Felt Heavy Duty

[Duchess]

I'm sure there's an oddball exception out there, but derailleurs just do whatever the cable tension against the spring tells them to do, so as long as it has enough travel, it doesn't care how many rings it sits over. This goes for friction or index shift since the shifter controls the length of cable movement. I haven't tried it, but I wouldn't doubt that a lot of at least lower end doubles would work with a triple setup with the only difference being where the factory set the limit stops. anyway, that's all you'll probably want to do—adjust the limit stops so you don't drop the chain off one end or the other.

 

[toro1978]

Thanks! Any info is much appreciated. I actually played with the front one a little and adjusted the limiting screws. They were self explanatory enough. So it looks like I set the cage to move only above the two rings. It seems that the 1/2 1/8 chain will be able to move freely through the rear derailer. It looks like the cable is coming from above. I will see if I could use only two of the positions of a 3 speed mtb twist shifter.

 

[Duchess]

If you set the limit stops right and the shifter you're using indexes the right amount for the spacing between the rings you have, the third position just won't do anything. I would assume the low gear would be the position not used since almost all derailleurs pull to shift up, so while shifting down an extra gear would release more tension on the cable, the derailleur would stay put due to the limit stops.

 

[toro1978]

I should have a look at all three front derailers and try to remember which one with what shifter corresponded.
The how to pages say put the chain on the big chain ring in the front and the biggest rear sprocket, which is only one here anyway... Without running the chain through the derailers. Then add one link for the rear derailer. Actually it looks quite good as it is:

That would be on the small chain ring:

Too much tension? It looks like the derailer is already 2/3 of its whole range in that plane. Might use a few more links perhaps.

 

[OddJob]

@toro1978 , couple notes on your drive train. First off, I think it's a really cool idea, and have been contemplating that for some time myself. Secondly, that chain, at the length you have it, might be just right as is. Check the 'chain line' when it is in both the big and middle position chain rings. I see it is in the middle ring in that last photo. Make sure the chain doesn't hit the tire or fender. You want to use the derailleur as a 'tensioner' basically in this instance. So you def want some spring tension on that rear der when it's in the middle ring, and then it will increase when it's in the big ring.

One thought; what if your front chain rings were closer in size / number of teeth? That way the gear jumps wouldn't be so far apart, and it would function more like a six speed, where the gear steps are more incremental. If it was me, I would downsize the big ring, so if that middle ring is like a 38t, put a big ring on that is a 42t, instead of the 48t that might be on there already.

 

[toro1978]

The chain line is far right, which means far from perfect. The tire clearance with the chain on the small chain ring is around 5 mm I guess. This will work OK because this crankset was used with the same tire clearance and with the same rear wheel and sprocket and there were no issues.

It might become problematic when I shift to the big chain ring, which is even further to the right.
So should the chain fall off (rather off the rear sprocket than the chain ring) I will probably try to use a bigger rear sprocket. The biggest I could use has 23t. I was hoping to have overdrive with the big chain ring, but I might actually end up with underdrive. Or a shorter BB, 127 mm instead of the 131 mm. But we will see, maybe won't be trouble at all, with the longer chainline and all.
By the way, the crankset is a double, not a triple, it is a track crankset so it is for 1/2 1/8 chain. It is a Thun Aero Coronado. An OK part, but I love the look with the holes and the ring guard. I hope the triple derailer will work with the ring guard, if not I will get a double derailer. It is aluminum though so fairly light. It is 42/52 combo. I used it as a single with the small ring on the fully, but it occurred to me that I could make it work with this hub which because of the roller brake instead of a coaster brake can work with the derailer/spring tensioner. It also uses smaller bolts than new sets so another ring size is not an easy replacement.
I realized that I ran the chain through the derailer before adding back the missing jockey wheel, also I have more teeth on the rear sprocket than the usual derailer enabled drive train. So the chain will definitely need a few more links, no going around it. But I have a new chain breaker so it is no biggie.

I am advancing well with scraping the rack, 70% of the long tubing done.

How I mocked the chain:

That's how the rack attachment works:

I found this useful part, but it is obviously the wrong size. I could massage in the right shape.

The derailer is fixed in position, it has a piece of cable holding it, still adjustable:

I should use a gear cable, this derailer was used as a tensioner on the fully so I used what I had on hand.
Now that I think about it this bike has an aluminum frame, crankset and pedals, wheels, brake levers and seat post, the ahead stems too. The rack turned out to be steel, to my surprise. The seat, handlebars, derailers and the igh innards of course, are steel too. The fork is Rock Shox XC32 and relatively light.

 

[toro1978]

I will probably try this Shimano tourney one too, it is massive.

 

[OddJob]

That Tourney with the Mega Range lower pulley might help retain the extra tension you want for the changes between the chain rings.

