clipins or flats - the science behind it

njee20

Agreed, but it's a skill that you can't cheat with on flats, whilst you can (and plenty of riders do) on SPDs.

rockmonkeysc

You can cheat with suspension though. Flats and a rigid bike to learn properly.

njee20

Haha, different sort of cheating though. You'll only ever get a few inches with the improper technique using SPDs, and there's a lot of potential for it to get you in trouble. Whilst suspension is cheating, it supplements the technique more than SPDs do.

poah

I like my time atacs because my feet are clipped in and in the correct position. Do the pedals help me lift the bike yes but its not cheating or any other stupid comment that people might make about flats V's clipless. You ride what is comfortable I really don't see what the argument here is all about.

njee20

You're misunderstanding my point I think - plenty of people learn to 'bunny hop' by just yanking up on the pedals whilst clipped in (me included). There's a big limit to how much you can get the back wheel off the ground doing that, plus if you ever unclip whilst doing it it's likely to end badly.

There's no inherent issue with using SPDs to bunny hop, or helping with the proper technique.

rockmonkeysc

It's much more controlled using the proper technique rather than pulling up on spds and much less likely to result in the front wheel dropping when boosting jumps.
You can still use proper technique when clipped in.

lostboysaint

Briggo wrote:

For me...

Road = Spd
Off road = flats

Hell if I'm going clipped off road with the terrain I ride on, I'll die.

You must ride some incredible terrain, bearing in mind that a lot of the WC DH guys use Crank Brothers Mallets. Worth looking at the video of Danny Hart winning the WC a couple of years ago in terrible conditions, clipped in.

Road = SPD SL
Offroad = Crank Brothers (various)

njee20

It's much more controlled using the proper technique rather than pulling up on spds and much less likely to result in the front wheel dropping when boosting jumps.
You can still use proper technique when clipped in.

Which is what I was trying to say!

welshkev

lostboysaint wrote:

Briggo wrote:

For me...

Road = Spd
Off road = flats

Hell if I'm going clipped off road with the terrain I ride on, I'll die.

You must ride some incredible terrain, bearing in mind that a lot of the WC DH guys use Crank Brothers Mallets. Worth looking at the video of Danny Hart winning the WC a couple of years ago in terrible conditions, clipped in.

Road = SPD SL
Offroad = Crank Brothers (various)

are you cycling down Everest? I ride spd's on all my bikes, DH included. I've ridden stiniog, cwmcarn, bike park wales, uk bike park and much more...all clipped in

lostboysaint

Hence my comment to him!

welshkev

lostboysaint wrote:

Hence my comment to him!

yeah sorry, I meant to delete your bit :oops:

ilovedirt

welshkev wrote:

lostboysaint wrote:

Briggo wrote:

For me...

Road = Spd
Off road = flats

Hell if I'm going clipped off road with the terrain I ride on, I'll die.

You must ride some incredible terrain, bearing in mind that a lot of the WC DH guys use Crank Brothers Mallets. Worth looking at the video of Danny Hart winning the WC a couple of years ago in terrible conditions, clipped in.

Road = SPD SL
Offroad = Crank Brothers (various)

are you cycling down Everest? I ride spd's on all my bikes, DH included. I've ridden stiniog, cwmcarn, bike park wales, uk bike park and much more...all clipped in

Aren't they all smooth surfaced trails?

welshkev

ilovedirt wrote:

welshkev wrote:

lostboysaint wrote:

Briggo wrote:

For me...

Road = Spd
Off road = flats

Hell if I'm going clipped off road with the terrain I ride on, I'll die.

You must ride some incredible terrain, bearing in mind that a lot of the WC DH guys use Crank Brothers Mallets. Worth looking at the video of Danny Hart winning the WC a couple of years ago in terrible conditions, clipped in.

Road = SPD SL
Offroad = Crank Brothers (various)

are you cycling down Everest? I ride spd's on all my bikes, DH included. I've ridden stiniog, cwmcarn, bike park wales, uk bike park and much more...all clipped in

Aren't they all smooth surfaced trails?

yeah :roll:

ilovedirt

Yeah, aside from that black, which is scary, I thought stiniog, relatively speaking, wasn't that tech. Bumpy - but that means if anything it's more suited to clips than flats.

welshkev

ilovedirt wrote:

Yeah, aside from that black, which is scary, I thought stiniog, relatively speaking, wasn't that tech. Bumpy - but that means if anything it's more suited to clips than flats.

