Sprocket wear

[WheezyRider]

It's like a blister in the fovea, it reduced in my left eye for a time, then returned, and each time lines became more warped in the middle... but when looking at straight lines with both eyes, the brain straightens them out. Far away objects of unknown shape, are harder for the brain to correct, hence balance isn't as good as it used to be. If it persists (how long is undefined), the prognosis is pretty bad. No treatment for it, no cause anyone knows of, but I'm pretty sure it's caused by stress and squinting at LED backlit monitors for long periods of time. Occupational hazard. Oddly, I believe jogging helps keeps it at bay.



That's an interesting thought - my handlebars are straight, I may look into it (but they may look warped in the middle ).

Bike design in 1885 - the Rover safety bicycle. Note the curve in the handlebars, it gives you leverage and better control. These things get forgotten when form triumphs over function.

 

[WheezyRider]

You may not have tried the right mid-drive yet, or one set up to suit you - Bafang have adopted CAN bus for their newer models, but the bbsXX(X) series, although not open, the protocol has been hacked, third party batteries can be used... and even if they cease to make them, there are so many in use clones will pop up all over the place, for many years of spare parts.

Maybe not. I don't like spending money on stuff, especially if it is going to be left unattended in the street, so spending more than £1k on a bike seems like madness to me. If I earned serious money, maybe my limits would be higher. But not much chance of buying a shop model mid drive for £1k. Maybe could build one for that, but the other issues I've mentioned put me off for now.

I have often toyed with the idea of getting a bare Tongsheng motor, building it into a properly cooled housing and getting it to drive the left side of the rear wheel using a generic controller and battery, but time has never permitted me to go beyond the back of the envelope stage.

 

[guerney]

Bike design in 1885 - the Rover safety bicycle. Note the curve in the handlebars, it gives you leverage and better control. These things get forgotten when form triumphs over function.

View attachment 49655

Perhaps I should try curved - I never had trouble hand signalling while riding my old 80's racer.

 

[guerney]

Tongsheng

It's torque sensing attraction isn't it? I would never ever buy one, after reading the many posts about problems on this forum.

 

[guerney]

I don't like spending money on stuff, especially if it is going to be left unattended in the street, so spending more than £1k on a bike seems like madness to me.

I bought my Dahon from a friend for £100 years ago, then it sat in the loft for decades... so in all, the entire build cost me about £900. And it folds, goes wherever I go. Bought locks, never use them...

 

[WheezyRider]

It's torque sensing attraction isn't it? I would never ever buy one, after reading the many posts about problems on this forum.

You don't have to have torque sensing with a bare motor and a generic controller. They get a bad rep because of shockingly bad heat dissipation design amongst other things, but build it properly and I think it should give good service.

 

[WheezyRider]

I bought my Dahon from a friend for £100 years ago, then it sat in the loft for decades... so in all, the entire build cost me about £900. And it folds, goes wherever I go. Bought locks, never use them...

I was editing my post as you replied to make it clearer I meant shop bought models

Nice conversion for a good price. Still, you would have to use your locks in most places I end up!

 

[guerney]

You don't have to have torque sensing with a bare motor and a generic controller. They get a bad rep because of shockingly bad heat dissipation design amongst other things, but build it properly and I think it should give good service.

That does sound like an interesting project, I hope to see someone do that. @Nealh addressed the overheating issue with mods on his TSDZ2 build thread.

 

[Sturmey]

Your sprockets have really lasted! Is that 2,226.6 miles per chain so far? If so, that's about 698.6 miles further than the 1,528+ miles my last chain managed with mid-drive bbs01b. It was almost 0.75% at 1,528 miles, changed at 0.75% after some more miles I didn't keep note of, perhaps about 140 miles further? I really should have kept track! Initially, there seemed to be no jumping off cogs with the new chain, then there was (smallest one, 11 teeth)... but not after liberal application of Hypoid 90 and about 72 miles of the new chain wearing to the old cassette.

But I am an 'easy rider' in terms of taking it easy on the pedals. I let the hub motor do most of the work but I do pedal most of the time, especially in winter to keep warm. I would imagine a strong fit cyclist would wear the chain quicker whereas a one legged cyclist with throttle would probably never wear out his chain at all!

 

[guerney]

Still, you would have to use your locks in most places I end up!

I cycle through rough areas regularly, so far nobody has been able to react fast enough to formulate a plan, let alone carry one out. I zip by too quickly at legal speed - 15.5mph is hard to keep up with on foot for long. There was one night I was being stalked by a car, but my flashing lights on "Horrify" mode scared them off. And I've added two more horrifying lights since then...

 

[WheezyRider]

I cycle through rough areas regularly, so far nobody has been able to react fast enough to formulate a plan, let alone carry one out. I zip by too quickly at legal speed - 15.5mph is hard to keep up with on foot for long.

