Double 1x

[Joe Bernard]

I had a nice 1x and wanted slightly lower gears for some crazy hills around here, but didn't want to lose the already relatively low top end so mashed some parts together and this is the result. 

Starting point: SRAM Rival 1 (with clutch) rear derailer, I believe the largest cog this is supposed to handle is 42t. I added a Garbaruk cage and pulleys and it shifts a SunRace 11-50 11-spd cassette with a SRAM Apex trigger shifter. The front is a Sugino XD crank with 34t chainring. 

Ok what happens if I want double rings? The manufacturer stuff says I can't use a 1x derailer (I don't know why) so I thought I would cheat a little and make it kind of two 1x's by adding a 30t inner ring, Shimano Deore (DynaSys 10-spd double) FD and a Silver2 thumbshifter on the stem. It works! 

Ok it doesn't work completely fabulously yet, the downshift to the small ring doesn't always take and I still have some fiddling to do but overall the bike works well for me using all of the gears in the 30t plus grabbing the top 2 or 3 in the 34t on occasion, and sometimes just staying in the 34t like before. It's not a massive increase in gear range, I think of it as an expanded 1x. 

Does it make sense? I don't know, maybe this can be duplicated by ye old triple drivetrains with 11-36 cassettes but I don't like triples. I like this! 

Joe "tried to ditch front derailers, ended up with a front derailer again" Bernard

[Hetchins52]

Looks like you can lower the new derailleur a tad. Have you tried that and run into interference?

David Lipsky

Berkeley, CA

[Joe Bernard]

That may be the next move but I suspect it's a spindle length issue. This FD was designed to run with an MTB double with a wide Q and 10-spd chainrings closer together, it's not quite snapping over hard enough to the small ring before running out of travel (limit screw all the way out). I don't want to put in a longer bottom bracket so I may need to pick up an older FD like Riv used to put on most of their bikes.*

*This is the part of the story where I remember why I gave up front derailers. 

[ascpgh]

Somewhere in the last two days I read something roughly this: "I tried to ditch front derailleurs on my road bike but they just work so well." Perhaps from one of the bike topic digest emails I get daily but oh so true. I solved my FD needs on my newest 2x bike with an NOS SunTour Superbe Pro from the mid '80s. Fit and worked better than all of the current FDs from three makers. 

When I see the size of those cassettes and necessity for expensive materials to keep their weight appropriate, RDs requiring clutches and reduced compatibility of shifters, it rekindles the thought that my 2x road drivetrains are pretty good. They are simple, elegant and yet sophisticated, durable and light. Above all I am not perplexed by their operation, adjustment or maintenance. i'm not going change what works for me, the struggle to reach that point had many lessons both near and far from home or a sag call.

What seems simple (1x) sometimes comes with great complexity once details start being ironed out. I'm not a fan of the complete component group drivetrain sales to volume manufacturers targeting new or newer cyclists being the driving standard. They are telling the experienced cyclist that they don't matter to them.

Shimano sales were down 17% in 2022, forecast to be down 22% in 2023. How's that model working out for them? CUES is their response. Hope they start considering the dedicated,, experienced cyclists a bit more.

Andy Cheatham

Pittsburgh

[Richard Rose]

I was just writing elsewhere that (so far) my 2 x 7 drivetrain I installed on my Gus is like having two 1x7 drivetrain’s. That’s the magic of the Silver wide/low crank with 38/24 rings. On road/gravel rides I’ve yet to use the 24 & I’ve not spun out in the top end. On local quite hilly singletrack I just put it on the 24 & leave it there.:)

Sent from my iPhone

On Apr 30, 2023, at 1:04 AM, Joe Bernard <joer...@gmail.com> wrote:

I had a nice 1x and wanted slightly lower gears for some crazy hills around here, but didn't want to lose the already relatively low top end so mashed some parts together and this is the result. 

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[DavidP]

You can also do double 1x with two chainrings and skip the front derailleur and shifter - manually shift the front when desired (usually while stopped but down shifts can be done while riding easily enough using your foot to nudge the chain).

-Dave

[Eric Daume]

CUES has a 2x option.

