UTC-4 Sam Perez wrote: >> >>> Any one know if a 7 speed 42 would work with a long cage silver triple? >>> Or is it only compatible with a wide double? >>> >>> Thanks >>> Samuel >>> >>> Sent from my iPhone >> >> -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/792b3503-d3af-491d-b67a-e2df395b8ed7n%40googlegroups.com.
