How to make your own motorcycle cables
Niche has a wide variety of ready made cables you can easily modify
Do it yourself!
Building your own cables can be really rewarding. It allows you to customize your bike with different bars, replace a vintage cable that can't be sourced or save you from having to buy expensive, factory cables. But if you don't know the tricks of the trade, it can be more frustrating than rewarding. I know, I ruined many cables over the years before I came up with a tried and true methodology. I had to do my homework and learn something about chemical bonding before I could successfully solder a cable every time.
So, if you have a short attention span and don't like reading, I'll share the most important tips of this tutorial before I get started. Keep these tips in mind every time you do this and it will make your life a lot easier:
Getting started:
You can use these same techniques to build any type of cable on a motorcycle - whether it's a brake, clutch or choke cable. I've used these same methods to make cables for vintage dune buggies, go-carts, experimental airplanes and boats as well. So it's a handy skill to have.
One way to save some time is to find a cable that is close to what you need and then modify it a bit. A really good source of ready-made, universal cables is Niche Cycle. They offer many types and have hundreds in stock. They also also have universal handlebars, levers and cable adjusters too. Niche also offers a small kit of cable fittings. These are perfect if you're adapting a universal cable. If you're looking to build cables from scratch and want to keep some supplies on hand, Venhill is an excellent resource for bulk cable. Both Niche and Venhill supply good quality, braided, stainless steel, inner cables with a Teflon outer casings.
Building your own cables can be really rewarding. It allows you to customize your bike with different bars, replace a vintage cable that can't be sourced or save you from having to buy expensive, factory cables. But if you don't know the tricks of the trade, it can be more frustrating than rewarding. I know, I ruined many cables over the years before I came up with a tried and true methodology. I had to do my homework and learn something about chemical bonding before I could successfully solder a cable every time.
So, if you have a short attention span and don't like reading, I'll share the most important tips of this tutorial before I get started. Keep these tips in mind every time you do this and it will make your life a lot easier:
- Measure your cable, then check your measurement and recheck it again before you trim the cable. You don’t want to make a careless mistake when you’re trimming the cable. It pays to be careful. When it came to cutting lumber, my dad always said "Measure twice, cut once." The same applies here with expensive cables.
- Get the right supplies before you start. Make sure you have the right solder and a good quality flux (more on that below). You’ll also need a small butane torch or an old-fashioned soldering gun and cleaning fluid.
- Be sure you don’t overheat the cable or the fitting. If it gets red, the end of the cable will have to be trimmed off. If that makes the cable too short, you'll have to toss it and start over.
- Preassemble your cable parts and check for size before you solder.
- Be careful not to fray the cut end of the cable. Use good quality, sharp wire cutters (dykes) for cutting the cable. A Dremel tool with a good cutoff wheel can also be used.
- Practice soldering. Use a cut-off piece of the new cable or practice on an old cable (i.e., if you’re soldering a stainless steel cable, practice heating a stainless steel cable rather than another type).
Getting started:
You can use these same techniques to build any type of cable on a motorcycle - whether it's a brake, clutch or choke cable. I've used these same methods to make cables for vintage dune buggies, go-carts, experimental airplanes and boats as well. So it's a handy skill to have.
One way to save some time is to find a cable that is close to what you need and then modify it a bit. A really good source of ready-made, universal cables is Niche Cycle. They offer many types and have hundreds in stock. They also also have universal handlebars, levers and cable adjusters too. Niche also offers a small kit of cable fittings. These are perfect if you're adapting a universal cable. If you're looking to build cables from scratch and want to keep some supplies on hand, Venhill is an excellent resource for bulk cable. Both Niche and Venhill supply good quality, braided, stainless steel, inner cables with a Teflon outer casings.
Those old cables are worth something
A great place to start is with your old cable. If it's intact and you need an exact replacement of the old cable, then having the old cable provide you with a lot of critical information. With a few measurements, you'll know the overall length of the cable, the outer cable length, the free length, the OD of the outer cable and and ID of the inner cable. You'll also be able to determine what components you need to build the cable, for example, fittings, elbows, adjusters, etc. If they're in good shape, you might be able to grab some fittings from the old cable as well.
