Don in Austin

This why my "road" bike has flatbars and MTB trigger shifter drivetrain.... I have lots of experience building bikes and setting up drivetrains, but essentially no brifter experience. Helping a friend who just acquired a 50cm Trek 1500SL with 650 wheels, 3x9. The front shifter was not working at all with the derailleur rotated about 20*! I got it parallel, I moved it up slightly because until I did the chain jammed 2-3. Set front and rear and everything is fine up and down except small to middle either doesn't shift up or tosses the chain. 2-3, 3-2, 2-1 are rock solid. When I ride it the 1-2 shift fails maybe one out of ten times, when the new road bike owner rides it, much worse. I have to make a very deliberate effort to back off the pedals and push the brifter HARD all the way over. Thjis is regardless of where the chain is sitting on the back. I can make it work, but it makes me think "flatbars for me!" We ran out of time and I have not inspected for chain wear, or taken a close look at the crankrings, but the bike does not appear to have been ridden hard or many miles.

When I get the bike back advice on what to target next appreciated.

Don in Austin

stevoo

Ran into this with Shimano middle ring before on a 9-speed road triple. The middle ring was not happy with the smaller granny ring I was running. The chain would actually spit off towards the frame on the granny to middle ring upshift. The bevel on the Shimano middle ring was the challenge/opportunity. Changed the middle ring to a nice ramped and pinned TA Specialties ring. Fixed the issue. Any other ring that has a nice flat side that has milled ramps and pins should fix the issue.

When carefully watching what was happening on the stand you could see how the bevel was the culprit. Also saw this with Cannondale house brand Coda middle ring 9-speed on another bike. It was even worse. Changed that one to a Race Face ramped and pinned and all was perfect. The Coda also had a similar big bevel like Shimano. It was actually more pronounced and it worked even worse.

Just my experience your results may vary.

fietsbob

What is the terrain like where and when you are trying to make the Big Upshift ?

this a 30 to 39t, or 30 to 42t? or what?

Don in Austin

I was rushed working on this during spare time at my real job, and never checked the tooth count, but I think it is 30-42-52. The shift is crappy cruising on level ground, even.

Don in Austin

Don in Austin

Thank you! When I get my hands on the bike again, I will take a close look at the middle ring.

And, yes, the chain does sometimes fall of to the inside.

Don in Austin

fietsbob

You let up on the pedal force for the shift?

Don in Austin

Yes and still doesn't shift half as well as any of my bikes with MTB drivetrain.

fietsbob

I'd need to do the work in the 1st person ... so I'm done..

new cables housing, clean and lube etc. ... good luck ..

HillRider

Shimano 9-speed triple front brifters have 4 positions. Starting with the chain on the big chainring: One click from big to middle. Second click trims cage toward inside of middle. Third click shifts to granny. Coming back up requires a small click to move the cage a bit outward then a second full sweep of the outer lever to complete the shift to the middle ring. Try it that way

cycle_maven

I've never found that necessary on my 105 triple front shifter- from the small, a sweep clicks twice to get to the middle ring which puts it into the outside of the middle ring, then twice more for the outside of the big ring. Minor clicks move it to the inside of the middle and outer rings. So basically, sweep once for middle, then again for large. Half-click down for inner. It's kinda hard to do the half-shift when shifting up, and even if you do, the next sweep puts it into the outside of the middle ring anyway.

I have the same problem on my Specialized crank, dropping the chain 1/3 of the time when upshifting small to middle. The bike was shipped from the factory with a "dog fang", probably because this was endemic to those cranks. My Ultegra crank shifts perfectly. So, a lot of the problem is the design of the ramps and pins. Also I've heard that the 52-42-30 cranks were worse for this; that's one of the reasons road cranks are now 52-39-30.

My suggestion: Get a new crank. Even the cheapest Sora stuff is pretty good these days.

Al1943

As HillRider said, there are 4 main position. From the small ring to the middle ring requires a single big shove to the 3rd position. The 2nd and third positions are used for trimming the middle ring. The 4th position is for the big ring.

If the cable attention is adjusted to tight it can cause the chain to fly off on the frame side of the smallest ring. And the FD should be as low as possible without jamming the chain between the middle and big rings.

The original 9-speed rings are a matched set, 30-42-52. The middle and Bing rings are ramped and pinned. You won't find any aftermarket chainrings that will shift better. A Shimano 10-speed 30-39-50 may be better but may require a matching FD to optimize shifting.