eggnoggbubble

a friend gave me a well-used instep trailer for free, which I'm going to convert to cargo/kayak us, but it seems the plastic wheels are broken (on one the rim is separating from the rest of the wheel), so if I'm going to replace I'm thinking about 20inch fat tire wheels, for less rolling resistance + I want to take it on the beach to carry my kayak and/or camping gear (detached from the bike, can't ride my pack rat on sand it's not a fat rack....)

anyone any thoughts on that? what do I need to know about the wheels, axles, etc. Anyone done anything similar?
And how would that compare to other trailers? Burly flatbed looks nice (lighter than the instep!) but I think I'd rather try out with the instep, never had a trailer before so I want to see how much use I'm getting out of it before I consider any upgrades...

I'm going to take it down to my LBS next week to see what he can suggest, but I thought I'd ask here as well.

thanks for any thoughts!.

10 Wheels

Mine. Grocery Store trips. It was Fun. 20 inch wheels.

KC8QVO

Wider tires/lower pressure will have more rolling resistance on asphalt and concrete (and HARD packed crushed gravel/limestone trails). However, they will have much more flotation for softer ground (softer dirt, sand, and.... soft crushed limestone/gravel trail - specifically the "in between" seasons where it is below freezing at night to freeze the trail solid then warm enough during the day to thaw the trail - the surface becomes mushy and lots of flotation would make a world of difference).

If you are primarily going to be riding on hard surfaces then I suggest regular size tires. And get ones that can hold at least 50 PSI. The harder the tires the lower the rolling resistance. This is my number 1 complaint about the kid trailer I acquired - tires are only rated to 35 PSI. The first time I used it I knew that would be an issue for me. That can be fixed with better tires. However, I am looking at making my own trailer from the ground up using 20" wheels so I am going to try to make do with what I have for a bit and see what happens. If I have to spend some $ on new tires I'd rather build up a good 20" wheel set and go with 20" instead of the 16" the kid trailer uses - more tire options also.

If you have any metal fabrication skills/abilities/tools the sky is the limit with what you can come up with on design - length, width, accessories, mounts, etc. So as to what you can haul with a bike trailer - use your imagination.

One piece of advice I can give - and the base line of this advice is the kayak use you allude to. A kayak is long. Advice - get the trailer long enough so that the weight is mostly supported by the trailer axle, yet you still have a bit of tongue weight. If you are going to carry gear in the kayak then you can use the gear position, perhaps, to "ballast" the load to tune the tongue weight further once you have the trailer built. Another bit of advice is to watch the beam width of the kayak - it might not fit between the tires on the trailer so you'll likely need an elevated "bunk" to rest the kayak on.

Good luck with it. Don't forget to have a lot of fun with it also!

eggnoggbubble

thanks for the reply! I won't be riding on sand, just pushing / pulling (detached from the bike), I figured I'd run the fat tires at high pressure, as a compromise that should work on asphalt and on the sand (maybe 40kg tops with kayak and camping gear all loaded). 20inch wheels for sure. No frost here, I live in Okinawa, Japan, subtropical (sorry!).

By "tongue weight" you mean the weight on the arm that attaches to the bike , yes? so that the tail end doesn't end up heavy enough to start lifting the front (near the bike) end. My kayak is pretty narrow as kayaks go, 99% certain it will fit between the wheels, but I should definitely check. I don't have any welding capacity (tho I do know a guy who has helped me with bicycles before), but I've got just about enough skills with drilling and bolting to be able to put something together, especially on the instep base.

cheers!

CliffordK

Your wheel choice may be based on what you can find.

A few bikes used 20" x 4 1/4 wheels. They may be big on your bike. Schwinn OCC Chopper had ONE each. Mongoose Massif had two.

16"x3" wheels were used on the smaller Schwinn OCC Chopper.



That is the 16x3 on the trailer, and 20x4 1/4 on the bike.

I prefer trailers that the frames wrap around the wheel, and can use standard QR or bolt on.

One of my trailers I've removed the fabric and just have a bare frame which works well for certain bulky loads.

KC8QVO

Yes on your description.

To elaborate - you want some weight on the tongue. You don't want it light or negative. This might get tricky with the length of the kayak. That gets back to my comment about the ballasting with your gear - shift it around so you can dial in the tongue weight better.

If you have the ability to weigh the trailer loaded (individual weights added up) and compare that to measuring the tongue weight then see if you can get about 15-20% on the tongue. Ride it and see how it feels.

Something I am thinking through after my weekend trip this weekend is stretching the trailer frame further. The reason is the longer the wheel base (distance between the trailer axle and rear axle of the bike) the better the trailer handles given the same load etc. If you imagine the tongue of the trailer being a lever - the longer the "lever" the less force it takes to move the load - think side to side. Flip that around. Make the load what starts the force. The longer the tongue the less that force affects what is pulling it.

If you have much mass behind the axle of the trailer then the handling of the trailer is going to go down the tube pretty fast - regardless of the tongue weight. So if you can get the load pretty much right on top of the axle or in front you'll be off to a good start. The longer the tongue in this scenario, also, the less weight you have on the tongue. Again, you do want some weight on the tongue - just not a lot and you don't want it very light, either.

eggnoggbubble

ok great, thanks for the extra details, yes I was figuring the tongue would need to be pretty long, the original tongue of the instep is just two bits of square pole bolted together so it'll be super easy to add an extra piece (on another thread someone suggested that making that tongue a triangle will dramatically improve handling). I see what you're getting at with rear mass and tongue weight, looks like I'll be making this trailer pretty long.....

thanks for the help, gonna go down to my LBS soon and see about some wheels as the first step...

KC8QVO

NP good luck with it.

If your trailer uses stub axles like what I am working with - post up what you find on wheels. I haven't had much luck yet finding stub axles. There are two common bicycle style hubs - cone and race and sealed cartridge bearings. You don't see too many sealed cartridge bearings on bicycles, per se (they do exist), but on trailers they are very common. Check out the Bikes At Work trailers for an example. They use composite wheels and solid axles with sealed cartridge bearing hubs. Interesting idea.

That all having been said - the "stub axle" type set up on the inexpensive kid trailers don't seem to have too many replacement parts easily available, at least that I have come across yet.