42t Big Chainring?
 

I have a new touring bike, a Traitor Wander that was custom built from the bare frame by the previous owner. It's an amazing bike and I find myself riding it instead of many of my other bikes for the pure fun of it. However, it's got a compact double 50/34 chainset on it, and it just doesn't cut it for anything I want to do other than tool around town. Ideal uses: commuting/light touring/exploring gravel trails/ very light singletrack.

I'm intrigued by the Deore M610 cranks, but in the USA you can only find them in 40t and 42t big ring configurations. I'd ideally like a 48t big ring, but I only find them overseas and about twice as much as the 42t version.

Is 42-11 on a 10 speed setup too low geared? Gear calc shows 90rpm on this gear is 27mph, which is pretty acceptable given the bulk on the bike, but I wanted to get other opinions as well. Thanks a lot.

Falcon3, I have a 42T on one touring bike and a 44T on the other. Either is perfectly suited to the uses you listed.

Brad

Is the concern the entire range?

What is out back? You have a 11t but what is the largest cog? I am willing to be you can get the same gearing out of your double as you can with a triple crankset with just a different cluster out back.

Crankset I'm looking at is 42-32-24 so I'd like to do 11-25 for close gearing.

You can find 48T 610 cranks on ebay from USA based sellers.

My last two bike tours on derailleur bikes were with a big ring of 46. I had triples set up with a middle ring of 42. While I liked having 42 and 46 (that was half step gearing with my eight speed 11/32 cassette), I would be able to tour on a 42 big ring.

That said, I can cite several times where I went down long shallow downhills on some pretty big gears and I used to tour with a 52 big ring. A couple times I was in my highest gear of 52/11, and I enjoyed those fast down hill runs. But, in a typical tour I might get up into my highest gears only a couple times. Thus, if I was going to lose any gears, I could afford to lose those highest gears.

My Iceland trip last summer on my Rohloff bike my gearing ranged from 16.5 to 86.5 gear inches. There were a few times I spun out because I did not have the high gearing. But, I needed my low gears more than my high gears so overall I was quite happy with the gearing I had.

A 25 for your biggest sprocket in back is not a very low gear. You might find yourself getting a bigger cassette some day.

I've got a 42/28 setup to 11-36 in the back. If I'm spinning out at 25mph+ on my rides I rarely/never care. I find 2x setups less fiddly to adjust and maintain.

Thank you all, my other bikes I just throw a compact on and a 12-28 and call if good, but I can't believe how much fun this bike is, and I really want it dialed in.

Just make sure your rear derailleur can handle the chain capacity for this setup. It most likely can since the cassette is extremely tightly spaced for a touring setup, but just want to make sure you consider it before pulling the trigger.

Rear changer is a Deore M592. Specs say it needs a 32 rear to shift correctly, but it's working great on my 11-27 on the bike now. Supposed to have a 45t chain wrap.

I'd look at Sugino 110/74 BCF triple crankset. I bet they make 10 speed compatible.

42 x 11 is a 103" gear. 50 years ago, 13 teeth cogs were not common and 52 x 13 = 100" was the norm for high gear. I like the idea of running bigger cogs for wear and reliability so I haven't gone smaller than 12 (9-speed) yet but I love the choices 110/74 BCD cranksets offer and the simple reliability and standardization of Sugino square taper cranksets.

(On that note, I just installed an older 175 mm 110/74 Sugino crank I picked up virtually new and cheap for my Peter Mooney for a unique triple fix gear combined with flip-flop track hub. That crankset slid beautifully onto a Phil Wood BB and rides like a keeper. (It did require a custom chainring bolt set and "dingled" rear cogs so this is NOT a bargain setup! but that not very expensive Sugino crankset is of quality to be legitimately part of this rather exotic whole.)

Edit: more on 110/74 BCD cranksets: I've used them for years with 53 (or 52), 42, 28 (or 26) x 12 (to 14)-23 (to 28) 7 and 9-speeds. More than 60,000 miles. Favorite setup of all time. With cassettes of freewheels of racing sizes, all of my old racing gears plus that 28 front. Climbed Mt Washington twice on that (granted when I was less than half my current age). If I toured now, I could just drop the outer ring down to a 48, the inner to 26 or 24, boost the cassette to 32 nad have real, no compromise touring gears.

My good bike currently has a Shimano 105 crank on it but when I see a sweet 175 mm Sugino 110/74, its going on with another Phil BB. My knees love low Q-factors and that setup (even including the Phil BB) costs the system less than one doctor's visit and me far less than knee replacement surgery.)

Ben

I have two bikes with 42 or 44 large rings, and with 11 or 12 smallest rear sprockets. Both bikes are 26in bikes so the 44/11 bike is probably very similar to a 40 or 42/11 in 700c . This bike gets spun out at about 55kph or so, which really isnt an issue, but I generally use this bike with a minimum of two panniers on, so my average speeds are much lower than if you ride this bike unloaded a lot.
Realistically spinning out up around 30mph is not something you will do often, but I guess what you can do is get the exact gear inches involved and ride your bike as is to see how it is for you at X gear inches as a top gear.

Same goes for riding your bike as is, but with X and Y lbs of stuff on it, so you'll have an idea of what you are dealing with, with the type of riding you will be doing carrying a load.

I've got a 42 large ring with a 15-25 cassette. It's perfect for gravel trails. The shift from small ring to large is pretty weird though. small- small to large -large. small ring is 28.

in good ol gear inches, my 26in bike with 44/11 and 2in wheels gives roiughly 103g.i, my 25+ year old tourer with 700/28mm wheels and 50/13 gave the same 103 g.i
and my mtn bike with 26/1.5 and 42/11 gives 95g.i

95 spins out at about 50or kph if I spin the crap out of it, I dunno, 120 rpm or more
103 spins out at about 55-60 if I spin the slightly less crap out of it

if you ride unloaded, a higher high would be nice, but then again, how often do you get to get to those speeds, I dont that often, as much as I'd like to go faster.

ps, on my other bike, with 111.5 g.i, I can sometimes get to about 70kph if I spin the crap out of it, but that aint happening that often, but I do admit for unloaded riding, I'd want a minimum of this as a high gear as I do like cranking down hills when I can.

I recently switched out the cranks on my road bike from 53/42 to 42/34 so I can can use it for touring. I'm really liking it, with 11T in the back, I can go plenty fast, up to about 32 mph on descents before I need to coast. I was even able to hit 50 mph on a really steep hill without any gear, so top speed is really not a big deal unless you're trying to race.

There is a good amount of overlap between the gears in the middle, but that's not a big deal for me. I think ideally I'd do a 42/28 for a hilly tour and 50/34 for a flatter tour. But I went 42/34 because I can't afford to buy any new parts at the moment.

One of my commuters is a 1x9 with 44T upfront and 12-36 in the rear, with 35-622 tires. That combination works well for my commute, which has only one very short steep grade. A 40T with 11-34 would give the same top end, with slightly lower bottom end; and a 41T with 11-34 would give the same bottom end with a slightly taller top end.

With 11-40 8 speed and 9 speed cassettes available from Sunrace, 1X becomes more practical. The 8 speed 11-40 has no worse jumps than at 7 speed 11-34; the same with 9 speed vs 8 speed 11-34.

A 34T with an 11-40 is an interesting combination; with 35-622 tires, provides 23.3 GI on the bottom end and 84.6 GI on the top end.