But what happens when stopped at lights, or when you pop into a shop?

 

[Bonzo Banana]

I totally agree with all this. If you look back I was not suggesting hub drives no not have their place and benefits. They obviously do, but they also have their drawbacks, specifically the hub motor does not have access to the range of gearing a crank drive does. To my way of thinking that makes them at best unsuited to mtb.
On the other hand some posters were writing off crank drive with exaggerated tales of wear.
As you say, horses for courses. If you need a bike to give its best on gnarly steep climbs and yet still be suited on gravel, single track and road you need crank drive.
If you never go near steep, stony, root infested off road climbs and spend your time commuting or on tarmac/dressed tracks of course hub may work fine. But to be honest I,m not convinced that even there the crank drive isn't better suited. Wife has a step through Raleigh /Bosch crank drive,nice narrow tyres, sit up and beg Type seating and hub gears. (very wide range) It's awesome on road. Don't see how hub drive could compete with it.
Sometimes there is a solution to mechanical issues that simply works and works better than probably all others. In my humble opinion that solution for ebike is crank drive. The other solutions are simply trying to emulate performance offered. Hub drives are simple, cheap, and available. Crank drive does give better performance on equal power availability. ie) If you compare like with like, same power motor, same battery size, then crank drive will give better performance. I, m afraid that is simply a fact, no matter how much folk defend hub drives. And, yes, you may pay for that improved performance with extra drive train wear. That is also a fact.

Your first point about range of gearing is a mute point as a hub motor ebike can easily have a 3x crankset if you wanted that where as most if not all mid-drives are limited to 1x crankset so more limited gearing. I take your point if that is what you are trying to make that mid-drive power is scaled through the gears but then that is where its real weakness beings the excessive wear rate of the drivetrain, chain breakages and some power loss through the chain. Problems that hub motors don't have at all in fact they massively extend drivetrain life over a conventional bicycle. Also a mid-drive can restrict its power by having its power through the drivetrain, if you have a 100Nm peak motor and you have a 48T front chainring and 32T largest cog on the rear you have 66Nm peak power minus the loss through the chain of maybe 2Nm so you are at 64Nm. Many hub motors are at 65Nm torque. The idea that hub motors can't climb hills is clearly false because standard bikes climb hills and hub motors can provide up to 3x as much power as person so its 4x the power for hill climbing including overall. Yes mid-drive might be able to provide 5 or 6x the power in comparison, its better but this is overkill for many especially with all the other disadvantages that come with it especially in the case of high cost, high maintenance proprietary designed mid-drive motors like Brose and Bosch.

The same power is false, mid-drive motors are the motors that make the most dishonest claims for power, they sell at 250W but often peak close to 700W. Most hub motor ebikes are cheaper models with smaller capacity battery packs and simply can't deliver the power that mid-drive motors get. If a Bosch motor is using a 36V battery pack that can peak at 24A momentarily, a cheap ebike might only have a peak of 11A typically with 7A being the normal current level for most riding. If all bikes were restricted to a battery of 36V and a rigid 7A and no more then all the torque advantage of mid-drive would be lost unless the internal gearing was made to operate at a much lower speed. Mid-drive motors are the same as geared hub motors in that there is only one internal gear ratio I believe. They don't have multiple internal gear speeds just a series of cogs and sometimes belts that takes the very high rpm of their smaller weaker motor and take it down to a usable speed using these cogs and belts. Hence why a Bosch motor at maximum torque is drawing around 700W. Lets not forget Bosch and dieselgate or their spy at Dyson, a very dishonest company that cares little for laws and following rules it seems.

I personally see mid-drive as vastly inferior because its a solution that is far more complicated and has excessive component wear. It has inferior reliability and causes components to run far closer to their failure point. It's performance engineering basically. It's expensive to make and maintain and ultimately it is scrapped far sooner. It's by far the worse solution with regard environmental impact compared to other ebikes. It makes total sense for a mountain bike where performance is more important and far less miles rode but for a commuting bike it seems the wrong option by far.

 

[guerney]

whereas a one legged cyclist with throttle would probably never wear out his chain at all!

A one legged cylist appeared on a travelogue I was watching a couple of years ago:

Long Way Up

Official website for the Long Way Round, Long Way Down and Long Way Up series following Ewan McGregor and Charley Boorman as they travel the globe on two-wheels.

www.longwayup.com

He was a former competitive cylist, who had lost a leg after being squashed by a lorry. His remaining leg was absolutely massive, and he was travelling at some mad speed when they caught up with him on motorcycles.

 

[guerney]

But what happens when stopped at lights

If it looks tricky, it's pavement time, well ahead of trouble.

wwhen you pop into a shop?

