The question we are asking here is…will a Carry Freedom trailer take me there and back? We’ve had many trailers go around the world. Many thousands of kilometres in wild conditions gives us a good idea of what will happen and where problems could appear. The list is long, which does not mean that all this will happen on a long trip, we are just exploring all the possibilities.
In order of frequency the following can happen:
- Rubber hub caps get lost.
- Pins and clips get lost
- Axles rust solid in the chassis
- Inner bearings get destroyed
- Red elastomer snaps
- The rider runs the trailer tires at too high a pressure and wastes more energy than they should
Ok, let’s take a look at each of these in turn
Lost rubber hubcaps
The rubber hubcaps are cosmetic, but for the worriers the best way of retaining is a zip tie between spokes or a spot of superglue on its edge. People get worried about water getting into the outside bearing, but it always outlasts the inside bearing so is not worth worrying about, unless of course your the type of person who enjoys worrying.
Pins and Clips getting lost
Its normally wise to replace the pins with M6 or 1/4″ bolts anyway as the spring arm on the pins can rattle against the frame, and over 25,000 miles this can be quiet irritating.
This is more a problem with older trailers with plain steel axles, modern trailers now all have either chrome plated or zinc plated axles.
Touring trailers will go for months without the wheels being removed from the trailer. Hot days and cold nights cause condensation build up between the chassis and the axle, and water plus steel plus aluminium leads to the axles not quick releasing on demand. This is normally discovered with 2 minutes to get on a train or ferry or whatever that’s just about to leave.
We offer three solutions:
– Grease the axles regularly and remove the wheels at night. This protects the axle surface from rust, and allows everything to dry out. The grease also protects the vulnerable inner bearing (see below). Also a trailer without wheels is a handy table for happy campers.
– Get brutish and fit the axles permanently in place. This is a workshop job, tear out the mechanism from the axles (snap either end off in a vice, and it spills its guts), cross drill the chassis axle beam with an 5mm hole to line up with the hole now vacated by the QR balls, and run a M5 bolt through all this. Now, if the wheels need to be removed, its “spanner time”.
– Find some stainless-steel axles, or zinc plated axles will ease the problem, but the axles still need to be greased.
NOTE: All new Trailers from 2022 on, have IGUS plastic bearings in the frame to isolate the steel axle from the aluminium frame. This should stop the “rust” reaction completely.
Again a issue on older trailers, modern trailers all have rubber seals on the bearings already and a rubber O ring to create a gap between bearing and chassis.
There is a narrow capillary gap between the trailer chassis and the bearing that draws water into it. This sits against the bearing seal until it is let through, and this happens, no matter how good the bearing seals are. This is not a issue on trailers whose wheels get regularly removed as the bearing can dry off, but 1 month through a monsoon kills the bearings.
a) Grease the axles regularly and remove the wheels at night. Pushing greasy axles into the trailer frame pushes the excess grease against the bearing, which creates a really effective waterproof seal as the capillary gap is filled with grease.
b) As we now do on the trailers, fit an O ring to the axle between the trailer wheel bearing and the trailer chassis. This gap allows water to escape and not build up, as well as killing another source of noise. Rubber O rings are of course easy to lose.
A very rare event which is more likely to occur when you have a harsh riding style, cycling over rough roads with heavy loads, and are miles and miles from help. This is the trailer’s equivalent of the Jesus pin on hand gliders, i.e. if it fails, you are stuffed. It’s also not something that can be fixed in the field, so worth carrying a few spares, and observing that because of the pointy end they make great spare tent pegs. Call me superstitious, but it’s also a part that’s guaranteed to fail if you don’t have a spare, but will last a million miles if you do.
Why use the Carry Freedom lollipop hitch? I make three observations.
a) The Carry Freedom hitch is rated and tested for a 90 kg trailer, and has passed the EN test to that effect.
b) The shape of the Carry Freedom elastomer makes it stiffer in the direction of bicycle travel while maintaining its flexibility when the bike falls over, thus making it less prone to the trailer pulsing while cycling with a non-smooth cycling technique.
c) In extreme conditions the Carry Freedom elastomer can be bodged out of any plastic sheet layered to get the needed thickness (like the original prototype), or replaced by a craftily tied length of rope, other hitches are more sensitive to their shape and material so more difficult to bodge (adapt?) in the field.
We don’t get too many reports of collapsed wheels, it tends to be cars reversing over unseen trailers followed by overloaded commercial trailers bouncing down kerbs that account for most wheels. That said, stronger rims increasing the spoke count and widening the hub flanges does no harm, and if you are in the mood for pimped wheels adding a grease nipple would be sexy in my eyes. Wheelchair hubs are the way to go for a higher spoke count, but be careful to get the European 12 mm axle diameter rather than the American 12.7 mm axle diameter.
We normally rate the Big Apples as being the best tire for the job. Spares aren’t really needed as the tire experiences no braking or acceleration forces, and relative to a bicycle tire its pretty lightly loaded taking 1/3 of the trailers weight, typically 15 kg tops on a touring trailer.
A typical rear bicycle tire will carry 60 kg or so. Very crudely because a trailer tire carries about 1/4 of the load of a bicycle tyre it is also 1/4 as likely to get a puncture, and should also run at 1/4 of a bicycle’s pressure. So if you run your bicycle tyre at 60 psi, then run your trailer tyre at 15 psi. Of course, the temptation is to just inflate it until it’s rock hard because surely that is good for rolling resistance? However, while it is indeed good for rolling resistance, it means that the trailer spends its life bouncing up and down, which is an absolute and complete waste of energy.
The Royal Mail at our suggestion tested the efficiency of trailers vs panniers, and found that under their test conditions, bicycles carrying a load by trailer rather than the identical load in panniers were 5% faster for a lower heart rate. I can go into the science of why this is, but no one ever believes me.
Spares wise we normally suggest a spare set of bearings, and a few elastomers, plus maybe an axle or two.
This post was a little longer than expected, but now you are ready, so off you go now and don’t forget to write and tell us how the journey was.
To see all the adventurers using Carry Freedom check out the link here: CLICK HERE