supras2kracer

This is a pretty weird problem and doesn't make sense at all.

My Front derailleur shifts fine when the bike is hung up on my work stand. When I stick it on a trainer or take it out to ride the FD won't shift into the big ring very well. It takes an extra amount of force to get the shift lever to click into the next gear. Most of the time it just clicks, makes the chain rub the derailleur and doesn't actually go into the big gear. I adjusted all the limits and cable tension properly.

Again, this only happens when there's resistance on the rear wheel. It works just fine when it's on the repair stand and the rear wheel is spinning freely with no resistance.

Any ideas?

Panthers007

Idea #1.

https://www.parktool.com/repair/readhowto.asp?id=75

Idea #2.

https://bicycletutor.com/adjust-front-derailer/

I'll give you a hint: Always take off a FD's cable and reinstall the FD from scratch. If you try to fix 'em still attached - you may solve 1 problem, but create 2 more! Reinstalling the FD from the beginning is the easiest way to go. Really! And the fastest.

Kimmo 

How old is the bike?

I'm guessing it doesn't have those little shifting ramps riveted to the chainring...

They were a nice invention.

Panthers007

Before you get confused by a barrage of questions from the Squirrel-House, here is my generic, one-size-fits-all answers. Feel free to copy this:

____________________________________________________________________________________________________ _____________________________________

Take the cable off the FD. Now install it from scratch as per Park Tool Repair:

https://www.parktool.com/repair/readhowto.asp?id=75

And BicycleTutor:

https://bicycletutor.com/adjust-front-derailer/

When you have it properly trimmed and are ready for the cable - a new one wouldn't hurt - you want to pull the cable taut - not too tight, taut. Then apply 48 to 60 inch-pounds to the pinch-bolt. Then put it through it's paces.

It's always easier and faster to install a FD from square-one, than it is to make adjustments with it already attached. This tends to fix one thing - while throwing another out of kilter. Start fresh. You'll get it.

Adding a barrel-adjuster can solve many problems with the cable coming loose - or being too tight.

supras2kracer

Ok, I'll give that a shot. Thanks for the simple tip!

To answer the other question: it uses an FSA SL-K double. The components are microshift arsis.

supras2kracer

I reinstalled the FD but the same thing happens. Shifts perfectly when the bikes hanging up but when I jump on it I can press on the lever all I want and it won't shift. The FD won't even move far enough over for the chain to jump up. It just rubs the inside of the big ring.

This makes no sense. Could something with the rear wheel be making the chain harder to push over? It's a 10 speed 105 cassette with 105 chain.

Al1943

Also check the chain for stretch.

supras2kracer

Chain appears to be fine. I guess I'll just take the bike in tomorrow and see if the pbk mechanics can fix it. I think it may be the lever, it clicks 3 times to get into the big gear but only once to go back down to the little gear. It didn't used to do that. The bike got knocked over the other day but I wouldn't think that would be strong enough to screw up the shift lever.

Thanks for trying

Panthers007

This may be a stretch in and of itself - but could your rear wheel become loose in the dropouts and cause the tire to rub on one of the stays?

This is really odd. It only does this when you are applying pressure? Something has got to be rubbing something. I'd check it again on your repair-stand. Get on it an pedal gently while trying to shift from small to large up front. Then if/when this happens - stop and get off the bike. Now - got a flashlight? - take a look to see if the rear wheel is rubbing something.

EDIT - Which side did it fall on? Derailleur-side or non-drive side? Another candidate I'd look into is your gear-shifter.

tonski 

I had this issue with FSA crank earlier this year. When I finally did get the chain to the big ring and shifted back down the chain would fall in between the rings. Yes, between. I measured the chainring thickness with calipers and the distance between the rings was quite a bit bigger than my DA crank.

So, what kind of derailleur is it and are they stock chainrings?

Edit: The problem I mentioned above had the same symptoms, shifted well on stand - like crap off of stand. It was also solved by putting my DA chainrings on the crank.

Panthers007

That sounds like an excellent option to try. Thanks for your input here. Do you, OP, have an old bike you could experiment in swapping out the cranks with?

In any event, get some good pictures of the FSA and derailleur and such. I, too, recall some nasty words bouncing about regarding FSA cranks.

tonski 

Chainrings should suffice if they're the same BCD, the FSA spiders seem to be fine. My old man had a lot of troubles with his FSA cranks too.

Jtgyk

Are ;you shifting at the right time?
I had much the same trouble until listening to a conversation at the LBS about shifting and force on the cranks.
The advice was to spin up to where there was very little pressure on the pedals a bit while shifting up. Or, if you were almost there, letting up on the force on the pedals for the shift to the bigger ring.
I tried it on my way home and had no problems with shifting afterward. If I try to shift while mashing...it's back to the original problem.

tonski 

If you're mashing you shouldn't be shifting up in the front.

The solution to the problem you mention above is adjusting the derailleur or better planning (or get rid of SRAM Red junk, the other 2 are acceptable).

Kimmo 

If your big ring has tricky bits hanging off it, this is pretty weird... maybe you just need to allow more movement in the FD cause it's only just changing under no load?

supras2kracer

Well, I've been using the set up for a couple months now and never had this problem but then again I hardly ever shift down into the little ring. I'll take the bike out right now and try what you guys recommend.

supras2kracer

Turns out that I'm a moron and you guys were right. The bikes fine but my common sense not so much haha.

But maybe I do have the same problem as you tonski. It doesn't fall between the rings, however.
The chainrings are stock and the derailleur is called forte microshift which is just a rebranded microshift arsis (more info on that on the web). It works just like the shimano components.

I can't figure out how to post a picture but you can see the derailluer here:https://www.flickr.com/photos/30297767@N07/4106858582/


Thanks for the help everyone!

tonski 

Is that one of those ebay frames? How do you like the lateral stiffness at the BB - I found the one I tested to be absolute ****.

Don in Austin

The closer the derailleur is to the chain rings the more positive the shifting. Move it down until it rubs and back it off to minimal clearance. This can make a BIG difference.

Don in Austin

Panthers007

The above statement ^^^ is also clearly explained in both the Park Tool site, and BicycleTutor. A triple crankset may require a clearance closer to 2mm, rather than 1mm, between the FD cage and the large chainring.

This is correctly adjusted for this particular set-up. Note the FD is in the middle of a shift - see the clearance? Very, very close. Worked well on this. Your mileage may vary:

tonski 

He already said he fixed it..I'm just curious how that frame is working out for him, stiffness wise.

Panthers007

I know. I was addressing the person above with the BOLD print. As well as posterity.

Woof!

tippy

You're part way there. Post the image somewhere that is accessible via the internet (has a URL to the image). Your above posted link works just fine. Follow the link and right click on the image and select "properties". The prompt will display the address/url to the image itself (not the page that contains the image).
Copy the image's address/URL. If you just paste the address/URL in your BF post, BF will automatically "sandwich" the URL between [ url ] [/ url ] tags, which ends up looking like this:
https://farm3.static.flickr.com/2548/...68de8a4ae8.jpg This is still a valid link and can be followed if clicked but if you want to actually see the image in the post (instead of a link to the image), do this ...

Instead just open the "Insert Picture" icon above the message box and paste the image's URL in the prompt and "ENTER". BF will "sandwich" the URL between [ IMG ] [/ IMG ] tags instead of the URL tags. You could also edit them yourself after posting if you want to do it the manual way.

Once the URL is between the IMG tags, the result looks like this: