Ctesibios' First E-Bike - Gatineau / Ottawa, Canada

... and first post on this forum!



I bought this e-bike off of someone in Ottawa. He had assembled the bike himself. The bike works really well, I have been enjoying it! There are a few issues to solve, but I've been pleased up to now!

Here is some info on the bike:

Electrical:

Motor: Crystalyte HS3540
Controller: Infineon C7240-NC (Grin Technologies)
Battery: Power Sonic SLA (3x 12V 14.0AH for 36V)
Cycle Analyst 2.25

Bicycle components:

Frame: Strong Commuter (Found this info on this site!)
Swingarm: Unknown (From an other bike!?)
Rear shock: Fox (model to come...)
Fork: Marzocchi Bomber (model to come...)
Gruppo: Shimano XT Shifters, derailleurs & disc brakes


Current issues:

1 - Rear brake caliper rubbing on motor. (Seems like a common issue!)
2 - Too high, ergonomics are bad.
3 - Too heavy. (Frame and SLA batteries at cause here!)
4 - Speed calibration possibly off??
5 - I want more power!!!


It seems having some mechanical, electrical, electronics, RC hobby, motorcycling and of course cycling experience has something to do with being inclined to riding these crazy contraptions!


This place really is "endless"! I don't have enough time to read all that I'd want!

nice bike love the frame..good motor also, just gotta ditch those SLA and pack 12s LIPO in there

Welcome aboard Ctesibios.

Nice to see another Strong frames used on the sphere.
Check my signature line , I am currently rocking a pair of Strong frames. I love 'em.
Poor mans Stealth.

I had not considered a repurposed swingarm.
It appears from the pic. that it is shorter than stock & looks like the shock is alot longer.
It is probably screwing with your geometry some.Try to compare your side pics to some of my build pics.
Once you lose the lead for a proper battery you will be shocked how much better that motor pulls & how much longer it lasts.

Congrats on your purchase & welcome aboard. You found the best place in the world to modify/fix ebikes.
Let me know if you have any ?'s or I can help.
Brentis

skeetab5780 said:

nice bike love the frame..good motor also, just gotta ditch those SLA and pack 12s LIPO in there

Click to expand...

SLA is pronounced slow... right? :wink:

I've been catching up on my RC hobby tech as I plan on using some LIPOs. You had the same idea, I'm thinking of going with a 12s. Then eventually 2 more 6s packs so I can add capacity or speed! The 6s 5AH seem to have one of the best value for money. I would of ordered some already, but I have to wait to get approval from the finance department! :wink:

Brentis said:

Welcome aboard Ctesibios.

Nice to see another Strong frames used on the sphere.
Check my signature line , I am currently rocking a pair of Strong frames. I love 'em.
Poor mans Stealth.

I had not considered a repurposed swingarm.
It appears from the pic. that it is shorter than stock & looks like the shock is alot longer.
It is probably screwing with your geometry some.Try to compare your side pics to some of my build pics.
Once you lose the lead for a proper battery you will be shocked how much better that motor pulls & how much longer it lasts.

Congrats on your purchase & welcome aboard. You found the best place in the world to modify/fix ebikes.
Let me know if you have any ?'s or I can help.
Brentis

Click to expand...

Brentis, thanks for the welcome!

I have been going to Barrie a couple times a year recently, we could possibly meet! I saw a few of your posts on the Strong frame... I will post something soon as I can as I've been comparing geometries. The Stealth... really thought about it until I saw the price!!

The geometry is really odd... I believe it was made to give it a lot of ground clearance. I think the bottom bracket has 15" of clearance. I am somewhat concerned with the fork rake angle, it feels like it dives too easily. I should check the preload (air pressure for my weight) to start with, then measure the rake angle.

I'm looking forward to getting involved with this forum.

I've always like the Strong design. You can carry a boatload of lithium in that battery box! Welcome!
otherDoc

Very nice bike!

I'm from Ottawa too, would you be interested in riding some trails in Quebec?

Issue 5 - I want more power!!!

Say hi to Peukert's law!

http://en.wikipedia.org/wiki/Peukert%27s_law

14 AH ... yeah right! I'm too power hungry I guess! It's ironic how all this "extra" capacity is hauled around for nothing!


From Wikipedia:

Peukert's law can be written as:

giving It, which is the effective capacity at the discharge rate I.

where:
H is the rated discharge time, in (hours).
C is the rated capacity at that discharge rate, in (Ampere-hours).
I is the actual discharge current, in (Amps).
k is the Peukert constant, (dimensionless).
t is the actual time to discharge the battery, in (hours).

So, in my case:
H = 20 H (From battery manufacturer specs.)
C = 14 AH (From battery manufacturer specs.)
I = 15 A (Average discharge rate.)
k = 1.1 (Guesstimated from values seen for SLA.)

and... It = 10.3 AH (Value too high from experience.)

Again from Wikipedia:
For a lead–acid battery however, the value of k is typically between 1.1 and 1.3. It generally ranges from 1.05 - 1.15 for VRSLAB AGM batteries, 1.1-1.25 for gel, and 1.2-1.6 for flooded batteries. The Peukert constant varies according to the age of the battery, generally increasing with age.

Let's try k = 1.25 since the batteries are getting older:

Same values with the new constant gives us... It = 6.5 AH (I usually get between 6 an 7 AH from experience depending on the max current limit that was set... usually between 30 and 40 A)

In conclusion, I'm only using half of the rated capacity!

binlagin said:

Very nice bike!

