jake_b27

Hello all, I'm new to bikeforums and I have a question. I have started riding my mountain bike more lately and I am not happy with my Front derailleur. I am somewhat picky about how my bike shifts and the performance I am recieving from my Suntour front derailleur is poor. I am thinking that I would like to change it, however I don't know which other derailleurs would work because my local bike shop seemed to think it was tricky to swap this item. I am currently riding a Jamis Durango 2.0. The bike was new in 2007. The componentry consists of Shimano Deore rear Derailleur, Shimano Deore shifters, and A Suntour XCR FD-XCR504. It also is a 27 speed with a triple up front. I have found the specs for this particular Suntour front derailleur and it is a top pull, and 31.8mm tube size. I do not however know if this is a "down-swing" or "top swing" style due to my lack of knowledge about derailleurs. This seems to be something I need to know for picking out a Shimano product. Here is a link to the spec sheet that I found in Suntour archives. https://www.srsuntour-cycling.com/SID...detail&tnid=69 I have done a fair amount of research and can't seem to figure out weather this will easily swap for a shimano product. I don't even know what quality this particular piece is. I have done a good amount of adjusting to this part and it just doesn't like to shift. I would really like to make the front derailleur match the rest of my componentry and get a shimano part but I don't know if I am opening up a can of worms that will be more headache than its worth. I'm willing to consider higher end parts as well if they are needed for the conversion (I'd even go XTR if needed). I just really want a part that will shift at least as smoothly as the rest of my Deore components.

tellyho

The problem is almost certainly not with your derailleur. Front derailleurs are pretty standard - as in, you don't get a whole lot more from an XTR level than you do an Altus level, other than lighter. Before you buy a derailleur, try new cable and housing, and check out your shifter. Also clean off your FD (if it's not already) and oil the pivots.

If it's properly installled and spec'ed for your drivetrain, the above should solve any shifting problems you may be having.

surfengine

what is the problem are you having with the FD?
sometimes it doesnt shift?
it shifts the chain off the chainring?

jake_b27

My problem is that when the derailleur is on the middle chainring it will only shift up to the top chain ring if you hold the shifter in. It also pretty much won't shift into the bottom chainring. I've had it adjusted at the bike shop a couple of times now and I'm just not satisfied. It seems to work ok when I'm there at the shop, but as soon as I hit the trail it fails to work properly. I'm frustrated, but maybe its more of a "get it fine tuned and stick with it" situation.

Panthers007

Adjusting an already-installed FD generally fixes one problem - and creates another problem. Here is my cut & paste solution for ALL FD problems:

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.

Al1943

Sounds like the problem is with the shifter or cable and cable housing. I doubt that there is anything wrong with the derailleur.

fuzz2050

+1 on cable tension.

jake_b27

Well, it sounds like I need to tinker some more with the FD that I have. I will use everybody's advice and see what I can come up with. Thanks everybody

dabac

Shifting a bike isn't like flipping a light switch, even if we would like it so. Sometimes when shifting to a bigger sprocket it really helps if you overshoot just a little bit when you push the shifter

Well, for that part there's not much point in blaming the operator , although it does wake questions about whether you're trying to shift under load(which is always more hesitant) and whether you're cross chaining or not.

jake_b27

Hello all,

I thought that I would give an update on my progress with that darn FD. I basically took all of your advice and started to tinker away. I now have a very good understanding of how the FD works. To make a long story short I believe the main problem was actually the cable housing. It was so tight that the cable could not to back through the housing when I downshifted into the bottom chainring. In my trying to fix this issue my self I ended up ruining the cable. I took the bike to my local dealer and he installed a new cable and cable housing. He also told me that the FD had been installed a little bit sideways (it came that way new because I haven't messed with that). He also told me that they have a lot of complaints about this particular FD and that he's not sure why they didn't use a slightly better part because the rest of the bike they used better parts on. So, long story short, the FD now works as I took it out and put some miles on it right awat. The FD doesn't work quite as I would like it to, but at least it works now. Thanks for everyone's help.