2haworthia

Asking for a friend:

they have a specialized diverge with a 2x8 setup (46/34; 11/34). Current low at 27.64 gear inches. They are planning a Maui loaded tour (30-40 lbs) with 5% grade. They'd like to upgrade for climbing. My recommendation so far:

• Move to microSHIFT M26 2/3 x 7/8/9-Speed Long Cage Rear Derailleur Shimano
• Upgrade rear cassette to 11/36
• Swap front low chain ring to a 30t

This move would put the low at 22.94 gear inches (pretty good).

Questions:

• If they wanted to get closer to 20, what are the options? Would the microSHIFT M26 push a 38 in the rear (even though it's spec'd for a 36?) That'd get it to 21.83"
• What do options for moving to 10 speed look like? It looks like the could swap out the front 34 with a 30, and then the what about the rear? Would the shimano xt 786 long cage rear derailleur play right with the Claris front chain ring setup? That would allow putting up to 42t in the rear. For shifting, are the Microshift 2x10 a good option for playing with the shimano xt786? This would bring low gear inches to 19.62.
• Other options?

Thanks!

Kyle

Tourist in MSN

When I see a double crankset that has a smaller chainring of 34T, I immediately assume that it has a 110mm bolt circle diameter, as that is a common inner chainring on a five arm 110mm double crank. Thus, you might want to double check that they can change that easily to a 30T without needing new crankset.

If it is smaller than 110mm, such as a 74mm five arm bolt circle diameter, they could go smaller than 30T. I have used 24T inner chainrings on triples that have a 74mm BCD.

More on bolt circle diameters here:
https://www.sheldonbrown.com/cribsheet-bcd.html

niknak

You could swap the crank for this Rivendell 38-24t crank. That'll get you much lower gearing.

djb

Hate to tell you, but you and your friend are getting into a lot of "the devil is in the details" territory here, and subsequent adding up of costs.
Ask at some local bike shops and note the options and costs involved.
A crankset change is probably the least expensive, but even then you're probably dealing with tech details that can limit or derail changes (bottom bracket type, front derailleur flexibility etc)
And don't forget, bike stores stick to what is official, so you're going to find limited suggestions from them and may be shocked at the prices
If you actually get things done, come back and report with details and costs, would be good for others in the same boat.

Check out pathlesspedaled on the YouTube's for the guys hacking attempts at changing stuff.

staehpj1

Yep. My advice is to keep it as simple as possible and don't go nuts searching for the lowest gear and most even largest spread particularly if it is for one tour.

An inexpensive crank can often be a good answer. If you get to swapping clusters and deraileurs and maybe shifters you are getting in pretty deep. If you can swap just the cluster with no other changes that could be an okay answer, but if the RD isn't up to the task then no.

Giving up a little or even quite a bit on the top gear isn't a problem IME.

5% isn't crazy steep so you don't need to go super low. Also if you can possibly reduce the load a bit that always helps.

I did a Southern Tier where I used a 7 speed 12-28 cluster and a 39/26 crankset. the range was 87.8 to 25.1 gear inches and it worked out fine with the very light load (ultralight backpacking type gear). I had a much lighter load, but also probably climbed some steeper climbs. That exact setup probably would not be appropriate, but the principles may apply. That is use a crank that gives you a low enough climbing gear and don't worry if you don't have a big top gear. I didn't miss the big gear even when riding with a strong young rider.

As far as the low gear goes, early in my touring "career" I used a 26" ring with a 32" cog (21.9 gear inches) as a granny on the trans america and it was okay with a heavy load. A 24" ring (20.3 gear inches) would have probably been nice here and there though. There were definitely long climbs much steeper than 5%.

Yan 

Holy smokes $280 for a square taper crankset in 2022? What kind of rip off is this? This is just a generic Taiwanese OEM part with a special logo stamped on it. The chainring doesn't even match the spider. This is literally picked out of a Taiwanese factory catalogue.

For that much money you could get an entire new Deore mountain bike groupset to throw on the bike.

GhostRider62

Other options?

Yes.

Load up the bike with all the touring stuff and try out a 5% hill. Don't think your buddy needs more gearing

27 inch low seems plenty low for 5%. It would only take 100 watts to go 4 mph (about 50 rpm) for rider and gear totaling 225 lbs and 145 watts for 325 lbs, for example.

niknak

AFAIK, the Diverge uses drop bars and the owner wants to keep using them. Even though the Deore MTB group set is a good value, it wouldn't work in this case.

Probably the best value is to find an older used MTB triple crankset and to swap out the rings to whatever low gear the owner wants. But some people like to save the hassle and buy something new. The Rivendell crank isn't the cheapest but it'd likely work really well for what the OP was looking for: a 2x crankset with a smaller inner ring. The large bash ring will probably work with the OP's existing front derailleur.

Yan 

Microshift makes bar end shifters that work with Shimano mountain groupsets.

scottfsmith

+1

My latest bike has a higher lowest gear than my previous (~26 gear inches now, ~20 before). I was concerned I would have to stand on any really steep hill but I can do up to about 15% seated no problems now, even with loaded panniers. It took me practice over several months to get to that point, you need a very even stroke at low rpms as there is little room for loss of momentum errors. Clipless pedals are also required (for me at least) to get that even stroke, you need to focus on the stroke all the way around with both feet to keep it even.

niknak

I wouldn't wish bar end shifters on my worst enemy

Yan 

I would never use brifters on a touring bike. If you gave me a free bike that came with brifters, I'd rip the brifters off and throw them in the trash.

djb

No you wouldn't, you'd either put them in your parts bin or sell them to some eager buyer ;-)

staehpj1

Personally I dislike bar end shifters and much prefer brifters (I also like down tube shifters just fine), but I have no reason to hate on the bar ends when I could just pass them on to someone else who would enjoy them. I hope someone somewhere is happily using my old dura ace bar ends. They were old enough to predate indexing and were 5 speed if memory serves correctly. I like to think they are on some nicely restored old touring bike and someone loves them, but you couldn't pay me to use them. Just preference though.

GhostRider62

Barends with a minimal saddle to bar drop and half step gearing was the bees knees back in the day.

I wouldn't go on a long, remote tour using SRAM AXS electronic shifters but anything under 1,500 miles in most areas, I wouldn't do it any other way. SRAM mechanical brifters really start to get to my hand nerves on really long tours and would probably rather have Shimano brifters.

Tourist in MSN

It is personal preference.

I have bar end shifters (Shimano) on two derailleur touring bikes and a folding bike, I built up all three so I had the choice of what to use. Brifters on my road bike and a brifter for the rear on my rando bike, all Campy. I built up the rando bike, that was the brifter I chose for it. The road bike came with Campy, that was a selling point to me.

I am quite happy with those choices for those bikes and the purposes that those bikes serve.

Also have a Rohloff twist grip on the bar end on my heavy duty touring bike, but that is off topic.

I think a lot of individual preference is based on what you learned on and have used in the past. If I learned with brifters, I would probably refuse to use anything else.

I started using bar end shifters in the pre-index shifting era (1980s) on a five speed freewheel. I had a choice, I could use downtube shifters (taking one hand off the bar to shift) or keep that hand on the bar to use for steering while I shifted. Hitting bumps in the road with only one hand on the bar was problematic on cracked and beat up pavement. Thus, bar ends had a huge advantage. A second advantage was that it was easy to shift both front and rear simultaneously. I think that bar ends were choice for touring decades ago for that reason. And they stayed a touring choice from the manufacturers simply because of past usage for that purpose.

The newer brifters are proving to be fairly robust and reliable. And I have met a lot of people that preferred them for touring.

