Red Bikes: Dolan Disc³

Now I've realised this it's excellent work.

Silly/advanced wheel build:

Front disc wheel with 16 paired spokes

Parts:
Shimano m758 32h 15mm disc hub
Halo aerowarrior 32h rim, drilled with new internal holes.
DT Swiss New Aero spokes + oversized washer + brass nipples
Impro 15mm -> 9mm axle (until I get a better one)

It has a 1 cross disc side/1.25 cross non-disc side spoke pattern. This combined with the very solid m758 hub should give equal braking torque to both sides of the wheel (did some calculations :)) so I still have 8 leading spokes resisting the brake forces.

The spokes are laced head-in on the disc side and head-out on non-disc side. The rim is drilled slightly offset. This moves the wheel dishing offset back from 5.5mm to something like 1.5mm.

The tighter spoke spacing means the wheel is only useable with slim hydraulic brake calipers, but as a plus the wheel is nearly dishless.

Internal nipples because reasons. (actually saves something like 1 watt of aero drag at 30mph...)

Impressions after 2 weeks of use:
Seems solid enough. Slightly flexier side-to-side/lateral than my previous wheel (24 of the same spokes in normal lacing on the same rim).
Braking torque resistance should be the same because of larger flanges, but is hard to judge (feels the same).

watch out for those forks, a messenger in stockholm snapped both fork legs on his last week .. :(

4 teeth out..

(your old one or another sample?) Sounds bad. The quality varies alot so I guess it is a lottery.
Do you have a picture?

thanks for the heads-up

yeah as you said, lottery on those china parts.

i will ask the guy for a picture, just heard the word on the streets, it snapped in joint betwwen carbon and aluminium.

Wheel on bike

Gusset porn thread >>>

Is that wheel suited for disc?

Rad bike is rad.

Wow Nice for the disc brakes :) ! Could you do holes for internal cable passage ? Or is it okay for you Like that ? (Sorry for the mistakes my english is not perfect)

Thanks

Is that wheel suited for disc?

That was the idea :)

Actually my guesstimate calculations show that a 20 spoke wheel should be optimal. If the wheel is built so the hub/flanges/spoke pattern transfers 50% of the braking torque to the non-disc side spokes, there should be less stress on each spoke compared to a more normal 24 spoke wheel.

16 spokes is probably pushing it a little...

The frame is aluminium so I wont drill holes in it. But I have thought of the second best solution: fairings! I have access to a plastic 3d printer and have previously toyed around with the idea of various aero profiles where the hose could run inside.

Some test for the old pompetamine frame:

There is still the problem of weight (could be a lot of abs plastic) and time to make it.

Okay :) I think it is better without fairings, but even if my question seems a bit stupid, if you drill a hole in the tube, it may cause a rupture point ?

Yes I think so unless the hole gets reinforced (=aluminium welding)

In the interests of crazy invention I think you should make them.

haha thanks, i´ll get on it then...

I made a mock-up disc cover about 2 months ago:

Made of old printing press plates: 0.5mm aluminium sheets + electrical tape. A slight cone shape.
It was really fun to ride with and the placebo feeling was strong! Felt faster. Especially in the wind. Gave a sort of a planted feeling. The "weight" center is pushed backward. And definitely free speed with the wind from the side/behind.

Why aren't more people riding with disc wheels all the time? :) ...Ok I live in Denmark and probably don't know the meaning of real hills...
The tape only lasted 14 days, and they were a bit noisy, like a lowkey bakingplate thunder rumble. But I am a fan and am looking for a more permanent solution with lighter weight and durability.

Now I also got a Specialized trispoke (from @JesperXT) and of course I had to try a disc-brake conversion. I am running it in reverse direction, using the freewheel threading for a rotor mount.

Again feels pretty fast and in the last 4 windy days great fun. It is like you are holding a sail in the wind and some turns are done leaning the bike slightly and turning the wheel the wrong way (sort of like speedway, drifting a corner). I haven't tried deep rim wheels before so maybe that is normal. But great fun.

The disc-brake setup is not too bad because I have earlier moved the hose to the bleed port and it is hidden behind the fork leg. So only half a caliper + a 2 mm disc rotor in the wind. Would probably be faster with a solid disc rotor.

There still lots of stuff to fix:
Somehow get threading cut on the other side of the hub so I can move the rotor over and run the wheel the right way round.

Cut 13mm off a front disc hub, get threading cut inside it and use that as an adapter, would be sleeker + one piece.

A axle with bolts ala tester's setup.

Some heatshrink for the fork leg + hose.

the disc brake caliper could also be placed lower/further down the rotor via an adapter. Then it would be hidden from the front behind the hub/axle

True frankenbike

yes! Thanks.

Your updates bring a smile to my face man.

Tubercles v0.5!

ABS plastic 3d print taped on to remove the sharp end of the airfoil. The wheel is mounted in reversed so the airfoil goes the wrong way... (because of also wanting disc brakes)

I will try to find some "car foil" to wrap each spoke for a better version. + print a new sharp trailing edge.

Does this offer any significant advantage?

Nature yo!

Also, one of the best threads on here.

Does this offer any significant advantage?

Luckily this question wasn't asked too often during this project.

Short answer: maybe... :)

Im still in the aero cargo-cultist category as I dont have a wind tunnel or power meter to prove anything.

But... there is research and practical examples that show that airfoils at that speed/size get a softer stall angle and lower drag after the stall angle. ei no benefit at 0 degree head wind but at 10-20 degree (sidewind) it helps. Softer stall should mean easier handling.

I mostly based this on this research paper as the speeds tested are near bike speeds: https://www.researchgate.net/publication/258246587_Performance_Variations_of_Leading-Edge_Tubercles_for_Distinct_Airfoil_Profiles

I still need to make a version with smooth transitions blending into the wheel.

A headtube with a big airfoil (15-20cm or more) is a another place where tubercles would work (coming later!). And a seattube leading on to a disc wheel.

So basically bumps everywhere...

This project just got more interestinger