 

[toro1978]

I added too much links, the chain hangs a bit so I will remove a few. The way I set this rear derailer the chain rubs on the igh gear joint cassette so I will have to fix this. I could simply put a bracket on the chain stays and bolt something to push the derailer a bit down. But if I use the Tourney derailer I might not have this issue. I must try that one too. I went with this one simply because it is already proped in a fixed position. After some tinkering with the front derailer I got it to shift without grinding noises. So it is a success in a sense that the drive train works. I have to connect the front derailer to a shifter and see how it goes.

 

[toro1978]

The Tourney derailer fits better:

If go with it I will have to sand it some.
This is the chain line with the small chain ring. A bit weird but clears the tire.

I know I planned on going with double stick shifters but I am contemplating on using a brake lever to shift. You know, attached to a/the stick shifter for the igh. Like bikers put their clutch lever on the suicide shifter:

Since I have only two positions I could simply use a bracket to hold the lever pulled - with the pull corresponding to the front derailer's pull. Releasing the lever would automatically switch back to the small ring.

 

[toro1978]

And the small derailer works too and because of the smaller size might be the right one. I think the Tourney derailer will clash with the rack because when the rack is properly installed there is more angle when the stand is unfolded.
There is some rattling because the jockey wheels are for a narrower chain so the chain pins come in contact with the cage. So I will probably try to use the big jockey wheels from the Tourney derailer so the chain would run farther from the cage.

 

[OddJob]

Any progress to report on the ' 2 x ' INT drive train? In your last photo the derailleur looks too slack, not enough tension. Maybe you hadn't removed the chain links you mentioned doing.
I'm really anxious to see this come together. It's a concept that I have been contemplating, and think it's cool that you are giving it a go!

 

[toro1978]

I haven't connected a shifter yet. But when I actuate the lever on the derailer (that the cable attaches to) it shifts to the big ring and when I let go it goes back to the small one. I did remove a few links, but now everything is disassembled.
I am not sure whether I use some brackets for the shifters or simply a second stem in the opposite direction, with a piece of handlebars that has the shifters mounted. I think this will be the way to go.
I haven't been updating because I started stripping the frame. I swear this is the last time I do this. If it wasn't for the Haribo logo and bear I would have simply left the original paint, but unfortunately this is the basis I had Last year I could have gotten away with a green frame if it only didn't have pink logos on the sides...
Once I am done with stripping it I will put everything back together and will connect the shifters and brakes.

 

[SwissGuy]

The Tourney derailer fits better:
View attachment 157235
If go with it I will have to sand it some.
This is the chain line with the small chain ring. A bit weird but clears the tire.
View attachment 157234
I know I planned on going with double stick shifters but I am contemplating on using a brake lever to shift. You know, attached to a/the stick shifter for the igh. Like bikers put their clutch lever on the suicide shifter:
View attachment 157236
Since I have only two positions I could simply use a bracket to hold the lever pulled - with the pull corresponding to the front derailer's pull. Releasing the lever would automatically switch back to the small ring.

You might need a break lever like this:

This one I'll need for my own build, but you can buy those in a "Sanitätshaus" with an attached workshop that repairs wheelchairs. Most of them have some of these on stock. Just talk to the mechanics there (I used to work in one of these workshops a long time ago...)

 

[toro1978]

Yeah, something like that.

 

[toro1978]

I dare to say that the major work is over.

I already see it:

What I have left:

The bottom side of the tank and a few inches of the down tube:

The BB:

The seat stays bridge:

Dropout area:

I used this rear wheel from my chopper for balance on the rack.
I might have to get a wire wheel for the BB, but I don't know what size to order. I wanted to go the lazy way and leave the head tube and the BB, and that bridge white, but I know the head tube will look mean in bare metal.

 

[hamqqea]

Wire wheels can leave deep scratches in aluminum requiring heavy sanding to smooth out unless you want the finish to look rough. I've applied non methylene paint stripper to a frame with stubborn paint in an apartment over night left in bag to break the paint down. Took it outside in the morning to hand sand. Stripping paint chemically has gotten harder due to regulations. Fortunately you don't have to be concerned with lead-based paint. My frame had lead.

 

[toro1978]

Well, I was thinking about cleaning the welds and the dropouts if they are too much for the sand paper.

 

[OddJob]

That gnarly knobbie in the rear on that raw frame has my attention!
Maybe just a lighter brushing with a hand held wire brush on the paint remover treated BB and head tube and drop out would get around and in between.

 

[toro1978]

Yeah, the knobbie does look crazy awesome on the black rim.
I did quite a lot this last two days. I finished the tank, only have to clean some more the weld on top.
Also the headtube is 70% done.
Basically what is left is the BB and the dropouts. Oh and the small spot between the seat stays but I might do it it later today. And some of the rack. I think next weekend the bike is going to be ready for assembly except for the gear shifters.
I have to score some finer sand paper, the finest I can get in my village is 240. I think I will have to use 500 for a little smoother finish.