Cassettes and gearing

[DCBassman]

Perzakkly. Not enough chain wrap without going to a long cage derailleur, I think.

 

[DCBassman]

Then if your front chainrings are 50+39+30 like current Scotts, I reckon http://gear-calculator.com/?GR=DERS...15,17,19,21,23,25&UF=2135&TF=90&SL=2.6&UN=KMH is your gearing, giving a range of 32.1 to 111 gear inches. If you could get 27T in the rear, bottom gear drops to 29.7 inches, or if you can get 32T there, it would be about 25 inches, only slightly higher than the notorious two foot gear

Counted the chainring teeth (not the big one - it's written on it!) - 52-42-30...

 

[T4tomo]

Fine so you can fit a 11-27 or 12-27 cassette (and new chain) and have a 8% lower bottom gear which will be noticeably easy on the hills. To be honest if you need to go lower than 30-27 then just walk, it will probably be quicker anyway.

 

[DCBassman]

Maybe it might be easier to change the chain and cassette for identical new items, then change out that Ritchey 52-42-30 for a Shimano Acera FC-M361 with 48-38-28T. Does seem a relatively inexpensive way to drop the gearing just that little bit...

 

[T4tomo]

Maybe it might be easier to change the chain and cassette for identical new items, then change out that Ritchey 52-42-30 for a Shimano Acera FC-M361 with 48-38-28T. Does seem a relatively inexpensive way to drop the gearing just that little bit...

Are you having a giggle, you think it's cheaper to change your chainset AND chain and cassette, than just changing your chain and cassette? A 11-27 will cost very similar to the existing 11-25 you are planning to replace.

 

[DCBassman]

What I'm saying is that they need renewing anyway. I was hoping that someone would have an opinion on whether that was a good move or not. I could still go the 11-27 route as well, and have it really easy!

 

[the snail]

If it's a triple with 74mm bcd granny cog, you could probably swap it for a smaller chainring. This would probably take you outside of the rear mech capacity, so you would want to avoid running in the small/small combination. On 9sp you could run a long cage mtb rear mech which would allow a bigger cog on the back and give more capacity overall.

 

[bigjim]

I'm running an 11-34 9 speed cassette with a medium cage Sora rear mech. B screw pushed right in. Compact double up front.