BikingViking793 

I noticed on my 81 Schwinn Super Le Tour that I can get all the rear gears when on the inner chainring, but can't get the inner most cog when on the outer chainring in the front. I messed around with it for a while but wasn't able to fix it. Any ideas? I assume it's harder to get in from the out chainring, but it should be able to? No experience really messing with friction shifting and couldn't find any good tuning tips.

SurferRosa

That's called cross chaining, and it's not recommended. Also not recommended that you ride in the small/small.

BikingViking793 

I thought maybe it would be an issue, but wasn’t sure with only 6 in back. And then all 6 work with the inner chainring. So outer chainring and inner cog is too much and shouldn’t work?

canklecat

As noted, you should avoid cross-chaining. It can cause premature wear. And the excessive friction is less efficient.

But under stress it's easy to unintentionally cross-chain. I've done it a few times on fast group rides on roller coaster terrain, forgetting to shift from the big to small chainring, while quickly shifting up and down the cassette. Or, with indexed brifters, I don't want to risk dropping the chain to shift from the big to small chainring on a short, steep, fast, punchy sprint-climb -- could be dangerous for anyone drafting my wheel if I suddenly lose momentum and need to veer off to the roadside to horse the chain back onto the chainring (usually I can do it without stopping, just by shifting and carefully moving the pedals without force). When it's noisy outdoors -- from wind, traffic, other cyclists -- it's almost impossible to hear the telltale warnings of cross-chaining, with slightly increased chain noise.

So I always ensure my chain is long enough to safely shift into the big chainring and largest rear cog. Some folks cut their chains a link or two shorter, but this can damage the rear derailleur, potentially damaging the wheel, frame and injuring the rider. So I'd rather risk a little chain slap from a slightly longer chain. Covering the chainstay on the frame will help protect it from chain slap. Usually there's already tape on the chainstay, but we can add tape (some folks use "helicopter" tape), or even wrap it with handlebar tape, strips from old inner tubes, even twine.

Regarding shifting across the entire range in both chainrings and across the entire freewheel or cassette, it's a matter of setting the travel limit screws to enable full range of shifting without overshifting and pushing the chain into the wheel and damaging the spokes, or getting the chain trapped between the smallest cog and frame cluster where the seat stay, chainstay and dropout meet.

You'll find good tutorial videos for derailleur adjustments on the YouTube channels for Park Tools, Art's Cyclery and a few others. It's easy to do once you've watched a mechanic walk the viewer through the process. Especially with friction shifters since you don't need to worry about the more finicky adjustments needed for index shifting setups.

madpogue 

The large/large and small/small combos are probably very close to some other combinations, if you do the math, you can figure out which alternate gear combo to select to avoid cross-chaining.

70sSanO

Everyone screams don’t cross chain, but it is not the demon everyone makes it out to be especially on a 2x6 setup. Old wive’s tale from a time when cogs were super thick and chainstays were long.

People are running 1x11 setups that are designed by the mfg’s that have a greater angle than your large-large. On another thread I asked what is the maximum chain angle and all I got were crickets. With a decent modern chain you’ll be fine with a 2x6.

I think there is some merit not cross chaining with a triple and 8, 9, or more cogs.

There is probably a good chance your chain is too short and doesn’t want to climb onto the lowest cog. If that is the case it is a good thing because you don’t want to destroy your rear derailleur forcing your chain onto the largest cog.

John

Edit Added: If the chain is the correct length, it could be an issue with top jockey wheel interfering with the large cog. If you rear derailleur is pre-B screw, you will need to move the wheel forward in the horizontal dropouts to get more clearance. This will help a slight bit with chain length if it is close.

dddd

What 70s SanO said.

Also, you didn't mention what kind of rear derailer you're using. Any derailer with an offset top pulley (offset from the cage pivot), such as all Shimano and most racing derailers, will have a larger "chain gap" (between top pulley and freewheel cog) when it's on the big ring. This reduces the motivating force for the chain to grab the largest cog (or any cog).