This kit from Niche Cycle has a variety of the most common fittings
It's also helpful to know the parts of a cable:
- The inner cable is the longest piece of cable. In this day and age, it should be braided stainless steel. You don't want a cable that can rust on you. This is the piece you will solder your fittings to.
- The outer cable (sheath) protects the inner cable from damage. Good cables are lined with Teflon. This creates much less friction between the cable and the sheath. There's also less of a chance of the cable failing.
- The elbow is sometimes used to keep a cable from bending the wrong way or kinking. The elbow can be found attached to the top of the carb or where the cable enters the throttle assembly. Elbows are often fitted with cable adjustment nuts for use in marginally lengthening the cable.
- The cap is fitted over one, or in some cases, both ends of the cable to keep it the plastic coating from pealing back.
- Adjusters can be fitted in the middle or either end of the cable. On the BMW cable pictured above, the cable adjuster is on the carburetor end.
- End fittings come in a variety of shapes and sizes. The most common are ball fittings, barrel fittings, nipples and pears - and they come in a wide variety of sizes. The image to the right shows a fitting kit from Niche Cycle.
Elbows with barrel end fittings
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Ball end-style fitting
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Mid-cable adjuster
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The Bernzomatic butane pencil torch is great for cables
You’ll need a few supplies and tools to get the job done: a good heat source, solder, flux and cleaner.
- Heat Source: The quickest way to solder cables is with a micro-torch. I recommend a Bernzomatic ST500 pencil torch or ST2200 Micro Torch. You can find cheaper models, but they don’t last. You can also use a heavy-duty, soldering gun. It takes longer to heat the cable with the gun, but it’s unlikely you’ll overheat the cable. You can ruin a cable in seconds with a torch. Most soldering pencils won’t create enough heat. Don’t use a larger propane torch. It will create way too much uncontrolled heat and become unwieldy.
- Solder and Flux: Don’t cheap out on this and take a short cut or you’ll waste the cable. You can’t use the flux you buy at Home Depot to sweat copper pipes. The chemical compound is completely wrong. That doesn’t mean some goofball on YouTube didn’t do it. It is possible and I have been one of those cheap guys, but you can't do it consistently without a problem and it does not create a strong chemical bond between the stainless steel and the solder. You might get it to stick for a while, but do you really want the soldered joints on your throttle cable coming loose?
You can buy solder in many sizes and types from SRA.
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The right solder and flux make the job easy
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Bonding a brass end to a stainless steel cable requires a specialized flux and solder. Flux performs three important functions: It chemically cleans metal surfaces to assist in the flow of filler metals over base metals (in our case, solder), it helps transfer heat from the torch to the metal surface and it assists in the removal of metal oxides which prevent bonding.
I was curious about how cable companies can make perfect soldering every time. I knew they must be doing something different than I was. So I started hunting around on the internet and found a company called Superior Flux. They've been in the business for years. I reached out for some help and spoke with their expert chemists. They provided me with the best possible chemical combination of flux and solder for joining brass and stainless steel. Their #71 stainless steel flux is formulated for bonding stainless steel and other dissimilar metals like brass. While it will work with different solders, a 60/40 blend of high-quality, tin-led solder offers the best performance. It melts at a low temperature (188 degrees) compared to other solders and creates the strongest bond. There are several companies that sell Superior's blend of solder and flux. I purchased the products you see in the pictures above from SRA. SRA sent me exactly what I needed. They provided friendly service and fast shipping. If you want to read the specs for yourself, the PDF for Number 71 is available on the Superior website.
How to solder a cable:
After you've double checked your inner and outer length, trimmed your cable to size, put on all the correct accessories (adjuster, elbow, cap, etc.), and checked it again, you'll be ready to solder. The first thing you'll need to do is make sure all the oils from your fingers and the bike have been removed from the cable and cable parts. I suggest using an alcohol based cleaner like the many brake cleaners you can get from an auto parts store. There are generally two types of brake cleaner - make sure you get the alcohol based cleaner. You could also use naphtha or denatured alcohol, which is available in any home improvement or most hardware stores.
NOTE: Some of these cleaning products are highly flammable so be careful! Make sure they are put away and fumes dispersed before lighting for torch.
Practice First
Before you start soldering, do yourself a favor and practice on a piece of scrap cable. Remember, you don't have to use one of your cable end fittings. The idea is just to get a feel of how quickly the cable will heat. Use the procedures below (without the fitting ) and practice getting the heat right and then getting the solder to draw into the flux. If the solder doesn’t melt, re-heat the cable a little more and try again. Keep practicing until you get the technique down.
