Suggestions for a custom Gravel Tandem?

I noticed a couple members ride tandems, and am hoping for some pointers.  My son has Down syndrome and very short legs--he barely clears the standover on his 24" kids bike--but he is approaching the 85lb weight limit on and outgrowing the Burley Piccolo tag-a-long that we use for biking together (nothing demoralizes someone like being passed going uphill on gravel by a big, not-young guy towing his son on a tag-a-long).  I'm 6'1 275 and typically ride something like a 60cm road/gravel frame.   I'm thinking of getting one that can handle a pretty beefy 700c wheel-tire combo and start off at 650b and then as my son grows, we can increase the wheel and his crank size.

Any advice for such a captain-heavy combo?  With his future growth, we could top out in 400-425lb combined rider weight then add bottles, panniers/bags, spares, tools, gear for some bikepacking, etc. for a 450+ load.  Having read more about the importance of having most weight sprung by larger tires and/or shocks for speed/efficiency on gravel as well as comfort, I'm thinking a compliant front fork will help with front wheel stress as well as the efficiency of not lifting all that weight every time the front end goes over a bump.

Tandem transport logistics I guess are also a pain--either limit yourself to TRP brakes with cable connectors to be able to use the S&S couplers and commit to a fair amount of assembly/dissasembly or find a way to transport a 1 piece tandem--any advice on the extra $$ for couplers?  

The da Vinci Tandem Independent Coasting System looks like a good idea for us, so we don't have to pedal at the same time all the time, and they have built some Tall-Small combos in the past. Any other builders to look at who have a design like ICS that doesn't require synchronized pedaling?  

Titanium is awfully pricey right now--more than carbon--so for a first tandem, it looks like aluminum vs steel to give us strength and ability to put a fair amount of stuff on a rear rack to even out the weight distribution, and with the weight, wheel base and tire size we will likely use, it seems like aluminum would be plenty compliant.  Any recommendations?
 
Thanks.

Familyridz wrote:I noticed a couple members ride tandems, and am hoping for some pointers.  My son has Down syndrome and very short legs--he barely clears the standover on his 24" kids bike--but he is approaching the 85lb weight limit on and outgrowing the Burley Piccolo tag-a-long that we use for biking together (nothing demoralizes someone like being passed going uphill on gravel by a big, not-young guy towing his son on a tag-a-long).  I'm 6'1 275 and typically ride something like a 60cm road/gravel frame.   I'm thinking of getting one that can handle a pretty beefy 700c wheel-tire combo and start off at 650b and then as my son grows, we can increase the wheel and his crank size.

Any advice for such a captain-heavy combo?  With his future growth, we could top out in 400-425lb combined rider weight then add bottles, panniers/bags, spares, tools, gear for some bikepacking, etc. for a 450+ load.  Having read more about the importance of having most weight sprung by larger tires and/or shocks for speed/efficiency on gravel as well as comfort, I'm thinking a compliant front fork will help with front wheel stress as well as the efficiency of not lifting all that weight every time the front end goes over a bump.

Tandem transport logistics I guess are also a pain--either limit yourself to TRP brakes with cable connectors to be able to use the S&S couplers and commit to a fair amount of assembly/dissasembly or find a way to transport a 1 piece tandem--any advice on the extra $$ for couplers?  

The da Vinci Tandem Independent Coasting System looks like a good idea for us, so we don't have to pedal at the same time all the time, and they have built some Tall-Small combos in the past. Any other builders to look at who have a design like ICS that doesn't require synchronized pedaling?  

Titanium is awfully pricey right now--more than carbon--so for a first tandem, it looks like aluminum vs steel to give us strength and ability to put a fair amount of stuff on a rear rack to even out the weight distribution, and with the weight, wheel base and tire size we will likely use, it seems like aluminum would be plenty compliant.  Any recommendations?
 
Thanks.

We have a custom built co-motion periscope tandem, built with S&S fittings. Weirdly, it was built with clearance for eg 29x1.75 at the rear - which is fantastic. The front fork is a squeeze with 700x28. Customer support was nil but it is a good frame. 

Got our gravel tandem from Cycles Chinook:
https://cycleschinook.com/

It was full custom and had a great experience in walking through the design and parts. My wife (aka rear admiral) and I have been road tandeming since '92 and the Chinook was designed for gravel. But to be honest I've hardly had it on gravel. Here are some of the gravel specific changes:
Will fit 700x50 tires front & rear
Titanium will take a beating
Ergon seatpost for rear admiral
Custom wheels have mtb rims

Setup with linear pull rim brakes and a disc as a drag brake. On long steep downhills even 200mm rotors have been known to warp. Yes rim brakes can overheat but that's where the drag brake comes in.  The fork also has mounts for a disk just in case I ever want to go that way. The larger mtb rims dissipate heat better, this farther reduces the chance of overheating a tire.

Went with mechanical shifting and cable actuated brakes. The disc is a HYRD, cable actuated hydraulic. The choice to go with cables was primarily driven by the C&C couplers and not wanting to deal with hydraulics.

SRAM wireless shifters would be an awesome upgrade but wasn't in the budget.

The fit was based on my road bike and our old C'dale road tandem.

The Chinook's road handling is awesome.

For road riding the wide MTB rims work great with 32mm Conti 4-Season tires but causes the tires to measure a hair over 35mm wide.  Conti Gatorskin Hardshell would be a bit slower and more sturdy.  For gravel I have Kenda's Small Block-8.  Initially I had Panaracer Gravelkings in a 700x43 but they have soft rubber which kept picking up glass. The Conti's have been MUCH better (read: no more flats). I might try the GK SS+ in a larger size...

I'm running tubes as I only have one wheel set and swapping tubeless tires is a PITA.

The drivetrain is SRAM 11speed: 52/46 in front and 11-44 cassette and a Wolf Tooth Roadlink for the Force RD.

Hope this helps...

Anfielder wrote:

We have a custom built co-motion periscope tandem, built with S&S fittings. Weirdly, it was built with clearance for eg 29x1.75 at the rear - which is fantastic. The front fork is a squeeze with 700x28. Customer support was nil but it is a good frame. 

If you want a tandem fork for gravel I'd suggest contacting Cycles Chinook to see about getting a custom fork with larger clearance. They provided a custom Ti fork for our tandem.  Calfee seems to be dabbling in adventure tandems so they might have a fork with room for a larger tire.