Well I guess most know getting parts is a challenge. A few months ago. I purchase a set of Hunt 650B gravel wheels for my Felt Broam. I will be using the 700 wheels with Maxxis Refuse that came with the bike. I will be using 650b mostly for bikepacking when route has some singletrack on some 27.5 x 2 rubber.
Getting a second cassette has been a challenge. I have not been able to find 11-34 casettes. I was thinking that I could use a 11-32 casettes for the 700C wheels since they will be use for specific rides. I would use the 11-34 cassette for my 650b which would be use for more rowdy adventure.
Would someone notice a BIG difference or marginal. This is only because shorts in parts and I dont want to change casette every time. I want both sets of wheels ready to go.
You will likely notice a bigger gearing difference between the wheel/tire sizes than the cassettes. Generally, the 11-32 ratios will be slightly taller across block.
Going from 32 to 34 teeth will give you about a 6% difference, on my bike about half a gear. Going from 650B to 700C wheels (with the same tire width) will also give you about a 6% difference. To me 6% is barely noticeable.
It's just a personal thing, but I prefer the 11-32 to the 11-34. The gearing selection makes more sense if you will be riding average speeds in the mid teens or above (of MPH). I'm not super sensitive to cadence changes, but the 11-13 and 13-15 shifts are a little bigger than I like for roadish rides. The 11-34 is oddly heavy too. The only real advantage is that it fits on 10 speed hubs and that's why I have one, to use some old CX wheels with a 10 speed hub. If you're already going to take the weight penalty of the 11-34, it may make sense to go with the 11-40 if you need the low range for bikepacking. The weights are what I wrote down for my personal XT / Ultegra level cassettes some time ago.
11-32 is 11-12-13-14-16-18-20-22-25-28-32 * 287 grams 11-34 is 11-13-15-17-19-21-23-25-27-30-34 * 342 grams 11-40 is 11-13-15-17-19-21-24-27-31-35-40 * 410 grams
32 and 34 teeth are very similar. The real difference between the two cassettes is actually in all the other sprocket choices; the 11-32 is a smoother progression with a largest jump of 14% while the 11-34 is lumpier with a largest jump of 18%. What's worse, the 11-34 puts the bigger jumps at the faster end of the cassette which is exactly where you don't appreciate them.
Most riders wouldn't really notice any difference either way but I'd be happier with the 11-32.
Sram cassettes tend to have more sensible sprocket choices, and it's worth looking into 11-36 or even 11-40 if you're talking about 10 speeds or more.
personally I like tighter gearing on my road wheels, and more of a grinder gear with my gravel tires. The tighter jumps in the smaller cogs is great when riding fast on slicks, while the bigger gaps when riding slower on gravel roads and gravel tires makes sense too.
so yeah, 11-32 is great for faster road oriented wheels
breadfreak wrote:32 and 34 teeth are very similar. The real difference between the two cassettes is actually in all the other sprocket choices; the 11-32 is a smoother progression with a largest jump of 14% while the 11-34 is lumpier with a largest jump of 18%. What's worse, the 11-34 puts the bigger jumps at the faster end of the cassette which is exactly where you don't appreciate them.
I don't say this to be a contrarian, but I appreciate that the gaps in the 11-34 cassette are all even between the 17t and 27t cogs (4-9), which is where I do probably 95%+ of my steady peddling (~13-21 MPH). The cluster being pushed up in sizes also makes it easier to stay in the big ring, although there is extra mass obviously.
I do agree though that when you need to use the 11t and 13t cogs, the gap can be pretty difficult if you have an optimum cadence for putting out a lot of power. The nice thing about 2x is you have much more gear choices based on personal preference / physiological needs.
Lower gearing exists for one reason, and that is to go up (steeper) hills. It is easier to find the “right” cadence with tighter gearing but I size my cassettes based on terrain. You didn’t mention your front gearing, but if an 11-32 cassette provides enough range for your typical route while running your 700c wheels, you are golden. In fact, a strategy to run lower gearing on your 650b adventure wheels is a good one.
One thing to consider is chain length and wear. Since chain length should be determined using the small chainring and your smallest cog, both cassettes can use the same chain. However, since components wear together be prepared to replace your chain more frequently than if you were swapping the cassette from wheel to wheel. This is especially true if you are going to run one wheelset a lot more than the other.
You will notice a difference and will perhaps need to shift up twice instead of once on the 11-32 to get that right gear as you start your climb. However, as mentioned previously you’ll adapt very quickly.
