pexio
For the price of one those Harris Cyclery cassettes, you can buy a 13-32 off-the-shelf cassette and a mountain RD (with an SGS cage) and be assured that you can reach the 32t sprocket as well as pull enough chain slack. The Tiagra RD only pulls 37t while a mountain RD pulls 45t. Your brifters will still work
+1
However, why not go for an 11-34, and give yourself a broader range of gears?
I tried one of Harris's
13-30 with a Shimano 105 LC rear derailleur, and I could not make it work to my satisfaction. I replaced the 30 tooth cog with a
11 tooth cog, and put it on my road bike. It gave me an
12-27. It is an Ultergra cassette, and that was a good use for it.
After talking to the folks at Harris, they sent me the 12 tooth cog at no extra cost.
The way they build the
13-30 cassette is to add a spacer and 30 tooth cog, and remove the 12 tooth cog from the stack of a stock
12-27 Ultegra cassette. the first 3 or 4 cogs are loose, while the rest are affixed to a carrier. The 30 tooth cog is just loose and is separated from the carrier by a spacer as you install the cogs. It is a cog from a low end cassette that was bolted or riveted together rather than using a carrier.
