eschlwc

in the land of c&v, say, upper mid-level,126mm old, mid-late '80s road bike with all the bells and whistles, what's your view of the 7-speed freewheel option over the 6-speed?

- does it shift as well with the same chain?
- does it offer a gear or two more that is worth any shifting issue it causes?
- if not racing, is the small incremental gearing worth the potential trouble?
- is it as quiet as a comparable 6-speed?
- is it as trouble free?

who here prefers a new 7-speed (like a close ratio sunrace 13-25t) over a regular 6-speed (14-28)?

.

background for this post:

- '84 davidson is my first 7-speed (suntour fw with campy nr fd/rd)
- new sram chain hangs up on top of the cogs on occasion
- upper pully damn close to the cogs
- noisy, especially in lower gears
- not sure what to replace (chain or fw?) nor what to replace it with.

SkyDog75

They should function and perform similarly, with the obvious difference being there's one more gear to choose from on a 7-speed cluster. There shouldn't be any difference in reliability, noise, or smoothness that's attributable directly to the number of gears.

As for the particular problems you're running into... Is the new chain replacing a particularly worn one? Is it possible the teeth on the freewheel are worn? (Likely if the old chain was worn significantly.) Does the bike use indexed or friction shifting? Is the new chain a 7-speed chain?

The upper pulley should be close to the cogs. If it's touching, or too close for your comfort, you should be able to adjust its clearance if your derailleur has a B screw.

Bandera

The same as 6 vs. 5, 8 vs. 7, 9 vs. 8 etc.

Having a Range of gearing that gets one over the toughest local climb w/o undue stress and down the other side as fast as one cares to go comes first. Cram as many cogs in between as possible for efficiency and proceed.

"Modern" derailleur systems have worked very well for last several decades: Nothing to see here, move along.

-Bandera

nlerner

You're making those Campy NR mechs work really hard! Set it up with SunTour Cyclone and go with 7-speed.

eschlwc

- it's a new build that came without a chain
- original suntour fw
- sram pc830 chain
- campy nr friction (pat '84 rd)

bandera, what's the "move along" quip about? can i not ask opinion on 6 v 7?

Wythnail

Is it friction shifting? If so as long as the limiters screws are adjusted correctly, couldnt most of those problems like the chain hanging and the noise be potentially because the rear derailer isnt lined up directly on a cog? If youve been riding 6speed for a long time it may take a bit of time to get used to the smaller distance between cogs on a 7speed.

My old schwinn had 6 and my new ride has a much more modern 7 speed cassette, ive been constantly overshifting bothvup and down and having to finetune mid ride to get rid of noise

Forgive me if ive misunderstood, I just always try and eliminate any adjustment errors before assuming that a part is bust or that theres an inherant inability to "get along" with another component.

Bandera

Sure you can, and you got a definitive answer.
More is indeed more. The basic technology has worked perfectly well for decades in many configurations.
This is not a recent revelation, suit yourself.

Were you expecting another answer?
Try this: "In the 80's we were Duped by the Evil 7speed technology which never did work properly and caused cancer in lab rats using indexed shifting."

Nothing to see here, as the police say. Move along.

-Bandera

LesterOfPuppets

I like my Sachs 7sp freewheel better than the Sunrace one I have.

Same for Regina and Suntour 6 speed freewheels I've had better than the 7sp Sunrace.

I'd probably get a 7sp Sunrace over a 6 sp Sunrace unless I needed 6 sp index, however.

eschlwc

^ thanks for the info, lester.

bandera, i'm not looking for snipy opinion. c&v isn't the place anyway.

i assume a lot of c&v folks aren't spreading their 126mm drops because "more is more." nor are a lot of folks "cramming" as many cogs in between for "efficiency."

the setup that sparked my post feels less efficient than my other bikes.

i hope others will give me some good insight without the attitude.

eschlwc

wythnail, yes, friction. and i do find myself trimming the rd a lot more to remove the subtle noise.

when i say noise, maybe that's an overstatement, but it's certainly less quiet than the 5- and 6-speeds on the others. i can barely hear them, they're so well adjusted and require little trimming.

do many of you run 7-speeds on your bikes with 126mm drops? what are your experiences?

Bandera

Apparently you are not familiar w/ the technical history of cycling as a sport.
Cramming as many cogs in between the low & high range for efficiency has been driving (sorry) force in drivetrain development for over a century.

3 to 4, 4 to 5, 5 to 6, 6 to 7, 8 to 9 , 9 to 10, 11 to ? All for the same reason, Range & smaller steps.

And that's how it was/is and will be.

For the 126mm C&V folk (myself included) 7speed worked a treat, with greater efficiency than 6.

-Bandera

SkyDog75

Friction shifters shouldn't care how many cogs are down there, so long as your hands are precise enough to line up the chain on a cog. If your new chain and old freewheel aren't meshing well and you can't trim it out by hand on the shifter, perhaps it's a worn freewheel? Even if it isn't, a newer one with ramped teeth may make for smoother shifting. I've had pretty good luck with newer SunRace freewheels. I'd feel comfortable suggesting one as a replacement for a possibly worn old SunTour, even though SunTour made some parts that were pretty well regarded in their time.

