Tourist in MSN

So, if I read this correctly you want to use a 12 speed cassette which likely means a 12 speed chain and a 9 speed compact double crankset.

You might want to talk to some people that know this stuff better than most of the people commenting here, as according to Park you might have a chain getting stuck in between your chainrings.

Pasted:
The spacing between front rings for a 8 or 9 speed chainring set will be relatively wide. Using a narrow 10 or 11 speed chain may result in the tendency for it to fall between the two rings during a shift.

Pasted from:
https://www.parktool.com/blog/repair...-compatibility

I am running an 8 speed chain on 10 speed crankset on a couple bikes, I added spacers to move my chainrings further apart to compensate for that, but you plan to do the opposite, use a narrow chain on a crank that was designed for a wider chain.

You also if I read this correctly want to use a cassette that has a 39 tooth difference from big to small sprockets, and also a crank that has 16 tooth difference between big and small. I stopped trying to keep track of capabilities of the latest derailleurs for huge cassettes, so I have no clue if your proposed rear derailleur can handle that much chain.

In other words, I do not have the answers, but gave you a couple questions for you to be asking.

Tourist in MSN

There are a couple former racers on this forum, you should tour with them. They might enjoy the competition.

Germany_chris

If you use an Ortlieb handlebar bag I’d try to figure out a way to give it a little extra support. I have the small 5L on my commuter and if you get it much more than half it’s stated weight limit it bounces around quite a bit.

sdimattia

I appreciate you trying to help. I was hoping to save some money by not having to buy a new crank.

I guess I'll buy a 105 r7000 11sp 2x crankset as it comes in the right length and won't be as drastic as difference like 9sp sounds like it would be. I was going to upgrade the Sora parts to Tiagra or 105 eventually one day anyway . . .

Germany_chris

https://specialites-ta.com

I’d try chainrings first, I’ve done 9/10 to 11 with just chainrings

sdimattia

Sorry, just to confirm, you are saying put 105 chainrings on the Sora crankarms since BCD is the same?

djb

Re road cranks 50/34 , first of all there's the whole technical aspect of front and road derailleurs and capacity with big cassettes (of which I too am not up on) , but most of this stuff is designed for 1x systems, well a 50t cassette anyway.

secondly, re a 50t chainring, add 20 or 30lbs to a bike and you'll see first hand that you won't be using the 50t very much, so I'd strongly suggest looking into smaller doubles, stuff like 42/28 or something, and then you'll have the added bonus of using a smaller, specifically tighter cassette with smaller jumps......but you're going to have to get good reliable info on what components work together.

good luck

Germany_chris

Id recommended going to the link and getting them there

GhostRider62

I use an old 10 speed crankset with 12 speed FD, RD, chain, and cassette. I have not dropped the chain nor has it fell between the two rings.

If your crankset does not work with the components selected, you'll know pretty quickly. I would try it. IIRC, 9 speed rings are a little thicker and spaced a little further apart than 10 speed setups.

Nobody knows the OP and whether 50/34 is too much. She has already said she was going with light gear, 10-15 pounds IIRC. It is not hard to get total bike and gear weight under 40 pounds but 30 pounds is a challenge. In that weight range, such gearing as she listed is not extreme for a moderately fit cyclists.

djb

Ghost, no we do not know how strong a rider they are. I do know that when riding unloaded on my 50\39\26 bike, I stay in the 39 ring until probably 40kph, maybe a bit less, especially with the 12,13,14,15 cogs close together, which is just enjoyable to use with tight shifts.

but as you say, the only person who knows is the person in question. Strap 20 lbs somehow into the road bike and see how it is.
But don't forget, I think it's highly unlikely that a Rd can handle a 50\34 and a big old pie plate of 50t cassette.

Do the research and get back, I'd be interested to know what works, what's available and at what cost.

And I still say that the scant few times we can sustain speeds over 50kph downhill are pretty rare, so imo with touring, it's always a priority to emphasize low to mid speeds, cuz that's where we usually are, in kph probably 15-30kph, so smaller cranksets easily cover that.
And if you have the inclination, conditions, tailwind and downhill, you can still set land speed records going down big hills and around corners fast. I love doing this and gearing doesn't hold me back.

