Bicycle Mechanics - Will RSX long cage RD work with a 10 speed indexed system?

Hi there guys!

To make a long story short, I recently purchased some shimano 7900 10 speed indexed barcons on ebay, hoping to upgrade my Miyata touring bike for an upcoming trip. As bad luck would have it, I found out after they arrived that shimano has dropped friction shifting from its most recent series of barcons.

I've decided to stick with the barcons, because the drivetrain is in need of some modernization, but I am trying to do it on the cheap.

I currently have a full RSX setup. 3x7 brifters, RSX FD and RSX long cage rear derailleur.

If I buy a 10 speed (11-30) tiagra cassette and 10 speed chain, will I be able to use the RSX long cage rear with everything?

Does older RSX gear have the same pull ratio as current 9/10 speed shimano road components?

Alternately, can anyone recommend a cheap way of upgrading my system?

Thanks!

1. sell the 7900 barcons

2. buy some older barcons that have a friction option instead


I think the RSX rear derailleur technically would index 10sp, but you're heading for bigger problems if you team up a narrow 10sp chain with your RSX crankset. Also, your 7sp rear wheel won't accept a 10sp cassette.

1. sell the 7900 barcons

2. buy some older barcons that have a friction option instead


I think the RSX rear derailleur technically would index 10sp, but you're heading for bigger problems if you team up a narrow 10sp chain with your RSX crankset. Also, your 7sp rear wheel won't accept a 10sp cassette.

+1

Cheap way? 10 speed is not it. Have you priced the cassettes and chains yet?

I'd recommend a set of 8S bar-end shifters. They are still available new. See if they work to your satisfaction with the 7S cassette. If not, get an 8-speed 11-28 cassette and lose the 11T cog. You might need a first-position 12T cog to take its place, and a new lockring to do this.

Buy a set of Dura Ace 7700 barcons. Buy a 9-speed casette that has an 11 and 12 tooth cog. Buy a 12 tooth lockring. buy a 9-speed chain.

Install everything except the 11 tooth cog and the lockring. http://sheldonbrown.com/k7.html#897

Or just get a set of Rivendale Silver barcons.

You said your current setup is 3x7 RSX which means your rear freehub is 7-speed and won't accept an 8-speed or more cassette which need a wider freehub body. So your 10-speed upgrade is also going to require a new rear wheel and possibly spreading your rear dropouts from 126 mm to the 130 mm needed by a 8 or more speed hub. This is getting expensive.

"On the cheap" and "10-speed" do not belong in the same paragraph.

FYI, for the future, I'm using a RSX long cage with 9 speed 105 brifters and everything works fine. If I upgrade that bike to 10 speed, I won't be trying the RSX unit but that's becuase I have other derailers.

FYI, for the future, I'm using a RSX long cage with 9 speed 105 brifters and everything works fine. If I upgrade that bike to 10 speed, I won't be trying the RSX unit but that's becuase I have other derailers.
I would expect the 7-speed RSX rear derailleur to work with 9 or even 10-speed shifters and cassettes. The OP's problem is his rear hub and a lot of other things aren't compatible with >7-speed.

Thanks for all the recommendations!

I appreciate the advice. I think I have been doing things comparatively cheaply. I have a new wheelset that I have yet to install. It is one of those Rocky Mountain Cyclery 40 spoke velocity dyad wheelsets with formula hubs. They were in a bizarre colour (orange) so I got them for $45 new. Also, the bar end shifters were used for $35. So far I think I've been doing pretty well.

Roccobike, do you know what the limits are on an RSX long cage? Do you think I could run it with a 30 tooth rear cog?

Also, the problems with the chin width for the front crank should be negated because I upgraded it to a 9 speed compatible 105 triple about six months ago (which cost a grand total of $25).

If the RSX will shift a 10 speed, I think I might just go ahead and buy a cheap tiagra 10 speed cassette.

Well, that information changes a lot of things. The RSX will almost certainly shift a 10-speed cassette and will probably clear a 30T cog. Give it a try.

feeling a need for the 10 speed stuff, is demonstrating marketing works ..

Adding "speeds" is not really doing ratio centered analysis, of gearing needed,
just packing in more cogs, then thereafter needing $100+ $ cassettes and $50 chains.

Shimano's 7 speed K cassette was touring perfect ratio set,
but the bike biz needs "new, improved" sizzle
to generate the Magazine/Web buzz every year.

I did it with 3x7 RSX to 10 speed Ultegra brifters and it worked fine. I'd still be running it if I didn't get a Ultegra RD for $25.