Efficiency test Geared vs Direct Drive Hub motors

[DogDipstick]

New DH racing rims and tires are tubeless, beadless, and we ride them with Cush Core inserts and slime. Better flat protection than most motorcycle tires. And they are softer gum than most motorcycle tires too, giving the extra grip to ride fast on a light weight bike. They have a short life of course, but that is the price to pay for a better ride.

Also very very expensive,...Name brand DH blingy DH rims start at 200$ for the RIM ONLY..... then the sky is the limit. I bet you could spend 1000$ on a name brand Dh rim/tire/hub/spoke setup....

and I doubt a DH tire is better flat protection than a 4ply MC tire. Uhtnt-Uh. My tire cost 32$. Rim 40$. Spokes/Nips 18$, hub 40$. ~$125 for the whole rolling getup. All cartridge bearing name brand and proven on ebikes for a little while now. Gonna give me more miles at 8x the power as my generic Kenda bike tire that only lasted 1000mi. Yes, the 4.9 lbs might be worth 875$ to some, but not to me.

Did you go with a HD or UHD tube?

Lots of flat tires, are apart of my riding experience as of late.

The lightest smallest one. The HD. Not the heavier one. Working fine. The option was a HD or UHD 2.1"-2.5" tube, or a 2.5"-3"... I use the 2.1"-2.5" lightweight duty tube. Cheapest and still has a threaded strong MC stem. Now I've yanked it.. hard.... so hard I bet a normal bicycle tire would have slipped the rim and torn the stem.

 

[markz]

The lightest smallest one. The HD. Not the heavier one. Working fine. The option was a HD or UHD 2.1"-2.5" tube, or a 2.5"-3"... I use the 2.1"-2.5" lightweight duty tube. Cheapest and still has a threaded strong MC stem. Now I've yanked it.. hard.... so hard I bet a normal bicycle tire would have slipped the rim and torn the stem.

So, you use the threaded part of the valve to lock the valve to the rim?
You must be using the rim lock to secure tire?

 

[Balmorhea]

When a tire slips with a metal stemmed valve, whether one of those threaded moto valves or a bicycle presta valve, the valve tends to tear out at the tube surface. Threaded valve bodies are not more reliable than ordinary Schraeder valves; they have a lot less bond area between the rubber and metal.

 

[DogDipstick]

I use the nut only to install. Then lock the valve cap. It is not for rim locking.... Just ease of install. Still 10 x more durable.

You leave it loose so hard flexing don't tear the stem.... You don't lock it down like that. BMW Motorrad is where I learned this..they recommend using it only for installation ease. .. NOT to clamp it down but leave it screwed up against the valve cap. This is the proper ( lesser known) way of using a threaded mc Schrader with an installation keeper nut on the stem. Most think it should be screwed down against the rim.... But that makes no flex. Listen to whomever... I listen to BMW Motorrad manuals.

You want it to flex a little or you get torn stems. I'll upload a pic. Presta stems are weak as F. Same with bike tube stems. Junk. No life depends on it. Lol.

I have ripped off both stems on my 150hp literbike a couple times ( at speed even). Ironically never happened with my 180hp liter bike that bike came with metal stems. Lol. They were tubeless stems though.... Began using metal ones all around.

 

[neptronix]

If you're wanting to prevent flat tires on city streets, moped/motorcycle tires are still the best way to go. The thickest bike tire i have ever measured has only 7-8mm of rubber, whereas 11mm ( beyond the average length of a goathead ) of rubber is pretty common for MC tires.

MC/moped tires also tend to have harder compounds, so something is less likely to slip through.
A goathead will go through even tire strips because those strips don't cover the sides of the tire. And i've had tire strips actually puncture my tubes before :/

So far, no bike tire based gimmick has worked for me over the last 10 years to prevent goathead punctures.. i can find dozens of them in my tires per ride at times, too. Never had a flat from them with MC tires.

I did some tests on tire thickness in this thread if ya wanna read:

https://endless-sphere.com/forums/viewtopic.php?f=2&t=97992

The cush core system won't help here because it is based on using thin walled bike tires as well, and the air is on the outside. I imagine it's great for preventing pinch flats though.

 

[Balmorhea]

The most promising bike tire enhancement I’m aware of is Tannus Armor.

Tannus mostly made airless tires until recently. Their innovation is a very thick tire liner made of the same sort of foam, but sandwiched between a normal tire and a normal tube. I haven’t tried them myself, but if I lived in goathead country I surely would.

