goldfinch

Big ring has 42, small has 24. So, what do you think the odds of a bottom pull derailleur working? I can go to the coop and try some used ones out, so I don't have to order without trying.

Retro Grouch 

Cable pull direction isn't a factor. Since your biggest front sprocket has only 42 teeth, you'll definitely want a mountain bike style front derailleur. They come in both top uull and bottom pull varieties and some can even be set up to work either way.

Bill Kapaun

"The front derailleur he put on will not go low enough, the cage hits the frame."

Maybe I'm misunderstanding the problem?
I'm assuming the "tail" of the FDER is hitting the chain stay???
A 48T large ring will have about 1/2" larger radius, thus not have to go down as far.
However, that raises the issue of a ring possibly hitting the chain stay if the proper length spindle is used.
Chain stays can have different curvatures that require a certain range of ring sizes.
Possibly, your bike is simply not suitable for a triple?

goldfinch

I wanted to post some pictures but the dang tool is not playing nice.

Retro Grouch 

It'd be nice to have a picture wouldn't it.

I'm thinking OP is trying to make an old road derailleur, that was maybe designed for a 42t small ring, work with a mountain triple with a 24t. The tail of the derailleur is going to stick back all wrong.

goldfinch

Did this picture go through? If so, I will try more.

goldfinch

Sorry about all the glare. Bright sun this am.

Bill Kapaun

IF you can try different RDER's at the Co-op, you might look for something with a physically shorter cage that will slide down more.
The curvature (as far as I can tell) doesn't seem "inappropriate" for the ring diameter.

Another aspect is some are designed for different seat tube angles. Typically 63-66 or 66-69 degrees.
I'd suggest you download the "big book" here-

Line-up chart - Shimano Product Information Web

Click on mountain and then FDER and you can see the various little "quirks" between them.

goldfinch

Still a worry. Going to the Coop on Monday and experimenting.

goldfinch

Went to the coop and put on a new cartridge bottom bracket with the appropriate spindle length. Now a front derailleur will move over to the biggest ring. The rings clear the frame fine. But, I spent an hour and a half pawing through front derailleurs, trying to find one that would not hit the frame and had the small clamp size I needed. I think I have one, a bottom pull, but I didn't have a chance to put a chain on to test it. It is tight so we will see. I still need to get stops and guides so it will be a bit before I know that I have a decent working bike.

Bill Kapaun

Many new Shimano FDER's come with an oversize clamp with a couple shims for smaller tube sizes.
They are somewhat "elliptical" so most of the excess space is taken up on the NDS.
There "should be" excess shims floating around out there....

goldfinch

Yeah, I put one of those derailleurs with spacers on my husbands LHT. No spacers at the co-op so I thought I would give what they had a try.

goldfinch

Still working on this bike. Gearing all works. Brakes don't. I found some single pivot side pull brakes. I put on some cantilever brake levers I had around, ran one long stretch of housing, and the rear brake just will not work. It will not pull the cable. There are no cable stops and I was doing a long run, coming up on the brake from the bottom as the frame is a mixte frame. I didn't do the front, a bolt is missing that I would have to track down.

How can I tell if I am doing something wrong in the set up? Should I buy some new but cheap long reach side pull brakes? Maybe double pivot? Or strip off what I have done and toss the dang thing in the trash? I note that most side pull brakes, and all the ones that are double pivot, have the cable enter from the top with no way to swap the top for the bottom. My cabling will be convoluted if I have to come from the top. Maybe use some brake noodles to try to make it work?

BTW, I looked at seeing if I could do center pull brakes but there is no way to run them because of the design of the bike. They have to be side pull. The bike looks much like the one in this post and this is how I cabled the brake:https://www.bikeforums.net/bicycle-me...l#post17434044

nfmisso

Hi Goldfinch;

For the front, go with a good dual pivot side pull - the front is the most important brake.

For the rear, stick with the bottom entry side pull arrangement you have. Diagnosing the issue: 1st disconnect the cable from the brake; does the lever pull the cable through the housing freely with the current path of the housing? Can you squeeze the brake together with your hands, and confirm that the pads hit the rim where they are supposed to, and the brake returns properly when you let go?

Also double check that they are cantilever levers and not linear pull (V) brake levers. Actually should not make any difference at this stage.

goldfinch

The lever pulls the cable through the housing just fine. The brakes don't seem to operate well when squeezed. I'll look again tomorrow. Maybe I'll try swapping the front and rear since I might replace the front anyway. The levers are cantilever levers.

goldfinch

Brake squeeze and release easily when cable is off. Cable moves through housing easily (housing is new) when you squeeze the lever without the cable attached to anything. But, if you run the cable through the adjuster/stop that is on the brake then it runs rough and hard, even a bit if the cable isn't tightened down at the bolt. Swapped the front adjuster for the rear. Same issue. Tighten the bolt and the brakes barely move.

Solutions? New brakes?

EDIT: I tried hooking up the front, no grinding but the brakes are too wide for the bike rim and don't meet where they should. For sure need a new brake in any event.

cny-bikeman

1. Is the cable housing line (with Teflon/plastic)? Almost all are these days, but if not the cable needs to be oiled or greased as you insert it.
2. Are the housing ends clear of any obstruction, bent/crimped metal?

goldfinch

Plastic line. Ends clear of obstruction.

I am thinking about this and my lack of bike experience and have a thought. I was looking at the reach needed for brakes if I get new brakes plus the width of the rim The rim is 34mm wide. The reach has to be 85mm. That is hugely long. Could it be that this bike was meant for 27 inch or 700 wheels rather than the 26 inchers I put on it? I can't seem to find replacement brakes that would clearly work on rims that narrow and have that kind of reach. I found some Tektro sidepulls that will reach long enough but they are meant for rims no narrower than 38mm. They were nice because of the dual pivot.

Sigh. This ceased being fun a while ago. Now I am powered solely but stubbornness.

I found these Tektros (on several websites) but nothing on how narrow of a rim they would work on: https://www.amazon.com/Tektro-984-Sid...+caliper+brake. Couldn't find anything on Tektro's site that said one way or another.

Kimmo 

Sounds like you need to get to a co-op; that's the go for this sort of thing.

Check the links in my tag for a local one.

goldfinch

Ordinarily I would co-op it, but I am careless for a month. I suppose I can wait.