(Some) EMTB weaknesses and possible solutions.

[lightning]

l did think that as they are from Greece ! The English language is not the easiest

 

[Philly G]

There are lots of markets that are not consumer led, instead being technology led.............and the EMTB market is definitely technology led. Whenever you see brands being interviewed you hear product managers/designers purporting to know what the customer base most want next in terms of development. As far as EMTB is concerned their perception is that the biggest requirement is more range. The most recent development has been almost universal change to 12 speed and electronic operation of gear change and dropper post operation, bigger heavier batteries and/or supplementary batteries.....who asked for those? I am pretty sure if a full market study was undertaken the consumer wish list would be rather different. Unfortunately bike brands can only really influence frame design and are slave to the components industries for virtually everything else on a bike, and most of them have very little focus on EMTB which is a very small niche of their overall market.
Could these be the main customer needs?.........
Better value for money
Better warranties
Reduced wear rate on components
Better reliability

If a brand came out with any or all of the above statements as its USPs I would then believe the market is driving the R and D of bike brands!!

I disagree that the major brands have very little focus on eMTB. Sales have exploded over the past 18 months and you'd have to be very shortsighted indeed to think this is only going to continue growing. Specialized even established a separate division especially for the research and development of their eMTB range

 

[Mikerb]

I was referring to all the 3rd party components on a bike......brakes/gears etc dominated by brands like Shimano and SRAM.

 

[Philly G]

I was referring to all the 3rd party components on a bike......brakes/gears etc dominated by brands like Shimano and SRAM.

Ah ok I misunderstood. But still, Shimano have their own motor which is specced on many brand's bikes, so this is obviously a big focus for them .

 

[Mikerb]

Yes, as E bikes become more popular, even in the road bike world, the big component brands will be looking at how they get their piece of the cake; but the fact that virtually all forms of E bike, are currently just ordinary bikes, using ordinary bike components except they have a motor strapped midships or in the rear wheel, tells you how far there is to go before we get genuine, designed from the bottom up, E bikes. It will happen in time though, and the first casualty needs to be the 19th century drivetrain!!

 

[Philly G]

Yes, as E bikes become more popular, even in the road bike world, the big component brands will be looking at how they get their piece of the cake; but the fact that virtually all forms of E bike, are currently just ordinary bikes, using ordinary bike components except they have a motor strapped midships or in the rear wheel, tells you how far there is to go before we get genuine, designed from the bottom up, E bikes. It will happen in time though, and the first casualty needs to be the 19th century drivetrain!!

Yeah the eMTBs of a few years ago were very much like a normal MTB with battery and motor bolted on, but the frames are all fully integrated now and designed from the beginning to be eebs. With the possible exception of the drivetrain though, what components do you want to be ebike specific? Everything from non-electric MTBs is perfectly fine, for example, stronger, wider rims and fatter tyres with stiffer sidewalls have been around for awhile already. Perhaps there is a lot of R&D going on behind the scenes for an alternative to the traditional drivetrain, but I have no problem with the current system. It may wear slightly faster on an eeb, but good maintenance and careful shifting go a long way in helping the longevity of the components

 

[Sidepod]

Oh no. It was only a matter of time before someone pulled the pin out of the “derailleur debate “ grenade.

 

[Penttithefinn]

Oh no. It was only a matter of time before someone pulled the pin out of the “derailleur debate “ grenade.

But the "derailleur debate" is closely linked to the "how many speed, how big should the lowest sprocket be" so hardly a grenade, just a question that will have different answers depending on when, and who feels the need to become involved, which I for one find interesting.

 

[Hamina]

Who would pay 650 euros for SRAM GX AXS if it would be totally new product with exceptionally lightweight openstructure cassette in the world where "all" eMTBs had integrated gearboxes. No one I guess.

Of course this is just a theoretic example and maybe it would be a big show on some weightweenieforum.

 

[1oldfart]

I think the transmission options are go 11 or 12 speeds to look cool or
go 9 or 10 speeds to save money.
I am 100% on the side of 9 or 10 speeds.
An 11-42 or 11-46 cassette is enough.