Eric

who doesn't miss the front derailleur at all

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[iamkeith]

On Sunday, April 30, 2023 at 6:46:46 AM UTC-6 rmro...@gmail.com wrote:

I was just writing elsewhere that (so far) my 2 x 7 drivetrain I installed on my Gus is like having two 1x7 drivetrain’s. That’s the magic of the Silver wide/low crank with 38/24 rings. On road/gravel rides I’ve yet to use the 24 & I’ve not spun out in the top end. On local quite hilly singletrack I just put it on the 24 & leave it there.:)

Agree.  But I actually think the magic lies in the long chainstays of the Clem.  You can stay on any chainring and still have use of the full range of the cassette, without worrying about cross-chaining issues like excessive chain wear or rubbing  on shift cages or adjacent cogs.  Much different than old short chainstay bikes where you HAD to move the move the chain through the front rings as you moved across the rear cassette, and ended up with far fewer usable gear combos than the numbers would suggest.  In turn (and to address Joe's issue)  it becomes much less important if the front shifts are super smooth or reliable.  The jump can (and might as well) be bigger, too.  If you think of it as two 1× drivetrains and only shift the front on occasion, and if you can live with some idiosycracies (read:  theft deterrent), it saves alot of stress of being a perfectionist.

[Joe Bernard]

I should add - I didn't realize my aside about it needing a little work would be so noticeable - that my front shifting works good enough most of the time now. My intent was to show how a narrow range double could work with one of those huge cassettes people use for 1x's. 

[Joe Bernard]

Or I can give up on the idea and try a 7-speed 11-36 S Ride Jim cassette with 26-34 front rings and an S Ride 7 trigger shifter. Works better, the front shifts properly, I like it. 

Btw - this isn't in the Rivbike product description, they somehow managed to get a 9-speed shifter to index it - the Jim spacing is indeed old Shimano 7. I'm sure 7-speed Deore DX or XT thumbies would work, too. 

[Nick Shoemaker]

+1 on the double 1x w/ no front shifter approach - I call it my 'manual granny.' I'm not good enough to shift it on the fly (at least not in moments when I urgently need that low of a gear...)

SunRace RDM900 derailer (1.7 pull ratio AND a clutch!)

Jim 13-42t cassette

36-24 crank

Silver thumbie

8 speed chain(s)

Pretty solid hillibike setup for not a lot of $. I am considering moving to an 8s 11-42 because I do sometimes wish I had one slightly faster gear on the road.

[Patrick Moore]

Years ago, probably close to 40 years ago now, a book came out describing the adventures of 2 British brothers' around the world bike tour on custom touring bikes. For some reason they forewent front derailleurs on their 2X drivetrains and instead carried little sticks on their handlebars which they used to shove the chain onto the small cog (forget how they upshifted). Does anyone recall their names or the title of the book?

Me, I had a front-derailleurless 2X8 or 2X9 drivetrain on my early '80s Ken Rogers tricycle; it was great fun to stop dead on a hill and backpedal with my left foot while nudging the bottom of the chain with the toe of my right, then continuing on in a low gear. I did have to reach down and grab the top run of the chain to upshift, a rather dicey move.

[lconley]

That was what came on the Rivendell Mystery Bikes, double crank on the front, 9 speed cassette on the rear, but only a rear derailleur and shifter. No shifter boss or cable stop for a front derailleur. I think it was referred to as a stick shift - you shifted the front by pushing the chain with a stick.

Laing

[Joe Bernard]

I love the idea of stick/kick shift in theory but - not unlike my dreams that I can ride a singlespeed around here - it's just not feasible in practice. My terrain is up/down/up/down all day, I gotta have those gears and they gotta be available at the flick of a lever. This place is a rollercoaster! 

[Brendan Aanes]

Some recent playing with a Rival 1 rear derailleur leads me to theorize that, clutch aside, the way it's different from a traditional RD designed for a double or triple is that it is built for a large cog, so the pulleys are lower, but has a shorter cage than a double would, so it can't wrap as much chain.

For example the Rival 1 "long cage" looks like it has about the same cage length as a "medium cage" Rival double derailleur, because it's taking up a similar amount of chain as a double with an 11-32 cassette would. That whole cage assembly sits lower to the ground to accommodate an 11-42 cassette.

Good to know it's working well for you with a double!