Electrifying my track bike

[jetzki]

Discussion moved here:

Help me choose a motor / battery set up :)

This is the bike I want to convert, I know it's not ideal but I would prefer not to have to buy another bike and I have my heart set on using this one. It was my first proper bike, I now have other nicer bikes than it but I still want to use the frame for something. I know someone will come...

endless-sphere.com

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I know that an aluminium track frame is not the most suitable frame to turn into an ebike. I do have some other bikes, which are also all track frames

I have youtube channel https://www.youtube.com/@jetthepanda where I film my people riding around the city. Some of these people are abnormally fast freaks of nature, some are even pro's and even though I am actively training to get myself faster, I doubt I will ever be able to keep up with them when they are really pushing. So I've started looking into the idea of turning one of my bikes into an ebike. I am happy to do most of the work pedalling myself. I just need a little extra boost to help me sustain the higher speeds, which I think electricity would be perfect for. The speeds I'm having problems getting up to quickly and staying at are around 30mph and up, I can get there but not as quickly as the guys I'm following and I can't maintain it long enough to stay on the guys I'm filming.

I want to keep the bike looking as stealthy non ebike as possible. I was originally thinking rear hub with a bottle battery. I found these hubs with controller and torque sensor built into the hub, all you need to do is plug a water bottle battery in.

Rear Motor

Rear Motor

keyde.com

Geeko Rear - Ebike Kit - 100g.tech

Geeko-Rear is the right ebike kit of cycling enthusiasts for daily commute, long distance riding, or serious mountain biking.

www.100g.tech

I contacted both of them and they do not provide their hubs for 120mm drop out spacing. I wouldn't be adverse to grinding the axle down myself. I build all my own bikes and wheels, I think I'm pretty handy when it comes to this kind of stuff.

Does anyone know of a similar rear hub that would fit into 120mm dropouts? Or do you know if it's hard to modify one of the above hubs to fit?

I then came across these friction drives, which I think are very interesting. I wouldn't need to modify anything, all I'd need to do is bolt the motor on. I could even take it off when I didn't need it.

Ebike Conversion Kit-Qiroll – Qiroll

qirollshop.com

https://www.aliexpress.com/item/1005005854667051.html

I am considering the Aliexpress friction drive because that, plus a water bottle battery enclosure, some batteries and a BMS seems to be the most economical route. I think it would be more powerful than the cheapest qiroll kit too QR-E MUTE +B60 Battery Kit I think the motor of the qiroll looks nice, but the battery and throttle button look terribly designed. I would much rather have a stealthy water bottle that actually looked like a water bottle.

What are your thoughts? Does anyone have experience with the Aliexpress friction motor? What BMS do you recommend for a small DIY water bottle battery? Will I be "spinning out" with these lower powered motors at the speeds that I want to go at or will they still be helping me along?

I do have a fork that can take a disc brake and I would use that fork with a disc brake if I went electric. I Would also mount a rear brake and change the fixed cog to a freewheel.

 

[A-DamW]

I thought this was a compelling approach:
My RC Mid Drive with Single Stage Reduction

 

[E-HP]

By stealthy do you only mean visually? There are many options, but only a few if you don’t want it to be noisy. A small geared hub would be visually stealthy, but won’t be silent. Why do you care?

 

[jetzki]

By stealthy do you only mean visually? There are many options, but only a few if you don’t want it to be noisy. A small geared hub would be visually stealthy, but won’t be silent. Why do you care?

Visually. I just want it to look like a normal bike for my own aesthetic preference.

I thought this was a compelling approach:
My RC Mid Drive with Single Stage Reduction

Thanks for that, I'm just taking a look through their thread now

Still quite interested in those friction drives I listed above!

 

[E-HP]

Brainstorming here, absent much knowledge about whether this is possible or not.

Use a small silver fast wind geared front hub (100mm O.L.D.), but mount it on the rear.
Since those bikes don't use rear brakes, utilize the hub's disc brake mounting screws to add a sprocket to the left side:

Cog & Carrier

Stamped cogs are inexpensive, but tend to take a bite out of your freehub. Wide profile cogs are great but tend to take a bite out of your wallet. Our Cassette Cog Carrier (CCC) is Shimano-splined and sandwiches a spline-less cog. This gives you a wide profile that won’t damage your freehub and...

problemsolversbike.com

Flip the bottom bracket to run the chainring on the left side.*
Add a freewheel to to mount the chainring on**
Use a Grin phaseruner for the controller because it's tiny, and for easy connection if you get a Grin hub motor. VESC would be another option.
Bottle cage battery is an option, but if you carry a camera bag/backpack, you could stash the battery there, mount the phaserunner on the seatpost or maybe under the seat, for a short run to the backpack.

