stormed

I have a Dura Ace 8 speed 7402 rear Derailleur and need some shifters for it. I already have a pair of SL-1055 which are 7 speed. Are these compatible?
I am not fussed if I use 7 speed shifters and cassette and just have 7 speeds.

Bianchigirll 

I don't think so. I believe the 7&8 speed DA only worked with DA shifters either 7 or 8 DTs and the 8spd Brifters.

You can always try it, but IIRC there was something different about the DA that shipmano tried to keep users from running the DA RD and 600 or 105 shifters.

b dub 

If indexing is not important you're fine.

rccardr 

BG, you are correct. with regard to indexing, 7400 series shifters and RD's are best compatible with each other and not any other Shimano series shifting equipment. Sheldon has a workaround on his site but in my experience it doesn't yield the same silky shifting feel as DA on DA. If you're OK with friction, then they work just fine with, well, anything.

stormed

Why does it matter though, the rear mech itself isn't indexed....

LesterOfPuppets

I use a 7402 w/ 7-sp Sachs freewheel and Exage 300EX shifters in index mode, works like a charm.

stormed

This is it. I seem to be hearing some people saying absolutely positively do not use anything other than DA shifters, then others, like the above poster, saying the 105 shifters are fine to use with an 8 speed 7400 derailleur. This noob is confused...

Bianchigirll 

The angle of the rear derailleur (RD), how it moves along the pulleys is slightly different than other shipmano derailleurs and so the indexing detents in the shifter are correspondingly different from other shifters.


Again this was another one of shipmanos many gimmicks and trick to ensure everyone used all shipmano on a bike and more importantly all DA. A lot of bike companies used to use say a full 105 group but upgrade the RD to 600 to make the bike look better than it was. shipmano tried very hard to discourage this and making the Dura Ace RD different was part of this.

STI, or shipmano total integration, which most people only think of as 'brifters" actually started with the rise of mountain bikes. shipmano started mounting the shifters to the brake lever to keep bike manufacturers from speccing shipmano derailleurs and shifters but other companies brakes and cranks.

SLR was another move. Everyone thought the return spring in the lever was a great idea and gave the lever a crisp snap when released, but they also lightened the spring in the caliper so mixing a shipmano brake with any other brand of lever created a sloppy feel.

shipmano was very devious about marketing and hiding technology as a method of controlling the market.

Bianchigirll 

What is the difference between the 300EX shifters and the 105 ones?

fietsbob

this.. friction shifers are just needing a bit more rider involvement , indexing helps the non cyclist get riding with out much mechanical involvement from the rider.

LesterOfPuppets

No idea. I only have 8-sp 7402 on hand besides those Exage 300EX I have on the Scapin. I have a right side 105 DT shifter, but no sense comparing that one

LesterOfPuppets

Might as well try it and see. All you got to lose is an hour or so of tinkering and test riding.

stormed

Yes, I suppose so

Dave Mayer

Nope. Wrong assumption. Your 7402 rear derailleur behaves differently than any other derailleur in the Shimano lineup, before or since.

For each amount of cable travel, it moves across the cogset a greater distance than other Shimano derailleurs.

Why should rear derailleurs behave in the same way? Certainly Campagnolo and SRAM derailleurs are different, and different generations of these brands behave differently. In fact, if anything, the manufacturers should be motivated to build incompatibility into their derailleur designs.

To be precise, your 7402 rear derailleur travels about 10% more than other Shimano derailleurs for each 'click'. So you'll set up the system, and it may work for a few cogs, but eventually the cumulative error will cause random clattering and missed shifts.

You could use some Shimano 9-speed shifters with your derailleur to index on a Shimano 8-speed cassette, but apart from this kludge, your 7402 is somewhat of a paperweight.

kunsunoke 

I have one bike with that derailleur - the Tommasini - and it uses nine-speed Dura-Ace SL-BS77 bar-end shifters. My other dura-ace bike (RADAC) has the RD-7401 derailleur, same shifters - same compatibility. Indexing works quite well - and both bikes have eight-speed HG clusters. You just lose one shift is all.

Dura-Ace brifters or downtube shifters will work, as long as they're from the same era. I wouldn't bother with the other shifters, though, unless you enjoy tinkering with alternative cable routings.

Shimano Dura-Ace Compatibility

Bikedued

Shipmano? That's definitely a new one on me. What does that mean? A clever disguise for a T?,,,,BD


The sad thing, is that proprietary must have been a good idea, because every brand is now. Nothing works with anything it wasn't made for.

stormed

If I swapped to 7 speed (7401) downtube shifters and matching cassette, and kept the 8 speed (7402) rear derailleur, I presume the indexing and travel be correct then, only with just with one less gear obviously? This way it would all be 7400 series; surely the only difference between the 8 speed and the 7 speed 7400 series Dura Ace shifters is the amount of 'clicks'?

SJX426 

@stormed - well maybe from an operational perspective but there were some significant changes between the 7 and 8 spd hubs and cassette. The 7spd is unique in this area and is to be avoided unless you already have one! Of the two, the 8spd is the more desirable one especially from a maintenance perspective (parts availability), IIRC.

Fred Smedley

No the spacing on 7 speed Shimano is 5.0 mm , the spacing on 8 speed Shimano is 4.8 mm. Campy 8 speed is 5.0 mm though .

Rear Shifting | CTC