Fabricating a Transportation Fixture for Off-Road Tandems

Background:

The Tacoma with the Triplet on Top

Regular, long-time readers may recall how back in November of 2018 we traded-in our 2006 Toyota Tundra / tandem hauler on a newer, smaller 2017 Toyota Tacoma long-bed pick-up.  Like our 2006 truck, I had this one fitted with a lockable A.R.E. camper shell so we’d have a dry and secure place to transport and store our tandems at cycling events and, well, a long-enough roof line for hauling our triplet. However, since the Tacoma’s long-bed, while as long as the Tundra’s, wasn’t as wide I wouldn’t be able to roll the tandem in with just the front wheel removed as I’d done with the Tundra and the two Chevrolet Suburban’s preceding it. Instead, I’d need to fabricate a fixture that would hold the Calfee tandem upright without its wheels so it could be slid into and out of the enclosed bed, which is how I transported our 1997 Erickson when I was still driving my 1989 Toyota SR5 X-Cab truck. Here’s a link to the full blog entry for anyone who’s interested: https://tandemgeek.wordpress.com/2019/01/12/fabricating-a-tandem-transportation-fixture-for-the-tacoma/

Realizing a New Transportation Fixture Was Needed:

The Calfee on it’s fixture in the Tacoma

I brought home another Fandango demo tandem — this time a DC-9 — on Monday, 16 August, laying down in the back of our 2017 Tacoma with the tailgate down: a far-less than ideal approach. I’d previously transported a demo Fandango GiGi and our Ventana on the tandem transportation fixture I’d designed around the dimensions of our Calfee road tandem. However, for both of the larger, off-road tandems it was less than an ideal fit where either seats had to be lowered and/or handlebars loosened and moved so the tandems would fit in the truck with the A.R.E. camper shell closed.

Note: Relative to keeping these fixture’s from moving around in the back of our truck, the tandem frame and fixture sit caddy-corner in the truck bed with the rear drop-outs pushed-up against the front, left corner of the bed: this ensures the rear derailleur is sitting in the deepest part of the corner where it’s protected and kept out of contact with the side or floor of the truck bed. At the other end, I attach a bungie chord to the fork holder at the rear, right corner to keep it tight up against the side of the bed. This also keeps it from shifting rearward which keeps the rear drop-outs firmly in the front, left corner of the bed and, for the off-road bikes, keeps the right handlebar end from rubbing up against the rear glass door: not a good thing. I do the same with the road tandem for the same reasons, even though it’s just the right rubber brake hood that ends up rubbing on the glass door and would also mar the window tint.

With that in mind, after getting the Fandango DC-9’s riding position sorted-out and the bike cleaned-up I did a “test fit” of the big bike in the back of the truck using the Calfee’s fixture on Wednesday. Sure enough, the saddle on the Fandango DC-9 needed to be dropped and the front handlebars had to be loosened and rolled-back to get it through the door: it was just too tall. And, even though there would only be a few times when this particular demo Fandango DC-9 would need to be pulled-in and out of the truck over the next week, I was cautiously optimistic we’d likely be replacing the Ventana with a Fandango in the not too distant future.

The moderate level of confidence was enough to compel me to go ahead and fabricate a 2nd tandem transportation fixture, but one designed with the taller off-road bike geometry in mind, e.g., a “Low-Rider” that would allow the tandem to slide-in and out of the truck bed without lowering saddles or repositioning the handlebars. I should note, the one I made for the Calfee needed to be tall enough to accommodate the larger drive and timing rings, but the Calfee’s drop-bars off-set the extra height so the Calfee could be slid into and out of the truck, narrowly sneaking under the camper shell’s rear door frame. My sense was, if I could position the center support piece below the two perpendicular support pieces that keep the fixture upright, I’d gain a 1/2″ of clearance. I’d also be able to use a lower-profile rear support cradle for the boom tube that would gain me another 1/2″ as would the 15mm x 100mm thru-axle alloy fork mount vs. the old Rhode Gear Shuttle System fork mount I used on the Calfee’s fixture due to the smaller drive and chain rings on the Fandango’s. Yes, it’s amazing how much a 1/2 to full inch can come into play when trying to get a tandem through the back door of a mid-size pick-up truck with a camper shell.

