BassNotBass

These are questions that I have that don't seem to be covered on the company or KickStarter sites in the specs or FAQs:

1. What is the gearing of the stock single speed? The specs don't mention chain ring or cog sizes which really would be helpful in figuring G.I..
2. Has the decision to use the S.A. 5 speed hub been finalized?
3. What kind of bearings are used in the wheel hubs and bottom bracket?
4. Concerning the wheels, are the rims double-walled and what type of spokes are lacing the rims to the hubs? What alloy are the rims? (In fact it would be nice to know the alloy of all aluminum/aluminium parts)
5. Is the swing arm bearing a proprietary one and only obtainable through Hummingbird? Is it a ball or needle bearing or bronze bushing type?

CliffordK

There are a couple of 5s options listed on the page, but you're right, I don't see a mention of IGH or Sturmey Archer. The BB pivot makes the IGH hubs a natural choice.

You might consider other hubs such as the Sturmey Archer S3X... for a rare BB folding fixie. Or, a Nexus or Alfine option, but those could come later.

BassNotBass

There's a FAQ section on the KickStarter page which answers the question, "What type of gearing will the 5-speed Hummingbird have?"...

A: "The 5 speed version will be an Internal Geared Hub (IGH). We are currently looking at Sturmey archer hubs with an integrated grip shifter."

fietsbob

the new ones
• Overall Range - 243%
• Gear 1 - 64% (Gear 2 - 25%)
• Gear 2 - 80% (Gear 3 - 25%) vs .75
• Gear 3 - 100% (Direct Drive)
• Gear 4 - 125% (Gear 3 + 25%) vs 1.33
• Gear 5 - 156% (Gear 4 + 25%)

prior 5 speed was a 3 speed and 1 gear higher and 1 (that .64) lower..

feijai

Recall that the tikit's pivot is in front of the bottom bracket. As a result the entire rear triangle, including the crank and chainring, are all one fixed unit which swings together; and the entire drivetrain is standard parts. This would be an awfully simpler design than the complexity involved in pivoting around the bottom bracket, particularly on a carbon fiber frame.

I can't envision why folding behind the bottom bracket would necessarily be a smaller fold: in fact in the hummingbird's case I think it'd be a bigger fold. But more to the point, it seems to me that folding in front of the bottom bracket is generally a simpler fold, since it's easier to rotate around without hitting anything (like the bottom bracket).

craciunptr

Hi All,

Thanks for all the feedback. Just to clarify a few things:

The Hummingbird is not a direct competitor with Brompton. We are trying to offer a different product.

The stock gearing for the single speed will be 9t 45t and 14t 45t for IGH. We will ask our backers what gearing they prefer as we can do 44-53 for the crankset.

All the bearings will be sealed cartridge bearings.

Rims are double walled we will use 7000 series aluminium.

The BB bearing is a Nylon gasket. Very easily replaceable, we will supply all spare parts.

As for the luggage capabilities I am working on our own bag design. The bike will be able to roll on the front wheel just like a cartwheel using the seat for steering.

BassNotBass

Thank you for taking the time to answer questions craciunptr!

Azreal911

9t and 45t for single speed? isn't that like ~90 gear inches?!?! wow you'd need legs of steel! my single speed is a piddly 60 gear inches so I save my knees going to work daily.

BassNotBass

I thought that is roughly 81 G.I. but then I'm just guessing at the circumference of the tires since different 16" (349) can vary. I normally prefer something in the low to mid 70s for my SS/Fixies, FWIW.

Azreal911

ah, i'm calculating them with 20" wheels which is what they came with but also 16" (349) is an option too. since it's a single speed hub you can probably swap out the rear cog easily for something less knee breaking.

and BassNotBass you have stronger legs than me! i popped in a cog to push my GI up to high 60's and then i was feeling it after a week on my daily commute so i backed off, need to save myself over fast cruising to work.

mingo

I really wanted to back this project by ordering a bike, but after paying close attention to how I use my Brompton, I've concluded that the Hummingbird will not be suitable for 2 reasons: Its folding size is not compact enough for me to carry it daily onto the crowded metro trains, and when it's folded, I cannot pull or push the bike through the corridors of the train station and the underground tunnels that connect my place of work with the metro station. Good luck with the project.

BassNotBass

What market/niche are you targeting?

craciunptr

Hi mingo,

To answer your two concerns:
- the Hummingbird id indeed a bit bigger than a Brompton when folded, but it is also twice as thin, so in the end the package isn't all that big.
- the bike does actually roll on its front wheel. If you use the seat mast as a steerer, it's actually pretty easy to move it around.

Also, the fenders could have wheels.

Hope this helps,
Peter

craciunptr

Hi,

We are trying to bring a modern folding bike to the market that puts its efforts into the innovative feature - the weight. We know that there are commuters out there that don't particularly enjoy carrying around a heavy bike, so we're trying to offer a new solution for them.

We want to create a good folding bike that takes into account the needs of commuters. Our bike is minimalistic, but it will be highly customisable and accessory-friendly.

Thanks,
Peter

BassNotBass

Uh yeah, "innovative feature - the weight"... I kinda got that innovative impression from the innovative sites.
Good luck with your innovative endeavor.

BassNotBass

A bit bigger? Can you provide a side by side comparison because honestly the 'bird looks quite a bit bigger. However since the Hummingbird doesn't compete with the Brompton (as you say) I don't know why you would make that comparison but if you refer to my 'box of rocks' vs 'canoe paddle' analogy in an earlier post you would understand why I think that your explanation doesn't quite jibe with reality.