I see what you're saying but I did the blue and red once and then spent the rest of the day on the black when I went.

ilovedirt

As in the black that the BDS was on last weekend? Every time I've been there it's been too wet for that trail to be enjoyable, for me at least! Just steep slidy slabs, not much fun.

welshkev

ilovedirt wrote:

As in the black that the BDS was on last weekend? Every time I've been there it's been too wet for that trail to be enjoyable, for me at least! Just steep slidy slabs, not much fun.

Yeah, I've only been once and we got lucky with the weather. It was sunny and about 20 degrees 8)

rockmonkeysc

welshkev wrote:

lostboysaint wrote:

Briggo wrote:

For me...

Road = Spd
Off road = flats

Hell if I'm going clipped off road with the terrain I ride on, I'll die.

You must ride some incredible terrain, bearing in mind that a lot of the WC DH guys use Crank Brothers Mallets. Worth looking at the video of Danny Hart winning the WC a couple of years ago in terrible conditions, clipped in.

Road = SPD SL
Offroad = Crank Brothers (various)

are you cycling down Everest? I ride spd's on all my bikes, DH included. I've ridden stiniog, cwmcarn, bike park wales, uk bike park and much more...all clipped in

I have ridden Gawton black and double black trails, Brendons trail at Triscombe, all the blacks at BPW and loads of other really rocky stuff clipped in. I find it easier clipped than on flats and I hate Crank Bros mallets, much prefer my old Shimano DX pedals.

dusk

Is there a cycling discipline that's against the clock/head to head where the majority (if not all) pros don't ride clipped in??

Roadies do, BMXers do, DHers do, XCers do, 4Xers do

rockmonkeysc

Only thing I can think of is speed and style competitions. I think all pure speed, against the clock cycling clips are more common than flats.

Xommul

The OP asks about energy efficiency of clipped in pedals, it's not such an easy question as it really comes down to technique and strength.

Being clipped in allows either leg to make use of more of the pedal revolution and with the introduction of egg shaped front rings from people like rotorq dead spots in the pedal stroke have been almost wiped out.

Each time you push down you are pulling up with the other leg, each time you push forward over the top the other leg is scraping back. So in effect if you achieve 15mph just pushing down done mainly using the quads and calves then using clipped in pedals and making use of hams and gluetes you can go faster or share out the energy needed to maintain the same speed between your muscle groups.

If you always ride with flats you may find your hams and gluetes are not as strong or developed so may take time to catch up.

I use spd's on the road and xc mtb but for safety sake flats for single track and DH due to lack of experience

rickbst170

Thanks all. Really useful to see the different opinions, as well as a few sciency comments. I think that there are two topics; are spds safe enough for DH, and separately, is pulling inefficient. Based on the previous comments I'm almost certainly going to go spd. If it's common practice in all disciplines I'll follow suit (after all, I'm building up a single crown giant reign, not a DH monster so can't get too gnarly anyway). Separately, I'm still unclear about efficiency as it surely must be down to each individual's muscle development. If quads are developed power output costs less enery, so could be efficient and if not developed, just don't 'pull' but stay clipped in and take the benefits of foot placement, control, crank position adjustability etc.

If I break myself pretty quickly I.might switch to flats, but will start out on spds.

dusk

I personally see spd's as being safer than flats, I've had far more hairy moments due to losing a foot off a flat pedal than I have from being clipped in.

And I never pull up, I can't say I know anyone who does with spd's. Just because you can doesn't mean you should....

peat

It all depends on what terrain you ride.

I always used to be a flats guy (who wasn't....?) but when i got a road bike i went straight onto SPD-SL. After a year of using them on the roadie,i decided to take the plunge on the MTB (mtb ones, not SL's).

I felt the benefit immediately on XC and climbing. I also find that riding clipped in encourages me to 'pedal through' the tricky/slippery stuff rather than wimp out/stop and put a foot down as a did before. The main thing that stopped me doing it sooner was fear of silly falls. So far, it has never come to pass, I have always managed to unclip somehow.