Fabrication of the Low Rider, Off-Road Tandem Transportation Fixture:

It was around 5:00pm on Thursday, August 19, when I headed over to Lowe’s to pick up a 1″ x 4″ x 8′ piece of sanded pine, a 2″ PVC Clean-Out T-Connector, a 2″ threaded plug and the hardware I’d need to put it all together. Back at the house I knew I had a second “Wrap-It” Velcro strap left over from the two-pack I bought when I fabricated the first transportation fixture as well as everything else I’d need to fabricate the rack on Friday.

The Fandango DC-9 on the “Low Rider” Fixture in the Tacoma

It was around 10:00am when I pulled-out my chop-saw, took a few measurements off the Calfee’s fixture and then figured-out how many pieces of wood I needed to get out of the 8′-long pine board and then had at it. The only unique feature of the low rider was having to cut and attach four 3″ x 4″ blocks to the underside of the ends of the two perpendicular support pieces since they’d be attached to the top of the center support piece instead of under it. After that, it was just simple “drilling & filling” four countersunk holes to connect the three major pieces of wood, then using 1 1/2″ wood screws to attach the 4 blocks of wood to the underside of the support pieces and then positioning and attaching one final 2″ x 4″ wood block to the center support piece where the boom tube cradle would be attached.

I would note, the cradle’s base was far more simple than the one I fabricated for the Calfee. For this one, I merely used two 1 1/2″ wood screws to attach the threaded 2″ PVC clean-out plug to the 2″ x 4″ wood block which secured what would be the “base” of the cradle to the block as well as the center support piece. As with the Calfee’s actual cradle I merely had to shave off the top-half of the 2″ PVC Clean-Out T-Connector with my chop saw, painted and then threaded it onto the clean-out plug. Well, threaded-on after cutting the end of the “Wrap-It” with the Grommet off so I’d have the two ends that get screwed into either side of the cradle and then foam padding wrapped with black Gorilla-brand duck tape is added to the cradle so it will have a no-mar surface for the boom tube to sit on.

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It’s the Details That Make the Difference:

Remembering the tandem and fixture are pulled-up against the right-rear corner of the truck bed and camper shell with a bungie chord to keep it from shifting rearward, there was also an issue I detected where the bar-end on the Fandango would end-up rubbing against the camper shell’s side tinted window and screen, so I fabricated a plastic “shield” attached to the window frame with Velcro to protect both the bar-end and the window/screen (see photo below).

When we were demo’ing the Fandango GiGi back in November 2020 I bought a 15mm x 100mm thru-axle alloy fork mount for the rigid EDGE fork I still had on hand. However, the MRP shock fork is a “boost” model with a 15mm x 110mm thru-axle, so I had to modify a 10mm-wide nylon bushing to work as a spacer. I’ve since tethered the bushing to the fork holder so it doesn’t go missing when the frame isn’t in use.

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Update: After buying the Fandango DC-9 Demo bike I went in search of a 15mm x 110mm fork mount so I wouldn’t need to mess around with the spacer long-term and was surprised how hard they were to find. There were adapters out there for 15mm x 100mm fork mounts, but that’s not what I wanted and they came in sets that were about the same price as some fork mounts. I finally stumbled upon the Truax Bike Mount Carbon Fiber Store on ebay and they were offering a number of different products made using 3D Printed, High-Quality Carbon Fiber, Polyethylene Terephthalate Glycol Material. And, sure enough, one of those products was 15mm x 110mm Thru-Axle Boost Bike Fork for a mere $13.99, including shipping. It arrived via FedEx in a mere 4-days from Ormond Beach, Florida, and it took me no time to swap-it out with the 15mm x 100mm mount. Heck, I even lowered the front end of the tandem in the stand another 1/8″. The Truax Bike Mount is a really a nice product in case anyone is trying to find a 15×110 fork mount.

The Calfee & Off-Road Tandem Transportation Fixtures

So, here’s what the two different fixtures look like sitting side by side with tandems fitted. And, yes… those small differences and adjustments allowed the “Low Rider” to meet it’s design objective: loading and unloading the off-road tandem without having to lower or loosen any hardware on the bike. Yes, it’s a tight fit, but one that can be accomplished using just a little bit of care and attention to detail, which is true of the Calfee, e.g., Debbie’s handlebar mounted Garmin computer either needs to be rotated forward on the bar or removed: it’s that close! Same thing goes for the Fandango DC-9: it slides in without coming in contact with the camper shell door, but only if you carefully guide the bar-ends through the two large camper shell rear door hinges.