That said, a friend of mine was getting ready for his third cross country ride, Northern Tier with ACA. And suddenly his rear brifter stopped working several weeks before the start of the ride. It was a decade old Shimano 9 speed brifter, thus an earlier model. And he could not find a replacement and he was in a hurry to prep his bike for his tour. He asked me about bar ends, I let him use one of my touring bikes for a test ride, he then had bar ends installed on his touring bike. When he was on that tour, the rear brifter stopped working for another tour participant. A couple bike shops got it to briefly work for a bit, but she ended up finishing Norther Tier with a three speed as all she could shift with was her front shifter on her triple. If I was along, I would have tried to switch her bike to downtube friction as a worst case scenario instead of completely losing rear shifting.

Yan 

I learned on brifters and like them on road bikes. On touring bikes I value the ability to change to friction mode. It allows you to keep shifting with a bent derailleur. It allows you to use a modern 11 or 12 speed setup without having to worry about spare parts availability. You can install any derailleur. You can install any cheap cassette from 7 speeds up as long as you have a Shimano HG driver. It will keep you going until you can get your hands on the correct parts.

staehpj1

Yeah, any number of possible shifters could have allowed at least some shifting on the rear if not the full range. Friction downtube as you mention would have worked, A bar end, MTB thumb shifter, or even an old stem shifter would have gotten some level of shifting working. It may or may not shift the full 9 gear range, but even 5 gears or so would be a big help.

On the other hand it may not have been so bad with three gears if the right one was picked on the back. It is one argument against 1X bikes though isn't it.

Tourist in MSN

A year or two ago I broke a rear shifter cable on my light touring bike. Was about 15 miles from home, so close enough to ride it home but far enough that I wanted better gearing. Instead of riding with my chain on my 11T cog in back, I used one of the adjuster screws to get my chain closer to the middle of the cassette. Thus, my three speed was a bit better than medium, high and really high gears.

Yeah, a 1X would be a poor choice. But, that is rare enough that I think the better reason to avoid a 1X system is the high cost of cassettes. With my 3X8 bikes, most of the time I am on the 16T or 18T cogs, if I had a 1X then most of my time would be on two or three cogs, thus the lifespan of a 1X cassette might not be much better than my 3X cassette. But on my 3X, a 11-32 Sram cassette is only $25, the 1X wide range 11 or 12 speed cassette would be pretty pricey in comparison.

When riding near home I do not carry spare cables, but I always do on tour.

Yan 

This is true. The SRAM NX 1x12 cassette is $108. SRAM NX Eagle is extremely popular with manufacturers. It is spec'ed on the majority of new mountain bikes in the $2000 range these days. With the popularity, we expect 1x12 to keep filtering downrange. Hopefully in a couple more years there will be even cheaper options. In the meantime there are third party cassettes that are cheaper.

Tourist in MSN

When I bought my road bike with a Campy 13-29 ten speed cassette, very soon after buying I instead put a Miche 12-29 cassette on there. And I have spare Miche cogs for most of the middle range cogs that I will wear out fastest. I really wish that option was more widely available for other cassettes since a lot of my cogs on a cassette will be in great shape once a few are worn enough to cause chain skipping. But at this time my only bike that has separate cogs available is my road bike. And with component shortages as bad as they are right now, some of the sizes are in short supply.

djb

So Haworth, has your "friend" started to get an idea of how much money is involved to lower the gearing?
any decisions or is it too much to spend?

rivers

I've done something similar to my gravel bike, which originally came with Shimano 105 throughout (50/34 chainrings, 11-30 cassette). I already had a 46/30 crankset so I swapped the crankset first. Next, I bought a Deore M5120 rear derailleur and an 11-42 cassette. To make the brifters play nicely with derailleur, I needed to install something called a Jtek Shiftmate which converts the cable pull from road to mtb. I did all of the work myself (first time doing such a project so watched some Youtube videos and asked some questions on a home bike mechanic facebook page). As I already had the crankset, the other parts cost me around £100.

cccorlew

S-Ride rear derailleur? with a larger cassette? I'm running 11 speed ultegra brifters with an 11-40 cassette. Paired with my 46-30 crankset it's almost low enough for me.

You might also look at the ProWheel forged alloy, 42/28, the crankset that comes on the new Trek 520 Grando that may or may not be available aftermarket.