merlinextraligh

^^ Thanks,

I’ve learned a little more talking to Jason at Calfee. The adventure tandem has a bit different geometry than the standard road Calfee. Specifically, it has less drop to give a higher bottom bracket height, for better off road clearance.

Because we want the bike to handle on road as close to our Dragonfly as possible, and it won’t get much if any single track use, iinstead of getting the Adventure, we’re going to do a custom Tetris, with the customization consisting of clearance to allow up to 50mm wide tires, and extra reinforcement for stiffness.

The reason for going with a Tetris frame rather than the Dragonfly is that the thicker tubing is better suited to resist impact damage off road, and it will be a bit less expensive, on bike that is not going to be a total weight weenie build

akexpress 

so you are basically building the same bike we built ! Fork choice is the main issue and changing head tube angle to match your Draginfly riding characteristics. I worked with Michael at the time but Jason had just come on board at Calfee during our build. Your rationale on a tetra is right on in my opinion. Our dedicated road Calfee is also a Tetra since we travel so much with it I sacrificed for durability and since we have 4 couplers it seemed a shame to do a Dragonfly but I envy yours.

akexpress 

We have a 29r Ventana full suspension tandem so we did not design the Calfee for single track riding

merlinextraligh

So we put down the deposit to start our build. I spec’d Calfee’s house brand rims, 50 mm deep, 28 spokes. 142 through axle hub. They’ll take tires from 25mm road tires to 45 mm wide off road tires.

short term plan is just to swap tires as needed. Eventually, these wheels will keep skinny road tires on, and we’ll get a second set of wheels for a set off road tires. I want the second wheels to be robust for off road use and touring with a moderate load. Any thoughts on rims for those?

akexpress 

We ended up with a set of Nextie Carbon 30mm wide rims on DT swiss hubs in 27.5 diameter and have run 47mm tires for those applications with good results. There are a lot of tire choices in that configuration and we only loose about 1/2 " of ground/pedal clearance and have not had a problem with that. I like the strength of the carbon rims and I think there a number of good choices available. We have had no issues running 28 spokes on these rims. Are you building it with electronic shifting and hydraulic brakes?

merlinextraligh

Yes Di2 and hydraulic brakes

akexpress 

FYI If you use the latest shifters ( Dura-ace or Ultegra) you will have to use Shimano BH90 hydraulic hose as Goodridge does not make the correct fittings for the shift lever end. Also these are designed for and come with flat mount brakes and the rear of the Calfee is a ISIS mount and usually requires an ISIS to post mount adaptor. There is no ISIS to flat mount adapter made. Also Im not sure the available fork choices for your intended purpose are also not flat mount compatible. The solution is a use the old style calipers. I am helping a friend rebuild his coupled Tetra and ran into these problems. We did order a flat to post mount adapter but this requires a adaptor to an adaptor and we haven't tested it yet as our plan for brake hose was foiled as we were planning on the Goodridge hose and had to order the Shimano hose.

merlinextraligh

Unfortunately, Calfee production is currently halted due to a shelter in place order in Santa Cruz County. We can wait for the bike, but i feel bad for the workers not able to earn a living.

merlinextraligh

So the frame is almost done, and we have settled on the final parts build.

Pretty much straight Ultegra Di2 with FSA cranks, and Calfee branded rims.

I went with Hope brake calipers with the hope that they are a bit more robust, than Shimano’s road calipers.

twocicle

Interesting. I wasn't aware of the Shimano compatible Hope road calipers.

FWIW, we run full Shimano hydro brakes on both our road (rs785 dual piston) and mtb (M8000 4 piston) bikes. Holding up and performing well.

merlinextraligh

I’m confident that the Shimano calipers would have been adequate. However, we are a llarger team (around 340 pounds) will add some weight in luggage occasionally, and have some 20% descents.

So for less than $100 and maybe 50 grams, thought the Hopes would be worth a try.

Also, the red anodized calipers work with our color scheme!