And like nlerner pointed out, a 28-tooth big cog may be pushing that Campy NR rear derailleur to its limits. A freewheel with a smaller big cog or a derailleur with more capacity might make the system a little happier.

More cogs generally means slightly narrower spacing between cogs, so the trimming needs to be a little more precise. (One of the reasons indexed shifting is widely considered a requirement for 10 & 11 speed drivetrains.) If you're using a worn derailleur, the play in it also might make precise trimming more difficult.

I have bikes running 6, 7, 9, and 10 speed drivetrains. All smooth and quiet.

I don't think it's particularly relevant that only one of those bikes has 126 mm spacing since the shifters and derailleur care about cog spacing, not dropout spacing. I'm running 6 speeds on that one bike, but only because the chain rubs the end of the seat stay when I install a 7 speed freewheel.

eschlwc

well, bandera, at least that last post was straightforward. thank you.

so i should replace the 6 on my moto as well with a 7 to be more efficient?

i know how bandera feels. is this what everyone in c&v land is doing?

AZORCH

I've run seven on a number of bikes, always in friction to the best of my recollection. As long as the chain and freewheel were not worn (and I normally try to replace both at the same time to better ensure they wear evenly), I've experienced nary a bit of chatter. Now, if you're hearing noise between large jumps, that's another matter entirely: that usually requires getting familiar with the space for shifting, and moving the chain from one cog to the next quickly and confidently. Other than these things, I can't think of another issue.

LesterOfPuppets

One thing I like about my 7sp Sachs - No ramps, just a bit of a twist on the teeth. If you're in between gears it's really loud but there's less "in between gears" there. I generally goes kerthunk into the next gear unless you're way off.

Steve Whitlatch 

Some Rd`s need trimming on every shift like the Campagnolo on my latest find. My Suntour Superbe Pro is fast smooth and very accurate in friction on a 7 or 8 speed set up . I hardly ever have to trim a shift. I guess it depends on what you are using.

The Golden Boy 

To my inexperienced mind- that sounds like all setup, not with the amount of gears.

From what I have experienced- I tried running a Suntour Superbe Pro RD on a 6 SP freewheel with a 30T cog. It would go into that gear, but the pulley was riding on the cog, and the B-Limit screw was maxxed out. The published specs for max cog size on the Superbe Pro and Sprint was 26, but I've read dozens of accounts of people using 28s all the time. But 30 was just out of its range.

I guess I'd try a wheel with a freewheel you know is good, and within the ranges of that RD and see how that runs in there.

I really don't believe it's because it's a 7 sp system- it's just the way the parts of your system are playing together.

eschlwc

this may be part of the problem. like i said, this is my first 7-speed. but it's not my first close ratio fw. i had a 6 before like that which worked beautifully.

are all 5/6/7 chains alike in this regard? i'm using the sram pc830 i use on the 5- and 6-speeds bikes.

that's what i'm thinking too. i just wanted some opinions. and i didn't want to jump the gün on removing the aesthetic of the way the suntour fw looked.

i hear ya. i have this rd working beautfully with a 14-28t on two other bikes, but both are 5-speeds. i can't change the make of the rd on this bike -- too much campy on it. but i could go to super record if that might help. that was actually original to it.

is your opinion to try a 13-25t sunrace 7-speed over either a 28t 6- or 7- speed with this particular rd?

Bandera

A) Probably not.

2) Some are "Period Correct" and would not consider using any component that was not OEM, or similarly miserable, on their machine. But they would happily harp on about the relative merits of 6/7 cog drivetrain components that they have never owned or used for quite a very, very, very long time.

iii) Some actually ride old bikes a good bit and modify them willy-nilly to meet their requirements. Who knows what those lads are doing?

-Bandera

eschlwc

lester, those sachs look pricey...

JTTDF

Don't know if this will be any help to you or not. I was running an ultra spaced Suntour Winner 13-24 fw on a Ciocc carrying a Super Record rear derailler. The bike had a 6-7-8 speed chain and it was cog shy especially when shifting down. It would skip a cog in the middle cogs and I would have to shift back up to find my gear. I went to a 9 speed chain and problem was solved. The bike shifts flawlessly up and down now. Might be worth a try.

eschlwc

bandera, the heat may be getting to you. causes a lot of road rage. i lived in houston eight years and saw my share. kinda funny actually.

eschlwc

this is highly interesting. anyone care to comment?

browngw 

This is not going to be a technical comment, but practical none the less IMHO. Some C&V people do not have a requirement for more or closer spaced gearing. Its the top and bottom gears for the type of riding we do that matters. I ride my bikes for fun, old and new, and would not bother changing a 6sp to 7sp if not necessary. Most times I don't care if I'm riding my late model 9sp or my 40 year old 5sp as long as I'm having fun.

The Golden Boy 

I find truth in that statement.