What's the answer?

[guerney]

old touring bike with powered front wheel

What's the answer?

To be, or not to be... front motored? When I tried cycling my normally responsive and agile bike with a circa 2kg front steel mesh basket attached, it was magically transformed into unbearably sluggish - perhaps a rear or mid-motor would go some way toward forming part of the answer?

 

[lenny]

https://www.amazon.co.uk/Alomejor-Brushless-Outrunner-Controller-Skateboard/dp/B07Q75BCQJ

 

[lenny]

 

[Sturmey]

Does adding weight really slow down a bike that much or is it that the bike feels slower?
In theory, for example, it would appear that if say a 85KG rider with a 15Kg bike, (total 100KG) adds say a freewheeling geared motor and battery (5kg) to their bike, then the most speed they should loose is about 5% when bike is unpowered compared to the bike before it was converted. However most riders complain of a significant loss of speed.
An interesting experiment I would suggest would be to time your favorite ride circuit before conversion. Then after conversion, time the same ride with the bike power off in similar conditions. Anyhow, just a thought.

The Actual Effect of Weight on Cycling Speed – Ride Far

ridefar.info

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[guerney]

Does adding weight really slow down a bike that much or is it that the bike feels slower?

With a 2kg steel front basket, it felt sluggish steering, and even more sluggish steering with 10kg of water inside the front basket... but acceleration was stil fast, unaffected. Voltage sag didn't affect acceleration because of the 19.2Ah battery, I'd zip up though the gears just as fast, the bike was just as responsive, even with the same 10kg weight on the panneier rack instead of up front - that was with the controller at 15A, and now that I've increased controller amperage limit to 18A, my 36A BBS01B 20" wheeled conversion is limited by the 25kph cutoff on most small hills, with even faster acceleration.

An interesting experiment I would suggest would be to time your favorite ride circuit before conversion. Then after conversion, time the same ride with the bike power off in similar conditions.

It's like cycling through diluted treacle with the BBS10B unpowered. Totally different to unconverted along the same route.

 

[Peter.Bridge]

I am working on it.
The kit I am using is Tongsheng/Shengyi DWG2NC with Mechaniker's torque sensor built into the motor. The motor weighs 2kg. I will add a bag battery.

This is my bike, weighing just under 10kgs.
The kit will add 4kgs but it will be very easy to swap out, just a 9-pin motor connector.

Is that motor with torque sensor a available commercially ? I quite fancied trying to do a lightweight build. If not I guess I could use a Bafang 370 or akm85sx and use your bottom bracket torque sensor kit

 

[Woosh]

Tongsheng should have shipped it a month ago but they said their national day holiday was in the way. They will ship it early next week. After testing, I should be able to arrange further shipment.

 

[AndyBike]

i cant beat that batt is in a back pack

Gets to 74kph

Hits pothole and discovers speed is nothing without control.

I'll bet that kind of speed would take some skin off

 

[thelarkbox]

what happens if your feet slip off the pedals at speed with a bafang bbs mid drive motor? I get winded just at the thought of all that high speed pedaling even if only nominal input is required..

Since my bike is no lightweight and neither am I on the flat the added mass of motor and battery make no difference at all that i can tell, and im regularly cycling out from home without power assist since its generally all downhill from here however im generally clobbered up with a few layers of coats atm and am also carrying about 5kg of locks when heading into town, If i were ridding a lightweight bike and wearing lycra and watching every gram of mass added to the bike perhaps it would be a very different story..

 

[AndyBike]

You can always tell a real cyclist by the state of their shins.

 

[guerney]

what happens if your feet slip off the pedals at speed with a bafang bbs mid drive motor? I get winded just at the thought of all that high speed pedaling even if only nominal input is required..

Not much all at legal speed, legs flail about until feet find pedals. Happened a lot with Dahon's slippy plastic folding pedals, but not with these MKS Mikashima FD-7 Japanese metal versions. Hand crafted by ex-underemployed Samurai swordsmiths. They cost near half what I paid for my bike pre-conversion, but well worth it. Folding pedals make walking past your bike in hallways easier, even if you don't have a folding bike. Easier to lean bikes against walls. If bikes are leant together, pedals don't end up in spokes.

https://www.amazon.co.uk/Unisexs-FD-7-Folding-Pedals-Metallic/dp/B004ALNICM

 

[Az.]

Gets to 74kph

Hits pothole and discovers speed is nothing without control.

I'll bet that kind of speed would take some skin off

THAT is a proper cycling lane!

 

[AndyBike]

BITD had the grippiest pedals. Odyssey Shark-Bite Pedals for example.
I think they were designed only to rip the hell out of your legs. Although I've a pic in my head of another retro pedal that looked so dangerous, you'd be mad to fit them.
I'll put a post up on retrobike, worlds nastiest pedal, see what pops up.

 

[soundwave]

clips

 

[guerney]

BITD had the grippiest pedals. Odyssey Shark-Bite Pedals for example.
I think they were designed only to rip the hell out of your legs. Although I've a pic in my head of another retro pedal that looked so dangerous, you'd be mad to fit them.
I'll put a post up on retrobike, worlds nastiest pedal, see what pops up.

The metal toegripped ones from my 80's racer are deffo contenders. Thin sharp metal edges all over the place. I've still got them somewhere, but I don't know why.

 

[guerney]

clips

Can you unclip quickly before shiz hits the fan, or do your legs become mangled inside the frame?

 

[soundwave]

i just twist my foot to unclip dont like shitmano ones cos you can get stuck if to tight

 

[AndyBike]

i just twist my foot to unclip dont like shitmano ones cos you can get stuck if to tight

Err.... loosen them with an allenkey

 

[Nealh]

I use the basic shimano clipons with a narrow platform on oneside for day to day flat sole shoes , never had an issue with unclipping . As Andy has mentioned one simply adjusts tension with an Allen key so one can easily unclip.

 

[AndyBike]

Probably 2 of the best spd pedals Shimano ever made were the 525(Deore) and the 737(XT) and of them I would rate the 525 as being utterly bomb proof

As said, not ideal for commuting, especially on an ebike, as the point of them is you can pull up on them in the up stroke -increasing speed/power, which is superfluous on an ebike, but the real problem is trying to walk in the shoes once you get off.
Offroad it doesnt matter, you're there to ride, not go to the shops.

Anyway, back to the shin rippers.

Odyssey shark bites.
Oooh look at those points, just looking for some human flesh to bite into


Or brooklyn machine works shinburgers