Have you tried REI. Last spring before the pandemic hit I had my bike switched over to the GRX 48/31 crank. My LBS couldn't find it anywhere but I found it at REI.
I live in the North, shipping from REI to Canada is a hit and miss. Last order was ship in 3 different shipment and it was with DHL. I got charge brokerage fee for all 3. I have found a cassette at my LBS, They expect the shipment in about 4 weeks.
Thanks for all the reply. Way more information than I needed. I like how some riders go pretty deep in the response. I appreciate the expertise. Great forum to be part of.
"Since chain length should be determined using the small chainring and your smallest cog..."
NOOOOOO!!!!
It is critical the chain length is sufficiently long for the ill-advised cross-chain big-big combination. I have witnessed first hand what happens when the chain is too and the rider accidentally cross-chains into the big-big combination when shifting the rear derailleur...
The chain will grab onto the big cassette, and since it is too short something will have to "give". The something that will be the rear derailleur. The "give" is the cage of the derailleur crumpling. In both cases the crumpling cage went into the rear wheel, breaking and badly damaging many spokes while also locking up the rear wheel and bringing the bike to a quick stop. Fortunately nobody in the paceline went down in either case but the bike was inoperable and the repairs were costly (new derailleur, new rear wheel).
So when sizing a chain, IMO anyway, make certain it can safely shift to the big-big combination. Yeah I know it's not ideal to use it but miss-shifts happen.
If the chain ends up being too long for the rear derailleur to keep tension on the chain when in the small-small combination then make a mental note of note of how many of the cassette's small gears to avoid. My gravel tandem for example has an 11-42 cassette and the RD can't wrap the chain on the three smallest cogs if I'm in the small chainring. If I miss-shift into these combinations nothing breaks but it gets noisy and I'll shift to the big ring.
Not sure if this would work, however, I might experiment with it: for loaded touring maybe switch the crankset XT 26-36 maybe. Still a pain to swap: chain length would be different and front derailleur would need adjustment. Chain lines are really close if you are using GRX (about 1mm different). Again, I might try the set up for drop bar single track. 26/32 or 26/34 would definitely change things vs 31/34. BTW, I use the GRX 48/31 w/ 11-34 rear. Even for this fat guy it gives me sufficient low gear for steeper climbs.
I agree with NoCoGreg that "It is critical the chain length is sufficiently long for the ill-advised cross-chain big-big combination".
We are both right!
I repeat, chain length should be determined (installed) while in the small cog and the small chain ring! However, I didn't explain the reason or the full process. Let me elaborate...
The longest the chain can be is so that when in the small cog and the small chainring, the derailleur cage produces enough tension to adequately take up chain slack. It's fairly obvious what adequate is, since a chain that is too long will ride the bottom of the derailleur cage. If you size the chain based on large/large, what happens when the large cog increases from a 32 to a 34? This is exactly how you get a "little extra chain".
The next step is to absolutely check that the chain is long enough for that "ill-advised cross-chain big-big combination". Sizing your chain based on the previous step almost guarantees you will have enough length for this situation with some added insurance. Say, going from that 32 to a 34 tooth cassette. If not, the only alternative is to special order a longer chain since the standard seems to be 116 links. Some really long stay bikes, like cargo carriers, will need longer chains.
The only reason to install a chain with the minimum number of links is if you are a weight weenie, which I totally get. Make sure to use the larger cassette when doing so, and yes base the length on the large/large combo.
I have a set 2x GRX Di2 with a set of 40mm tires and a 11x34 cassette and a set of road-ish wheels with 32mm GP5000 with a 11x32 cassette. I use the 31x34 regularly on tough gravel climbs and every time I've thought of getting a tighter cassette, I hit a tough climb and thank my stars for the bail out gear. My experience with the road wheels is different. Frankly, the road tires roll so well if I had to do it again I'd probably drop to a 28 cassette (I did a 6500' / 60 mile route with tons of climbing and with the 31 chain ring never really needed the 32 tooth). YMMV.
xseal wrote: ... the road tires roll so well if I had to do it again I'd probably drop to a 28 cassette (I did a 6500' / 60 mile route with tons of climbing and with the 31 chain ring never really needed the 32 tooth). YMMV.
Yup my thoughts exactly... IMHO dropping from a 34 to 32 is hardly any difference. Shimano's 11-30 has nicely spaced gearing.
But as Xseal said, "YMMV" It's really a personal thing with the tradeoff being smaller jumps versus range and a few extra grams.