If you could provide a demonstration of this it would be quite helpful. As I see it a person would have to lift up on the seat to lever the bike onto the front wheel and then push the whole assembly forward on a front wheel that seems to not be locked in place, kinda like a wheel barrow with a broken axle while only holding onto one handle, and would therefore wobble making the whole proposition a little awkward.


Sure. And the Hummingbird 'could' have Easy Wheels on the 'yet to be developed fenders' that hopefully will be sturdy enough to bear the weight but until you provide a working example it's all just speculation.


Petre, please excuse my previous mis-spellings of your name in previous posts, I'm merely trying to engage you in what you presume to love, as stated in your bio/pic.


-Jens Zastrow (aka BassNotBass... pic and actual name provided to make this a little more personable and on even ground)

BassNotBass

OK, blame insomnia or the fact that I usually go on 4 hours of sleep per night but I couldn't let this go. I took a pic of Petre's prototype with 16" wheels and compared it to a Brompton basing the overlapped images on the wheel sizes. Y'know, the 'Bird looks substantially longer than a Brompton so sorry Petre... your words are more than optimistic.


But right... it's all about the weight.

mingo

Thanks for saying and illustrating what I was thinking: To roll it on the front whee while folded, I was thinking the front wheel would wobble left to right and rub against the folded back wheel, and without a video demo, I don't see it as a viable solution. If you are able to post a video, please do. When folded, most of the time, I transport my Brompton on its easy wheels; the only time I carry it, is when going up or down stairs. A lighter bike would be nice, but it needs to be compact. For me, the folded size is the ultimate deal breaker, because seated on the metro train, the Brompton fits in front of my legs without encroaching on the leg space of the passenger next to me, or the aisle for standing passengers but parking the Hummingbird bike perpendicular to my seat would block the aisle completely.

invisiblehand

I think that with the handlebar against the side of the frame, rolling the folded bike on the front wheel would be OK. But it would not be able to handle a big lateral push unless the handlebar is locked in place.

My take is that someone thinking of a Mu Uno should be thinking of this bike too. Just from a few folks that I know, weight really matters since steps are a practical concern. Out of the box, I think this bike will be roughly 5 pounds less than most alternatives which seems significant to me. I do think that there are some rough edges to the concept at the moment. What precisely is one going to do with this front wheel for a more compact fold? Can the designers make it more rolling-while-folded friendly?

I think fenders are a must. The more I think about it, I doubt that people will carry a lot of stuff on the bike. I imagine folks using messenger bags and the like with it.

Anyway, if the alternative is a Mu Uno, that's a competitive price point.

invisiblehand

I think he's taking off the front wheel when making the comparison.

BassNotBass

The more I read and watch the video about the Hummingbird the more I'm doubtful about the seriousness behind this endeavor. Petre and co-founder Ligia have stated that there's only one prototype, the 16" wheeled version shown in the vid. That means every picture we see from the 16" vs 20" wheeled versions to the pictures of the various color combinations that supposedly will be available are just 'photoshopped' pictures of the one prototype in existence.

I knew a fellow back in the late 80s by the name of Brent Trimble. Most people have never heard of him but he and his brothers James and Roo were using carbon to build bike frames and components (Kestrel 4000, Carbon Cross, Trimble Aero, Inverse 4, Roobar, solid disc wheels). They built dozens of prototypes of each project, constantly perfecting their designs. However it seems there's still only one Hummingbird and during the year since it's creation it appears that no design improvements have been made. There's talk about rack mounts and fenders yet there aren't any prototypes or even mock-ups of these items to be seen. Based on our questions just on this forum there's speculation and promises of how the bike 'can do this' or is 'capable of that' yet there isn't even a simple demo video addressing these concerns. Surely we aren't the only ones to have asked these questions during the year Petre has ridden the bike.

It really would help to see more concrete/physical evidence that the Hummingbird bike isn't just a pipe-dream.

Azreal911

hmmmmm
Someone thinking of a Mu Uno (10kg) which you can get in the states for $556 USD with free shipping ...... and then decides to look at a hummingbird $1900 USD + $150 USD shipping (for the 20" equivalent model @ 7KG)

I would be hard pressed to say they are competitive of the same market at all .

keyven

I'm quite surprised about the pricing. It's a pleasant looking bike but they need to be offering more than a light-weight bike at that price.

craciunptr

Hi guys,

Thanks for all your feedback. It helps me a lot to see what people need.

Just to clarify a couple of things:
- At the time when I designed the Hummingbird I was a student. Carbon fibre is by no means cheap and for my current situation as a student at the time, all of my money went into building this prototype. Then all of my money went into buying different components and testing them out to see which one works best and provides the best value for money. As we have investors at the moment, it will be easier for me to test different options. The designed has changed a lot in a year, but all the photos you see are of the best solution I have at the moment, physically.
- I am aware of the fact that the Hummingbird is bigger than a Brompton. When I designed it, this was not my main concern, but I wanted to focus on the weight. Now that I have that sorted, I will be able to concentrate my efforts into making the package smaller.
- The pricing is this high because of carbon fibre. The costs aren't that cheap as I chose to not produce it in China, because I thought that having my hands of the first prototype when it comes out of the factory was most important. I want to have quality control at this moment and make sure that what we deliver is a safe, beautiful and optimized product.

I am working on the Hummingbird as we speak and I can post some photos of it with fenders and the way it folds with the front wheel detached.

Thanks for the feedback again. Any constructive feedback is very much appreciated and I will try my best to implement your suggestions.

Thanks,
Peter

mingo

Thanks for the info. Are you using the same frame for the 16" and 20" wheels or will the larger wheels have a different frame? Will you be able to post a video to show how it rolls when folded?