 

[neptronix]

okay that's interesting! coincidentally, that company is located in my area, aka goathead hell :thumb:

 

[amberwolf]

i guess this is really ot, but it's interesting; i had just seen those on amazon last night when looking up the cushcore mentioned by madrhino.

i saw that cushcore (tubeless only, as it sits against the rim itself) could be used as a run-flat option to prevent tire/rim destruction for an emergency after a flat, where you don't have the option to stop and fix it or to just walk it. but i don't really want to go tubeless (at least not unless i get tires / rims / etc designed for that; not sure it would really be better).

according to this site
https://www.messingschlager.com/en/brands/tannus

If you do get a flat tire you can still ride for a limited period at up to 10 km/h without damaging your wheel.

they make a range of sizes
https://www.messingschlager.com/en/products/puncture-protection_t46/tannus-armour-3in1-20-x-1.95-2.5-puncture-protection-tire-liner_a519126
though the largest 20" (the size i'd need for one trailer and for the sb cruiser trike) is the 1.95"-2.5". not sure that would be large enough for the shinko sr 714 2.25" moped tires i'm running on there (which will go up to the 3" version as soon as i can rebuild the frames to allow those to fit).

the 26" x 2.5" versions would do fine for the main trailer (or front wheel of the trike), but it would need four (it uses two wheels on each side like independent duallies).

 

[MadRhino]

There is a variety of tire foam inserts now. They are catching up in DH racing like they became the norm in off road motorcycle racing a decade ago. The Cush Core are improving the tire action and let us ride lower PSI, making them the favorite right now.

Of course, it is an expansive solution, like any other racing aftermarket components. Yet, DH bikes are now coming stock with tubeless rims and tires. The variety of tubeless tires availability is growing fast, some extremely resistant with radial high tech fibre plies. Expansive tires as compared to motorcycle tires, but they are another world. We can’t compare a modern DH racing fork with a MX fork that is many times the weight and primitive tech. Same goes with tires. If you find that you can speed safe on moped tires, you'd want to ride on walls with DH racing tires.

 

[DogDipstick]

We can’t compare a modern DH racing fork with a MX fork that is many times the weight and primitive tech. Same goes with tires. If you find that you can speed safe on moped tires, you'd want to ride on walls with DH racing tires.

I believe you about the sophistication of some tires for bikes.. but..

I can absolutely compare a modern DH fork to modern MC suspension. THe MC suspension is better, pound for pound and damp per damp and rebound per rebound. Very light, responsive, modern cartridge design with adjust ability in five areas without openig the fork... Tune with stacks and oil.

My "modern Dh fork " is nice.. but only has one spring, no high and low speed, and very simple rebound and compression adjustment. No external preload. Modern MX forks have all that.. plus DLC and are usually identical ( my Dh fork isnt)... and actually have two spring.. fact is a fork build around one spring is a horrible design. I have never seen high and low speed, or DLC coating, on any bicycle fork.

I am sure there are better (35mm?)DH forks than mine, but still, (40mm-45mm) racetech or some other MX fork > (greater than). Plus you can custom tune them, easier than a DH fork.. the shim stacks and custom tunes are very much more integrated into the user ( racing) demographic... That I know from..seeing what is availible for bothin the open market... I came from MC though, not MTB for my Ebike career. Mebbe a lil biased. They are long and leggy, and if I could have a Showa 45mm SSF racetech or a brand new DVo on my bicycle, I would decide on the DVo cause 'Blinngy... but if I was building a lawless performance ebike, it would be moto forks.

 

[MadRhino]

I can absolutely compare a modern DH fork to modern MC suspension. THe MC suspension is better, pound for pound and damp per damp and rebound per rebound. Very light, responsive, modern cartridge design with adjust ability in five areas without openig the fork... Tune with stacks and oil.

My "modern Dh fork " is nice.. but only has one spring, no high and low speed, and very simple rebound and compression adjustment. No external preload. Modern MX forks have all that.. plus DLC and are usually identical ( my Dh fork isnt)... and actually have two spring.. fact is a fork build around one spring is a horrible design. I have never seen high and low speed, or DLC coating, on any bicycle fork.

Well, you haven’t seen much in DH racing forks. Low/high speed compression and rebound control are implemented for a long time already. Remote tuning options and presets on the handlebar, more recently. No springs on most racing forks for a decade. They are now used on trial motorcycles in competition, for their low weight especially. 6.4 lbs.
MX forks are more robust, much heavier because of the big jumps, but now mimic the tech evolution of DH racing forks, a few years behind.