If you can adjust the chain gap by perhaps sliding the axle forward or using a longer chain, then the shifting response will be more effective. Many derailers feature adjusting screws or nuts to adjust chain gap to better suit a particular size freewheel on a particular bike, which is why I was wondering what derailer you have.
Modern chain is more flexible, so is more sensitive to too large of a chain gap.
Most any derailer can be adjusted for chain gap if one is willing to tinker with it's spring tensions, whether or not any direct adjustment screws or nuts (as with Simplex) are provided for this purpose.

randyjawa 

You probably can't go big ring to big cog because your chain is not long enough to do so. That said, I agree with avoid cross chaining. Cross chaining does put unnecessary strain/wear on the chain and sprocket teeth, in my opinion.

P!N20

Slightly disappointed this thread wasn’t about someone pairing downtube shifters with a 12 speed block.

nlerner

As others have said, your chain is likely too short or go with an 8-speed chain, which will have more flex than what you have now.

Fwiw, on several bikes in the fleet that are 2x8 or 2x9, I can ride big-big with no problems. But those are with compact double cranksets, which might play a role.

Schlafen

It's your bike, you can ride whatever combo you want, but, if you don't use components that work together it will wear your drivetrain really fast on top of very poor performance.
Use a modern mtb chain, which is designed to flex more on 1x10, 1x11 even 1x12 setups. This will wear your components at both far ends if you ride that combo alot, but not any faster than any modern 1x setup.
Even though 2x6 doesn't have the same spacing as half of an 11 speed or 12 speed cassette, it's not too far off.

John E

Assuming a long-enough chain, if small-small works much better than large-large check your driveline alignment. With a 2x6, the chainrings should align with the third and fourth cogs. To bring them into better alignment you either need to move the cogs to the right, assuming sufficient clearance at the dropout, or move the drive side crank to the left, assuming adequate chainstay clearance. I had a 2x5 Nishiki Competitoin from the early 1970s, and I never could get large-large to work without grinding.

ThermionicScott 

That's what I was expecting, too!

BikingViking793 

is there a good video that is friction shifter specific? I’m pretty good with indexed shifting.

Schlafen

- set H (small cog) and L (big cog) limits
- take the slack out of the cable.
- done.
You have mastered friction shifting adjustment.
Bike mechanics had it so tough back in the days smh.

OldRailfan

You could make a table of which combinations overlap and use that to get the most efficient way to use the gears.

canklecat

Derailleur adjustments are pretty much the same regardless of shifter: friction, indexed downtube, bar-end, integrated brake/shifter brifters.

With indexed downtube or bar-end shifters, I have to add one step to center the pulleys under the middle cog, using the barrel adjuster. That's unnecessary with friction shifters, and the most crucial steps are eliminating most cable slack, and setting the travel limit screws.

The feel of a friction shift lever depends on the design. Up until the late 1980s, most used metal washers, and some contained some variation of the retrofriction design with springs, so it was possible to finesse the shifting feel without excessive friction or tension. Later indexed shifters with an optional friction mode used more plastic and it was harder to finesse the bolt tension to get the desired friction. I gave up trying to use my Suntour GPS Accushift levers in friction mode because the feel was mediocre. I had to crank the tension really tight to avoid ghost shifts under pressure. Every time I'd stand to pedal it would ghost shift both front and rear derailleurs, unless I cranked down the bolt so much it was hard to shift at all.

But I have some Shimano L-422 Light Action shifters, which are friction only, with a retrofriction type design and little springs to help ensure light but even tension. They're a pleasure to use in friction mode. The only tricky bit was minimizing cable slack before clamping down the cable clamp bolt. I had to redo that a time or two before I got it right. And despite being nominally a 6-speed shifter, it pulled enough cable to work with my 7- and 8-speed freewheels and cassettes.

And the Shimano bar-end shifters on my hybrid aren't bad in friction mode. They don't use a retrofriction design, but there are micro-detents with slight but palpable clickstops, so the shifters don't creep under pressure. Even the cheap but very functional SunRace SLM10 thumb shifters have a pretty good friction feel with micro-detents to prevent creeping

70sSanO

I don’t know if they are a best kept secret, but L-422’s are just marvelous. I used Simplex Retrofriction for years, but those spring loaded L-422 were just about as nice. I removed the ratchet ring out of mine and they were so smooth.

John

canklecat

Yup, those L-422 shifters are so nice I'm thinking about getting another steel frame to set up for friction shifting. I think I already have a set of older Shimano 600 derailleurs from the 6-speed era. One of the local clubs I occasionally ride with hosts an old school steel ride once in awhile and it's fun to see what other riders bring.