WGB 

I have an SR Semi-Pro frameset. Building it up with Suntour components.

No matter what I do I cannot get the Fd to shift to the large chain ring. Can anybody offer any advice??

I tried two separate cranksets RX-100 and 600 tr-colour, two separate AR front derailleurs and two separate bottom bracket axles, oh and two shifter cables. I removed and re-installed the bottom bracket cups (and tried the two separate axles). I have loosened the H screw to the point (as shown below) that the screw is actually loose.

First photo shows that Fd and the Rx-100 chain set (sorry see it's blurred)
** The space between derailleur cage and chain is actually about a dime thickness, appears I photo'd at slight angle.



Shifter photo is just to show it's cranked down fully




This photo shows the limit screws (the H screw is just sitting there)



This last photo included to show that the space between cranks and BB is small and there is not a large gap. I can measure and see how long the axle is if needed but it looks correct to me.

shelbyfv

I'm no C&V expert but it looks as if the crank is about twice as far from the BB as it should be. Check your chainline to verify.

WGB 

@shelbyfv

i just checked the crank and the lock nut is fully inside Not sure how to move in tighter? Believe me I'm not questioning your answer but seeking a suggestion on how to proceed.

Unsure if would've had an affect but I'd originally installed a 6 speed corn cob freewheel and by switching to a generic 5 speed freewheel I can get it to a"almost" shift on its own and with a hand it will go onto the large ring.

Andrew R Stewart 

Besides the mentioned issue of chain line (rings too far out from freewheel centerline) there's the lesser issue of in proper cable routing through the BB cable guides. The frt shift cable needs to be guided by both portions of the brazed on guide. The photo shows a common but wrong routing with only the first lip of th guide engaging the cable. I suspect the cable now also runs along the seat tube's surface to travel to the anchor bolt. This is not right.

Both issues show a basic lack of understanding of how a bike is set up. I strongly suggest a return to your home work on both what chain line is WRT the rear cog set and how BB axle length affects this. When the rings are centered (as close as possible w/o rubbing against the chain stay, maybe only a couple/3 mms of gap) then re route the ft shift cable around the rear portion of the brazed on guide, if the cable is too short get a new one. The cable will likelt almost but not graze the ST's back side. Now is when the fine tuning of a frt der begins. Andy

Mad Honk 

WGB,
Two thing jump out at me in the pics you posted. The derailleur seems to be a bit high,but it may just be the photo angle. the one thing I see that I would change is the angle of the cage. Best installation is with the outer plate even with the outer chain ring. When in that position you are correct that the outer plate should not be any higher than 3mm above the outer ring. Check the cable tension and make sure there is not any slack in it, but you already know that.
I would try using a very light oil on all of the pivot points and hand moving the derailleur to get it moving to maximum inward and outward travel. You can try a canned cleaner like 3M brake cleaner to blast the pivots clean but be very careful with that stuff it can sometime damage paint. Hope this helps a bit. Smiles, MH

WGB 

Andrew R Stewart

I apologise. I corrected the cable before posting the original post but didn't re-photo to show that.

I see what everyone means about the chain rings having to be closer but unsure how to achieve that. I've never had this issue before as every other time the crank set fit correctly. The issue seems to be that I must somehow get them closer when they already seem to be fully seated onto the axle. I should say that there is no play in the BB so that can't be at fault.

This is why I've tried all the other avenues (switching components). I'm wondering now if the BB axle could be the wrong taper?

Mad Honk

I'll try oiling as you suggest with perhaps a penetrating oil like PB Blaster. I might pull the FD back off and clean and oil after.

Wesley.

Mad Honk 

Wesley,
Have you overhauled the BB recently? If so you may have re-inserted the spindle in backwards? That could change the chain line by a few MM and get you to the point you are. It sometimes is very close to same clearances. But not with out checking before re-inserting the spindle you can inadvertently put it backwards and get the few mm in different chain line. My rule of normal is to be able to read the stamping on the spindle to be read by being on the bike. HTH, MH

shelbyfv

Read up on chainline and figure what is needed to make it right. It might be easier to buy a complete cartridge BB of the correct size. They are inexpensive. If this seems too involved, take it to a shop. Edit- plus what he said^^^^

WGB 

The crazy part is I tried two separate axles (spindles) and tried each both ways!

The current axle (spindle) is installed as you said with writing as can be read. It almost repeat almost shifts which is the best yet.

In the past year I've rebuilt 15+ bikes alone and each stripped of every part I could get off. Rebuilding the BB is where I start each one. Cups off, even fixed if possible, clean thoroughly and replace grease and bearings then reinstall and each time the cranks go on and it all snaps back together. My usual issue is adjusting shifting.

If it doesn't work tomorrow I'm going to seek out assistance from someone in the flesh. I'll post the issue when I find it. I'm sure it'll be something stupid I did.....

masi61

In the shifter photo you show the front shifter pulled up, yet the caption says “it’s cranked down fully”. What does this mean?

When you move the front shifter forward all the all the way is there slack in the cable? I don’t think that a SunTour “AR” front derailleur is a reverse spring in it like the old “Spirt” FD does it?

Even though you tried 2 different bottom bracket axles it is possible that they are both too long for the cranks you are using. How much clearance is there between the small chainring and the chainstay before it rubs?