Raise pedals???

[Beekeeper]

We have dropper seat posts. Can we not have telescopic dropper crank arms? ?

just one more switch on the cockpit.
Along comes a nasty rock with imminent pedal strike but a quick flick on the button shortens the crank arms and no pedal strike, Just like a dropper seat post.

my powered car wing mirrors have a similar button when approaching close objects. I’ve never had a ‘mirror strike’

 

[Zimmerframe]

We have dropper seat posts. Can we not have telescopic dropper crank arms? ?

If someone was clever they'd work more like a cam. Once you're at the bottom part of the stroke, you're not applying as much power as when the crank is horizontal, so ideally the crank would become longer (say 175/180) when horizontal and shorter (140/150) when vertical. They did oval chain rings, but you really need an oval crank action. Only ..... this adds weight and complexity - to a part of the bike where huge forces are at play ! (maybe not when I'm riding though).

my powered car wing mirrors have a similar button when approaching close objects. I’ve never had a ‘mirror strike’

You know that buttons there really to angle the mirrors so you can "check yourself out" and see how cool you look ... It then works the other way, on the off chance that there's someone more attractive than yourself in the vehicle behind that you might want to check out.

 

[Beekeeper]

You know that buttons there really to angle the mirrors so you can "check yourself out" and see how cool you look ... It then works the other way, on the off chance that there's someone more attractive than yourself in the vehicle behind that you might want to check out.

 

[urastus]

If someone was clever they'd work more like a cam. Once you're at the bottom part of the stroke, you're not applying as much power as when the crank is horizontal, so ideally the crank would become longer (say 175/180) when horizontal and shorter (140/150) when vertical. They did oval chain rings, but you really need an oval crank action. Only ..... this adds weight and complexity - to a part of the bike where huge forces are at play ! (maybe not when I'm riding though).

I don't think the clowns have figured that bit out yet. You ought to try and get them organised Their crank / wheel timing is out.

 

[Rosemount]

There is NO proof.

FFS. What suits an individual rider best is down to personal preference, physics and physiology. Not trying out 3 crank lengths, listing the positives and negatives of the outliers and going with the middle one!

?

Oh ,,, when you were throwing around insults the other day I thought it was definitively proven .

Like I told you the other week . The suspension system is a factor . Yes you can measure sag and say ground clearance is X mm . When traveling up a gradient and the rear wheel hits a bump and activates do you have an equation regards how much suspension travel it will use ?What is the ground clearance at that moment . For all suspension systems and their individual kinematics ?
Then the characteristics of the shock on the rear of the bike . Does it start its travel with more or less energy / force .



Nah just watch where you`re going . Don`t bother looking up the trail . Look at your feet at all times . lol .

 

[Gary]

Of course sag, suspension travel, dynamic ride height and suspension support make a difference.
Any decent rider takes all of these factors into account while riding... you know... While also actually looking ahead, scanning the terrain, adjusting position and planning their line.
No decent rider ever looks at their feet. You should already know what your foot position is without having to look at them. and you should be capable of timing a pedal stroke or lowering/raising a pedal to avoid an oncoming object.
These are all BASIC riding skills. Dare I suggest you make some time and intentionally practice them?
If you're constantly smashing your pedals into stuff it's down to poor planning, poor judgement and poor riding skill.
This isn't an insult. it's just good old fashioned honesty



Make life easier for yourself by not bothering to improve your skills at all and simply swapping to super short cranks if you want... I don't actually care. but please don't try to blame it on your (not particularly low) BB height or your perfectly suitable suspension settings.

 

[speedkills]

my powered car wing mirrors have a similar button when approaching close objects. I’ve never had a ‘mirror strike’

I love those powered mirrors! I end up using them a few times a month when taking my Disco out in the woods, the 4x4 trails in Colorado are quite tight.

 

[speedkills]

I almost put a poll up for this, but couldn't be bothered, but wondered recently if there aren't multiple reasons different people are concerned about pedal strikes?

I guess some people don't like smacking their pedals into the ground and scratching their pedals, in which case ratcheting is a perfectly adequate solution. I don't like letting up on the power, in which case ratcheting is the problem, not the solution. I full well know how to time my pedal strokes, by stopping pedaling for a moment, which is the problem, not the solution for me most of the time, and in many cases I'll purposely take a light pedal strike over stopping pedaling.