GhostRider62

I use a 53/39 or 50/34 and 11-32 11 speed and absolutely never use the small ring at 40 km/h. My touring cadence is around 70-72 rpm. Spinning a 39 chainring at 40 km/h is very inefficient, metabolically and mechanically. I am not sure why you are talking about 50km/h.

As far as doing some research, no thanks. You do realize one does not need to use every ratio on the cluster, right? Or that the unpublished chainwraps are very conservative, right?

staehpj1

Yeah, The 11-50 is almost certainly intended as being for a 1x setup. I have to wonder if the RD will wrap enough to handle all that and a double. The 18.5-123.5 gear inch range seems like a bit much. Personally I find 18.5 to be lower than I want/need, but many here want/need that, but 123.5 on a touring bike? Seems like gross overkill to me, but we each get to pick our poison.

djb

Everything you say is correct, and yes I meant I can use the 39t to spin up to 40 or whatever, but the main issue here is that we are talking about touring. (Plus I'm an old skinny dude)
But again, it's up to the person in question to figure out what gearing works for them, those of us who have toured a lot can only give recommendations.
As for research, neither you or me want to take the time to figure out components and gearing ideas, but this person will have to.
Ya, I've gone past official ratings before, but again we come back to the specific stuff they would like to use.

Anyway, I hope they sort it out and more importantly, see if they actually like touring.

GhostRider62

A Shimano mountain RD wrap is probably 45 teeth. Just don't use the 34t chainring with the smaller cogs, set the b screw all the way out, and set the chain length to big-big. If that does not work, a tighter front chainring set or crankset would be needed. No real harm trying.

If OP wants a new crank, go for it but even with just the 34 chainring and a wide range rear, that is enough to handle most situations and certainly any hill. I got the impression that she wanted to be careful with spending on gear and secondly, her statements about lightweight backpacking gear says she has very transferable skills.

djb

as we got off topic (ish) I can see the confusion-- we had mentioned the old 20-100 gear inches recommendation for touring, and a 100 g.i bike spins out at about 50k. My heavy duty touring bike has 103 or 104 g.i with 2in tires, and I spin it out at about 55k if I really spin gerbil fast on a downhill---which is ok by me, and I can still easily pedal at 40k or the very infrequent short times that one has either a long long gradual downhill or a super strong tailwind, but even then lets face it, you'll only hold this for a short time, whereas I can guarantee you that I've spent hours and hours and hours at 5, 6, 7, 8, 9, 10 kph climbing long Latin American hills--and exactly why I chose from experience to set that bike up with a 17-104 range.

as others have wisely said, somewhere in the 20 g.i range or higher if she really does carry a light load will work also, it really comes down to figuring this out from actual experience.
I do agree though that to me, its pointless having a high gear on a touring bike much higher than 110 or thereabouts, simply because panniers and crap are terrible for aero, bike is like a four mast schooner with sails , and unless you have a honking tailwind, I find it hard to get past 60, 70kph even though I would love to just hammer it.

takenreasy

I can attest that the LHT can handle miles. I've got a good 50K on mine (2011 model). It has handled every kind of weather four seasons can throw at it. It has essentially been rebuilt , at least , once for those miles due to necessary maintenance. Unfortunately, a lot of those are commuting miles. I'm getting ready to retire from my day job and have recently replaced all components on the bike. My goal is to head out on the open road and really put some miles on it. Stay tuned.

sdimattia

I'm definitely trying to spend less, rather than more. I actually am switching out the current rear Sora derailleur (limited to 34t) to the Sram NX Eagle derailleur that goes with the NX eagle 11-50t cassette I will also be putting on.

While keeping all of your great tips in mind, I based my low gearing off the biggest hill I've had to climb with just me and the bike (0.4mi long, 11% average gradient). I got up with 29GI. Add another 20-30lbs of gear and tired legs, I figured 18.5GI would get me up similar climbs. But also, like Tourist in MSN said, at some point, I'll have to walk.