I'm from Ottawa too, would you be interested in riding some trails in Quebec?

Click to expand...

I'm interested, but I'm not too comfortable yet with the bike's handling! Whereabouts do you ride?

I had a little spill yesterday coming back from work. I guess I'm lucky to be able to ride some trails to and from work!

I'd like to go to a proper DH bike frame someday!

Usually the Gatineau trails, but I'm trying to find a spot where I can ride a little more... agressivly

2 weekends ago we drove to the top in my truck... rode down the trails... then I rode the ebike back up to Champlain lookout!

Ctesibios said:

binlagin said:

Very nice bike!

I'm from Ottawa too, would you be interested in riding some trails in Quebec?

Click to expand...

I'm interested, but I'm not too comfortable yet with the bike's handling! Whereabouts do you ride?

I had a little spill yesterday coming back from work. I guess I'm lucky to be able to ride some trails to and from work!

I'd like to go to a proper DH bike frame someday!

Click to expand...

Id take it real easy until you sort the geometry.
My guess, the sweet Fox rear is to long. Trade it for a shorter model.
What does it measure eye to eye? Stock is 6".
How about the swingarm? What does it measure from BB axle to rear hub axle? I have 18"+.
Howsabout some close-up swingarm pics. :wink:

Id be happy to take a ride with ya around the lake, anytime your in Barrie.
send a pm from here. I check almost everyday

Brentis said:

Ctesibios said:

binlagin said:

Very nice bike!

I'm from Ottawa too, would you be interested in riding some trails in Quebec?

Click to expand...

I'm interested, but I'm not too comfortable yet with the bike's handling! Whereabouts do you ride?

I had a little spill yesterday coming back from work. I guess I'm lucky to be able to ride some trails to and from work!

I'd like to go to a proper DH bike frame someday!

Click to expand...

Id take it real easy until you sort the geometry.
My guess, the sweet Fox rear is to long. Trade it for a shorter model.
What does it measure eye to eye? Stock is 6".
How about the swingarm? What does it measure from BB axle to rear hub axle? I have 18"+.
Howsabout some close-up swingarm pics. :wink:

Id be happy to take a ride with ya around the lake, anytime your in Barrie.
send a pm from here. I check almost everyday

Click to expand...

I'm getting more comfortable with the bike now as I'm using it more off pavement.

I've also lowered the rear by taking some preload off the shock spring. Also, I measured the shock unloaded from eye to eye and it is 9.5" long.

I will try to measure the swingarm tonight.

Well, well... guess what I broke yesterday!?


Halfway to work the chain decided I had pedaled enough!! :x


Hopefully it's nothing more than replacing a chain link!

Ctesibios said:

I will try to measure the swingarm tonight.

Click to expand...

Brentis, I measured the swingarm and i got 17" from the bottom bracket center line to the wheel axle.

The chain is now fixed and tested! I replaced the bad link with a master link!

Brentis said:

Try to compare your side pics to some of my build pics.

Click to expand...

OK, lets start with the seat tube angle:


I drew a vertical line and an other parallel to the seat post / seat tube. Then you measure the angle... uhm with what? I don't have any special software, so here is what I did.

To calculate the angle, you can use the lengths of the two sides of the right-angled triangle. How to measure the length... count the pixels! Not literally! I used MS Paint: I placed the cursor on the triangle corners to get the positions. So position X1 minus X2 equals X length. Same method for the Y axis. Then you use the ARCTAN (inverse tangent) of the result of Y divided by X: ARCTAN(Y/X)

For the picture above of the Strong frame, I got 72 degrees relative to horizontal. (That's assuming Brentis had the camera level when taking the photo! :wink: ) It seems that 72 to 73 degrees is pretty much standard after searching the net.

Since I have the same frame, I wanted to know if it's close to its original angle. I measured my angle and I got 75 degrees, so it's slightly steeper. It also means that the whole frame is slightly tilted by a couple degrees. That includes the fork rake angle, which was a concern of mine.

So after all, 3 degrees off isn't as bad as I thought. I have lowered the rear end since then, so it should be even better now.

One step closer to LIPO!

I made myself a charger power supply from an old PC power supply. Cost: under $20 for a few miscellaneous bits and pieces!



Here are a few links that are helpful to do the conversion:
https://sites.google.com/site/tjinguytech/my-projects/convert-pc-ps
http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply
http://jumperone.com/2011/06/atx-power-supply-tutorial/

Here is what I usually ride to go back home after work!

It looks like someone changed your swingarm which isn't really a problem, the problem is the longer shock. The rear suspension has about a 2.5-3: 1 leverage ratio, your shock is 9.5" stock is 6 or 6.5" , so that's at least 3 " longer, times the ratio of 2.5:1 or 3:1 that's 7.5-9 inches the rear end has been raised! I think every inch is about a degree of angle for the steering and seat tube , that puts your head tube angle at about 80 degrees! So either get a shorter shock, or figure out how to remount that one to gain back the 3 inches. I like the frames , and it looks like someone tried to upgrade to good suspension , fix the geometry and it should ride pretty good!
Looks like a great place to ride!

Nice looking trail, where is that one?

You're going to love Binlagin's and I's "Secret Offroad Race Track Testing Grounds", right in Ottawa haha

First ride is the snow with the ebike! (from last week)



I wasn't expecting to ride so late in the season! My motivation comes from avoiding the bus! I can't stand waiting for the blasted things!