Show me your 700c! (Or, Project "electro weight weenie")

[LI-ghtcycle]

Ok, I have been slapped down with the goodness of the E-Bike, no more will I question it's holiness or commit blasphemy by speaking of pedal bikes. :lol:


I must have really had a good day that I thought I could ride my Bianchi up hill and not pay for it! I have made that same trip again 2-3 times and it KILLS my knees and has me stopping for breath half-way up, so even though on a good day I can almost keep the same average speed as my E-Bike, and I love the light simplicity of a good road bike, the E-Bike still wins AND I still arrive sweating if I WANT a work-out, and I can just take it easy and no get sweaty at all. :wink:

 

[AussieJester]

can't have them running out of things to stew a-boot

:: giggles:: Don't you be hitting on those Canadian 'eh'

Kepler drive on lightest bike you can find would be the ticket to get what your
after...

KiM

 

[LI-ghtcycle]

Great stuff guys, thanks! 8)

I'm now anxiously awaiting the production units of the Kepler Drive being available!

I pulled the trigger on 6 of these baddies to power my K-Drive

http://www.hobbycity.com/hobbyking/...Turnigy_nano-tech_6000mah_4S_25~50C_Lipo_Pack

I was going to hold-out for the 45 - 90C batts, but I'd rather have more AH's for my money, and it's still going to be less than half the weight of my current battery pack.

I think 25C - 50C burst is going to be more than enough. 8)

 

[Tiberius]

Even with all the crap... the bike came in at 63lbs with 15Ah 48v battery, bags, lock, tools etc...

More proof that < 70 lbs is possible. What would that come down to in racing trim?

For road purposes, I'm convinced that choosing the right tyres is all you need for suspension. But then you have to get the pressure right too because that affects the handling.

Nick

 

[LI-ghtcycle]

Even with all the crap... the bike came in at 63lbs with 15Ah 48v battery, bags, lock, tools etc...

More proof that < 70 lbs is possible. What would that come down to in racing trim?

For road purposes, I'm convinced that choosing the right tyres is all you need for suspension. But then you have to get the pressure right too because that affects the handling.

Nick

Yes, I think your right there, and especially if we are talking the glass smooth 'kart tracks of the "death race", short of the "Malachi Brothers" seeding the track with pea gravel, I think it's safe to say that you don't NEED all that suspension unless you have a lot of weight.

I was thinking about this even more riding through the gravel on rock hard tires of my Bianchi on the way to church across a road that is all torn up with construction. I definitely went slower and more carefully with my Bianchi over the bumps, but it only required my getting out of the saddle and using my legs to soak up the beating, and the bike did fine.

Granted this would have been a different story if I had a 120+ lb E-Bike with the same tires and lack of suspension, so I'm gonna try out the K-Drive and see how much I can push the envelope with a 63MM motor and as much voltage as I dare. I doubt I will be much competition in a race, but I think the idea of going for maximum efficiency VS just brute power might win-out over-all. This idea will evolve into a semi-recumbent bike with a sock or similar aero, but for now, I just love the idea of light and then maxing the power to weight ratio. 8)

 

[amberwolf]

For road purposes, I'm convinced that choosing the right tyres is all you need for suspension.

Mmm...depends on the road. Here in Phoenix the edges of many roads (maybe even most) are full of potholes, ridges, sinkholes, construction-cutouts which may be over an inch higher or lower than the surrounding road, etc., most of which cannot be avoided during heavy traffic.

Well, unless one takes side streets that are also poorly maintained but at least have little traffic, allowing one to ride near the center which is at least not destroyed. But taking those side streets can add at least 1/3 the distance to your trip, sometimes as much as nearly doubling it, because of the detours one must take around sealed-off areas. (gated communities, shopping centers, schools, canals, "planned communities" with no grid pattern to the streets, etc.)

So a suspension is, if not necessary, a really good idea.

On the canal paths, even the gravel ones, they are generally pretty smooth. Probably because multi-ton vehicles aren't driving on them when the asphalt is very soft from the daytime heat, deforming under them over a short amount of time. Also because there is virtually no construction or maintenance done on things running under them, unlike the main roads.

Welcome to Phoenix, City of Gophers.

 

[LI-ghtcycle]

Yeah, I know it's gonna suck when I get back to Montana and I'm not spoiled with all the bike paths and near perfect roads like I have here in Oregon! I don't discount the need for suspension on rough roads, but as long as I can get away with it on decent roads and a light bike, I'm going to take advantage!

My current E-Bike is going to be my test mule for the heavier stuff since I really went over-board anyway with all the lights and such, it all adds up! :lol:

 

[KTP]

Thanks LI-ghtcycle. The bike is around 23lbs. The rack itself is around 4lbs but it was what I had lying around, so I used it. I wanted the rack for a larger battery pack for some long distance riding. Previously, I had the battery in a small rack mounted to the water bottle bosses and the bike weighed in around 42lbs.