 

[Penttithefinn]

Who would pay 650 euros for SRAM GX AXS if it would be totally new product with exceptionally lightweight openstructure cassette in the world where "all" eMTBs had integrated gearboxes. No one I guess.

Of course this is just a theoretic example and maybe it would be a big show on some weightweenieforum.

So this is the problem as I see it. Group sets used on eMTBs were (mostly) designed for anolog bikes where weight is seen as the holy grail, and yet on eMTBs most complain about the wear rate/robustness, and yet some say its all down to bad shifting/ poor maintenance!

 

[Msawyer110]

Er... What?
Who'd be controlling the revs and how?
For me anything other than torque and cadence controlling assistance just wouldn't be cycling.

Personally I do find the fact that pretty much every mid drive Emtb motor tapers off its assistance above 100rpm but I'm a bit of a anomaly in that I can happily spin at far far higher than that for long periods and hit 200rpm+ peak pretty much anytime I like on a normal bike so long as its in a low enough gear not to make the power output (torque) required ridiculous.

The pw-x2 motor supports cadence up to 150 I believe. It feels wild

 

[1oldfart]

The pw-x2 motor supports cadence up to 150 I believe. It feels wild

I think that means there is ***some support***
i doubt 149 RPM is part of the optimal zone.
My Giant has that motor but the software is from Giant so i cannot speak
for all the Yamaha PW-X2. I have read that the Giant software offers the full
80Nm from the start and by the feel of my Stance E + 2020 i have to believe it.
Anyway the support that gets delivered is according to many sensors,
cadence is one factor.

 

[Hamina]

So this is the problem as I see it. Group sets used on eMTBs were (mostly) designed for anolog bikes where weight is seen as the holy grail, and yet on eMTBs most complain about the wear rate/robustness, and yet some say its all down to bad shifting/ poor maintenance!

I don't have any issues on shifting performance on my current NX/GX setup. It's just the idea that cassette is open structure and all the mud is affecting it during ride and it's takes a lot of work to clean it every time. If there would be only one sprocket like in enduro motorcycles it would be more simple structure BUT that might and will bring up complexity on closed integrate gearbox side.

Would be interesting to test Rohloff of Kindernay. It's been said that the shifting doesn't have the same "flow" as derailleur based systems. How would this change if gearbox is integrated to motor?

I could say that integrated gearbox would be winning feature for me on the next eMTB and maybe just for curiosity on technics.

 

[steve_sordy]

Yeah. Fair enough.
You also think 1g of weight loss has a finite monetary value. Because some other dude who talks shit once said it.
It's bollocks.

It's not actually difficult at all to build a strong, light bike for fairly reasonable cost.

I once posted that I had noticed enough times for it be worth commenting, that upgrading to lose weight on a bike seems to cost £1/gm. Conversely paying less seemed to incur a weight penalty. Without taking the time to search for the post, I probably gave a few examples. I asked if anyone else had noticed this.
That was it, I wasn't proposing that it was a law of upgrades or anything. I do not think that 1g of weight loss has a finite monetary value. But many do, or they wouldn't be paying to switch out steel screws for titanium ones, or maybe for items made of carbon fibre. I believe that the discussion rolled on to £1/gm cannot be "a thing" because it would be different in countries with a different currency, weight system, or both. The human brain looks for patterns and coincidences probably in a search for meaning and order in the chaos that is life.

 

[Sidepod]

Ok this is starting to confuse me. People are saying that eebs add increased load to a derailleur. How? All of the increased load is through the top drive side of the chain which the derailleur sees nothing.

 

[Gary]

They don't.
Folk talk a lot of shite about Emtbs.
A lot of Emtbs simply see far MOAR use. Especially if the new owners chose to go electric assist because of laziness/lack of fitness /weight /age /disability/ill health/injury/lack of time etc.
Riding a normal bike to the same extent will wear the drivetrain a similar amount.
As would shifting under load all the time.
Also don't discount the fact a lot of emtb riders seem oblivious where there feet are while riding nevermind the fragile dangly bit hanging off their chainstay.

