How To Buy a Springer (and a Lot of the Other Stuff You’ll Need for Your Project)

Buying a springer might seem daunting, but at TC Bros. we try to make it straightforward. Choosing a springer isn’t just a style choice. We have fairly universal options and fit-specific springers. Your purchase decision should hinge primarily upon the bike you’re working with, which in turn will also shed light on what ancillary items are needed.

Milwaukee-Eight Softail

If you’re swapping over a 2018-2021 Street Bob or Softail Standard to a springer, we have an easy-peasy solution: our springer conversion kit. This kit includes a 4-piston billet brake caliper, brake line, rotor, headlamp bracket, wheel spacers, and handlebar riser adapter. 

This kit’s as easy as it gets. All you need is a set of neck bearings, races, and dust shields, rotor hardware, grease, and some brake fluid. You can reuse your OEM wheels, master cylinder, handlebars, headlamp, risers, and digital gauge display. If you have all the parts on hand, you can take your Softail apart in the morning and ride it around with a new front end in the afternoon.

One important note here is that there’s no fender solution for this kit. If you want to run a fender (many people do not), you will have to fabricate something.

Dyna or Late Sportster

If you’re working on a Dyna or a rubber-mount (2004-2022 air-cooled) Sporty you’ve also got a shortcut option: buy a Moto Iron Wishbone Springer. They’re set up to help you in four ways that you won’t get with more universal options:

• The Wishbone is offset so your rake and trail stay close to factory measurements so your bike won’t handle strangely. Safety isn’t a concern if you’re not experienced with calculating rake and trail or the mechanical factors that affect them.

• Our Wishbones have steering stops placed to work with your factory frame’s neck boss; you won’t have to buy pricey internal stops or fabricate your own external stops.

• Moto Iron Wishbone springers come set up to accept a super-common Sporty/Dyna wheel and rotor—but the fitment range is narrower than the springer. Your existing wheel might just work if you’re in that fitment range, but even if you have to buy the correct wheel, you won’t have to cut spacers. (We carry the wheels, so you can make it a one-stop shop and save on freight.)

• Wisbones come with a lower spacer and shorter top nut. Since these frames have a recessed lower bearing, we include a spacer to move the bearing to the correct position and the appropriate top nut.

A bike-specific Wishbone springer will save you time and money. However, you’ll probably still want a few other items if you don’t have a deep parts pile. Bring this checklist to the swap meet or start clickin’ links if you aren’t that patient and pick up the following components:

• Wheel (and maybe a tire and tube): If your bike falls outside the range of 2000-2003 Dyna or 2000-2007 Sportster, you’ll need a wheel for the springer. This guy is the one you want. Finish and diameter are your choice, but if you’re trying to save a few bucks, choosing the same rim size as what’s on your bike now will allow you to reuse your tire and tube.

• Brake caliper: We’d encourage you to use the Moto Iron calipers we sell since they bolt right up. Other calipers may work, just recognize you may need to make custom brackets and spacers to use those items. Similarly, our ability to tell you how it all plays together is a bit more limited than if you are using parts we sell.

• Brake rotor: Any Harley-Davidson front five-bolt pattern, zero-offset 11 1/2” rotor will work here. This Moto Iron disc is an affordable option, but there are plenty of others at TC Bros. that work. But measure yours—odds are excellent your rotor is this size already.

• Brake line: A universal line makes this easy; just pick your length and then the correct ends for whatever master you are using and the caliper. If you’re using our caliper, you’ll need a 3/8” banjo fitting at whatever angle your line routing calls for.

• Brake master cylinder: Your caliper will determine what to use here. Moto Iron calipers call for a 9/16” bore master; if  that’s what you have, run it. If not, you’ll need one. This Moto Iron direct replacement will work with stock equipment; we have other styles if you aren’t using stock controls. If you are gonna scoop one of the stock-type ones just mentioned and are wondering what size fitting it takes due to the previous bullet point, it’s a 7/16” banjo in whatever angle you prefer based on how you choose to run the line. If you don’t know what bore your existing master is, pull it off the bike—a lot of the time the bore size is cast into the body.

• Banjo bolts and crush washers: These come with Moto Iron calipers and master cylinders, so there’s no need to buy them if you’ve got those both in your cart, but if you’re substituting something else, all bets are off. Moto Iron calipers use 3/8”-24 banjo bolts, and the stock master mentioned previously uses a 7/16”-24 banjo bolt.

• Risers: Springers have risers that are set farther apart than your factory front ends. If you have two-piece risers, you can use those, but if either or both parts of your risers are joined, you’ll need new ones. We have a lot that can work; these are a safe bet for most setups. 

• Handlebar: Because the risers sit in a different spot, the knurling on the bar will be visible if you use a hydraulic-fork-style bar on a springer. It technically will work (though the risers might have trouble biting into the smooth finish). But most people agree that’s pretty unsightly. Any springer bar for sale will work; this TC Bros. bar is a perennial best-seller if you don’t know what to choose (and will most likely prevent you from needing a longer clutch cable, too).

• Neck bearings, races, and dust shields: You’re already in there and I know you don’t ever grease these things. It’s easier to install new units than try to reuse your old ones without damagin’ em. 

