10

Since you have a relatively "flat" spot there (at least flat in the longitudinal direction) you have two options: You can epoxy on a replacement boss I did this on a recent Al frame with the exact same problem. I bought a metal (steel) cable boss from the local bike builder and epoxied it myself. I used Loctite's Metal/Concrete epoxy since it's designed ...


9

Rode downtube friction shifters bikes for a while. I can see two possible causes : either the shifter was too lubricated, or the screw isn't tightened enough. Try to tighten it more, but pay attention not to tear the screw. Usually the lever is pretty rigid when moving. If it's easy to move it to the point it moves alone, it's probably because it wasn't ...


7

You'll need longer cables in order to bridge the distance between where your original downtube shifters were and the stem (where the new shifters will be mounted). And you'll need to install a shifter cable housing going from your new cable stops (on the downtube where the original downtube shifters were located) to the new shifters on the stem. If you plan ...


6

Good epoxy is known to bond metals, especially aluminum very well. Make sure the surfaces are clean and slightly rough for a better bond. I use the same two part epoxy hobbyist aircraft builders use for fixing pretty much anything, including broken ceramic mugs, small broken metal things and even as an insulator on the bottom of PCBs to prevent any shorts. ...


5

Without any additional knowledge on the bike, my advice would be don't drill into the down tube. You run the risk of making it structurally unsound. That being said, some bikes with downtube shifters have a hole drilled in the downtube with a rod going between the mounts and maybe some epoxy using something like this: Some other options are: Find a ...


5

The community generally seems to advocate against upgrading your bike. I'm not sure why, it often makes alot more sense than buying new and more than buying used much of the time. If your bike was originally equipped with Shimano 600 the likelyhood is that it's a good quality frame with other good components so it's probably worth upgrading if you love it. ...


4

If you have a 3D printer, you can design cable stops that fit your frame and print them. This is one I made: I have been using this version for a few weeks now and it also feels super strong on the frame. Even with some amount of force it can't be moved or turned by hand. It is printed with PLA. For the 3D modeling I used TINKERCAD. I just made an improved ...


4

You already have the correct answer for you (tighten up the friction screw) but there's something else you should look at: balanced stem shifters. Regular stem shifters hold their place by friction -- that's why they are also called friction shifters. There's a fine line between not enough friction to hold the gear, and too much friction which makes ...


3

Downtube shifters are usually called "friction shifters" and friction is key when fixing the issue you describe. I own and periodically use an old Cannondale with such system. Every now and then I find myself with the same problem as yours. How to fix it? Easy, just tighten the lever of the shifter. Mine came with an integrated metal triangle handle (...


3

I tried epoxying the frame stop onto the frame, and took utmost care but front deraileur cable stop came off. Now I am considering this "On Frame Cable Stop, Alloy Double, 31.8mm , Black" instead.


3

You just remove the downtube shifters, put cable stops in their place on the bosses (e.g. Shimano SM-CS50), and then route the cables for the brifters using those cable stops like you would any other bike. Tons of people have done this and are perfectly happy with it. There isn't a problem with doing this so long as the shifters are matched to drivetrain ...


3

You can find what you're looking for under names like "downtube shifter lever boss kit".. You should be able to find something at a bike shop (especially one which works on older bikes) or a frame builder. Another alternative is to use a clamp.


3

I don't know a great deal about the old shifter types, but two thoughts come to mind - 1. Very obvious, but have you tried tightening them to increase the friction? 2. Might there be grease in the friction surfaces? You could try opening them and cleaning them with deagreaser/brake cleaner to see if you can increase the friction in them


3

The 740x rear derailleurs are unicorns that only index with 7400 shifters. I believe there is an SL-7402 downtube shifter. 7400 shifters have a cable anchor routing trick that allows them to work with latter generation RDs, but there is no such trick that works the other direction for RD-7400 et al.


3

Basically everything shifting related. 9 speed uses a narrower chain and a wider cassette so you’ll need: New shifters, new chain, new cassette, new rear derailleur, new chainrings. Your old front derailleur+shifter might work. New cables+cable housing will probably be necessary. It’s possible you need a new rear hub (could be cheaper to get a whole wheel) ...