Now, I like the DVO but it is still old tech, and not seen much on WC tracks. I would never build an ebike with a motorcycle fork, nor motorcycle wheels. The weight is prohibitive, and does escalade: extra weight of motorcycle components are making for the need of a bigger battery, and the extra weight of a bigger battery is calling for more motorcycle components...

 

[markz]

Motorcycle fork makes little sense.
Motorcycle rims and tires makes sense for some with problems related to flat tires.

At a certain point, some just give up on counting ounces.

 

[DogDipstick]

Well, you haven’t seen much in DH racing forks. Low/high speed compression and rebound control are implemented for a long time already. Remote tuning options and presets on the handlebar, more recently. No springs on most racing forks for a decade.

... mps, but now mimic the tech evolution of DH racing forks, a few years behind.

Now, I like the ..

Correct. I have not seen many. Thankyou for the info.

 

[Balmorhea]

Motorcycle fork makes little sense.
Motorcycle rims and tires makes sense for some with problems related to flat tires.

At a certain point, some just give up on counting ounces.

It’s not the ounces that bother me about motorcycle parts, it’s the kilograms. It makes me tired counting all the extra ones.

Most MC parts are horrendously underperforming for their weight. Even if you scaled them down to bicycle proportions, they’d still have the qualities of the cheapest and nastiest bike parts.

 

[DogDipstick]

No springs on most racing forks for a decade.

... mps, but now mimic the tech evolution of DH racing forks, a few years behind.

Now, I like the ..

Also, of note, I think air springs are inefficient, worthless in EV, high speed, or reliable use. Air springs being in modern forks are a downfall. Junk. MC tried air sprung suspension, if it was any good the OEM of the world would use it. None do, like cars and trucks and race mc and whatnot.. yes there are airbag trucks and fancy caddilac/mecedes air rides but for the most part it is a tuned spring oil, and nitrogen in a tuned damper.

Something you dont see in DH fork ( nitrogen over oil,..? or oil valving?) . Air springs are junk for good motorcycle suspension design. If they were good the race bikes ( machine powered, not human) would use them.

I am pretty sure the consensus is that air forks and air rear shocks are not good for ebikes and a good coil boxxer ( even with its 1 ( single) spring coil) or coil DH shock is better. . Cost, reliability, bling/mile ratio.. you know... Arnt the "Zoom" air forks Dh junk? DNM? Too? So you have to pay out the ass for a good 2018-2020 DH fork and get air, high pressure, rebuilds, and chips from EV use.. ?

What do they do to the aluminum tubes? Nickasil it? Nikasil sucks. Gimmie chrome/steel of the Domain over the Nikasil/aluminum of the Boxxer.

just learning more here, thanks for humoring me. While pedaling involved the bob puts the spring and suspension choice under a microscope for our applications and efficiency. I get really good efficiency on my bike I think.

 

[markz]

I'd still rather add a kg then deal with a flat every week.

 

[DogDipstick]

How do you calculate rolling resistance in a rubber / asphalt scenario? Anybody know? How can you compare across brands / treads?

 

[Balmorhea]

How do you calculate rolling resistance in a rubber / asphalt scenario? Anybody know? How can you compare across brands / treads?

You calculate rolling resistance by testing it. But you can make a good educated guess based on tire casing stiffness, tread rubber thickness, and the % area and height of tread features. The more rubber being flexed and distorted, and the greater the amount of deformation, the more rolling resistance. Moto tires have thick tread rubber and stiff sidewalls, so they’re slow. Off-road tires have a lot more distortion in the tread elements than smoother tires, so they’re slow. Knowing what the tread looks like tells you a lot. Knowing what the tire weighs tells you more, and being able to feel and flex the tire usually fills in the blanks for you.

The most efficient and comfortable tires have thin supple sidewalls, thin slick tread rubber, and no anti-puncture belts. Such tires are very easy to puncture, so almost everybody uses a tire that offers some kind of compromise between flat protection, durability, ride quality, loose surface capability, and efficiency. For me, the sweet spot is a tire with textile armored belting and moderately thick but smooth tread rubber, like CST Sensamo Master, WTB Thick Slick Deluxe, or Panaracer Ribmo. If I rode on dirt more than once in a while, or if my riding area were relatively free of glass, wires, and thorns, I’d probably make a different kind of compromise.

I think moto tires definitely have a place along that continuum of performance compromise. I also think that place implies some other features, like registration and insurance.