But then again, I have an uphill channel on one of my trails that is a channel a couple of hundred yards long. With my suspension in low position, I would strike at every pedal turn, which would be absurd, but with it in the high position I cruise right through it. Ratching up the whole thing would be the dumbest and more importantly slowest solution you could think of but I guess if you just have a few rocks or roots on your ride, sure, maybe ratcheting is a better tradeoff, but for my riding area, it is no comparison to just flipping the chip, which seems like probably why they designed the suspension that way in the first place.

 

[Beekeeper]

I wouldn’t be too concerned with scratching pedals, especially my cheap plastic ones. I’m more worried about damaging the motor from a big pedal strike. Even laying the bike down in its side worries me for this reason. Transporting the bike in the car I always remove the pedals. Going over road bumps plus the weight of the bike can’t be good with it lying on its side in the car. With pedals off its probably less likely to do damage to car or motor

 

[Gary]

Even laying the bike down in its side worries me for this reason. Transporting the bike in the car I always remove the pedals. Going over road bumps plus the weight of the bike can’t be good with it lying on its side in the car.

You're over thinking this one. All Emtb motors should be designed to deal with repeated side loads far greater than the weight of the unladen bike against the ground or speed bumps inside a car can place on a pedal /crank arm.

 

[urastus]

You're over thinking this one. All Emtb motors should be designed to deal with repeated side loads far greater than the weight of the unladen bike against the ground or speed bumps inside a car can place on a pedal /crank arm.

My sometimes riding buddy has bent a few crank arms - he rides giant. He was told that the crank arms are made soft so that all the force is not transferred to the crank shaft. My buddy was surprised at how easily they bend - I actually straightened one a fair bit with a 12" shifter. So there might be a chance of bending the crank arms.

 

[TheRealPoMo]

Anyone know for sure if crank arms for 2020 Bosch Gen 4 fit the 2019 Gen 2?
Difficult to find 2019 specific ones, especially 165.

 

[Jackware]

Anyone know for sure if crank arms for 2020 Bosch Gen 4 fit the 2019 Gen 2?
Difficult to find 2019 specific ones, especially 165.

You need to find some measurements - the actual spline drive is a standard but a bike's frame dimensions also effect the crank designs, this picture is for a fat bike crank from the Miranda Bike Parts website but makes the point clearer;

 

[Gary]

Never straighten a bent crank arm. Bin it and replace it ASAP.
A twice bent Alu crank arm may fail on you (ie. Snap) at the worst possible moment.
How do I know this?
Hmmm...
?

 

[urastus]

Never straighten a bent crank arm. Bin it and replace it ASAP.
A twice bent Alu crank arm may fail on you (ie. Snap) at the worst possible moment.
How do I know this?
Hmmm...
?

Yes, initially it was just to finish the day; quick repair at the car. I'm guessing you bent a normal one, tempered harder and more brittle. Must have given you a fright when it went! Funny thing is he left it like that for ages - I gave up rolling my eyes each time I met him for a ride, with the same crank . One day he took my bike for a spin, and was trying to tell me that my left crank was bent .

 

[TheRealPoMo]

You need to find some measurements - the actual spline drive is a standard but a bike's frame dimensions also effect the crank designs, this picture is for a fat bike crank from the Miranda Bike Parts website but makes the point clearer;

View attachment 34593

Yeah they look very similar in profile but the detail around the crank spline end is unclear. I would have thought someone would have done it given the seeming scarcity....but maybe that's an Australian issue.

 

[Jackware]

Yeah they look very similar in profile but the detail around the crank spline end is unclear. I would have thought someone would have done it given the seeming scarcity....but maybe that's an Australian issue.

As far as I know the gen3 CX motor used the smaller Bosch BNI (Bosch Narrow ISIS) fitting while the Gen4 uses the larger more common ISIS spline but @Bearing Man would be able to confirm.

 

[Bearing Man]

As far as I know the gen3 CX motor used the smaller Bosch BNI (Bosch Narrow ISIS) fitting while the Gen4 uses the larger more common ISIS spline but @Bearing Man would be able to confirm.

Gen 3 never had a CX version and is only fitted in road bikes, but you are right, it does have a smaller spline. Gen 2 CX and Gen 4 CX both have the larger standard ISIS crank.