I'd like to believe I'm reasonably fit, I cruise around flat NYC on a single speed at 71GI, which gets me up the bridges and 98% of the hills with little issue. Probably a little spinny for some people but it works for me. Once I have all my parts, I'll load the bike up and do a couple of test rides. I'll torture myself with the 11% hill again as well and go from there.

All that being said, I haven't bought anything so I am still playing with the gearing and whatnot.

sdimattia

I think I figured it out (and saved some money):

Shimano GRX 46/30t crankset
Shimano 105 front derailleur
Shimano 105 2x11 shifters for mechanical disc brakes
Shimano GRX rear derailleur
Shimano SLX 11-42t cassette

saddlesores

noticed on your 6700, you currently have
36/26 crankset with 11-42 cassette..........

howzabout loading 30 pounds on your 6700
and hitting some long hills before you buy the 46/30?

then see how that gear setup feels with weight
off-road since that's in your future plans.

djb

with a 20 g.i. low it will be fine, I biked a good chunk of the Pyrenees and west coast of the States on my old touring bike that I changed stuff to get to 21 g.i. , and from Montreal to Boston on that cross bike of mine with a different cassette so about 22 ish , and on these trips, never had to walk.
The times I've had to walk (which I don't like doing, bang shins) it was eons ago on bikes with too high gearing, which made me figure out gearing and how to lower it.

Keeping the load down and if you do have light weight stuff, it'll be fine.

if you can, it's really good to put the hours in on a loaded bike, but if you're in relatively good shape and you don't load up everything and the kitchen sink, this gearing range works.

As another light person, 135, I can attest that we do notice more or less weight of a touring load, but you'll figure that out on your own.

to put gearing in perspective, the super low gearing on my Troll was because I knew I'd be carrying more crap, spare this, more tools, extra water, and I knew I'd encounter stupid steep stuff, 20% or more for short bits. In Latin America, the terrain and budgets and all that mean that you get way steeper stuff than we do in Canada or the US, and pedalling a heavy touring bike is easier than pushing it.

apparently the Appalachians are kick ass hard, folks here who have ridden them say they are harder than the Rockies.

hope you get out touring one day.. After a week on the road, you get the packing order, eating drinking, amount of sleep, etc in order, and it's cool when you start to feel touring fit too.
cheers

staehpj1

That is true for the sampling of each on the Trans America. FWIW, I wouldn't assume it to be true for riding or even crossing the two ranges in general. There are plenty of crazy hard climbs out west and probably easier ways across the Appalachians. Reportedly the Eastern Express is MUCH easier and looking at it I think that would be true. Also there is some insanely hard stuff out West I found that out when I rode the lower half of the Siera Cascades Route.

Many places in the East the roads were build with no or at least not much grading. Out west many of the roads were built later with more effort at grading and routing. The TA benefits from that. Not everywhere out there does.

sdimattia

I'd have to figure out how to fit the gear on there first. When I first mentioned it, I forgot the 6700 didn't have mounts where the rack arms would usually connect. Unless I can use p-clamps (is that recommended to connect 30lbs on a rack to p-clamps?), there is not enough clearance to use a seatpack or frame bag. I was thinking off-roading in the sense of something a gravel bike could handle. Or, my Surly since it can take 26x2.0" tires.

As it is, commuting (me+10-15lb backpack), the gearing feels fine and so far, the 36t has covered all my ratio needs so far.

sdimattia

I appreciate all your insight and support so far! I am actually planning to go cross-country this summer.

Once I get the bike sorted, I'll post pictures and do some practice runs. In the meanwhile, and more so when it gets a tad warmer, I'll be doing daytrips and overnights outside my usual routes.

Tourist in MSN

I think that is a good range of gears for a light touring bike. You will almost never use your top gear but it is a nice gear if you have several miles of shallow downhill. And 19.4 is a good gear for most of the steeper hills you will need to climb.

With a 46 front and 42 back, depending on how long your chainstays are, you might need a few more links than a stock chain. Thus, you might need to add a few links from a second chain to assemble this. I have never used an 11 speed chain, but I assume you can use quick links easily enough if you need to do that.

djb

stumbled upon this bikepacking.com youtube vid of some grx shinanigans, dont know if its of any help, but there you go. Might be of help goatlink wise ideas or whatever.