[bobbinogs]

Folks, a friend is struggling with the hills and is looking for some lower gears to help. He is running 9 speed Tiagra with a 50/34. He currently has 11-25. I was thinking something like 12-27 but am beginning to think that might not be low enough for him. There are a few hg50 options like 11-30 but I am not sure if a 30 will fit…and 11-30 is a big range for 9 speed. Any thoughts on a cost effective way forward?? Thanks.

Topic

[Orbeaman]

I went from an 11-28 to 13-25

I went from an 11-28 to 13-25 on my Sora 3000 winter bike, the difference between 25 and 28 is quite a lot.

 

[bobbinogs]

Many thanks for all the
Many thanks for all the comments, plenty for him to think about ?

[ed-m]

I dealt with this exact

I dealt with this exact problem on a mate’s bike recently. Ummed and ahhed and went for an Acera derailleur and 11-34, he’ll be fine on the hills now! It probably will be a bit gappy at points, but that’s a much better compromise than walking up hills. Could have gone Sora derailleur but think the shadow design on the Acera is an improvement.

[Simon E]

I’m not sure if the Tiagra

I’m not sure if the Tiagra 4500 mech will run smoothly with a 30t cassette (Shimano are conservative with their compatibility figures) but if you fit the cassette and wind the b-screw out far enough then you’ll soon find out if it shifts cleanly.

The simplest alternative is to get hold of a Sora 3000 series rear derailleur, which will comfortably handle up to 32t cassette. Shimano says the medium cage GS will take 34t.

I run 11-30t with 50/34 chainrings with a Sora derailleur and don’t find any big jumps. When you’re in the 34 ring on a steep pitch reaching for the next gear down the 3 or 4 tooth jump in the bottom gears is a godsend, not a problem!

You might need to add a couple of extra links in your chain. Park Tool show how to calculate this correctly.

[wtjs]

mine is a Sora rather than

mine is a Sora rather than Tiagra groupset. Mine came with a 11-32 cassette and a FSA Omega sub-compact 32/48 chainset.

This is a great setup- 9 speed is ideal for people without infinite amounts of money. I spent a long time working all this out until I got a Vitus steel gravel bike in last November’s sales and it’s the best all rounder I’ve ever had. These FSA sets are using 120/90 BCD rings and the bike came with 48/32 as above, and 11-32 cassette. I really wanted 46/30 and 11-34 to tow my trailer up big hills for camping trips, and that’s what I’ll get when these wear out! I was worried that there would be no 120/90 rings because Shimano has moved to 110/80, so I bought some for future proofing

[Woldsman]

You would need to check if

You would need to check if the rear mech is a ‘long arm’ type and could cope with, say, a 30T sprocket. Another way of getting lower gears in your friend’s situation is to fit an MTB cassette – say 11-34 (and new chain) – and an MTB rear mech. 9 speed stuff is starting to get trickier to get hold of, but something like a Deore M591 or M592 are the standard rear derailleur options. (If interested just check whether a barrel adjuster is already fitted or if an in-line one is required.) 

[james.bowman]

I have 9 speed Shimano
I have 9 speed Shimano although mine is a Sora rather than Tiagra groupset. Mine came with a 11-32 cassette and a FSA Omega sub-compact 32/48 chainset. If your friend wants to stick with their existing compact chainset then going for a wider cassette could definitely work. I find the gaps between gears okay although the jumps at the bottom end do start to become more pronounced.

[Author]

Replies