* Have to think this through, due to the threads, etc. There are other bb options that may be easier to reverse. Had a beer to kick off the brainstorming, so too much detail for this stage, LOL.

** This may need to be fabricated. There are some freewheel cranksets out there.

Thoughts - Small silver hub might be mistaken for a Nexus, etc. so may not attract too much attention. Chain line may be a challenge. You didn't mention your budget. Those RC motors can be obnoxiously whiny, but I saw one a couple of months ago that wasn't so bad.

 

[rafalg]

Looks like you don't need electric bike to be fast, you just need to ignore all the traffic rules

 

[2old]

For me, Aliexpress is a no no, but your experience may be different. You might consider the small rear motors employed by Bianchi and other European makers. Or, there is an individual who posts here (Kepler AIR) and seems to have perfected friction drive.

 

[Chalo]

I think yours is a great candidate for a simple minimal front hub conversion with battery and controller in a handlebar bag or on a front rack. One of the Bafang dual stage geared hubs would be good for that. Use a sine wave controller if you want it to be very quiet.

I strongly suggest using a coaster brake rear wheel or at least a freewheel. Fixed gear on the street is always a super sketchy prospect, but most especially when the motor can drag you along. There are some nice looking aluminum shell coaster brakes from KT and Wheelmaster these days. No need to add a lever or cable to use one of those. Also it enlists your "pedal backwards to stop" fixed gear instincts.

 

[999zip999]

It may be easier to find a different bike with a 7-speed rear free wheel. They're inexpensive and buy a small geared motor for the rear or the front see if you can find a complete kit that doesn't look too out of place for you. It won't be invisible.

 

[Catnap]

I used a Keyde P160 All-in-one motor to electrify my Brooklyn Machine Works Gangsta track bike. Keyde does make a version for 120mm dropouts and a screw-on cog vs. freehub. I special ordered it from Alibaba, cost around $800 shipped to the USA from China and took about a month to arrive. It's working as advertised, syncs with the phone app well. I'll see over time how much range I get out of one charge, but so far seems up to the task of tooling around the city.

 

[ebike4healthandfitness]

I used a Keyde P160 All-in-one motor to electrify my Brooklyn Machine Works Gangsta track bike. Keyde does make a version for 120mm dropouts and a screw-on cog vs. freehub. I special ordered it from Alibaba, cost around $800 shipped to the USA from China and took about a month to arrive. It's working as advertised, syncs with the phone app well. I'll see over time how much range I get out of one charge, but so far seems up to the task of tooling around the city.

Nice!

That is the all-in-one hub motor as well!

P.S. Another hub motor available in 120mm is the Cute Q100 ---> motor for 120mm drop out hub drive?



Chainline of Q100 on 120mm spacing:

 

[Catnap]

One thing I’m trying to figure out is when / how the electric motor kicks in. If I pedal gently, it comes on full blast and will rocket me up a hill. However, if I start to pedal harder, the motor actually throttles back and I go more slowly. It kind of annoying because that’s when I want more power, not less. Changing it from “speed mode” to “torque mode” didn’t change this, although I’m thinking that torque mode might actually require an external pedal sensor to work.

I'm currently running a 42-tooth chainring in the front of the bike and an 18-tooth cog in the back. i have a 22-tooth cog I can put on the hub, and I’m wondering whether that will get better performance from the motor. I would then be running 42 / 22, which is a very low gear. It might allow the motor to kick on more, but on the other hand, it could also spin out on descents.

 

[ebike4healthandfitness]

One thing I’m trying to figure out is when / how the electric motor kicks in. If I pedal gently, it comes on full blast and will rocket me up a hill. However, if I start to pedal harder, the motor actually throttles back and I go more slowly.

Here is the description of the Keyde Ramp sensing system:

"Ramp sensing system is used to optimize torque sensing. When going uphill, the electric motor automatically increases torque without pedaling hard."

So when on a incline it automatically turns the motor power up.

When you say "if I start to pedal harder" are you on the flat or downhill?

 

[Catnap]

When you say "if I start to pedal harder" are you on the flat or downhill?

occurs on a flat and on downhill

 

[ebike4healthandfitness]

occurs on a flat and on downhill

OK, that must be the ramp sensing system working then.