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BUT WAIT, THERE’S MORE! The Wheel Caddie / Bike Stand

The Problem Statement: There’s Got to be a Better Way to Carry Those Wheels

When we used the off-road tandem fixture with the Fandango DC-9 for the first time this past Sunday I quickly realized using a a long bungie chord to hold the very large wheels and tires up against the sides of the truck bed: (A) consumed a lot of valuable, prime-location luggage/equipment storage space, (B) would make a mess out of anything if we ended up riding through mud, and (C) just didn’t look tidy. So, I needed to figure out how best to carry those big tires so they could be put in the “dead space” behind the tandem that’s hard to access with the tandem in the truck bed while also keeping them separated from any other luggage and gear and not having to sit on or against the BedRug liner.

The Solution: Fabrication of a Wheel Caddie

My first thought was, hey… I’ve got a couple wheel bags at the house, both single and double wheel bags. But, then I remembered just how large these 27.5″ x 3.00″ wheels and tires were and quickly ruled out the use of those bags: the singles are tight fits even for 700c x 28mm wheels and tires and my 26: mountain bike wheels with oversize tires barely fit in the double bags no way these 28.8″ tall wheels / tires or potentially 29″ tall wheels / tires would fit.

My next thought was to fabricate a wheel caddie out of PVC pipe and fittings, something I’d seen used in the back of open-bed pick-up trucks to haul multiple mountain bikes in a quasi-bike rack configuration. If I limited my wheel caddie / rack to just the two 27.5″ x 3.00″ wheels it would easily meet all three of my design criteria, so I did a quick check of the Internet to find where someone had taken the time to share their own design of a simple four-place, two bike rack made out of PVC and then created my own design roughly based on their dimensions. My conceptual drawing allowed me to figure how many feet of PVC pipe and the number and type of fittings I’d need for a basic prototype I could then easily “tweak’ by changing the length of the pipes and/or making some other changes to the basic design.

As before, I headed over to Lowe’s (they give veteran’s a 10% discount every day) to pick up the PVC pipe and pipe fittings I needed to make my wheel/tire transportation fixture. I had left-over PVC primer and glue at home and was about all I needed, pending any other changes I’d like to make after seeing how well the prototype worked. The trick would be getting the dimensions right so it would hold the over-sized wheels & tires in such a way that kept them off the bed of the truck and sitting deeply enough in the fixture to keep them from rolling out when the truck accelerated or went up a steep hill, while taking up as little room as possible.

Back at the house, it only took me a couple of very hot, sweaty hours to cut the PVC into “approximately” correct lengths and then dry-fit those pipes and fittings into the basic frame design. While it worked, it just wasn’t quite right. The wheels just didn’t sit in deeply enough to resist rolling-out with just a moderate amount of leverage and they also didn’t sit up high enough to allow me to put a towel under them if they ended up being wet or muddy.

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I ended up making a few adjustments such as adding a pair of short, front legs and altering the length of 8 pipes to rotate the fixture a bit further back so the wheels sat more deeply in the fixture, but still didn’t end up sitting on the bed of the truck. And, as you’d expect, once I had the “functional” design features taken care of I felt compelled to give the fixture a paint job, pure vanity so I excluded that cost from the project which then came in at nearly the same cost as the wooden tandem frame transportation fixture: about $24.

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So, I’m pretty pleased how the final product appears to have met my design criteria: it allows me to put the wheels & tires in the back corner of the truck where there was “dead space” behind the tandem, freeing up valuable bed space for luggage, and providing for separation from the bed liner and luggage, so long as I pack carefully and the wheels stay put, which I believe they will.

As an added bonus, and although not originally part of the design criteria, the wheel caddie will also function as a light-duty bike stand, which is really what the original design I based this upon. Because of how deep it is, it’s not something that can be used for holding a rear wheel due to interference with the rear derailleur — something that happens with even mass-produced retail bike stands — but it works well enough with the front wheel but, again, only for light-duty. There’s just not enough mass/weight in the stand to deal with the leverage that comes from a 40lb, 8-foot long tandem if it leans in one direction or the other. So, at a minimum, it could be used at the truck when installing mud-guards or some such instead of leaning the bike up against the truck. As for using as an unattended bike stand in, say, a tandem storage area… probably not a great idea: it takes up too much valuable floor space and, again, would allow the bike to fall if it was bumped hard-enough in the wrong direction.