cpsqlrwn

Looking into some Shimano down tube shifters and want to know whether Dura Ace 7402 (8 spd), 600 6400 (7 spd), and 600 6401 (8 spd) down tube shifters perform in pure friction mode or produce a click ratcheting action when set to run in friction mode. Thanks for any info!!!

Jeff Wills

Shimano shifters are pure friction in friction mode.

"Click ratcheting" in friction mode is a SunTour characteristic. I'm not sure if you're referring to their "Power" shifters (pre-index) or the "soft index" mode on their Accushift shifters.

JohnDThompson 

With the original SIS index shifters, you switch between indexed and indexed and friction mode by rotating the D-ring on the lever:



There's about 90° of travel between full indexed mode and full friction mode, and if you set the ring in between the two end points, you get varying degrees of indexing, from a pretty solid "click" with each shift to a subtle bump before the indexing completely disappears.

cpsqlrwn

I am wanting pure clickless friction shifting. I read a lot of posts about shifters that have both indexed and friction options but the friction option has ratcheting characteristics which is what I want to avoid. Thanks for your post. I picked up a couple of these and didn't want to find out after assembly that it wasn't pure friction.

cpsqlrwn

Good to know. Didn't realize you could ride in a middle position. Always thought it was one or the other. Thanks for the post.

RobbieTunes 

You want "quiet friction," and they are, in full friction mode.
If you need a set of shifters, you can PM me.....

Bianchigirll 

cpsqlrwn

Preaching to the choir, Bianchigirll. I have those on a 7 speed Chorus bike replacing the Campy shifters and I have two more pair sitting on the shelf, one a very nice band mount. They are definitely the best pure friction shifters. A joy to use with great tension and perfect touch to the shifting, both up and down. Just wanting to try out these Shimano first on a tri color build and a Dura Ace build. I kinda like the index option for a change of pace from time to time. I will be surprised if Shimano's friction shifters do not perform well.

ThermionicScott 

I might have used the term "micro-ratchet" incorrectly in the other thread... rather than 5 or 6 or 7 "big clicks" in index mode, the Shimano friction mode has many tiny soft detents which help it to stay put. They perform well, but if you desire smooth clickless shifting, I'll be the first to say you might not like them.

cpsqlrwn

Your post is one of the reasons I asked this question. Might be we need some clarification. Several posts here indicate these are true friction in friction mode and that was my understanding previously although I do not know Shimano well at all. . Are you saying that when dialed all the way to full friction, these shifters have a slight detectable (no sound or pronounced feel) backward tension (what you are calling detent) that improves cog transfer up and down in the rear or are you saying that while this action might not be considered ratchet style shifting, this feature is quite noticeable and produces distinct functional limits (with low audible clicks) between gears that minimize any required shift lever management and must be passed through to move more than one gear at a time? In other words, not a clean movement of the shifter over more than one gear. I am a little confused at this point. Thanks for the post.

ThermionicScott 

Yeah, "ratchet" was a poor word for me to use, as it can imply that the mechanism catches in one direction and releases in the other (like the SunTour front shifter on one of my bikes.) Let's see if I can find a better way to describe it.

With a lot of home and car stereos of the last few decades, you can feel a notchiness to the volume and tone knobs. Lots of tiny clicks, sometimes accompanied by a number on the display counting up and down. It's not resisting you more in one direction than another, but you need to move the knob through a bunch of little detents to go louder or softer. That's how the friction mode of Shimano's rear shifters feels to me. I just threw one of my 7-speed bikes on the stand, and it took about 4 tiny detents to shift from one gear to the next. I haven't taken one of these shifters apart, but it wouldn't surprise me if the index/friction switch just selects between a gear with big teeth for index mode and another gear with much smaller teeth for "friction" mode.

You'd get what I'm trying to say instantly if you had it in your hands.

cpsqlrwn

Thank for the quick reply. Two thoughts come to mind. First, it doesn't make much sense that Shimano would have engineered a gradual reduction in the click mechanism all the way around the selection dial on the shifter (per one of the responses above) without taking it all the way to a pure friction mode at the stop. Possible, but it doesn't make sense to me. Second, your 7-speed shifters appear to be 6400. Perhaps the tri color 6400 7-speed shifters function differently from the 8 speed Dura Ace 7402 shifters and the 8-speed tri-color 6401 shifters. I understand exactly what you are saying about the detents on the stereo knob. I wouldn't want any part of that on a downtube shifter. At this point, I'll wait for more input or just ask my LBS about it. Thanks for your explanation.. Appreciate it.

Jeff Wills

I've had Shimano shifters fall between the "index" and "friction" positions and they don't work well. The friction tension changes and the index positions don't index. It's my opinion that Shimano designed them to operate correctly in the either the "index" and "friction" position and anything else is not correct. In fact, there were a lot of reports of the 9-speed indexed bar-cons failing due to broken mechanisms when the switch fell between the two positions.

cpsqlrwn

I appreciate all the responses and input to this point. I am going to proceed with the Dura Ace 7402 build and post back the results on the friction sometime this coming week. Thank you very much and any additional info would certainly be welcome.

RobbieTunes 

If you need 7402 brake lever parts, I have a bag, including hoods.

cpsqlrwn

Thanks, Robbie. You the MAN!!
I'll let you know if I need anything.