Tom: I think you could add some more links. Many recumbents need about 1-1/2 chains.
Regarding your cassette idea, I have a similar set-up on my Atlantis. I use the standard Shimano 7 speed with 13-28 cogs plus a 34 tooth cog from a 9 speed cassette. The whole thing is spaced using 8 speed spacers. The crankset is Riv's standard issue Sugino, same as yours. Shifters are 8 speed indexed Ultegra bar ends, and shifting is flawless. I think I just got lucky with the ramp locations on the 34 tooth as the shift from the 28 to the 34 often under load & still dependable & quiet. I use the entire cassette with the middle ring & only avoid the 34 when on the big ring. Not sure how the Atlantis chainstays compare to yours but I just install a new chain "as is" out of the box. It's just long enough to handle that unintentional 46 x 34 if it ever happens. One thing to look at on your old cassette is whether or not the cogs are solid or are a lot of them mounted on a carrier? A lot of cassettes save weight by mounting a bunch of the larger cogs onto a carrier. If you can live with a bit more spacing between gears, Shimano also makes a 13-34 7 speed. With the 4.5 mm spacer you could get a useable range & only give up 2 teeth on the bottom end. dougP On Thursday, December 27, 2012 9:55:22 AM UTC-8, Tom Harrop wrote: > > Hope everyone had a nice holiday. > > I'm due for a new chain and I'm thinking of switching to a 7-speed > cassette. I'm sorry about the long post, but I could use some of the > group's wisdom. > > I currently have the 12–36 9 speed HG61 cassette with the Sugino 46-36-24 > that Riv sells, with Silver (friction) shifters. There's nothing really > wrong with the gearing at the moment, except that I get the occasional > ghost shift and the chain skips under load sometimes, and I can't actually > use the 36t sprocket because my chain isn't long enough. Well, it's not > long enough for the 46×36 combo, which obviously I wouldn't use, but I > don't trust myself not to shift into it accidentally so I've got the limit > screws on the rear derailer set so that I can't get into the 36t sprocket. > The chainstays on the Bombadil are so long that I think I need 118 links > for a 36t sprocket! > > This brings me to my first question: Is there anything wrong with getting > two chains and connecting the required length with Power Links, so I'd have > two Power Links in the one chain? > > In terms of the cassette I'd like to go 7- or 8-speed for chain life and > hopefully to fix the ghost shifts. Since all the 8-speed cassettes I can > get locally seem to start with an 11t sprocket, which I don't want, my > hare-brained plan at the moment is to get the 7-speed 13–28 that Shimano > makes, and since I'd need a 4.5 mm spacer to put that cassette on my > 9-speed freehub, just use the 36t sprocket from my old 9-speed cassette > with a 3 mm spacer instead. So I'd have a 13–28 plus a 36t 'bailout'. > > I guess that's a large jump so the shift wouldn't be very pretty, but it's > not a sprocket I'd use terribly often... or I could always use the 32t from > my old cassette instead, or take a 34t sprocket from another 7-speed > cassette. I just thought I'd check with the group to see if anyone's done > this, before I go ahead and try? > > Thanks, > > Tom, in rainy Germany. > -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To view this discussion on the web visit https://groups.google.com/d/msg/rbw-owners-bunch/-/Fcx9TOkiHtEJ. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
