Weight Weenie Ebike

General Discussion about electric bicycles.
LewTwo
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Re: Weight Weenie Ebike

Post by LewTwo » Fri Jul 10, 2015 3:27 pm

mfj197 wrote: ... I think we're moving away from the idea of a "weight weenie ebike" ...
A valid point. I admit I really like the concept of a mid drive. I am afraid I was letting that influence my good judgement (questionable under the best of circumstances). This thing has a really skinny fork. It is so close that I will have to have the motor to actually see if it fits. Note: The Q75, Q85 and Q100 all have the same indifference point in common.
CT-7000 front fork - close fit(smaller).JPG
CT-7000 front fork - close fit(smaller).JPG (16.53 KiB) Viewed 743 times
The Bafang SWXU may be a better fit (darn shame that there is not a rim brake version ... that I can find). 180-220 watts @ 1.9 Kg
CT-7000 front fork - bafang(800).JPG
CT-7000 front fork - bafang(800).JPG (17.52 KiB) Viewed 743 times
mfj197 wrote: ... Singlespeed makes quite a lot of sense with a hub motor.
I want the extra acceleration of a lower gear particularly when crossing 6-10 lane roadways. That is not the time to discover your motor assist is not working (dead battery, faulty wiring, whatever) and all you have is a road gear.
mfj197 wrote: ... using just sidepull caliper brakes ...
The argument can be and has been made that rim brakes are as effective as disk brakes. Here is one interesting piece on the subject: http://www.rodbikes.com/articles/disco- ... fever.html
mfj197 wrote: But why is more power needed? "Only" 200 watts is actually a goodly amount of power for a cyclist.
You missed the point about it being sensorless. The 250 watt number is often referenced as the equivalent of the average adult male pedaling a bicycle. That seems like a good starting point.
mfj197 wrote:Hope those ramblings are of some use!
Anything that sparks a thought is always helpful.
Alex W wrote:I'd recommend riding a PAS bike (which is what the BBS0* builds up into) ...
Fortunately PAS can be disabled or ignored. I prefer to have a throttle.

Another thing I am considering is that with a properly packaged front hub drive (controller and battery in a small handlebar bag along with an attached thumb throttle) one could quickly convert back to a sub 20 pound pedal only road bike (of course that would require another front wheel build). A bit like having your cake and eating it too. :D

Question:
Does anyone have any experience with the Bafang SWXU that they would care to share?
Last edited by LewTwo on Sun Jul 12, 2015 2:57 am, edited 1 time in total.
The more I learn the more obvious the immensity of my ignorance becomes.
Weight Wennie E-Bike https://endless-sphere.com/forums/viewt ... 3#p1173723
Shaft Drive Grocery Getter https://endless-sphere.com/forums/viewt ... =6&t=90718
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2old
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Re: Weight Weenie Ebike

Post by 2old » Fri Jul 10, 2015 6:26 pm

Interesting thread; if you want to read about some really light ebikes, go to electricbike and open "top 10" (top of page).

LewTwo
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Re: Weight Weenie Ebike

Post by LewTwo » Fri Aug 28, 2015 3:50 am

If anyone is interested I have been refining my spreadsheet.
WeightWeenie(800).jpg
WeightWeenie(800).jpg (108.83 KiB) Viewed 658 times
I found an error in the calculations such that the wheels were only counted once --- oops.

With the exception of the cork handlebar grips everything is on hand or on order. I do not think that there are any practical options to shave more weight short of starting with a different frame or leaving off the brakes. I have verified that the SWXU hub fits in the front fork and have trial fit the torque arm to it (required a bit of grinding to clear the cable). The biggest change was driven by the tires. I tried a spare rim and a kenda Kwest 700Cx32 tire. It rubbed the inside top of the fork. I was looking for 700Cx28 tires when I ran across the Thickslick and noticed that the 700Cx25 race version only weighed 260 grams. Several reviews mentioned that they also tended to run a bit large for the stated size. I decided to give them a go.

The other major change is the Race face handlebar. It requires a 31.8mm clamp so I ordered a Origin8 Quill adapter and a Cycle King stem.
Now it is time to start work on building wheels.
The more I learn the more obvious the immensity of my ignorance becomes.
Weight Wennie E-Bike https://endless-sphere.com/forums/viewt ... 3#p1173723
Shaft Drive Grocery Getter https://endless-sphere.com/forums/viewt ... =6&t=90718
...and thanks to Justin!

aCeMadMod
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Re: Weight Weenie Ebike

Post by aCeMadMod » Fri Aug 28, 2015 3:43 pm

hi if you want ligth wigth ebike you starting with a Tank frame forks and cranks. i can take out 1 kg on this prats lone. use a 15 year old alloy race frame and carbon fork not super hight end too.

if i want to use can make whole road ebike under 7 kg with lipo .
my road bike wight 4.0 kg alot carbon. 8)

get money to burn it not cheap...

