My 40lb diy whip

[bajaboy]

18 Enduro s-works, 520wh battery, 3" tires,170mm & low tech. I do have to be careful on big roots when going slow but I can remove it in 5 minutes and throw cranks on her for Whistler DH if I want!

Trying to figure out why the big boys can't be closer to 40 than 50?

 

[Rob Rides EMTB]

18 Enduro s-works, 520wh battery, 3" tires,170mm & low tech. I do have to be careful on big roots when going slow but I can remove it in 5 minutes and throw cranks on her for Whistler DH if I want!

Trying to figure out why the big boys can't be closer to 40 than 50? View attachment 22642

Cool! Where’s the battery?

 

[bajaboy]

Stuffed in to the down tube through the SWAT hatch. 14s2p.

 

[Mcharza]

Stuffed in to the down tube through the SWAT hatch. 14s2p.

That's cool

 

[MattyB]

Stuffed in to the down tube through the SWAT hatch. 14s2p.

Sounds like you may be using a Lipo rather than a LiFe chemistry battery; if so that is a major part of the answer to your question, as lipos have a significant advantage in terms of energy density. Unfortunately they have lower cycle life and aren’t as safe, hence why the mainstream manufacturers go for the (heavier) LiFes.

 

[steve_sordy]

Is it an optical illusion or is that down tube looking a bit too thin?

 

[bajaboy]

Samsung 50E....I have rebuilt a Tesla Roadster battery and have 1000 miles on the bike with 0 issues and no bmb.

 

[steve_sordy]

I'm dazed and confused! (And probably a bit slow on the uptake). So humour me please.

Are you saying that you have taken a regular bike and added a motor and battery?

 

[bajaboy]

I'm dazed and confused! (And probably a bit slow on the uptake). So humour me please.

Are you saying that you have taken a regular bike and added a motor and battery?

Yes, exactly. It was 38lbs but then I doubled the capacity for winter. 250wh was good for a 13 mile 2500ft ride in summer but not in the cold. I'm going to add a heat pad in a week or two so maybe go back to one in the down tube and one that can be carried in h2o holder.

 

[HGmtb]

Yes, exactly. It was 38lbs but then I doubled the capacity for winter. 250wh was good for a 13 mile 2500ft ride in summer but not in the cold. I'm going to add a heat pad in a week or two so maybe go back to one in the down tube and one that can be carried in h2o holder.

Very impressive - what kind of motor are you using ?

 

[bajaboy]

Tongsheng tsdz2 36v motor with 52v controller.

 

[GrandPaBrogan]

Stuffed in to the down tube through the SWAT hatch. 14s2p.

Not saying I don't believe you... because I do. But I just can't visualise even a slim battery (not that I've seen any of those either) fit into that downtube. From where again did you insert it from?

Any pics?

Thanks.

 

[MattyB]

Samsung 50E....I have rebuilt a Tesla Roadster battery and have 1000 miles on the bike with 0 issues and no bmb. I think Lipo's are plenty safe.

Correct me if I am wrong, but I do not believe any current Tesla product uses lipos...

A Look at Tesla’s Latest Battery Technologies

Battery Choice | Tesla

...and I don’t think the Roadster has been released yet has it?

Tesla Roadster (2020) - Wikipedia

Fundamentally though you are correct that with the right knowledge lipos can be operated perfectly safely, but they do have a lower cycle life if you are utilising their additional energy density to the full, and if a fire does occur it is self sustaining. These are the reasons they have not to date been used for an ebike where the chances of a significant impact are relatively high.

 

[Zimmerframe]

...and I don’t think the Roadster has been released yet has it?

I suspect @bajaboy is referring to the original Tesla Roadster (2008)

Tesla Roadster (2008) - Wikipedia

Or Elon's spacecraft roadster ..

Elon Musk's Tesla Roadster - Wikipedia

 

[Gary]

But I just can't visualise even a slim battery (not that I've seen any of those either) fit into that downtube.

Google "14s2p batteries" and you'll get it.

He already said he inserted them in the bike's SWAT compartment. Google that too if needs be

 

[HGmtb]

Tongsheng tsdz2 36v motor with 52v controller.

With the torque sensor - have you ridden a Levo, and if so how does the power delivery compare ?

 

[Zimmerframe]

It's quite a large space in fairness .. this video gives a good idea of what could be stuffed in there capacity wise ..

 

[GrandPaBrogan]

Tongsheng tsdz2 36v motor with 52v controller.

What’s the power delivery like with your Tongshen?

I’ve tried a Bafang build... its nice and torquey and super quiet, but it surges at the start of the pedal stroke and can be a bit unruly in tight switchback ascends.

 

[MattyB]

I suspect @bajaboy is referring to the original Tesla Roadster (2008)

Tesla Roadster (2008) - Wikipedia

Or Elon's spacecraft roadster ..

Elon Musk's Tesla Roadster - Wikipedia

Sorry, had forgotten about that particular spacecraft... As far as I am aware it still did not use lipos though.

 

[bajaboy]

I'll snap a few pix when I get home of the batteries crammed in there....I'm on a beach in Baja right now.

The motor is ok, I haven't ridden a levo to compare but I can't say it is bad or surges. I mostly use it to climb in 1st or 2nd level....not turbo mode.

There is a group of hackers on endless sphere that have created new firm ware that they say puts it on par with the Brose. As it is it works fine for me.

 

[bajaboy]

Not much to see but here it is....one full 7x2 in the upper tube with a 4x2 tucked in and wired to 3- 2x2's in the bottom. Very snug fit for sure.

 

[CjP]

That’s pretty sick!
Specialized FTW with the SWAT frame. I have an 18 enduro sitting at home, this thread gives me bad ideas.

 

[GrandPaBrogan]

That’s pretty sick!
Specialized FTW with the SWAT frame. I have an 18 enduro sitting at home, this thread gives me bad ideas.

I was quite surprised that Spesh would place a large opening in the downtube. They've obviously engineered it so the hole doesn't compromise structural strength.

But yeah, I was thinking the same as you - very handy. You could put lots of things in there!

 

[CjP]

And you can see that beautiful weave.