2x10 gearing advise.
 

In a previous thread I posted my newly acquired Disc Truck. I mentioned that I want to trade out my double crank for a triple. Someone suggested changing the chainrings. As it sits now the cranks are 170's with 50/34 110 BCD and the cassette is 11/34. What chainrings should I be looking for? My plan is to some fairly long touring and eventually coast to coast. Thanks.

Unfortunately (I am assuming that you are looking to have lower/ easier gearing) with the 110 bcd bolt pattern, 34 is the smallest chain ring that will fit. If the (right) crank arm is drilled/ has threads it the inside of the crank arm, then you could add a third chain ring with a wider bottom bracket.

Yep, as soon as I posted this I did a search for chainrings, not much options for 110BCD. So If I were to buy another double crank, what chainrings should I look for? Staying with a double I wouldn't have to change shifters.

I'd strongly suggest figuring out what sort of low gear you will need in gear inches. If you've never toured before this might be hard, I dont remember if youve toured before.
How low a low--that will depend on many factors, how much weight youll carry and how you are as a rider, but lets be completely honest, for a coast to coast trip, you'll want low gearing and the age old touring gearing recommendation of a 20 gear inch low gear is still a fairly good one to follow. Lower is fine too, doesnt make a hoot of a difference what speed you ride along the flats for 90% of the time if you have lower gearing available.

figure out what gearing you think you need for a low, and then get into the spaghetti bowl of dealing with technical aspects of this and that and that and this, because changing out a crankset and maybe larger cassette or rd will get into a whole slew of "the devil is in the details" stuff......

ps, refresh our memories, why is your surly disc trucker set up with a 50/34, and what shifters??

sorry, didnt see other thread.
Clear now.
What an odd change to do to a dt frame....(previous owner)

honestly, for a coast to coast trip, I think you should just look at switching stuff out, put on a triple and shifters of your liking--but you might be lucky and be able to find a mtb double that you'd be happy with, like a 42-26 or something, but you'll have to research this to see what is available and figure out chain line issues.

its a 26in trucker right?

Yeah 54cm 26" wheels. The owner bought the frameset new and put his choice of components on it then never rode it. I'm pretty sure he just does it as a hobby and flips them. My first choice would be a triple and bar end shifters. I'll probably just ride as is and change later, I'm mainly riding in central Indiana which is flat as a pancake.

As stated before, you might consider a 46/30 crank and possibly change cassette to a 11-36 if needed but it really depends on your own youth, athleticism, and the terrain you need to tackle. If you want lower gearing, you'll need a mountain bike crank (might remove the largest chain ring of a triple) but may be spinning out on the high end frequently.

Sub compact chainset option for lower gearing.
 

Cycling Weekly (2017): The super compact chainset, otherwise known as a sub compact chainset is the latest gearing system to gain traction — especially in the world of gravel or all-road cycling. With even lower ratios than the original compact, which used a double 50/34 set-up, a super compact chainset runs 48/32 or even lower. From the likes of FSA, Rotor, Praxis, White Industries and now Shimano (GRX range of components).

TA 110 BCD Zephyr Inner Road Chainring in 33 teeth...wiggle.co.uk.

I personally run 46 - 34 rings (110 BCD) up front and a 12-36 cassette (9 speed) out back. I switch to a 11-34 cassette when I feel the need for speed unencumbered.

Does anyone make a 44/28 crankset ? A while back I saw a manufacturer that claimed it was in their future but can't remember which company, Stronglight ? Sugino ?

i was thinking similar, mtb crank, ignore the big ring or replace with a rockring.
keep the two smaller rings, maybe 26-38 and pair with suitable cassette.
how often do you use the big ring anyways?

ya, sounds good, and if you take the time, you should be able to find a triple that will turn the bike back into the touring it was designed for gearing wise.

Btw, the choices and availability of 46/30 cranks have expanded a lot recently and hence the costs have come way down, much more affordable now.