LewTwo
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Re: Weight Weenie Ebike

Post by LewTwo » Fri Aug 28, 2015 5:21 pm

aCeMadMod wrote:hi if you want ligth wigth ebike you starting with a Tank frame forks and cranks. i can take out 1 kg on this prats lone. use a 15 year old alloy race frame and carbon fork not super hight end too.

if i want to use can make whole road ebike under 7 kg with lipo .
my road bike wight 4.0 kg alot carbon. 8)

get money to burn it not cheap...
I would really like to see a picture of that 4.0 Kg road bike.

At just 4.56 KG Trek claims that their £11,000(British Pound) Émonda SLR 10 is the lightest production road bike.
http://roadcyclinguk.com/gear/trek-emon ... VHd0H0L.97
"The 690g claimed weight of a painted 56cm Émonda frame is said to be lighter than the Cannondale SuperSix Evo (710g) and Specialized S-Works Tarmac SL4 (897g)."
Note that those weights do NOT include a fork.

To get a bit of real world perspective I put together a list of the weight of a few naked frames and forks:
  • Miyata Sixten Touring 54cm/27x1-1/8, Double Butted Cromoly Steel Frame and Fork: 3.27 Kg (7.2 pounds)
    Bill Holland Custom 54cm/650C, Steel Frame and Fork: 2.5 Kg (5.5 pounds)
    BIANCHI VIRATA 55cm/700c, CARBON Tubing, COLUMBUS Fork: 2.3 Kg (5.2 pounds)
    Trek 1500 50cm/700c, Aluminum Frame, Steel Fork: 2.2 Kg (5.0 pounds)
    Miyata CT-7000 54cm/700C, Frame and Fork: 2.19 Kg (4.8 pounds)
    Trek 2500 57cm/700c, Carbon/Aluminum Frame, Aluminum Fork: 2.1 Kg (4.7 pounds)
    Specialized CRUX E5 56cm/700c, Aluminum Frame and Carbon Fiber fork: 2.0 KG (4.5 pounds)
    Ritchey Pro K2 (2005), 54-57cm/700c, Carbon/Aluminum Frame, Aluminum Fork: 1.91 Kg (4.21 pounds)
    Bill Holland 49cm/650C, TI Frame and Aluminum Fork: 1.9 Kg (4.2 pounds)
    Chinese CF Frame 56cm/700C, Full Carbon Fiber Frame and Fork: 1.4 Kg (3.1 pounds)
    Taiwan UltraLight 50cm/700c, SMALL Aluminum Frame and Fork: 1.3 KG (2.8 pounds)
The Chinese CF Frame looks like a clone of the Émonda.

The CT-7000 is not the lightest but then it if far from the heaviest as well.
The least expensive member of the Trek Émonda is the S6 that comes in at 8.38 Kg for £1,800.
That is not bad company to be in. :)
The more I learn the more obvious the immensity of my ignorance becomes.
Weight Wennie E-Bike https://endless-sphere.com/forums/viewt ... 3#p1173723
Shaft Drive Grocery Getter https://endless-sphere.com/forums/viewt ... =6&t=90718
...and thanks to Justin!

ScooterMan101
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Re: Weight Weenie Ebike

Post by ScooterMan101 » Fri Aug 28, 2015 7:49 pm

Where do I find those Chinese and Taiwan CF bikes ? Do you have links ?
Is that frame and fork , with a headset ?
Be careful of buying carbon from ICAN in China, they sell the same products under different names. they do not pack their products , a carbon handle bar came to me with the box completely smashed !
no packing at all . None , They would not refund my $$ and wanted me to pay for shipping back to them.

I am interested in the Taiwan bike .

Have you looked into the Q100cst ? it is 4.6 lbs. for the hub, you can get a good DT Swiss rim for a real light weight rear hub motor/rear wheel build.
There is someone here in the states now that is selling them. PM me.

Keep in mind these hub motors have 135mm dropout spacing, so that means a 29er or Disc Road/Disc Cyclocross/Disc Gravel Bike.


