mortona42

I broke a shifter (Tiagra), so I want to replace them with the new 105's. Shimano's compatibility chart shows that it will work with my 105 rear on a 10 speed, but mine is 9. It also doesn't mention compatibility with a tiagra front derailleur. What do you think?

My bike:
tiagra st-4500 shifters
tiagra fd-4500 front derailleur
105 rd-5600 (pretty sure, but how do I verify?) rear derailleur
fsa omega compact 50/34t

operator

The shifter speeds have to match the # of cogs in the rear. The 'new 105' is 10 speed only. That is 5700 series. So will not shift 9 reliably and was not designed to be compatible.

There is a shiftmate that will allow you to use a 10s STI on a 9s shimano rear as well. I really recommend against doing this.

vaultbrad

I'm really frustrated by 10spd. What if a guy wants to buy nice NEW sti shifters for 9spd and doesn't want to buy NOS or some garbage. 9 speed works well and is still more gears than most every human will ever need. More and thinner parts means decreased durability in my book.

mortona42

I really don't want anything that will be poorly compatible with the setup. For me to upgrade to 105 shifters, i'd have to replace my rear cassette, chain, and possibly FD? What are my other options, without a major component overhaul?

wrk101

If you want brand new Shimano STI in nine speed, you need to shop one of the UK sellers, or eBay. Myself, I have always taken a chance on used nine speed stuff. I have four bikes right now with used nine speed STI drivetrains, one Ultegra, two DA, and one Tiagra.

Nerull

You should only *need* to replace the rear cassette and chain to go from 9 to 10 speed. There is no mechanical difference in the RD or FD. The crankset spacing might be slightly different, but not so much that it won't work.

mortona42

I'm happy with the tiagra shifter/105 rear, but the front tiagra set never shifted that great. How much of that is caused by my chainring ratio, 50/34?

I just want to replace the left shifter, and I'm willing to get a new fd if it will improve shifting.

options I found:
Ultegra 6510 - $100
105 5700 or ultegra 6600 - $180

leaning towards 6510, thinking it probably offers the best price/performance. Will these even work for me?

motobecane69

i have a microshift double shifter and an ultegra FD and it shifts my compact crank fine, I also had a sora on it before and it also shifted fine. sounds like you had an adjustment issue.

Al1943

Your best option is new 10-speed 105 shifters, cassete, and chain.

Alan Edwards

Spaceing on 9 and 10 speed cassettes are the same, the lowest (largest # 10) is closer to the center of the hub. If you use 10spd brifters with 9spd cassette you have one more shift that doesn't go because you hit the RD limits, hi or low depending on which way you set it up. There is vary little difference between 9spd chainrings and 10spd, and a little more difference with 8spd. I have seen 8spd cranks used with 9 and 10 speed chain and cassettes. You should have no trouble.

FastJake

No, it's not. 9 and 10 speed cassettes use significantly different spacing. https://www.sheldonbrown.com/gloss_sp-ss.html#spacing

OP: your best bet is probably to find some new old stock STI 9-speed shifters, or just get the new 105 units with a 10 speed cassette and chain. Your derailers should be fine. You may decide to replace the FD, but I doubt it will be an issue.

***Edit: you only want to replace the left shifter? As far as I know, almost any left STI shifter meant for a double should be fine.

mortona42

After reading up a bunch on it, I think my issues are more with gear ratios than with shifting. Either way I'd like to replace the broken shifter with something more durable.

Will an ultegra st-6600 work with my components? Found one for $100.

oldbobcat

6600 is ten-speed.

mortona42

I'm just talking about the left shifter. Sorry, think I forgot to mention that.

operator

God there is a lot of incorrect misinformation on this forum.

I've said it already and i'll say it again. 9 and 10 speed spacing is different and shifters for either are not cross compatible. 10 speed front derailleurs also differ from 9 speed front derailleurs, especially the newest 10 speed gen stuff 7900/6700/5700 etc.

The rear derailleurs has as slightly different max cog spec 28 instead of 27 but are otherwise compatible across 8/9/10 speed shimano. This is the ONLY component that can be almost freely mixed.

operator

This is 1000% wrong. Do not listen to this.

Listen to these people and you'll be buying into a problem.

mortona42

Thanks Jake, pulled the trigger on the ultegra 6600 (left). Dunno why it was cheaper than a 105 or tiagra, but thanks ebay! I think I would really appreciate a 10 speed upgrade, but I don't want to spend that kind of cash now.

operator

I wouldn't bother anyways. With the price of electronic ultegra coming in at mechanical 7900 dura ace, thers no reason to buy old 10 speed shimano anything.

mortona42

Yup, by the time I really want to buy that much upgrade, I'll probably get a nicer bike and keep this as my trainer/commuter. Nice bonus for myself next time I switch jobs.

Boye

A 10-speed shifter can be run with a 9-speed cassette, if you attach the cable differently: https://www.sheldonbrown.com/dura-ace.html#indexing under "Alternate cable routing".

mortona42

You're missing the point. A 10 speed Dura Ace shifter hacked on to a 9 speed bike may shift your gears, but I can't imagine that it would perform better than a 9 speed tiagra.

Boye

It shouldn't be worse either. And since your shifters are broken, everything will be better than that. I haven't tried it myself, but seen it confirmed from different sources.

My statement was also targeted towards others: many need new shifters for their 9-speed, fancy under the cable routing, but are reluctant to all-in on 10-speed ("vaultbrad" in this thread).

cycle_maven

I agree with Boye. I've tried it and it works perfectly. I have 10-speed Ultegra brifters shifting a 9-speed Ultegra derailleur and cassette with the alternate cable routing, and it actually works *better* than any Tiagra 9-speed stuff I've ever tried. The shifts are just like the 9-speed Ultegra on my other bikes, with the addition of the more comfortable (to me) hand position. There is no compromise, here. It was designed to work properly- maybe the first time ever that Shimano didn't completely obsolete a groupo.

Many touring bike owners want to use road shifters with a 9-speed mountain derailleur and cassette for the lower gears, and don't want to be limited to Tiagra and Sora shifters. This is a easy and clean method to get there, and it works beautifully.

endleesss

now I'm wondering if the 105s will work with the sora 3x9. after reading the posts above, i'm guessing it will work. any thoughts? Thanks

Kimmo 

Except that it uses even less cable pull per shift than a 9spd shifter, making it as finnicky as a 10spd.