Step-by-step soldering
I was curious about how cable companies can make perfect soldering every time. I knew they must be doing something different than I was. So I started hunting around on the internet and found a company called Superior Flux. They've been in the business for years. I reached out for some help and spoke with their expert chemists. They provided me with the best possible chemical combination of flux and solder for joining brass and stainless steel. Their #71 stainless steel flux is formulated for bonding stainless steel and other dissimilar metals like brass. While it will work with different solders, a 60/40 blend of high-quality, tin-led solder offers the best performance. It melts at a low temperature (188 degrees) compared to other solders and creates the strongest bond. There are several companies that sell Superior's blend of solder and flux. I purchased the products you see in the pictures above from SRA. SRA sent me exactly what I needed. They provided friendly service and fast shipping. If you want to read the specs for yourself, the PDF for Number 71 is available on the Superior website.
How to solder a cable:
After you've double checked your inner and outer length, trimmed your cable to size, put on all the correct accessories (adjuster, elbow, cap, etc.), and checked it again, you'll be ready to solder. The first thing you'll need to do is make sure all the oils from your fingers and the bike have been removed from the cable and cable parts. I suggest using an alcohol based cleaner like the many brake cleaners you can get from an auto parts store. There are generally two types of brake cleaner - make sure you get the alcohol based cleaner. You could also use naphtha or denatured alcohol, which is available in any home improvement or most hardware stores.
NOTE: Some of these cleaning products are highly flammable so be careful! Make sure they are put away and fumes dispersed before lighting for torch.
Practice First
Before you start soldering, do yourself a favor and practice on a piece of scrap cable. Remember, you don't have to use one of your cable end fittings. The idea is just to get a feel of how quickly the cable will heat. Use the procedures below (without the fitting ) and practice getting the heat right and then getting the solder to draw into the flux. If the solder doesn’t melt, re-heat the cable a little more and try again. Keep practicing until you get the technique down.
Step-by-step soldering
- Clamp or place the cable where can sit at least a few inches above your working surface. You don’t want to catch anything on fire! You’ll also need to be able to heat the cable evenly from top to the bottom. If you're using an open flame torch, make sure there are no flammable chemicals sitting around.
- Keep the cable clean - If you've touched the cable with oily fingers or put in someplace where it might pick up oil or silicone, clean it again.
- Slide your clean end fitting onto the cable. I build a lot of throttle cables for Mikuni carbs. The round slide (VM) carbs use a tiny little nipple for the end. If you happen to be doing one of those, I suggest you look closely at the fittings. I sometimes use a cheap, head-strap magnifying hood from Harbor Freight for getting a closer look at the cables and fittings. It can also protect your eyes should the solder splatter. On these tiny fittings you will notice that there are two distinct sides. One side of the nipple has a chamfer and it looks like it has a wider opening. If you're working with this type of fitting, be sure to slide the nipple on with the chamfered side facing the end of cable.
- Dab the cable with a few drops flux using a Q-tip. Or, if you have a big enough bottle, you can dip the cable end into the bottle. Don’t use your finger to spread the flux on the cable. Your fingers retain body oils that will make the cable reject the solder, and you don't want that stuff on your fingers anyway. It is toxic and poisonous.
- Heat the cable slowly and carefully. Start with the flame about six inches away and move in slowly heating only the cable. Do not expose the nipple or fitting to direct heat and be careful not to overheat the cable - it can happen fast! If the cable glows red or becomes sooty, you will have to trim both the outer and inner cable and start over (that’s if you have enough room left on the cable). That’s why I suggest you practice on a bit of the leftover cable first. Ideally, you should heat the cable to around 180 degrees. Do not heat the nipple. Observe what happens to the flux. As it starts to bubble, touch the tip of the solder to the nipple and the flux should immediately draw the solder in. Let the solder cool completely for a few minutes before you attempt to touch it.
- Test the cable. With the cable completely cooled, grab the end of the fitting with a vice grip. Remember these fittings are soft brass so don't clamp so tightly that you'll misshape it! Give the fitting a good tug. If it stays on, you've successfully soldered the cable and you're ready for your next one.