 

[Sidepod]

Good. That’s that cleared up. I’ve been wondering what it was I wasn’t understanding.

 

[Mikerb]

I used the term "drivetrain" meaning all elements involved in the transfer of the torque developed at the cranks, to rotation of the rear wheel. So it is not about the rear mech/derailleur per se. The elements that need to transfer that torque include the chain ring, chain, cassette, freehub, rear axle/rear hub bearings, spokes and rim. Mid drive motors enable up to 4 times the amount of torque the rider develops, yet the transfer of that to the rear wheel consists of standard mtb equipment.

 

[Sidepod]

I’m fairly confident there is a fair amount of redundancy in a standard mtb drive train. Increased load means increased wear/maintenance. Increased strength means increased weight so where do you draw the line?

 

[Gary]

The human brain looks for patterns and coincidences probably in a search for meaning and order in the chaos that is life.

You realise you've just described ASD?

 

[Mikerb]

Quite...and I am happy to live with that because that is where we are currently: but my point was that none of this stuff was designed from the ground up for EMTB (for understandable reasons), but that is what needs to happen in terms of development.

 

[1oldfart]

The switch is simple. 60 years ago most companies were selling products to consumers/customers.
Progressively it became emptying bank accounts.
In Canada most have no clue about the price of their car.
It just drips, x amount per month until they die.
Same for stupid phones, the reflex to look for value has been eroded over decades.
The repeated mesage is U R worth it, U deserve it.
Obviously adding the rider power to 300% from the assist will shorten the life.
Obviously power shifting is for racers who do not pay for bikes/parts.

 

[Sidepod]

Probably worth bearing in mind that the actual torque the drivetrain sees is about 75% of what the manufacturers quote for their motors.
A dyno/test rig at Boschmanoaha will produce more torque than will appear at your ebike rear wheel

 

[Mikerb]

Torque for a motor is typically measured at the crank or flywheel ( if fitted). Yes of course not all of that survives to the rear wheel......it is all of those components in the drivetrain I mentioned that incur the loss due to friction and air resistance.....meaning they each absorb some of that force, much of it converted into heat or air vortices.

 

[Sidepod]

Another thing I’ve noticed. Interrogating the bikes display after a ride shows the motor doesn’t actually put out as much grunt as you might imagine. Obviously it depends on the route etc. The point being, the drivetrain isn’t seeing 90Nm of tyre shredding torque for the entire ride. Far from it.

 

[Philly G]

So this is the problem as I see it. Group sets used on eMTBs were (mostly) designed for anolog bikes where weight is seen as the holy grail, and yet on eMTBs most complain about the wear rate/robustness, and yet some say its all down to bad shifting/ poor maintenance!

I dont think anyone is saying drivetrain wear is all down to bad shifting / poor maintenance. Merely that careful shifting and good maintenance help a lot to reduce wear. Just as it does on non-e mtb . @Gary makes a good point about an eeb simply being ridden more. I definitely ride a lot more each time I'm out on my eeb than I ever did on my accoustic bike

 

[Gary]

Another thing I’ve noticed. Interrogating the bikes display after a ride shows the motor doesn’t actually put out as much grunt as you might imagine. Obviously it depends on the route etc. The point being, the drivetrain isn’t seeing 90Nm of tyre shredding torque for the entire ride. Far from it.

Depends on your imagination really.

A competitive roadie might spend years training just to try and increase their sustainable wattage by 10 - 20w..
Take a minute to think about that?

 

[steve_sordy]

You realise you've just described ASD?

I had to look that up. I am sorry if you or anyone in your life has ASD. If that is true it will give you a unique insight into what it means to have ASD. Many aspects of normal human behaviour taken to extreme can be deemed a syndrome or a disorder of one kind or another, but pattern recognition (man in the moon, cloud formations, constellations, etc) is perfectly normal. Likewise the recognition that something has happened before, that B follows A and so forth are survival skills once essential to our species, now just useful. Searching for meaning again is part of the human condition. You got me on the "chaos of life" phrase, I accept that was a bit over the top.

 

[Gary]

Don't be sorry.