loky1179

I am building up a drop bar mountain bike. I have a pair of 8 speed Sora brifters I picked up on sale a LONG time ago, but the front brifter is only for a double crank. The rest of the drive train is set up for triple.

It seems like it would be easy enough to set it up to use the large and middle ring, but then have some sort of quick release in the cable line to dump it into the granny gear, should it ever be needed.

Something like the Shimano inline quick release - though it is designed for brake cables. Maybe I'll try it, just wondering if anyone else had done this.




Sounds like IthaDan knew of some such gizmo; but this quoted post is from 2012:

HillRider

I remember the part IthacaDan describes but I'm equally at a loss for the manufacturer's or part's name. It allowed you the choice of two chainrings in each position; big and middle or middle and granny.

That brake release you show is likely to allow too much cable slack in the open position to be useful.

IthaDan 

*whew* thank goodness for email notifications. It's been a while.

That was a different critter than what you've linked. I don't know MAYBE the QR you've linked would work, but most likely it'll have too much throw.

I can't remember the name of the thing either, I think I have it somewhere...

Don't forget that *i think* all 7700/6500/5500 generation left shifters are triple- if not, the XX03 model number ones certainly are. Perhaps as a reaction to the widget I posted about 4 years ago which worked to make a triple shifter out of the 7400/6400 (tricolor)/1056 generation shifters.

E: the piece I was talking about in that 2012 post would sit right on the housing stop of the shifter, not inline with the housing.

E2: don't forget that a downtube shifter or a barcon would probably work well for this as well.

E3: I FOUND IT!!!!! Of course Saint Sheldon has an entry about it. It was called the Erickson "Gizzmo". Good luck finding one though.

HillRider

The 8-speed STI's came as either double or triple front shifters and you had to buy the right one. The XX00 were doubles and the XX03 were triples. I had 8-speed 105 STI's (1053) and they were triple specific.

For 9-speed, the left shifters, at least for Ultegra and 105, were both double and triple compatible.

IthaDan 

IIRC, triple front shifters never made it higher upstream than 105, which is why the gizzmo existed- to be able to run 600 (ultegra) and DA.

loky1179

Wow, that's great! I looked as Sheldon's site as well, but I guess I looked for "quick release" or "adapter". Funny that my guess of calling it a "gizmo" is actually in the item name , and there are pictures as well!

I'm sure there is no chance of finding one, especially with triple cranks seeming to be out of favor these days, but it is an elegant looking little device.


I may just try the Shimano quick release. I'm sure I wouldn't have any trim available, and might even have to stop the bike to shift. But if I need that granny gear, I'll do what it takes.

HillRider

Oh no, the 6500 9-speed Ultegra shifters were both double and triple compatible and there was an FC-6503 triple crank and corresponding FD-6503 front derailleur that were part of the group along with a BB-6500 118.5 mm triple Octalink bottom bracket.

I don't know if the Gizmo would even have worked with later 9-speed cranks since their chainring spacing was a bit narrower than 8-speed.

dsbrantjr

The quick release would probably work to drop down into the granny, but I wonder if it has enough leverage to get you back up to the middle ring. This might be especially problematic if you forgot and tried to upshift with your brifter before flipping the quick release back.

corrado33

I'd guess that since the QR would have too much throw that the cable would be slack and shifting up while in the granny would do nothing but take up some slack of the cable. The low limit would hold the derailleur in place. You'd have no trim function however.

dsbrantjr

I was thinking that if you accidentally upshifted then you would be trying to shift straight from the granny to the big ring with the QR; if you tried to downshift the brifter to correct this it might not release cable properly without any tension from the derailleur due to the slack cable. Then you might end up caught somewhere in no-man's-land, gearwise.

CliffordK

Interesting concept.

I have a triple on my "rain bike" which I never get into, but would like it once in a while for towing cargo.

Also, perhaps for a "quad" configuration.

Actually, what would be good would be range.

1/2 vs 2/3

But the adjustment would have to be very precise to get that to work.

IthaDan 

It wouldn't have to be THAT precise. if you relied on the shifter for the largest and mid sized rings, dumping cable tension would leave the FD to sit on the lower limit screw.

The challenge would be to make sure you're not leaving enough slack in the cable that it flops around and hooks on something like a bottle cage, and also whether whatever widget you have inline in the cable has enough leverage to tighten it back up against the FD spring. (already been said, but worth repeating).

IthaDan 

We're missing each other here- I was trying to say that the 7400/6400/1055 generation didn't have triple stis for at least 7400 and 6400. I.e. triple shifters didn't go further upstream than, as you say, 105.

CliffordK

It wouldn't have to be very precise if one just wanted to dump it into low gear, depending only on the limit screw.

But, on the other hand, if one wanted to be able to do low gear range (1/2) vs high gear range (2/3), then the adjustment would have to be precise enough not to leave a lot of loose cable.

HillRider

Yeah, I was thinking 5500 and 6500 series. The 6400 series Ultegra didn't have a triple anything.

IthaDan 

... Which is why we're talking about this doodad in this here thread.

Now that I've stepped back from this a tiny bit, I'm actually kind of surprised to hear there was a double sora. I kind of figured they were all triple.

loky1179

Well, now that makes me want to double check. It is still in the box, so it should be easy.

IthaDan 

I'm sure you know all this, but, in the name of posterity:

Best way to check is to thread a piece of cable through the shifter and use your other hand for tension. relying on just the clicks can be tricky without any load to help things along.

Count the clicks, if it's a triple there might be four or five of them.

Also the model mumber, something like "ST-3XXX" should be molded into the body.

CliffordK

Go Campy...
Most of them don't differentiate between double & triple.

loky1179

Ah, still has the Nashbar price tag on it from 2006.

The Shimano product info included lists two models - ST-3300 (double) and the ST-3304 (triple). Apparently I have the ST-3300.