 

[Rosemount]

Of course sag, suspension travel, dynamic ride height and suspension support make a difference.
Any decent rider takes all of these factors into account while riding... you know... While also actually looking ahead, scanning the terrain, adjusting position and planning their line.
No decent rider ever looks at their feet. You should already know what your foot position is without having to look at them. and you should be capable of timing a pedal stroke or lowering/raising a pedal to avoid an oncoming object.
These are all BASIC riding skills. Dare I suggest you make some time and intentionally practice them?
If you're constantly smashing your pedals into stuff it's down to poor planning, poor judgement and poor riding skill.
This isn't an insult. it's just good old fashioned honesty



Make life easier for yourself by not bothering to improve your skills at all and simply swapping to super short cranks if you want... I don't actually care. but please don't try to blame it on your (not particularly low) BB height or your perfectly suitable suspension settings.

SHORTER CRANK ARMS ON LEVO / KENEVO?

Shorter Crank Arms on Levo / Kenevo?

@RobbieJay great shout. I’ll put something together.

www.emtbforums.com

@Gary , hmmmm ...

 

[Errol1098]

SHORTER CRANK ARMS ON LEVO / KENEVO?

Shorter Crank Arms on Levo / Kenevo?

@RobbieJay great shout. I’ll put something together.

www.emtbforums.com

@Gary , hmmmm ...

Not sure this proves anything really, he mentions technique a lot and also says you don't need the leverage of longer crank arms on an ebike but also says the new cranks are 140 g lighter and every little bit helps - really on an ebike 140g makes a difference?
And by the way he still had pedal strike, so should he just keep going shorter?

 

[urastus]

I've noticed that youtubers are moving more into the advertising business. For example, this video is for miranda cranks - not shorter cranks in general. A week or so ago it was pirelli tyres (rob and embn), and earlier than that it was specialized levo sl (again, rob and embn). Those few examples were very similar - as though the manufacturers gave rob and embn the pertinent points to address. It's still a good way to research stuff (Rob explains the wider q factor), but it is no longer unbiased. It is the same with Sam's bikes; I unsubscribed from his channel because I couldn't trust much of what he says about stuff he reviews. Also notice that none of these channels discuss the elephant in the room, ever! That is the poor reliability of the e systems for mtb use. I believe this is because it would be highlighting a big fault of the industry that they rely on for income. Embn is a classic for this. After one video they had that was clearly biased and not based in reality, a lot of the commenters to the video highlighted the reliability issues. Shortly after embn came out with this wanky video that did nothing to address or look at those reliability issues - pure PR for the emtb industry. It's unfortunate and seems to be unique with emtb youtube channels. I have other interests and I'm always researching and generally the reviews are unbiased. So why is emtb different? Because they're all pretty unreliable - industry wide - that is the unique thing with emtb. Most people coming to emtb know nothing about the reliability issues (I was one of them) because most of their research is based on youtube!

Anyway, I'm not going shorter. 165 is already short for me. I ride in hills where I need big torque to get over those obstacles on an already steep climb. Rob has ignored the one glaring obvious disadvantage of shorter cranks - less torque input by us. True, I could go boost or trail but I want to stay familiar with supplying that explosive power myself (as pathetic as it is ). I was definitely surprised at the pedal strikes coming to emtb - never had that before. However, my only real concern now is motor height - it's quite low on my bike. I still get a couple of light pedal strikes per ride, and sometimes these surprise me - as in unexpected. The more time I ride the more I'm beginning to think that others who have been mentioning technique and familiarity here, are right. I do seem to pedal through stuff more, whereas on the non e bikes it was more quick power strokes before then roll and manoeuvre through maybe with some half strokes. I seem to be holding a more uniform cadence now through more stuff. That might be the reason for more strikes? So, I'm trying to relearn the explosiveness required to get over obstacles (via my input), rather than just sit there and spin through stuff or not really try hard. Whatever it is, I'll persist and give it time. It will become subconscious soon

 

[EebStrider]

I’m tempted to go with shorter cranks, but my knees have been playing up again recently. I’m thinking that shorter cranks would actually make the knee pain worse, as I’ll have less knee movement. What do you lot think?

