How to break a collarbone...

[pollywaffle]

So I clipped a pedal and went otb in a full SCORPION. It bent my crank but I've been wanting some 155mm cranks anyway so I guess it's an opportunity

I wasn't going too fast or being a dickhead, it was just one of those things.

 

[MitchF]

Ouch

 

[B1rdie]

Sorry to hear that. If I meant to ride with clip pedals, I would take one with smaller platform, maybe they would be more efficient to avoid clipping a rock or berm than using shorter cranks.

 

[Jamsxr]

Ouch, get well soon.
I’m sure it’s just a coincidence but most of the injuries my riding mates have experienced this year have happened to people clipped in...

 

[pollywaffle]

Good point about the pedals' platform size. I haven't really liked them from the get go so I might switch to flats but it'll take a while to get used to them. Haven't ridden flats in 30 years. I only scorpioned because I was clipped in and I wonder about the added force of a 20kg bike landing on me.

 

[miPbiP]

been there done that got the metalwork.

wishing you best for a fast recovery.

 

[Rusty]

With the wider Q factor on an ebike I have no intention of riding with anything other than clips.

 

[miPbiP]

With the wider Q factor on an ebike I have no intention of riding with anything other than clips.

why is Q factor relevant? (I switched to flats on my Levo and am now riding flats on all my bikes, after 10 years on SPDs).

 

[Rusty]

why is Q factor relevant?

It is why people on ebikes have more pedal strike than on their analogue bikes. My Scott Genius and the eGenius have close enough to the same clearance from the ground to the bottom of the crank arm but I have pedal strike probably 8-10 times on my big loop on the eGenius where I rarely have strike on the analogue version. As my times are pretty close except for the big climbs being faster on the ebike and many of the more level trails I am 6-10kph faster on the analogue as I am not hitting a wall at 32kph I consider the only real difference is the Q factor. I lean the bike over in the drive and the analogue will go somewhere between 5 & 10 degrees lower than the ebike. Do actually need to get a decent measure of that some day.

 

[miPbiP]

ah yeah, wider rather than lower, good point thx.

 

[pollywaffle]

wow, i've never noticed the pedals being wider apart

 

[Gary]

it's still a foot placement/sighting/planning issue rather than a 3mm wider (each side) Q-factor issue.

Shimano XT Q factor is 168mm non boost and 176mm boost
E8000 is 175mm (ie. 1mm LESS than ALL modern regular mtb cranks)

most folk pedal strike more when switching to riding emtb entirely due to user issue and the temptation to keep pedalling towards and into objects as the motor means they approach a lot of situations faster and with less effort. This is why so many "fix" the issue by fitting shorter cranks. If these same folk actually just took the time to get used to the differences emtb riding throws up, re-calibrated and adjusted riding technique it would stop happening so frequently.

from the pic and video it looks like you clipped a trailing (rearwards positioned) or dropped (6 oclock position) pedal @pollywaffle. I'd just chalk this down to a lapse in concentration, possibly poor line choice/foot positioning and bad luck. It's all a learning curve. and it's how progression works
Get well soon

 

[pollywaffle]

@Gary Yup, struck a rock somewhere around 7 o’clock in the motion of pedalling. And i was fatigued after doing about 25kms. I’ve trained myself over the years to look ahead down the trail but i maybe need to train myself to see what’s right in front

 

[pollywaffle]

PS: I also cannot recall a pedal strike ever while descending. Always on tech climbs, which can be just as dangerous despite never having crashed that way before.

 

[miPbiP]

strikes on small stumps aren't rare on my patch (hand made trails in natural forest mostly). man you fly, ricocheted down the trail. some of us have had big smacks that way.

 

[Gary]

@Gary Yup, struck a rock somewhere around 7 o’clock in the motion of pedalling. And i was fatigued after doing about 25kms. I’ve trained myself over the years to look ahead down the trail but i maybe need to train myself to see what’s right in front

Yeah. that's the danger with an E bike. you're tired but turning the pedals still makes you go as fast as (or faster than) if you were fresh on a regular bike. And that's where the timing mistakes come in.
You should scan the trail at all times. your brain will take in the obsticles. it's mentally tiring. on a regular bike you have waaay more time to take in the info on the climbs. so on an emtb you get mentally tired quicker. If that makes some sense. Now you've been caught out badly. hopefully you'll be cautios of this happening in future.
Bet you're counting the days until you are fit enough to ride again.
Injury sucks

 

[pollywaffle]

strikes on small stumps aren't rare on my patch (hand made trails in natural forest mostly). man you fly, ricocheted down the trail. some of us have had big smacks that way.

Could have been way worse eh. Landed on side of face and flat across collarbone.

 

[pollywaffle]

Yeah. that's the danger with an E bike. you're tired but turning the pedals still makes you go as fast as (or faster than) if you were fresh on a regular bike. And that's where the timing mistakes come in.
You should scan the trail at all times. your brain will take in the obsticles. it's mentally tiring. on a regular bike you have waaay more time to take in the info on the climbs. so on an emtb you get mentally tired quicker. If that makes some sense. Now you've been caught out badly. hopefully you'll be cautios of this happening in future.
Bet you're counting the days until you are fit enough to ride again.
Injury sucks

Counting the days for sure. Can’t complain much though. I’ve had almost zero pain either at the time or after. Mainly discomfort. I can move my arm all over the place without a problem except I can’t lift my arm directly out in front. Yet.

Here’s where the pedal struck hard.

