bivinco

@ all
Would like to introduce a custom tandem bike which I build last year and was shown at the Bespoked in Bristol. Total weight was below 14 kg. Full disclosure: I am the maker of that tandem beauty which is made by HILITE-Bikes.
Rohloff Speedhub 14, SHIFT:R Road for Rohloff, Gates 2x39 CDX sprocket with the 174T belt (742mm boom tube), on 650b wheels.
The images are done by the photographer Ben Broomfield of the Bespoked/UK in 2019.
Looking forward for your questions and feedback. Many thanks and all the best

rocknrollin

Fantastic Build! Thank you for sharing it!

I have been trying to wrap my head around a single-sided beltdrive myself for the last weeks - mainly for a lower q-factor and more flexibility with the cranks. I've mainly been looking into cannondales modular cranks. Its nice to see a slightly different approach and that it can actually be done. Several questions come to my head:
How much space did you leave between the two belts/ at what chainlines do they run? I assume the Rohloff belt runs at 55mm.
Did you flip one of the gates chainrings? The teeth on the gates chainrings look symmetrical, so it should be possible. Flipping would allow to increase the spacing by an additional 1.5mm due to the asymmetrical flange offset, but i couldn't find any information whether people have done it before.
Was longevity of the timing chainrings a concern when speccing them? CoMotion uses 42t now, but both options are much smaller than the >66t that have been previously used for the timing chainrings.
Does the current drivetrain give some flexibility to change the sprocket ratio? And which eccentric BBs did you use? I couldn't find the exact fore-aft adjustment range for a Bushnell EBB, but I'd estimate it to be +/ - 8mm. That might allow to go up/ down by 2 sprocket teeth, without having to change the belt drive, depending on the chainstay and belt lengths.

Thanks also for pointing out the manufacturer, I was not aware of it. The pricing seems competitive for a Ti frame. Do they also build frames with S&S couplers? I could not see couplers on any of the pictures.

Russ Roth

Very sweet looking, I've been wondering at the viability of running same side driveline and using a triple crank to build a 2x drivetrain, this breaks it down further and looks very nice. The weight is also quite impressive.

lichtgrau

What a phantastic tandem. Living in Europe I know the brand Hilite, but I've never seen one of their fancy builds "in the wild" ;-)
14 kilograms is... redicolous. Please don't tell me that this weight includes fenders and rack (congrats to that decision, I've never liked being sprayed when riding without fenders...).
Long story short, great frame, great build, nothing to criticize

(colors are always a topic of individual choice, I'm just curious: Having a red front hub, didn't you think about a red Rohloff too?)

bivinco

We have finalized another custom made Rohloff race tandem with 14kg (w/o pedals). Very special about this tandem is the stoker boom tube is large size as the captain. The maximum stoker length w Gates parts is normally M size. We have to make some parts for that, without going into details. Due to limited availability of the Shimano XTR 985 crank, we used the Cane Creek eeWing and the Cane Creek Hellbender BBs.
In 2-3 weeks we will finalize another race tandem but with a derailleur, chain, and a belt for timing. Owner from the US.
P.S. Stoker handlebar tape was fitted after the image was done. Better images will be done in a few weeks.

CaptainHaddock

So aside from style, why do you prefer the lateral beam for your tandems (because I can't seem to think of the right phrase, I mean the tubing from the top of the head/steer tube, to the lower rear bottom bracket)?
Also, are you using a mono-gauge tubing, or some kind of butting schema?

bivinco

Besides from design, the additional tube increase the lateral and especially the BB stiffness. We have run a simulation on the different variations of "lateral" tubes and without. And our conclusion was that this type of lateral tube makes a profound difference.
Yes we are using tubes with different buttings to keep the weight low. The frame weight is below 3kg.

jonathanluu2

Where did you open the rear triangle to service/put the belt drive in?

bivinco

Hello jonathanluu2,
almost not visible. There is a Z-type with a formfit frame splitter welded into the left seat stay above the left dropout.

bivinco

I would like to share our latest build from autumm last year. Very impressive weight. Without the front carrier, hubdynamo, light system and TT extension the tandem is 12,5-13kg. With all that stuff it is 14.5kg.

Tandem with SRAM Red AXTS Etap

We have used SRAM Red AXS Etap combined with XX AXS Etap rear derailleur combined with the 10-52T cassette.

jonathanluu2

You got that right! I did not see any screws or anything to screw the seat stay together. Very clean builds. I like the simplicity of the black on metallic. Good work bivinco.

bivinco

You can see a very small gap and the end of two M5 screws which we sand papered. It is very clean and difficult to see even if standing in front of the bike.