WTB: 13T first gear & lockring

[smdubovsky]

Hi, Im looking for a 13T first gear, 9sp, shimano HG compatible (if it matters?) plus the matching lockring. Im told they come off 9sp road cassettes. I'm going to start calling LBSs today, but figured I would ask here too. If you know of a LBS that would have one in stock that would be great to know too.

FWIW, Im installing a 38T cog behind my 11-34 XT cassette on the 29er (weak legs I know). Since the stock 11&13T gears are special I just found out I need to replace the XT 13 & LR w/ a 13T first gear so it has the correct spacer built in (and the lockring teeth).

[rciracing]

You can get them in Ultegra or XT for $7 tops. Any shop can get one for you from QBP.

[g_barr]

Hi, Im looking for a 13T first gear, 9sp, shimano HG compatible (if it matters?) plus the matching lockring. Im told they come off 9sp road cassettes. I'm going to start calling LBSs today, but figured I would ask here too. If you know of a LBS that would have one in stock that would be great to know too.

FWIW, Im installing a 38T cog behind my 11-34 XT cassette on the 29er (weak legs I know). Since the stock 11&13T gears are special I just found out I need to replace the XT 13 & LR w/ a 13T first gear so it has the correct spacer built in (and the lockring teeth).
Don't forget to check your rear derailleur capacity. Shimano's XTs are spec'd with a 34T maximum but they might shift into 38T acceptably. Are you running all three chain rings? There could be lots of slack or a straight pull through the RD pulleys if you size your chain big ring to big cog + two links.

Judging from what I've seen taking apart Shimano 11-32s, the two "loose" cogs look like they have the same built-in spacer but I haven't measured them. One thing about Shimano mountain cassettes is the "group" designation (ap, aq, ar, as). My loose cogs are universal though - you'll see they are stamped with three or four group numbers even if the "bundled" seven are marked with only one group ID.

I'm not sure Shimano uses the same group ID system for its road cassettes. It might not matter. The 9-speed road 13T cogs all appear to have the built-in spacer. The real difference may be the diameter of a road spacer might not fit (well) into a mountain cassette.

[smdubovsky]

Opps, I meant to post in the classifieds section...

Yeah, I know I can order them but I was hoping to ride w/ it on Fri. I've had the big cog in hand for a few months but didn't predict the whole small cog issue when I went to swap it in yesterday(long story). Procrastiation sucks;) From the few calls I've made so far it seems a 12T is common but no one has a 13T in stock. I'll keep calling.

[smdubovsky]

G_barr,
Yes 38T. I think a 37.5 or something is required to restore the gear inches of a 29er back to that of an equivalent 34T of a 26er. I rounded up instead of down;) It was either this, or drop the crank 22T down to 20, but there are clearance issues doing that on a 4bolt XT crank.

Running a 2x9 configuration w/ long cage on the 29er so that part shouldn't be a problem. There is some question as to whether an X9 rear deralleur can work w/ a 38 properly but thats the next hurdle (I think I might need to install a longer b-screw but that should be a snap in comparison.) I need to get all the gears mounted on the hub first.

The XT 11-34 has a very unique built in spacer on the 11. Its wider and actually nests into the 13T slightly. Part of the HG compact hub design. One can't be used w/o the other. The larger road gears don't have that need so Im told a 13T first-location gear from a road cassette will do the trick.