LewTwo wrote:
aCeMadMod wrote:hi if you want ligth wigth ebike you starting with a Tank frame forks and cranks. i can take out 1 kg on this prats lone. use a 15 year old alloy race frame and carbon fork not super hight end too.

if i want to use can make whole road ebike under 7 kg with lipo .
my road bike wight 4.0 kg alot carbon. 8)

get money to burn it not cheap...
I would really like to see a picture of that 4.0 Kg road bike.

At just 4.56 KG Trek claims that their £11,000(British Pound) Émonda SLR 10 is the lightest production road bike.
http://roadcyclinguk.com/gear/trek-emon ... VHd0H0L.97
"The 690g claimed weight of a painted 56cm Émonda frame is said to be lighter than the Cannondale SuperSix Evo (710g) and Specialized S-Works Tarmac SL4 (897g)."
Note that those weights do NOT include a fork.

To get a bit of real world perspective I put together a list of the weight of a few naked frames and forks:
  • Miyata Sixten Touring 54cm/27x1-1/8, Double Butted Cromoly Steel Frame and Fork: 3.27 Kg (7.2 pounds)
    Bill Holland Custom 54cm/650C, Steel Frame and Fork: 2.5 Kg (5.5 pounds)
    BIANCHI VIRATA 55cm/700c, CARBON Tubing, COLUMBUS Fork: 2.3 Kg (5.2 pounds)
    Trek 1500 50cm/700c, Aluminum Frame, Steel Fork: 2.2 Kg (5.0 pounds)
    Miyata CT-7000 54cm/700C, Frame and Fork: 2.19 Kg (4.8 pounds)
    Trek 2500 57cm/700c, Carbon/Aluminum Frame, Aluminum Fork: 2.1 Kg (4.7 pounds)
    Specialized CRUX E5 56cm/700c, Aluminum Frame and Carbon Fiber fork: 2.0 KG (4.5 pounds)
    Ritchey Pro K2 (2005), 54-57cm/700c, Carbon/Aluminum Frame, Aluminum Fork: 1.91 Kg (4.21 pounds)
    Bill Holland 49cm/650C, TI Frame and Aluminum Fork: 1.9 Kg (4.2 pounds)
    Chinese CF Frame 56cm/700C, Full Carbon Fiber Frame and Fork: 1.4 Kg (3.1 pounds)
    Taiwan UltraLight 50cm/700c, SMALL Aluminum Frame and Fork: 1.3 KG (2.8 pounds)
The Chinese CF Frame looks like a clone of the Émonda.

The CT-7000 is not the lightest but then it if far from the heaviest as well.
The least expensive member of the Trek Émonda is the S6 that comes in at 8.38 Kg for £1,800.
That is not bad company to be in. :)

LewTwo
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Re: Weight Weenie Ebike

Post by LewTwo » Fri Aug 28, 2015 8:59 pm

ScooterMan101 wrote:Where do I find those Chinese and Taiwan CF bikes ? Do you have links ? Is that frame and fork , with a headset ?
"NAKED" means no bearing, no screws, no nothing except frame and fork. I found a vendor on Ebay that was selling the CF frames. I was not worried about packaging or delivery as I was not planning on buying one. The seller's name was 88bike. Here is the URL for a 1.4 Kg 54cm frame and fork: http://www.ebay.com/itm/FR322-Full-Carb ... 5423732265
ScooterMan101 wrote:I am interested in the Taiwan bike.
That is a 48 or 50 cm frame. A tad small for me.
See this URL: http://www.ebay.com/itm/Aluminum-Road-B ... 339fe113d0
ScooterMan101 wrote:Have you looked into the Q100cst ?
No and Yes. I prefer an IGH to derailleurs thus a front hub is preferable. Also I want to be able to quickly swap out the the entire motor package. That is much simpler with a front hub.
The Q100 front hub fit was too close to call.
The more I learn the more obvious the immensity of my ignorance becomes.
Weight Wennie E-Bike https://endless-sphere.com/forums/viewt ... 3#p1173723
Shaft Drive Grocery Getter https://endless-sphere.com/forums/viewt ... =6&t=90718
...and thanks to Justin!

ScooterMan101
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Re: Weight Weenie Ebike

Post by ScooterMan101 » Fri Aug 28, 2015 9:23 pm

The CF one looks good, but it has 130mm rear drop out spacing . So it would not work.

http://www.ebay.com/itm/FR322-Full-Carb ... 5423732265


and the Aluminium Taiwanese one
Looks nice, but also rim brake = 130 mm rear dropout spacing. and at $ 700 there are complete used bikes in my area for just a little more.