 

[R120]

You have to remember Rob shot the video over two years ago, and at that time his channel was tiny, this forum was a small outpost on the internet, and we where all still new to EMTBs and everything was bit of an experiment. I look back at a lot of the content I posted when this forum started and its asking many of the same questions that new members ask now, and actually thats one of the strength of the forum is that now there are members who have put thousand of miles on all the motors in all conditions, and on a huge variety of bikes, giving real world feedback, whereas back then everything was a first or someone trying something new.

There is no way @Rob Hancill , or other channels of that size, can put out content without having to do some sponsored elements, but this is alway made clear in the sponsored videos themselves. I think EMBN whilst good is really let down by its lack of pointing out the downsides of ownership and don't make clear their commercial tie ups that clearly influence their content, but I dont think Rob falls into this category, if you watch the live show or some of the podcasts he and Jon and pretty blunt with the issues they and others have had with both motors, and the warranty process in general.

One of the main issues is that, if you are reviewing snowboards for example, you can go and get a demo board from any shop, not have to deal with the manufacturer in any way, and do a review, whereas with bikes in general you need to get the bikes off of the manufacturers press fleet to do a review.

 

[HGmtb]

I’m tempted to go with shorter cranks, but my knees have been playing up again recently. I’m thinking that shorter cranks would actually make the knee pain worse, as I’ll have less knee movement. What do you lot think?

I've got 155 mm cranks on my Levo, and hardly ever get pedal strikes now - and no knee pain whatsoever (and no ACL in my right knee either). Trust me, there is no perceptible difference in pedalling effort using short cranks on an eMTB.

 

[EebStrider]

I've got 155 mm cranks on my Levo, and hardly ever get pedal strikes now - and no knee pain whatsoever (and no ACL in my right knee either). Trust me, there is no perceptible difference in pedalling effort using short cranks on an eMTB.

OK, good to know, thanks.

 

[Gary]

really on an ebike 140g makes a difference?

of course it does.
140g for just ONE component is a lot of weight to save and accumulative weight savings is how you end up with a light bike.

What does your Eeb weigh?

 

[Gary]

@Gary , hmmmm ...

What's your point?

Rob spends pretty much the entire video sat down. intentionally using poor crank position AND poor technique in general. It's actually quite painful to watch.

Git gud? Nah... that takes too long.. I'll just BUY kids cranks instead

 

[Rosemount]

Well @Gary

The pedal strike in the video was from the side from what I saw .
I can`t tell if he is stood up or pedaling from this view ...


Shortening the cranks won`t help to see sniper rocks or stumps covered by grass or foliage on the edge of the trail .
Which is what I believe took ole Rob down in that video .
A shorter / narrower pedal would make more difference in that case . I deliberately bought pedals with narrower width from the crank arms to increase ground clearance when tipped over .

So all the crank swapping generated by Rob`s video may have been triggered by not fully understanding what actually happened in the video . Sniper rocks are lateral hazards . Pedal strikes are vertical hazards .

Scraping the pedals through lack of ground clearance is another issue all together IMO . Like I said earlier in this thread the suspension kinematics and the action of the rear shock are active factors with pedal strikes . If the bike is pointed up hill and you are pedaling hard your theory re ground clearance and sag are changed by the way the suspension activates and weight distribution and force to the rear suspension when pedaling . It doesn`t stay in the same sag position as it travels over bumps .

I have been riding the Cube 160 for a cpl of months and rarely strike the pedals . On the Cube 140 which you inform me should have better ground clearance . I struck the pedals regularly .
Obviously some other factors are at play .[ more torque from next gen motor , different leverage ratio on the rear suspension ? ] Because I didn`t just wake up one morning and magically learn to avoid striking the pedals .

 

[Gary]

OMG mate. I don't actually care. Like I said. buy whatever special needs aids you want for your mobility scooter.
Pedalling through foliage/ long grass when you don't know or you can't see what's hidden in it is always going to be a risk. Which is precicely why dropping a pedal or putting a pedal stroke in without first scoping it out is poor riding technique.

Obviously some other factors are at play

No dude. It's the RIDER. ie. you.

now please do me a favour and stop tagging me into your boring discussion and to read a multitude of excuses when you refuse to admit the issue is down to your own poor riding traits and habits.
You've been harping on about this for almost 3 months now.

 

[Rosemount]

@Gary
LOL .