• Grease and brake fluid: You’ll need grease for those neck bearings, of course, and stop-juice for your brakin’ system. DOT 5 is the stuff to use if you are using Moto Iron brake calipers.

All Other Harley-Davidson w/ 1” Neck (or Motorcycles That Have Been Converted to Accept Common 1” Stems)

If you’re building from scratch or chopping a Harley-Davidson that’s not a Dyna or a later Sporty, use a Moto Iron Springer, either Standard or Vintage. If you’re working with a frame that has stock rake and wheelbase measurements, take your pick based on what style appeals to you. 

If you’re trying to “go long,” the standard is the better format since we make those in a 6”+ over configuration; that’s not true of the Vintage. They’re both inline springers, so they’ll help you keep your trail numbers reasonable so you don’t have a heavy-feeling front end.

In general, this will be a custom setup, of course, but we can provide at least some guidance that may help you select parts you’ll probably need.

• Risers: Springers have risers that are set farther apart than your factory front ends. If you have two-piece risers, you can use those, but if either or both parts of your risers are joined, you’ll need new ones. Lots of springer-specific risers will work; these are a go-to for many people. 

• Handlebar: Because the risers sit in a different spot, the knurling on the bar will be visible if you use a hydraulic-fork-style bar on a springer. It technically will work (though the risers might have trouble biting into the smooth finish). But most people agree that’s pretty unsightly. Any springer bar for sale will work; this TC Bros. bar works well. We encourage you to pick your bar and controls during mockup but before buying anything to plumb your bike, since you may change things during mockup. Remember bar height will also influence the length of your clutch and throttle cables.

• Neck bearings, races, and dust shields: Start a build with fresh goodies; pulling apart a chopper to repair something like this after the fact is a pain in the neck. (I’ll show myself out, thanks.) We think installing a new set of neck cups into a frame is easier than fishing races out of existing cups. Let your wallet be your guide. 

• Grease: We’re assuming you’ve got this. If not; pick some up locally. 

• Wheel, tire and tube: These springers are set up to accept the hub or wheel from a 1984-1999 Softail. Finish and diameter are up to you to pick, but if you’re trying to save a few bucks, choosing the same rim size as what’s on your bike now will allow you to reuse your tire and tube. We sell a variety of wheels that will work, from fat 16s up to dual 21s in chrome and black. We also have spool wheels. If you’re running a spooly for the stripped chopper look, the items mentioned so far should be most of what you need. If you’re running a brake and fender, however, you have more components to consider.

• Fender and mounts: The fender is an item that’s kinda-sorta optional depending on your area’s safety inspection and how often you ride in the rain. If you plan to run one, your wheel options get narrowed (ha!) to a skinny narrowglide wheel. If you are also running a front brake, which is likely, that narrowglide wheel needs to be 19” or larger so it doesn’t hit the caliper. These mounts work with all our springers except the Milwaukee-Eight-specific kit. This fender bolts to those—paint it and go! A fender is theoretically possible if you’re using a 1984-1999-style Softail hub, except you’ll have to offset it since the wheel is not centered in the springer. It might look a little weird, so we generally say that fat front tires and fenders are sort of mutually exclusive.

• Brake caliper: If you elect to use the Moto Iron calipers we sell, they bolt right up. These springers are indeed wide enough to accommodate two brakes, if a dual-disc springer is something that interests you. Other brakes may work, just recognize you may need to make custom brackets and spacers to use them and our ability to tell you how it all plays together is a bit more limited than if you are using parts we sell. It’s important to note that brakes are unique to aftermarket springers; no brake calipers or brackets interchanges with any factory springer early or late.

• Brake rotor(s): Any Harley-Davidson front five-bolt pattern, zero-offset 11 1/2” rotor will work here. This Moto Iron disc is an affordable option, but there are plenty of others at TC Bros. that work. But measure yours—odds are excellent your rotor is this size already.

• Brake line: A universal line makes this easy; just pick your length and then the correct ends for whatever master you are using and the caliper. If you’re using our caliper, you’ll need a 3/8” banjo fitting at whatever angle your line routing calls for.

• Brake master cylinder: Your caliper (or calipers) will determine what to use here. The Moto Iron caliper calls for a 9/16” bore master; we carry a variety of styles that can be used with stock controls if needed or more custom options (that also require a bit more work to fit; it kind of just depends on what you’re working with). Note that if you are using a Moto Iron caliper it specifies DOT 5 brake fluid; you’ll want to select a suitable master cylinder.

• Banjo bolts and crush washers: These come with Moto Iron calipers and master cylinders, so there’s no need to buy them if you’ve got those both in your cart, but if you’re substituting something else, you may need them.

• Brake fluid: DOT 5 is the stuff to use if you are using Moto Iron brake components up front; you might want to keep that in mind when you’re shopping for a rear caliper so you’re not stuck using two fluids on your bike—those two are not compatible with one another, so you can’t sub one out in a pinch on the road.

• Springer shock: This is optional, but keeps pogo-ing to a minimum. Choose this shock for everything but the Vintage; those use this other kit.

• Headlight mount: Fabricate your own or use ours. This one works with everything but the Vintage; those springers use this mount instead.

With these quick checklists, you should be able to determine if you have what you need to get your new springer on your bike quickly without multiple parts orders.