Shimano Bar End Shifters

[velorog]

I am planning to buy some 9 speed bar end shifters as I'm fitting 8 sprockets from a 9 speed cassette to a 7 speed hub. These shifters often appear on eBay as 8/9 speed compatible. Currently there are some listed which are marked as RD7700(9s) or RD7400(8s) compatible. My understanding of Shimano rear mechs is that apart from 10 speed they all have the same cable pull ratio. The variation in shifting for different cassettes is achieved by the shifters pulling different amounts of cable. Is this assumption correct and if so how do these shifters index on both 8 and 9 speed.

[CREPELLO]

You need 8 speed specific shifters for an 8 speed cassette. I've never heard of 8/9 speed compatible, although they're compatible in friction mode of course.

[531colin]

I'm sure the bar end levers would be compatible with all sorts of R mechs.........but its the lever that does the indexing....
An 8 speed lever will index 8 sprockets with a rear mech. marked as 7,8, or 9speed...?
Can you give us a link to the actual advert, I think its nonsense, probably.

[velorog]

Have a look at

http://www.ebay.co.uk/itm/shimano-bar-e ... 1321wt_936

This is not the first time I've seen shifters claiming to be 8/9s compatible.

[Brucey]

Dura-Ace 6,7,8speed had a different pull ratio to later Dura Ace. They changed in 1997 when 9speed came out, so that Dura-Ace then used the same pull as other shimano stuff.

All Shimano 9speed is the same rear mech pull ratio (MTB, Road, Dura Ace) . All Shimano 10speed road is the same pull as nine speed. It is also the same pull ratio as all Shimano (non-Dura-Ace) 6s,7s,8s,9s.

A lot of 'N' speed thumbshifters etc have a 'hidden click' which allows the use of N+1 gears. Some even have N+2 hidden away inside them, accessible with a little work ... I don't know if Dura-Ace 8-speed ones are like this or not, but because they use a different pull ratio, Dura-Ace 8s shifters actually pull almost exactly the same amount of cable per click as Shimano 9s shifters do.

So the bottom line is that a Dura-Ace 8s or 9s bar-end lever should work an 8-from-9 setup, and Dura-Ace 8s bar-end shifters may also work 9s systems if they have a 'hidden click'.

More info on pulls etc here (although CJ has assumed that no-one will want to use DA shifters, you can infer what they do from the other values in the tables)

http://www.ctc.org.uk/desktopdefault.aspx?tabid=3946

cheers

[deliquium]

Shimano bar end levers are marked with model numbers under the grey plastic covered actual moving lever part

SL-BS50 is the original 7 speed (and confusingly sometimes later 8 speed !)

SL-BS64 is definitely 8 speed

In as much as I use both and know they work.

Don't know about 9 speed - that's too many sprockets for me

[531colin]

They are off a 9 speed Dawes Galaxy twin he bought this spring, so we don't have to worry about pre 1997 Dura Ace, really. (or Dura Ace at all!)

The really irritating thing is all my shifters are marked with how many speed.......in this photo the ring you use to change from index to friction could be covering it.



I don't know why they are marked with nonsense about R. mech. compatibility...to be sure to be sure, you could ask him to photo it with the ring flipped the other way.

[deliquium]

A quick Google says that Shimano 9 speed bar end levers are marked SL-BS7700 - again like previous models - under side of both shifting levers - stamped in the grey plastic lever cover.

Too late in the night to go down to the bike shed to photograph

[velorog]

Thanks for the info Brucy.
If I understand your reply correctly the RD7700(9s) compatibility will pull 2.5mm of cable and will be will work with all modern mechs (except 10s MTB) and that the RD7400(8s) compatibility pulls the same amount of cable but will only work in 8s mode with old Dura-Ace. I've just found that old DA had a group reference of RD7400. This dual compatibility is very confusing and should be ignored as it will only work for 8s with obsolete mechs. These shifters should be regarded as 9 speed only.

[Brucey]

Thanks for the info Brucy.
If I understand your reply correctly the RD7700(9s) compatibility will pull 2.5mm of cable and will be will work with all modern mechs (except 10s MTB) and that the RD7400(8s) compatibility pulls the same amount of cable but will only work in 8s mode with old Dura-Ace. I've just found that old DA had a group reference of RD7400. This dual compatibility is very confusing and should be ignored as it will only work for 8s with obsolete mechs. These shifters should be regarded as 9 speed only.

For most practical purposes you have a point, but.... the '8s compatibility' is still valid for later DA 9s (and I think 10s) rear mechs, too; the cable can be mounted in an alternate fashion on the rear mech to give the 'old' DA pull ratio. Shimano designed it that way and the service instructions include this feature.

The same thing (which is a sort of reverse Hubbub) works on many other mechs, too. I have some old SunTour Superbe Pro index shifters (same pull ratio as DA more or less) and they work a 7s index setup using a shimano 8s MTB rear mech. The only thing that worries me about this arrangement is that the cable rubs worse than normal in the rear mech, and that is saying something; it normally rubs horribly at the best of times anyway.

cheers

[byegad]

You need 8 speed specific shifters for an 8 speed cassette. I've never heard of 8/9 speed compatible, although they're compatible in friction mode of course.

I have and it is labelled on all three of my bar end shifters. So it should work.

[531colin]

Its as easy as that, for all standard, current applications.

the lever is this part No.