Pull-behind cargo and camper trailers behind Gold Wings, Spyders and big touring bikes run small wheels, small bearings and a lighting system that often does not match the bike. Rider boards ask three questions: which bearing, how to repack it, and how to wire the lights. This guide answers all three, and is plain about what we stock and what we do not.
Find your bearing: read the cone, then measure the spindle
Every tapered roller bearing has two parts. The cone is the inner race with the rollers and cage. The cup is the outer race pressed into the hub. Both carry a stamped number. Clean off the grease and read them.
If the numbers are worn away, measure the spindle with a caliper where each bearing sits.
- Straight spindle: the same diameter at the inner and outer bearing, so the same bearing goes at both ends.
- Tapered or stepped spindle: a larger seat for the inner bearing, stepping down to a smaller one for the outer.
These are the numbers you are most likely to find on a small trailer:
| Bearing | Bore (spindle size) | Type |
|---|---|---|
| L44643 | 1.000 in | Inch |
| L44649 | 1.0625 in (1-1/16 in) | Inch |
| L68149 | 1.3775 in (about 1-3/8 in) | Inch |
| 30205 | 25 mm bore, 52 mm outside, 16.25 mm wide | Metric |
Bore figures are from the Timken and SKF catalogs.
Bearings by trailer
Can-Am RT-622
Owners on SpyderLovers report that the RT-622 uses the L44649 bearing, which one owner describes as a Knott bearing "the same as Timken L44649". That cone has a 1-1/16 inch bore. Per owner reports the trailer runs it on a 1-1/16 inch straight spindle, so both bearings in each hub are the same number.
The catch is the parts supply. Owners report that BRP lists no replacement bearings and sells only the complete hub, which cost one owner $81 in 2015. Owners in the same thread list TCM 15192TB or SKF 14840 for the inner dust shield and NAPA 14832 for the seal. Match your old seal before ordering.
Harbor Freight tag-along style trailers
These are metric. Owner reports agree on a 30205 bearing: 25 mm bore, 52 mm outside and 16.25 mm wide. One owner measured the spindle at 0.979 inch, and the seal runs on a 30 mm surface. He used a 50 by 30 mm metric seal. A later owner found that seal only snug in the hub. An etrailer expert confirms these trailers use a non-standard size and says to read the stamped numbers or measure.
25 mm is close to 1 inch but not the same. Do not put an inch bearing on a metric spindle.
Owners on GoldwingDocs also report that the factory hub grease is "too little and low quality". Repack a new Harbor Freight trailer before its first long trip.
Everything else
Bunkhouse, Time Out, Kwik Kamp, Uni-Go, Bushtec, Mini Mate, Hannigan and home-built trailers vary by year and by axle supplier. We could not verify a published bearing list for any of them. Read the numbers off the cone and measure the spindle.
What we stock, and what we do not
Our 10-inch Timken kit has an L68149/L68111 inner, an L44649/L44610 outer, a 10-19 double-lip seal and grease. It is built for the stepped spindle on a 3,500 lb axle, with a 1-3/8 inch inner seat and a 1-1/16 inch outer seat.
- It does not fit a 1-1/16 inch straight spindle, such as the RT-622's. The kit's inner cone has a 1.3775 inch bore and would sit loose, and the seal is sized for that larger inner.
- It does not fit a 1 inch spindle either.
- We do not stock metric motorcycle-trailer bearings such as the 30205.
- We do not sell the L44649 on its own, and we do not stock a 5-to-4 wire converter or an isolator.
If your cones read L68149 inner and L44649 outer, the kit fits. If they read anything else, send us the numbers and we will tell you what to ask a bearing supplier for. Every bearing service also needs a new cotter pin; check ours against the old one before you rely on it.
Repacking small bearings
A small trailer tire turns many more times per mile than a car tire, so its bearings work hard at highway speed. Small hubs also hold little grease. Repack at least once a season and before any long trip.
- Lift and support the trailer, then pull the wheel. On many small trailers the hub is part of the wheel assembly.
- Pry off the dust cap, straighten and pull the cotter pin, and remove the nut and washer. Slide the hub off and catch the outer bearing.
- Drive out the seal and the inner bearing from the back of the hub.
- Clean everything in solvent and let it dry. Look at each cone and cup for pitting, rough spots or blue heat marks. If you find any, replace the cone and cup as a set.
- Pack each cone by hand. Push grease into the wide side until it comes out between the rollers all the way around.
- Fit the inner bearing and a new seal, tapped in square. Put a light coat of grease on the spindle.
- Refit the hub, outer bearing, washer and nut. Tighten while spinning the hub to seat the bearings, back off, then snug by hand and line up the next slot. The hub should spin freely with no play. Fit a new cotter pin.
- Feel the hubs at your first stop. Warm is normal. One much hotter than the other is not.
Our repack guide has photos of each step. If you are weighing grease caps against repacking, read Bearing Buddy or repack.
Lighting: 5-wire bikes and 4-wire trailers
Most trailers use a 4-wire system. The standard colors are brown for the tail lights, yellow for left stop and turn, green for right stop and turn, and white for ground. The brake light and the turn signal share one wire on each side. When you brake, both lamps light.
Many touring bikes keep brake and turn separate. That is a 5-wire system: running lights, brake, left turn, right turn and ground. Plug a 4-wire trailer straight in and its brake lights will not work properly.
A converter fixes this. Sellers call it a 5-to-4 or a 4-to-5 wire converter. It combines the bike's separate brake and turn signals into the trailer's shared stop and turn circuits. RIVCO describes its plug-and-play converter as letting 5-wire motorcycles work with 4-wire trailers.
Pair it with an isolator. An isolator takes power for the trailer lights straight from the bike's battery and switches it from the bike's signals. That keeps the trailer's load off the bike's own tail-light wiring. RIVCO calls the isolator required to prevent damage to factory motorcycle wiring, and sells a CAN-bus version for newer bikes. Do not splice the trailer onto the bike's tail-light wires.
- A 5-wire trailer with separate amber turn lamps behind a 5-wire bike needs no converter, only the isolator.
- Wire colors on 5-wire motorcycle harnesses vary by maker. Follow the diagram that came with the harness, not the 4-wire colors above.
- Test every function at the trailer with a test light before the first ride: tail, left, right and brake.
We do not stock converters or isolators. Buy them from the maker of your hitch or harness so the connectors match the bike.
Related guides
- Trailer wheel bearing kit by axle rating and lug pattern.
- A-frame and pop-up camper bearings, brakes and seals.
- 7-pin trailer connector guide.
Send us the numbers off your cones and cups, or your spindle measurement, and we will tell you straight whether anything we stock fits. Everything ships from Upland, California, and the counter is open if you would rather collect it.