Looks like a 29 er CF frame is the way to go, however there is the added cost of a fork .

The new Disc Road/Cyclecross/Gravel or a 29 er with a disc CF cyclocross fork, are the right frames for a light weight , rear hub motor build.

Are you sure you want to use a front hub motor on a good fork ?


ScooterMan101 wrote:I am interested in the Taiwan bike.
That is a 48 or 50 cm frame. A tad small for me.
See this URL: http://www.ebay.com/itm/Aluminum-Road-B ... 339fe113d0

LewTwo
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Re: Weight Weenie Ebike

Post by LewTwo » Fri Aug 28, 2015 9:41 pm

ScooterMan101 wrote:The CF one looks good, but it has 130mm rear drop out spacing . So it would not work.
Take a look at the his Ebay store they have number of different frames. You might find another more to your liking.
ScooterMan101 wrote:The new Disc Road/Cyclecross/Gravel or a 29 er with a disc CF cyclocross fork, are the right frames for a light weight , rear hub motor build.
Most road bikes come with rim brakes. Disk brakes are heavier than rim brakes so that is sort of self defeating. http://www.rodbikes.com/articles/brakes.html
ScooterMan101 wrote:Are you sure you want to use a front hub motor on a good fork ?
Among other things: I have already have the Miyata CT-7000 frame.
The frame is carbon fiber over aluminum which is really unique. There is a reason why vintage bicycle forks have that nice graceful curve at the bottom end. I do not think that the 250 watt motor is much of a risk on this fork although I am putting a torque arm on it anyway.
The more I learn the more obvious the immensity of my ignorance becomes.
Weight Wennie E-Bike https://endless-sphere.com/forums/viewt ... 3#p1173723
Shaft Drive Grocery Getter https://endless-sphere.com/forums/viewt ... =6&t=90718
...and thanks to Justin!

ScooterMan101
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Re: Weight Weenie Ebike

Post by ScooterMan101 » Fri Aug 28, 2015 9:53 pm

I have not read that article yet, However I have seen the Videos by GCN here : https://www.youtube.com/watch?v=JplymlruPZ8

Keep in mind these commentators do this for a living everyday, so they have developed a sense of humor along the way to keep their work fun.

>
ScooterMan101 wrote:The new Disc Road/Cyclecross/Gravel or a 29 er with a disc CF cyclocross fork, are the right frames for a light weight , rear hub motor build.
Most road bikes come with rim brakes. Disk brakes are heavier than rim brakes so that is sort of self defeating. http://www.rodbikes.com/articles/brakes.html

rsilvers
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Re: Weight Weenie Ebike

Post by rsilvers » Fri Aug 28, 2015 11:27 pm

Wow, they have 100% positive feedback and 15000 sales. If I had no bikes I would probably get a carbon frame and then spend $1200 on a DuraAce group or less on an Ultegra, and then $600 on carbon wheels from China. For about $2500 you could build a bike that Trek would sell for $12000.
Merlin Titanium XTR, Mac 10T, 48v 820Wh, CA V3.

ScooterMan101
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Re: Weight Weenie Ebike

Post by ScooterMan101 » Sun Aug 30, 2015 11:08 am

Or one of these Ultegra spec'ed bikes ... http://www.performancebike.com/bikes/Pr ... 1___400784 ( this is the womans version , there are mens versions as well , just posting this link to show what is possable ) ... http://www.performancebike.com/bikes/Pr ... 1___400784

I have seen other brands of bike with Ultegra Di2 as low as $ 2,600 for a complete 2014/2013 Road Bike, on clearance on American Web Bike Stores.

rsilvers wrote:Wow, they have 100% positive feedback and 15000 sales. If I had no bikes I would probably get a carbon frame and then spend $1200 on a DuraAce group or less on an Ultegra, and then $600 on carbon wheels from China. For about $2500 you could build a bike that Trek would sell for $12000.

LewTwo
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Re: Weight Weenie Ebike

Post by LewTwo » Mon Apr 11, 2016 2:13 am

The more I learn the more obvious the immensity of my ignorance becomes.
Weight Wennie E-Bike https://endless-sphere.com/forums/viewt ... 3#p1173723
Shaft Drive Grocery Getter https://endless-sphere.com/forums/viewt ... =6&t=90718
...and thanks to Justin!

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