The only shops I venture into cycling home, are the big supermarkets: bike folds into a big trolley easily. Although unfolding in infested with crazies car parks afterwards can be a bit concerning, those spaces are so large, I can unfold and speed away faster than they can get close the distance.

 

[WheezyRider]

Your first point about range of gearing is a mute point as a hub motor ebike can easily have a 3x crankset if you wanted that where as most if not all mid-drives are limited to 1x crankset so more limited gearing. I take your point if that is what you are trying to make that mid-drive power is scaled through the gears but then that is where its real weakness beings the excessive wear rate of the drivetrain, chain breakages and some power loss through the chain. Problems that hub motors don't have at all in fact they massively extend drivetrain life over a conventional bicycle. Also a mid-drive can restrict its power by having its power through the drivetrain, if you have a 100Nm peak motor and you have a 48T front chainring and 32T largest cog on the rear you have 66Nm peak power minus the loss through the chain of maybe 2Nm so you are at 64Nm. Many hub motors are at 65Nm torque. The idea that hub motors can't climb hills is clearly false because standard bikes climb hills and hub motors can provide up to 3x as much power as person so its 4x the power for hill climbing including overall. Yes mid-drive might be able to provide 5 or 6x the power in comparison, its better but this is overkill for many especially with all the other disadvantages that come with it especially in the case of high cost, high maintenance proprietary designed mid-drive motors like Brose and Bosch.

The same power is false, mid-drive motors are the motors that make the most dishonest claims for power, they sell at 250W but often peak close to 700W. Most hub motor ebikes are cheaper models with smaller capacity battery packs and simply can't deliver the power that mid-drive motors get. If a Bosch motor is using a 36V battery pack that can peak at 24A momentarily, a cheap ebike might only have a peak of 11A typically with 7A being the normal current level for most riding. If all bikes were restricted to a battery of 36V and a rigid 7A and no more then all the torque advantage of mid-drive would be lost unless the internal gearing was made to operate at a much lower speed. Mid-drive motors are the same as geared hub motors in that there is only one internal gear ratio I believe. They don't have multiple internal gear speeds just a series of cogs and sometimes belts that takes the very high rpm of their smaller weaker motor and take it down to a usable speed using these cogs and belts. Hence why a Bosch motor at maximum torque is drawing around 700W. Lets not forget Bosch and dieselgate or their spy at Dyson, a very dishonest company that cares little for laws and following rules it seems.

I personally see mid-drive as vastly inferior because its a solution that is far more complicated and has excessive component wear. It has inferior reliability and causes components to run far closer to their failure point. It's performance engineering basically. It's expensive to make and maintain and ultimately it is scrapped far sooner. It's by far the worse solution with regard environmental impact compared to other ebikes. It makes total sense for a mountain bike where performance is more important and far less miles rode but for a commuting bike it seems the wrong option by far.

Some really good points there, but would it be fair to say many hubs are more than 60 Nm torque and still "legal"?

Bafang G20.250 is 45Nm. Yose power 250W is about 35Nm, Voilamart 250W 15Nm. The only one I know is the Bafang BPM or CST at 60 Nm.

That said, I've never had someone on a mid drive get away from the lights faster than me - though I am not at all competitive...just saying for scientific purposes

 

[Zlatan]

I mostly agree with you, I do like the idea of mid drive as it allows you to have geared hubs instead of derailleurs. However, for me, a proper mid drive should have the crank separate from the motor. The motor should have its own drive train and not interfere with the rider at all. I also don't like the way mid drive motors tend to be installed. They should be a lot better at cooling than hubs, but they are often badly designed and heat can't get out as well as it should.

Another issue about the cost is that it makes them attractive for theft. A kid in my street saw me on my bikes and was keen to get into pedelecs. He went out and used all his savings and bought a really nice mid drive for more than £3.5k. He had it a couple of months, then he got mugged by 5 yobs and ended up in hospital. Some of these mid drives are worth serious money and it can make you a target. Yobs see me on my home made hub contraption and they ignore me, maybe poke fun...but I'm the one who is laughing I would not be able to justify losing serious money on a bike if it got stolen. Ok, you can be insured, but then your premiums go up as soon as anything happens.

Then there is the issue of how proprietary most mid drives are. Systems locked down so after a short number of years you may as well buy a new bike, just because of a battery or motor issue.

So for me mid drives, nice, but I'll stick to hubs for now.

I see point of splitting motor from crank for wear reasons but you, d also be losing access to gears for motor. Agreed motor is more capable of coping with spreading torque over a wide range and system could have bility to dump current into it at low rpm to up torque, but the system where torque at back wheel can be increased by gearing is always going to be more efficient. (ie allowing motor to spin at its optimum rpm)

I have a very long slogg of a climb (from Snake pass upto Lockerbrook farm,) which rises approaching 1000ft in 2 or 3 miles. I have checked temp at top (and have seen power meter reading of 608 w(on Giant) going up there), motor is barely warm. Its not an issue on either emtbs I have.

