Do I need more capacity? Mountech or Alpine Gear Tech?
 

Suntour BL FD-1900 in front RD-3300 GT in back.
Chainrings currently 45 / 28, but ordered a 32T so that I use my 50.
Cogset broke a tooth on 16 and added 34 (14 / 19 / 23 / 27 / 30 / 34).

Suntour lists a gear capacity of 18T for the derailleur but I'm having a tough time with the 17T difference I have now, being careful not to criss-cross. Chain gets wedged against the 45 and then kind of torques over the top and falls to the outside.

Am I set up wrong or does functionality just get funky toward max capacity?
For wider capacity, any advice or preference between Mountech and Alpine Gear Tech for a front derailleur?

Slightly unrelated, does anyone know if Suntour ever made a 13T threaded cog for Perfect freehub? according to Sheldon these aren't very interchangeable :(

I'm pretty sure you can fudge a GT caged Blue Line derailleur to handle a 32 and probably the 34.

I would NOT go the Mountech route (the potential for bad is overwhelming with the first generation Mountech- the 2nd generation really just looks like an MII Cyclone with an extra pivot and a really long cage and a really big jockey pulley) and the AG is pretty 'all steel' beastly- consequently- heavy.

I am kinda confused- as the standard "half step and a granny" setup was a 50-45-28. I've used several different FDs and had zero problems.

Make sure your chain is long enough-

If you're intent on changing stuff within that time period- the XC derailleurs are excellent. (the "XC" alone, not "XC Sport"- although the later XC Pro and XC Comp equipment is the most excellent.

I have a triple pulley unit- Pastor Bob actually used my unit on a freewheel with a 38T cog. There was also an excellent "normal" 2 pulley long cage as well. Also- the Mountech front derailleur is one of the best touring FDs ever (as opposed to the RD)- I've had one working on a 26-46-50 triple and it works great on a double as well. And it weighs less than a Superbe Pro. Plus, I don't recall ever seeing a mangled one.

https://live.staticflickr.com/4674/3...5bfdbc8c_o.jpgSuntour XC by Dave The Golden Boy, on Flickr

https://live.staticflickr.com/4627/3...7f1b03e4_o.jpgSuntour XC by Dave The Golden Boy, on Flickr

https://cimg3.ibsrv.net/gimg/bikefor...89df85ef29.jpg

Thanks goldenboy,

I'm mostly curious about front derailleurs, when they list an 18T gear capacity, in the case of the BL, should I actually be able to get that. Having trouble with the 17T gap between my 28 and 45, and I would like to move to a 32 / 50 chainring setup. I ordered an Alpine Gear (AG) Tech Suntour derailleur that lists a 26T gear capacity, so I'm hoping that allows me to cover it.

Is it generally best to stay away from front derailleur gear capacity limits?

Alpine Gear
 

Got the AG Alpine Tech derailleur, it's wider and much cleaner shifting 30/45 than the BL Blue Line was. Stoked! Getting better at keeping the chain on. Thanks again for the help all.

Sometimes three pivots and three pulleys is the answer.
https://cimg5.ibsrv.net/gimg/bikefor...437e62870.jpeg

Wow, what a chain wrap! Great condition too. So this was the Frank Berto influenced, Huret inspired Curse of the Duopar for Suntour?

I guess I’ll have to google pics of that AG? 🙄😉

I’m using lower-level Shimano derailleurs & shifters now, that came on this Miyata, but I kept my first-generation XC derailleurs and Suntour Power thumbies, from my previous High Sierra. 😎

I already put my old cranks on (this bike had 165s, mine are 175s), but still need to lube & clean everything. I have a brand new Shimano UN-55 BB, that I still need to install, and want to start experimenting with chainrings a little.

I have 28-38-48 rings on it now, but I might have a good 44 tooth ring, gotta check the bolt pattern yet. That should work a little better, with my bad knees. 😉

Then I want to find a smaller granny, and play around with those crazy Biospace ones a bit. 😁😎

BTW, I have Miyata dust caps on my cranks now. 😍
https://cimg5.ibsrv.net/gimg/bikefor...635ea2e6a.jpeg

BTW, those cranks in the previous post were the 165s. I’m using Sakae FX for now, which goes well with my Slingshot stem (Sakae- Ringyo MTS-101), which I don’t have a current pic of. 😁😉

Wow! Now I feel like such an amateur mad scientist with my meager 3 pulley Superbe.

https://live.staticflickr.com/65535/...f4b1ec51_c.jpg