kbagel

Hi there,

I'm in the process of a building a Soma ES into a commuting bike/city workhorse. I was planning on doing a 1 x 9 because I already have a Shimano DuraAce bar end shifter and a 9-speed cassette. Can I use a Tiagra 10 speed rear derailleur with this? I could always fall back on the Shimano Claris but I was hoping to get something a bit higher quality. There is a small chance that I would use this bike as a light touring bike in the future and would only have to upgrade the crank set and add a front derailleur then.

And, aesthetics are important and I would like to keep the derailleur silver.

Thanks!

fietsbob

'Speeds" is a cog count .. the lever has 10 clicks the RD has none. it goes where it is pulled.

jeffpoulin

Yes, the Tiagra derailleur will work fine with that shifter and cassette combo.

jeffpoulin

Unless it's a dynasys RD where it has a different pull ratio.

kbagel

Thanks! I didn't think it would be a problem but there is a lot of conflicting info out there. The specs on the Shimano website are also a little confusing. The info on the derailleur says it's compatible with a 10 speed cassette.

This is my first build and I'm having a lot of fun doing all the research, taking the time to understand it, and picking the parts out.

fietsbob

my Rohloff is self contained .. there is just a drum with 2 cables on the bars pulling in both directions.
everything else is inside the hub.

all single cable derailleurs have the detent spacing in the front move the cable
a measured small amount , pulling the RD sideways , the return spring pulls it back .

yea they play pull ratio games amongst themselves . but still no clicks in the RD itself.

OP ? good luck.. obsolescence is how marketing driven the world turns ..

tjspiel

Not entirely true. My Huffy Sante Fe with Shimano Positron II shifting had only a single "cable" and detents at the derailleur. It was ahead of its time.

fietsbob

and we are grateful its time has passed .. before it's time...

dynaryder

'Speeds' is also now a width. 8/9/10spd cassettes are the same width,but to get the extra cogs in,they are made thinner. The chains are also thinner,as are the front rings.

kbagel,if we were talking high-end,the derailleur's jockey wheels would prolly be designed to work specifically with a 10spd chain,but the Tiagra should work ok.

TransitBiker

That is what i was curious about. I have had aquaintences try to use a 7 speed chain on a 9 sprocket cassette, and it kept hopping off in different places at the back.

- Andy

gregjones

That's because cassette are cassettes and jockey wheels are jockey wheels. Both are round toothy things but they are different. A thinner single gear will run inside a wider chain. (Given realistic boundaries.....like in the bicycle world, I'm sure some aerospace engineer could point out that a skinny jockey wheel won't run in a 630 motorcycle chain---but, we're talking general bike world in this case.)

That given, a 7 speed chain will run over a single 9 speed jockey wheel, provided it fits inside the cage of the individual RD. A 7 speed chain won't fit in the smaller spaces between the cogs on a 9 speed cassette.

TransitBiker

I see. That does make sense. I've only really ever used single sprocket drives with big fat beefy chains so i wasnt sure.

- Andy