When I bought my Giant Propel in 2016 it came with a 52-36 chain set and 11-28 cassette. Whilst I am reasonably fit I found that the 36/28 lowest gear was a bit to high for me for some of the hills around the Midlands (UK) and I changed it out for a 50/34 which was a much better compromise (and matched my other bike for the front chain set - although I run an 11/32 cassette on this other bike as well)
I still found 34/28 a bit high for some of the hills round where I live and this actually meant that I was choosing to leave the Giant in the garage if I wanted to climb some of the bigger hills more easily. The biggest climbs I have from my house are Dovers Hill, Saintbury Hill and Larkstoke Hill, all about 30 miles away. These are not huge hills and 34-28 is do-able but it's then a long drag back home and it always felt a lot easier on the other bike.
Once the cassette on the Giant got to around 9000 miles and I was coming up for the 4th chain swap I decided that perhaps it was time to get a new cassette as the original was getting worn. I thought about getting an 11-34 but without even trying felt that this was just going to be too big for the medium length derailleur so opted for an 11-30. I don't plan on going Alp hunting on the Giant to be honest as it is heavier than my other bike
The original cassette is an Ultegra 6800 model but I just could not bring myself to pay Ultegra prices for a few grams of weight saving, so I bought a 105 7000 series 11-30 cassette. At the time of writing this the 105 cassette is typically £54 and the Ultegra £90
The gear ratios are:
- 11-28: 11-12-13-14-15-17-19-21-23-25-28
- 11-30: 11-12-13-14-15-17-19-21-24-27-30
The only difference between the 2 cassettes is the lowest 3 gears
The Ultegra 11-28 weighed in at 247 gram whilst the 105 11-30 weighed in at 297 gram. Accepting that the 105 unit will be a little heavier just because it has a few bigger rings shows that actually there's not a lot of extra weight going to 105 to worry about.
Here's the 11-28 Ultegra cassette weight:
I didn't want to put on a longer chain for the sake of 2 cassette teeth as the 34-11 combination was already at the practical limit of length so I fitted the 11-30 cassette and left the chain the original length. Here's a photo of the chain in 50-28 combination (i.e as it was with the original set up):
And here it is in the new 50-30 gear combination
The rear derailleur is a medium cage unit and it just about manages it.
I am not going to consciously ride in the 50-30 gear but I needed to be sure that it it was selected by mistake there would be no issues - it's probably on the absolute limit but shifts up and down fine
