vins0010

My new set-up (on my commuter/light tourer) has 9 speed Ultegra shifters, a Shimano 105 long cage derailler, a SRAM 950 cassette (11-32: like some range), and a SRAM 970 chain. It has been running a bit rougher than I expect; namely, it seems as though the 9 speed chain might be a bit wide for this 9 speed system. I've noticed that when the chain leaves the jockey wheel, when on the second largest cog, a side-plate on the chain will catch on (but not hold, ultimately) on a tooth on the largest cog. This sometimes happens on the fourth smallest cog as well. I could live with it, but when I can get my wife's old 8-speed working much smoother, it makes me think something is up.

I can adjust a bit and get it not to catch (but still be a little loud) by sacrificing a little quickness/smoothness in the shifts to larger cogs. I do this by playing with the cable tension (relaxing just a little bit so the chain isn't quite as far towards the inside). I am wondering if I am pushing the capacity of the derailler too much (it is a 105 long cage, 10 speed) or if I am experiencing something odd with this particular cassette (it is the cheapest one SRAM makes). If I had to, I'd replace either the cassette with a higher end one (perhaps Shimano) or even just one with less of a range (to 28 cogs, maybe) - but I'd like to keep the range. Any thoughts?

JonathanGennick 

Are you able to check your hanger alignment with a guage? That's usually the first thing I check when faced with any sort of wonky behavior like you're describing.

berner

Another thing to check is the B screw adjustment which effects how close the upper jockey wheel is to the cogs. Read up on this adjustment here https://www.parktool.com/blog/repair-help. I suggest this because I've just cobbled together a custom cog set with a 30 T low gear and the B screw adjustment was necessary to cure sluggish shifting.

operator

1) Let's make sure we know how to adjust b-screw AND
2) Verify that it is correct
3) Verify hanger is straight in ALL DIMENSIONS

32 is really pushing it for a road derailleur unless you have longer than normal dropouts. My bet is that even with b-screw maxed out the derailleur is hitting the larger cogs. If this is true, then your only solution really is to run a smaller rear cassette, in terms of largest cog.

vins0010

Well, the b-limit is good and the derailleur is clearing the cogs. I've had the hanger alignment issue come up enough that with today's Nashbar 20% off sale, I went ahead and ordered the Park DAG-2. So, I'll be able to figure that out when it arrives. It generally works fine, except for the sideplate or two that catches sometimes. The problem, while riding, is actually worse on one the smaller cogs (the fourth one) where the same thing happens. This is worse because it is in the middle of the cassette where I tend to hang out. If I look from in front while the cog is spinning, this cog does look a little more off than the others in terms of appearing to deviate from some center line (for lack of a better term) - but it would have to be pretty sensitive for this to matter. I guess it could be either the chain, the cog, or the derailleur alignment - or all three...or something else. Who knows. I'll find out about the alignment in about a week. For the time being, I'll make due. I'll give an update when I have one.

shelbyfv

I have used SRAM cassettes and chains for years, but the last 970 cassette I bought seems to have issues similar to yours. I have not investigated it as thoroughly as you have, I'm not riding that bike much. The finish on the cassette seems more crude than the older ones.

vins0010

It has been a bit, but I have resolution on the issue. It has been awhile but I got the replacement parts a couple of weeks ago but didn't have time to work on the bike until today. The derailleur hanger was out of whack...a good bit, I discovered, from my using the DAG-2. I fixed it and the bike shifts very well now in all gears. This is a lesson for me...when the chance presents, I think I'll be checking the alignment on all my bikes. The ease of fixing the issue also lets me know the ease with which these things can get a little off. With other things, I am lucky the 105 long cage fits my large cassette for my particular bike. In the future, I probably would go with a mountain RD if I want any cassette larger than 28 cogs, just to be sure.

shelbyfv

Thanks for the update!