 

[frankenbike]

I switched from 175mm w/platforms to 155mm (Miranda) cranks and clip-in pedals (speedplay). Used to have crank/pedal strikes frequently - haven't had one since in the last ~500 miles. Also, being an eMTB affords the opportunity to crank at a lower cadence than on a push bike (side benefit is motor is quieter at lower rpm - on my bike chainring and cranks turn at same rate) - lower cadence means less strike risk events per distance travelled. In addition to risk of personal injury, unlike push-bikes, eMTBs have extra internals that can be damaged by the high shock loads of strikes. FWIW - I don't notice the difference in crank length at all in terms of how it feels, so for me it was one of the best upgrades. I cringe just thinking about those old cranks and the accumulated battle scars - lucky not to have ever been injured although one time it was a near miss as it sent me flying off the trail.

 

[Gary]

Here’s where the pedal struck hard.
View attachment 19161

Oh... Devil pedals?

ever ride flats?

 

[Gary]

Just like on any bike a pedal strike issue is almost always entirely due to rider error. Don't kid yourself it's inherently an emtb issue.
As i've said previously the main difference between emtb and mtb is the higher speed you approach stuff for less rider effort. and the ease at which you transmit power through the rear wheel means it's tempting to keep pedalling when you really shouldn't be. You still have to time pedal strokes and pay attention to foot position. it just takes a little time to adapt. and when tired or offline it's harder to concentrate on foot position.

I haven't had a single pedal strike in 1000s of miles mtb or Emtb with normal length cranks. Mainly coz I just don't pedal into stuff and pay attention to foot/pedal placement when descending and freewheeling through technical terrain. and time my pedal strokes when climbing. My E-sommet has about the lowest BB height of all 160mm Emtbs out there but all my FS mtbs have far lower BB heights than it so I've been used to how a low BB bike needs to be ridden for decades.. If you choose to percevere with standard length cranks, in time you'll also reduce pedal strike rate.

it's not all roses with shorter cranks. they also raise centre of gravity. both while seated at full seatpost extension and while turning weighting the outside pedal. It'll also create bad/lazy habits if you ever switch back to riding an mtb. Which i still do a lot. hence why I'll never go short on my Emtb.

The above isn'tmeant to be preachy or judgy.. just factual nerding out on the subject.

enjoy riding however you choose to.

 

[frankenbike]

I mostly disagree - in my experience the shorter cranks have been nothing but "roses"; the effect is a very high incidence of scenarios where with the longer cranks I would have to stop pedaling to avoid a strike whereas with the shorter cranks I can keep on. The message that the solution lies mostly in exercising better technique is, well, obvious and does not lend much value to the conversation imo - kinda goes without saying. Specific technique suggestions on the other hand, can provide much value - e.g. leaning the bike over to the side opposite the low crank rev to avoid strike is a useful technique. I never have strikes on my push bike but the combination of low bb and long cranks on my emtb was a bad recipe that was completely transformed with the crank swap. I challenge the idea that shorter cranks has an adverse effect due to raised cg, as this is an order of magnitude more a matter of where you locate your body mass center, which is why dropper posts and posture are such huge factors. And when seated, that assertion is completely false, as the net cg of your legs cancel each other (e.g. the longer cranks will raise the high leg higher than a shorter crank). Lastly, saying that shorter cranks will make a rider lazy and transition to push bike difficult - not sure where to start with that one - it's like saying using a dropper post makes a rider lazy - maybe it's just a better tool..... just sayin'

 

[Gary]

You're wrong to think there's no difference made to COG from having a higher saddle when seated OR a higher outside weighted crank arm.
it's kinda why proper low BB bikes corner so well.
As for legs evening it out. seriously? Have an actual think about that one, eh?
What Emtb do you have that has a properly low BB BTW? I wasn't actually aware any did.

Nothing I have said is anything like saying "riding with a dropper is lazy" I rode more with a slammed saddle than an extended one for years and years before droppers were available. The arrival of droppers has undoubtably improved riding. Having said all that dropper posts genuinely did make me a weaker rider but only as I then stopped being stood up while riding for hours on end without a sit down at all.

 

[frankenbike]

Whatever man, not into belaboring the issue - just wanted to share with folks my positive experience with shorter cranks

 

[Gary]

Your positive experience is fine to share.
doesn't mean there aren't any negatives. Everything is compromise.

I'm still interested in hearing what emtb you have that has a genuinely low BB Height?

 

[pollywaffle]

What is the definition of a genuinely low bb? I just thought it was having the bb lower than the line between the axle height if you draw a line between the front and rear axle. I don’t claim to know jack about jack though.

 

[Gary]

It's not really as simple a question as that @pollywaffle . What is considered a low BB height will depend on the amount of travel the bike has and it's wheelsize. Intended use comes into it too. eg. A pure descending bike (DH bike) can benefit hugely from having a lower BB than an all round XC bike

BB intersected by a horizontal line drawn through axles on a rigid 29er with large tyres would a very high BB. but on a 200mm travel 26" DH bike would be quite low.

My point is emtbs generally don't have low BB heights. I haven't found a single emtb with a lower BB height than the ESommet (taking wheelsize and travel into account) and it's really not all that low. I happen to love low BB bikes. Hence my interest in what bike Frank has and how low it actually is.

 

[pollywaffle]

Okay, yeah right @Gary I have a 29er with 150mm travel and the specs say it’s bb is -15mm. So sitting on the bike it might be -20mm or more with sag. Is that a low bb do you reckon?

 

[Gary]

Okay, yeah right @Gary I have a 29er with 150mm travel and the specs say it’s bb is -15mm. So sitting on the bike it might be -20mm or more with sag. Is that a low bb do you reckon?

No. not even vaguely low

 

[pollywaffle]

Well there you go. I am truly confused. But I’m used to that