Sorry, no build thread. I built this over 2 years ago, long before I joined this forum. The motor is an old Kollmorgen/Currie 400watt driving thru a Spectro P5 internal gear hub. (There is a 600Watt MAC motor that would work too.) I geared it so 5th will get me about 42-43kph without pedaling and around 46-47kph with me assisting. Thus 1st gear will get my 175lbs up a 7% hill at 15kph consuming around 350watts. When I had 5th geared for 32kph, I could get up some really steep hills but I prefer the faster speed. So depending on how much you weigh and how steep of a hill you want to climb, you could always adjust the driven gear to suite your needs. I'm curious though, why do you want to climb without pedaling?

Rayy, would you mind giving out a bit more info on your setup? I happen to have two of the Kollmorgen motors (new) and while I really like my 9c 6x10 on my tadpole recumbent, I have a 700C specialized crosstrail that maybe I could put something similar to your setup on. Mostly I am interested in how the Spectro P5 hub works and how you have it connected to the brushless motor. Is it the coaster brake version of the P5 or the drum brake? Is there a freewheel anywhere or does the Spectro P5 have the ability to freewheel internally? If that was the case, then it would look like a really simple setup for FWD...simple mounting bracket for the Kollmorgen, a small sprocket on it's shaft, a chain to the P5, done.

thanks for any extra info.

 

[Rayy]

...Rayy

 

[KTP]

Wow thanks for taking the time to describe all of that!

Unfortunately, it looks like using the Kollmorgan with the internal gear hub on the front tire is significantly more work that I had first imagined, based on your description. I do have the cnc equipment to do it, but probably not the time this summer. I may just slap another hub motor on the specialized crosstrail for now to get me by until the nasty rainy winter (Seattle) when I could work up a drive system like yours or a mid-drive.

 

[veloman]

My basic ebike commuter using a 30lb rigid mtn bike came in at 49lbs with the 3 Fatpacks. It was near 54lbs with 5 Fatpacks or 20 mile range no pedaling.

The roadie I built but haven't used yet, comes in at 42lbs with the 5 Fatpacks. I got sick with mono and haven't ridden except around my street. I'm thinking of tearing it back down and forgetting the road ebike for now. I just hate the feeling of hitting bumps with it and that extra unsuspended dead weight on those 120psi tires. Here's some pics:

 

[Rayy]

Hey KTP, yes it was a little more work than I imagined before I started as well. Nothing like knowing better before you start. If you ever need more information or even parts, pm me. I'm sure I have some spares.

 

[drewjet]

Here is mine. I just weighed it as 52 LBS (23.5K) I know the rear isn't a 700C, but the front is. I wanted a bit wider tire in the rear, plus I had the doublewall rim free of charge.

 

[LI-ghtcycle]

Here is mine. I just weighed it as 52 LBS (23.5K) I know the rear isn't a 700C, but the front is. I wanted a bit wider tire in the rear, plus I had the doublewall rim free of charge.

DROOOOOOOL!!!!!!!!!!!!

Love your Bike Frame! What is it exactly?!? Can you still get replacement polymer for the rear susp?

I'm really encouraged seeing these builds!! Not only is my dream possible, but it's been accomplished in many forms and my only question if you would, please also list the no-pedal speed on the flat no wind! 8)

 

[LI-ghtcycle]

Oh, I forgot to mention also, when you keep the weight down, no real need for disc brakes! I regularly go 38 - 39 MPH (both GPS, and Radar confirmed .. we have a little radar trailer on the hill) and when I first rode my Nishiki Olympic down, the previous owner had the bars reversed so that your weight pushed down on the break levers, and I almost went over the bars doing a stoppie because of it! :lol: :lol:

Needless to say, correct me if I'm wrong, but it sounds like decent rim brakes can do the job on a sub- 50lbs E-Bike traveling at 40 MPH or less. 8)

 

[drewjet]

The bike is still a work in progress. Rim brakes are fine, I would say to about 30 maybe 40 MPH on a relatively light bike.

I forget the bike brand name and I am at work right now. Before I bought it I did some research on the polymer. It appears as though they can be found.

I have a Bafang geared in the rear. On 48 volts it does 23 MPH with no peddling. I had a different geared hub, forget the name now, but it would do 28 MPH no peddling. But it cracked and needed to be replaced. I am fine with the speed, In fact I usually set the cruise for about 16 MPH and then peddle it up to about 18 or 19 and around 170 watts. Doing that I can get about a 40 mile range on 48 volts 10AH Turnigy batts. 4 sets of the 20C arranged as 12S2P

 

[drewjet]

It is a Proflex Newport

 

[veloman]

A good quality v-brake with good brake pads will stop very well. The problem is a lot of older bikes don't have such, and stop nowhere near as good as they could.

I could endo while seated on a mtn bike with very little effort, the pads were very grabby. Disk brakes have their real benefit in the wet.