2

This is a good question. I speculated about this over the weekend and came to two conclusions. Friction shifters were designed for narrow(er) rear cassettes. The largest cluster I've ever seen a friction shifter work on is 8 speed. I don't think it will pull enough cable for you to access all the speeds in your ten speed cluster. EDIT: As an insiteful ...


2

We need to see what is under the cable stops. My guess is that is is probably a standard squared off shifter boss, but you never know. If it looks like this Then any friction downtube shifter should work as a backup. You want to get one that is not indexed if at all possible since that way you can use it for either front or back derailleurs. Bar end ...


2

I don't know anything about the history or whys, but I have seen shifters by huret that match up with this type of mount (as @danielrhicks was getting at): As you can see they have a square baseplate that acts as a stop for the shifter. I had always just assumed it was some sort of French standard that didn't last very long. I have also seen simplex ...


2

That calls for a shim. Cut a narrow strip from a drinks can, about 3-5cm long and lay it under the cable stop before re-tightening the screw. Make sure all the surfaces are clean and degreased. The soft aluminium of the shim will 'absorb' the remaining roughness of the tubes and the cable-stop and make slipping more difficult. (I've solved the problem of the ...


2

Some pictures of the levers and the RD may be welcome and clarify the situation. Shimano 600 was an indexed shifting system and stands at the beginning of the Ultegra line of products. It can be switched from friction to index by turning the toggle at the side of the right down-tube lever (if you have the original Shimano 600 levers). However if you have ...


2

I think it will work fine for a while, but the slight angle will increase friction and therefore wear on that point of the cable. This will make it harder to move too over time. Water from rain or road spray will rust in there a little faster, and this can result in the housing popping out of the retainer easier. I'd suggest using some calipers to measure ...


2

7 and 8 speed cassettes have the same spacing, so you can use either in your situation. As for indexing on the rear, usually there is no indexing, though I've seen 'semi-indexing', where they do have an index mechanism, but it still requires several clicks to switch chainrings. Additionally, you sometimes need to adjust a little bit based on what gear you ...


2

Basically you may drop steps 2, 3 and 6. You'll just remove the shifter cables from the STI levers. It might not please the aesthetes but it will work. If the STI levers have the shifter cables run through external housings you remove these as well. If the housings run under the tape, you leave them alone, you just cut them where they come out from under ...


2

Solved it, it was the nut oriented incorrectly on the dura-ace downtube shifter. Turning the inside nut so that its oriented correctly against the main tube, inside from the lever, and retightening the cable to remove all slack, and then setting limit screws again, I now have the shimano 105 derailleur with the Sugino working correctly (non-indexed). Thanks ...


2

When I bought bar-end shifters for my 8-speed drivetrain bike, I had to select the bar-end shifters marketed as "8-speed Ultegra". Those ones marketed as "8-speed Dura-Ace" are the ones intended to be used by the early Dura-Ace systems. I did not have an old Dura-Ace rear derailleur so I had to use the Ultegra bar-end shifter. I suspect ...


1

For the rear derailleur, you may be able to run a full length of housing all the way, regardless of if the cable is routed on top of or on bottom of the bottom bracket. That would be the least expensive solution, and is up to you. For the front derailleur, you will probably need a cable stop somewhere. The item you linked has some additional options, ...


1

There is a nice instruction video from RJ The Bike Guy on youtube on how to convert from downtube shifters to brifters. Perhaps that can be some idea for you. In case the video is taken down, I'm posting a written answer. Yes, it is possible to convert from downtube shifters to brifters. Here's what you need: brifters compatible with the cassette and front ...


1

I'm not familiar with those shifters but perhaps this will be of assistance: Campy Syncro 2 shifters The left/front shifter is a standard friction shifter. To convert (the right one) to pure friction, you can actually just remove the springs and optionally the boss collar -- the springs are all that is required to (re)move.


1

Tsunoda are/were a mass manufacturer in Japan somewhat similar to Schwinn in the USA. Most of the bikes they produced were low end though they did make some mid-to-upper end models (I once had a Tsunoda made Lotus branded frame from the early 80s). I believe the brand is still around in the Japanese market but now mostly making folding bikes. Your bike ...


1

Stick with the friction shifters. Changing a non indexed bike to index is expensive and unnecessary. You will need a new dérailleur to index correctly along with a rear wheel that can mount a cassette (assuming your running a freewheel). You will also need new shifters which if your running a road bike are very expensive. If you must have index shifting ...


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