However, I ran them on a MTb holiday in Morocco recently and they were great for 90% of the tour but crap for the 10% of really slow technical rocky bits. I would have much prefered a flat in those situations.

Horses for courses. I like them, for XC they are bill (IMHO).

njee20

Separately, I'm still unclear about efficiency as it surely must be down to each individual's muscle development. If quads are developed power output costs less enery, so could be efficient and if not developed, just don't 'pull' but stay clipped in and take the benefits of foot placement, control, crank position adjustability etc.

How can they be less efficient? Obviously someone who's much stronger will be faster on flats than someone untrained on SPDs, that's common sense! Don't really understand what you're saying from the rest of your post.

Daz555

I ride SPD on road and I love the change to the pedal stroke - in particular the ability to rest muscles by changing the focus of my stroke on long climbs - eg pedalling "forwards" rather than up and down when my quads begin to tire.

On the MTB tho - no way. Yes I can get out of my SPDs in double quick time but it is still lightyears slower than with flats. Flats are the only sure way to easily chuck your bike away when its all gone pear shaped mid air.

rickbst170

njee20 wrote:

How can they be less efficient? Obviously someone who's much stronger will be faster on flats than someone untrained on SPDs, that's common sense!

I read that the additional drive you have being clipped in (I.e. using the full pedal stroke to turn the back wheel instead of just the downstroke) generates more power per pedal rotation. Agreed, pretty obvious.

However, I read that it was inefficient to pull on the pedals and hence this thread.

Example (making this up and not sure what units to work in) - pushing burns 10 calories per stroke and generates 100rpm of the back wheel. Pulling burns 20 calories and generates 100rpm. So if you pull and push, you run out of calories 1.5 times faster.

If you think about it, you'll probably lose a race if you only pulled and your mate only pushed (used flats), so pulling does generate less power than pushing. Pushing uses your bodyweight behind it, pulling doesn't. With spds you can push and pull each pedal rotation, so more power per pedal rotation, but you'll run out of energy faster. So will you have gone further before you hit the wall and turn to jelly? Don't know. What's the science behind it and has it been worked out?

I guess spds are good for races over a few hours, but if it was a 'distance covered before collapsing', maybe flats would be more efficient.

I have no idea which is why I asked, but as everyone on the tour is clipped in I guess there must be someone who has considered and disregarded flats for tour races. Thought it was rubbish when I read it, but I started thinking about it and kinda see the logic.

rockmonkeysc

rickbst170 wrote:

njee20 wrote:

How can they be less efficient? Obviously someone who's much stronger will be faster on flats than someone untrained on SPDs, that's common sense!

I read that the additional drive you have being clipped in (I.e. using the full pedal stroke to turn the back wheel instead of just the downstroke) generates more power per pedal rotation. Agreed, pretty obvious.

However, I read that it was inefficient to pull on the pedals and hence this thread.

Example (making this up and not sure what units to work in) - pushing burns 10 calories per stroke and generates 100rpm of the back wheel. Pulling burns 20 calories and generates 100rpm. So if you pull and push, you run out of calories 1.5 times faster.

If you think about it, you'll probably lose a race if you only pulled and your mate only pushed (used flats), so pulling does generate less power than pushing. Pushing uses your bodyweight behind it, pulling doesn't. With spds you can push and pull each pedal rotation, so more power per pedal rotation, but you'll run out of energy faster. So will you have gone further before you hit the wall and turn to jelly? Don't know. What's the science behind it and has it been worked out?

I guess spds are good for races over a few hours, but if it was a 'distance covered before collapsing', maybe flats would be more efficient.

I have no idea which is why I asked, but as everyone on the tour is clipped in I guess there must be someone who has considered and disregarded flats for tour races. Thought it was rubbish when I read it, but I started thinking about it and kinda see the logic.

Mechanics isn't your strongest subject is it?

rickbst170

What makes you say that?

rockmonkeysc

Your very dodgy understanding of the mechanics of how it all works and in particular your confusion between energy, power and speed.
I could explain it for you but I can't understand it for you.