But, if you, ve found a system that works for you, stick with it.
But, I would add. I tried a few hub drives and borrowed a home built one for a few weeks when I was researching. (6 years or so ago).
I was impressed with home built one but when I tried Haibike on a demo day out at Ringing low via James Cycles I was blown away. Drove to shop and bought one same day. Was a step change in my ability on bike. Climbs previously too technical /steep were easy. And, even now 6 years later both bikes still impress every time I ride them.
And, from post above.. Mate who has rear hub drive (750 w) can and does leave me from traffic lights and generally on road. He can't live with me on climb to Lockerbrook and his is way illegal. ??? Personally would rather be legal, slow(ish) on road and have fantastic off road climbing ability. But I don't do much road work. (just for access really)

 

[WheezyRider]

I see point of splitting motor from crank for wear reasons but you, d also be losing access to gears for motor. Agreed motor is more capable of coping with spreading torque over a wide range and system could have bility to dump current into it at low rpm to up torque, but the system where torque at back wheel can be increased by gearing is always going to be more efficient. (ie allowing motor to spin at its optimum rpm)

I have a very long slogg of a climb (from Snake pass upto Lockerbrook farm,) which rises approaching 1000ft in 2 or 3 miles. I have checked temp at top (and have seen power meter reading of 608 w(on Giant) going up there), motor is barely warm. Its not an issue on either emtbs I have.

But, if you, ve found a system that works for you, stick with it.
But, I would add. I tried a few hub drives and borrowed a home built one for a few weeks when I was researching. (6 years or so ago).
I was impressed with home built one but when I tried Haibike on a demo day out at Ringing low via James Cycles I was blown away. Drove to shop and bought one same day. Was a step change in my ability on bike. Climbs previously too technical /steep were easy. And, even now 6 years later both bikes still impress every time I ride them.

Someday it would be nice to get out and try something like that. Most of my riding is pretty mundane stuff. Would be good to try different bikes over such a terrain.

I tend to be someone who doesn't like automation butting in and trying to think for you. When the motor is on the same drive system I find it is like having to tune into to what the motor is doing, rather than enjoying the ride, so it's kind of unnatural to me. It's difficult to explain.

I suppose the answer for gearing on a left hand motor drive would be having some form of auto gearbox like you can get for non electric rear hubs now.

 

[WheezyRider]

If it looks tricky, it's pavement time, well ahead of trouble.



The only shops I venture into cycling home, are the big supermarkets: bike folds into a big trolley easily. Although unfolding in infested with crazies car parks afterwards can be a bit concerning, those spaces are so large, I can unfold and speed away faster than they can get close the distance.

Why does this remind me of some zombie apocalypse film? "Quick, they're coming! Get the bike unfolded!!!!"...

 

[Zlatan]

Someday it would be nice to get out and try something like that. Most of my riding is pretty mundane stuff. Would be good to try different bikes over such a terrain.

I tend to be someone who doesn't like automation butting in and trying to think for you. When the motor is on the same drive system I find it is like having to tune into to what the motor is doing, rather than enjoying the ride, so it's kind of unnatural to me. It's difficult to explain.

I suppose the answer for gearing on a left hand motor drive would be having some form of auto gearbox like you can get for non electric rear hubs now.

Yep, I do know what you are talking about. Find similar on mine. In highest power setting the bike is more in control whereas in lower ones everything feels more natural and intuitive. But, I have got to point in lowest setting I don't think motor is helping.. I have to switch off completely to remind myself it actually "was" doing. In an odd way running out of battery with a couple of miles left has done me a favour. Reminds me just how much I now appreciate (take for granted?) the motor.

 

[guerney]

Why does this remind me of some zombie apocalypse film? "Quick, they're coming! Get the bike unfolded!!!!"...

We must exploit any and all opprtunities of acrapalapse (laspes in judgment made by The Walking Crap).

In highest power setting the bike is more in control whereas in lower ones everything feels more natural and intuitive.

I have a gradual onset and sudden droffoff of assistance set in firmware. On lower assistance settings, my cadence sensored bike is simply easier to pedal. On higher levels, it doesn't feel natural, but boy it's fun.

If I thought a rear hub-motored bike conversion could haul bike trailers uphill like my bbs01b can, I'd give one a shot - but given what I'm asking of my bike is at the limit of it's and my physical ability, I don't think any legal hub can do the job... which is irritating, because it seems there is less to go wrong with hub motored systems.

The only one I know is the Bafang BPM or CST at 60 Nm.

Are those 500W?