I was looking at the Shimano GRX 46-30. I wouldn’t need to change bottom bracket or shifters. But I want to make sure I can climb steep grades when the time comes.

well with the new one by trend , there are now cassette cogs as big as your chainring... the big one..

On my tours My low was 0.7:1

Still had a few occasions the 2 foot gear was needed ..
will other Marines shame you for pushing a loaded touring bike up a steep hill?





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put on a 11-36 and the 46-30 and you'd have 20-104 gear inches, a pretty darn good touring range. Personally I'd find the 46 too tall and you'd mostly be in the 30 which would wear it over time, but hey. A 10 spd mtb triple would be pretty handy also, but then you get into shifter issues, and all kinds of stuff.
This chart is with 1.5in tires.
https://cimg2.ibsrv.net/gimg/bikefor...f037016af1.png

As a Marine I will shame myself for pushing my bike.

René Herse (formally Compass cycles) has double and triple cranks between 52-42 (In increments of 2) and smaller rings between 44-24. You can pick the combination that works best and they’ll assemble it for you. These are good quality and look great. I put a 46/30 on my wife’s Rivendell.

Of course your wallet will be so much lighter you might not need as low gearing. Haha

86 bcd crankarms would work. I have a couple of sets at my Lancaster home waiting for me to arrive.
Both Stronglight 80, 99, and 100 crank arms and SR Apex Cranks are 86BCD, they can go as low as 28t
https://i.etsystatic.com/5760052/r/i...72781_hatk.jpg

I've ran 50/34 with a 36 cassette using a RD592. Even using big/big on occasion and never had a problem.
I gave up on the compact and bought some 46/30 rings for some FSA Omega cranks I already had laying around and put that on. I will be at least 46/30 from this point on until I eventually need MTB gearing :)

If it weren’t for the COVID supply chain problems, I would suggest a square taper Sugino triple like the xd 600.

That is what comes stock on the LHT. I have run mine 22-36-chain guard with 10 speed 105 brifters and 26-36-46 with bar ends. I can spin pretty fast, so I top out around 28mph with the current 36-11 high gear.

Or go nuts, put on a 48\36\26 change 26 to 24 or egads even a 22, and use gevenalle 10 spd triple shifters, road or dynasys, and use a tighter cassette and it's fun fun fun til your daddy takes the T-Bird away (song reference, look it up or ask your grandma)

Some of us do remember The Beach Boys...or what's left of them :)

48T (Tioga) 36T (Shimano SG-X) and an Onza stainess steel 24T...on venerable Shimano Deore LX M560 Low profile cranks ('94) with an 11-28 8 speed cassette. That brings back some fond memories of rodie chasing on Sundays many moons ago.

I put in some years in the Navy .. the Marines were passengers on Navy vessels.. you guys were Cargo that Ate.

On a 1983 tour one of the people on the tour used a TA 50-28 double.. 13-28t freewheel

Now modern stuff, I think you would get a White Industries VBC crank, SQVBC ? White Industries
Or Rene Herse Cranks https://www.renehersecycles.com/




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This is actually hilarious to me, because you basically nailed my setup. My touring bike came stock with 44/32/22 up front and 11-32t x 10 speed cassette, with bar-end shifters. I eventually got tired of hitting escape velocity, so I switched it to a 48/34/22 up front and kept the 11-32 in the rear. I think next time I replace the cassette I might narrow it to 11-28t, because I don't like the jump from the 12-14 cog.

My bike came stock with pretty similar gearing. I switched my front to an FSA adventure cranked with 46-30 chainrings. I got a new cassette in rear with a 11-36 spread. It made the world of difference. I still have the original tiagara derailer in the back so im outside of manufacturer specs but as you fool around I think you'll find shimano is pretty conservative with what they spec out. If you wanted to mix and match road shifter and newer mountain stuff you may want to look at wolftooth components. The Tanpan will adjust the pull ratios to you can use new sti shifters with mountain derailers to get larger ratios if needed.