Sigh.... I you'd dropped into our local bike Co-op while I was wrenching, I would have done the following:
- Pull apart your existing 7-speed cassette and split it into the spacers and cogs.
- Then reach into our bin of loose HG cogs, and access a 30. Cost: $1.
- Then replace your current 26 with the 30.
- Put everything back together.
- Replace your chain: because statistically every bike that comes through our doors needs a new chain. Don't even need to measure.
Total cost: $14 in parts and 15 minutes of shop time. Our Co-op charges out time at $5-15 per hour, based on your ability to pay.