Swap guts of DA 11s barends into 7900 DT shifters?

[Look585]

Does anyone know if the shifting guts from a rear 11s bar-end shifter can be moved into a 10s DT lever (DA7900)?

This post from a few years ago indicated it might be possible in previous generations.

http://forums.thepaceline.net/showpost.php?p=1074198&postcount=14

[thirdgenbird]

I've have seen a bike with 9000 and downtubes. They claim to have done the swap you are suggesting but I've got no details if it was direct. It would be cool if it was.

[rccardr]

I don't think so. Shimano has two kinds of indexing shifters.

One is fully enclosed and encapsulated by the shift lever itself, beginning with 1050 series 105 and extending through 7700 and 7900. Some of these units are indexing only (7900), others are indexing/friction (1050, 1055, RX100, 7700). When you look at the backside of this design, it fits directly into the boss/spacer with no extended tabs. The guts of this design are not removable without performing major surgery.

The other design is completely different (and somewhat less reliable) and was introduced in the Shimano 600 6208 series. It uses a pocket/socket in the lever and a separate removable indexing unit. All of these units can be switched from friction to indexing. All Dura Ace 7400 series shifters (6,7 and 8 speed) work this way, as do the B78 7800 series bar end shifters. When you look at the backside of this design, you will notice six tabs extending from the indexing unit, which mate with indentations in the boss/spacer. This is where the reliability issues come in, because on earlier versions the tabs would brake off over time and eventually indexing function would be lost. Not much of an an issue in the later 7800 bar ends, but a common problem with original 600 shifters.

The conversion is simple and works great-just pop out the guts of one shifter (they literally drop out when tounturn them over) and move them into another socketed shift lever. I have indexed 7800 bar end guts in the Shimano 6208 down tube shifters on my '86 Centurion Ironman, and they work flawlessly with 130OLD wheels and the original Shimano 6208 derailleurs.

Although I haven't examined a set of 9000 bar ends in person, after looking at pictures supplied by Shimano it appears that you could simply mount the bar end shifting unit on a standard boss/spacer on the downtube. Although not as long or perhaps as elegant as a true downtube shifter, it would provide indexed shifting to the rear and friction for the front.

[thirdgenbird]

So are you saying the 9000 bar end guts may fit into an older downtube set?

[gpendergast]

I believe Iran Ryan did this on the Breadwinner B-Road he built and raced (and won) on the oregon outback a few years back.


http://www.cxmagazine.com/winning-gravel-grinder-oregon-outback-winner-ira-ryans-breadwinner

[rccardr]

Sadly, not for mere mortals, although I'd like to see better details on Ira's Breadwinner setup.

Based on the pictures I've seen and this exploded drawing from Shimano http://bike.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/SL/EV-SL-BSR1-3465_v1_m56577569830812351.pdf
it appears that the shifting unit in the SL-BSR1 bar end shifters does not come out of the lever unit.

However, based on the type of boss/spacer used to mount the lever unit in the base mount, I believe the entire lever unit could be mounted to the downtube and utilized as an 11 speed downtube shifter. On bikes with traditional smaller diameter downtubes, this would require the alternate boss/spacer that has a curved back to fit the tube. Larger diameter downtubes (like on Cannondales) could use the flat boss/spacer.

[unterhausen]

maybe I didn't understand the question, but it appears to me that the bar end pod is just a simulation of a square DT boss. That has been the case with the 10 speed bar ends I have used.

Although the 10 speed would convert to friction, which is how I'm using them right now.

[Look585]

Sadly, not for mere mortals, although I'd like to see better details on Ira's Breadwinner setup.


I believe Iran Ryan did this on the Breadwinner B-Road he built and raced (and won) on the oregon outback a few years back.

http://www.cxmagazine.com/winning-gravel-grinder-oregon-outback-winner-ira-ryans-breadwinner

Cool, thanks gentlemen. This is exactly what I'm after. I wonder if Ira would divulge the process?

Ira’s B-Road had a couple interesting personal touches. He gutted a ten-speed down-tube shifter and managed to fit the guts of an 11-speed TT shifter inside it, “to my knowledge, it’s the only 11-speed down-tube shifter in existence.”

[jds108]

If anybody solves this puzzle, I hope they'll post all of the details here. I'd certainly like to know how to do it.