[Closed] Why can't I get any power down on my road bike?! Crank length?

why do you expect to be doing 4mph more than you are doing, and how fast are you going?

why do you expect to be doing 4mph more than you are doing, and how fast are you going?

Manage your expectations. Unless you're going slower on your road bike than your MTB, even then it's likely to be due to the different ergonomics and the fact you don't ride it, rather than crank length.

....if you not riding it much - why you expecting so much?

4mph is a massive gain to expect!

Are you running your tyre pressures like a MTBer (<100psi) or like a roadie (>100psi) ❓

Crank length will feel different for about 5 minutes, but won't have any effect on performance that will make a difference.

I don't understand the 4mph slower than I should be thing; ride it faster then..

Learn to pedal faster and smoother!

Mountain bikers tend to mash the pedals and only put in effort on the downward stroke of the pedal action. Learn to pull up with your feet as well - it takes some time and feels odd at first.

Turbo trainers are great for improving your cadence.

Best excuse I've heard for a while! "Sorry, I would have gone quicker but my cranks are too short!" As mentioned, it's more likely to be general ergonomics, position and the lack of regular riding. How fast are you actually going and why do you expect to be faster?

I assume the 4mph difference thing is from an 'average speed to complete the route' kinda working out?

I found going from a 'conventional' 53/19 to a 'compact' 50/34 made a huge difference, which initially sounds counter-intuitive, but I find that as I'm an old man now, with tired knees, I can push a 50 'round far more efficiently over distance than eventually struggling to grind the 53 out.

Have another look at your riding position on the roadbike too, even slightly not-quite-right ergonomics can wear you down, and, in my experience, a road bike is more critical of it's set-up than is a MTB, as there is generally less fidgeting about when you are riding (although you can still entertain yourself bunny-hopping white-lines, drain covers and the like (or just riding it off road)).

Something as simple as a big headwind will kill it dead too tho' so you'd need to repeat it a fair few times to average out any number of variables.

I hate to nit pick muffin man... I know what you mean with the 'mountain bikers mash the pedals' comment. However some research published by the USPS Pro Cycling Team in 2001 indicated that the cyclists with the smoothest pedal stroke were XC mountain bikers due to the requirement of maintaining traction whilst climbing steep and slippery stuff.

Obviously one piece of research does not immediately debunk your comment, I just thought that the above might of interest.

Anyway...my two penne 'orth...

"...I just can't efficiently ride my road bike (which I don't ride much)."

I think that that, right there, might contain the answers you seek. Ride more...get better at riding...

I'd also be interested to know why you feel that you can't get the power down, why you feel that you're 4mph slower than you should be and how you arrived at the figure of 4mph? What are you using to calculate power?

Crank length on a road bike is about your inside leg size very few road bikes have 175 cranks.Are you pushing your gears rather than using a fast cadence .

Weak legs.

If you were 12.5% stronger you would be 1.37% faster. Do the maths.

Jesus, MTFU.

Cranks my arse.

🙂 @ Bez

Wheeliejim - get that front wheel on the road and marvel at change to average speed

However some research published by the USPS Pro Cycling Team in 2001 indicated that the cyclists with the smoothest pedal stroke were [b]elite[/b] XC mountain bikers

FTFY

To get back to the original crank length issue, plenty of people use 170 on a roadie and 175 on a MTB. Personally I have 172.5 on my roadies, but the difference between that and 170 is piddling in the wind - I certainly can't tell the difference between them and riding the MTB/tandem with 175.

Actually, now I come to think of it, is it the 150mm cranks on my uni which makes me so much slower on that?

back to the OP

- what cadence are you doing?
- what gearing are you using?
- 4mph slower average speed or current speed?
- define what you mean by "efficiently".

I think you seriously need to manage your expectations.

Wheelie serious

Don't get [b]cranky[/b] about your lack of power,just try hanging a sausage to the back of the saddle ,then ask the owners of the most crazy and starved canines to let them out behind you(10 second start). 😀

To clarify: for a given route, on one bike (a hybrid) I can average 17.5 mph and on this bike, it's like 13.8 or something, and on one straight where I would be doing 20mph on one bike, on this one, it's 16. And given the supposedly more aerodynamic position of this bike, you'd think it would be faster if anything.

So it's absolutely nothing to do with "expectation", as I'm comparing performance on the same route with different bikes - I didn't make that clear...

Serious question. Is your computer set up right?

If you google crank length there's a load of different views, lots contradict, the science on crank length isnt exactly clear but I recently changed my road cranks from 170 to 175 not even aware the old ones were short so just bought what I thought I had. I haven't changed anything else about the ride position and I know 'feel' I can put more power down and have seemed faster on the daily 30 mile commutes. I suspect it's just subjective, no science, but in essence I guess I have stretched the legs 5mm at the bottom of the stroke. Maybe the length just suits my style better. I don't know.

I don't think it's the computer, it's a garmin gps based one, so should be consistent moving it between bikes.

Have you got it set for 2 different bikes or using one readout (like me)

Maybe bike 1 is using mph and kph the other?

This will have nothing to do with crank length btw

Perhaps the bike's just a bad fit.

My first mountain bike was too small and I had a similar thing with that - it just made hard work of riding.

Perhaps you need to press on a bit harder. You're the engine, after all.

It's not the computer 🙂

Besides, I can feel that I'm not getting and speed out of it.

It "feels" inefficient in the same way you can feel the inefficiency as when you put your saddle down too low.

(My saddle isn't too low...)

Perhaps you need to press on a bit harder. You're the engine, after all.

Yes but if you put the engine on one bike and it does 20mph and the engine on another and it can only (painfully) do 16, then I'd want to kno why 🙂

Have you checked everything is free bearings transmission brakes binding tyres at correct pressure

if you want to go faster,pedal faster,not harder.
someone said that.
get a fit done.ride in the drops.higher cadence lower gears.
get a fit done,then fine tune it.takes a few years to really find your position.

Train harder, for longer, embrace the pain, slam your stem & take a healthy does of MTFU.

Alternatively, if speed is your issue try riding faster

Similar thing with me, really.

Recently acquired my first drop bar road bike - a Wilier La Triestina - and the gains in average speed over my Roadrat, doing the same hour-long loop, are about 1.5mph faster - quite a bit less than I'd hoped might be the case.

Still getting to grips with the bike though and adopting a gingerly approach on some of the descents, compared to the Roadrat, because not being able to automatically extend a finger and brake gives me the Fear.

Still not using the drops very much either, unless it's really windy. I guess it'll take time before putting your hands away down there becomes a natural inclination.

quite a bit less than I'd hoped might be the case.

What are you people expecting?
Really, what did you think would happen with a new road bike?

You
Are
The
Engine.

Press on to go faster.

🙂 I know how daft that sounds. I know fine well the answer is to ride more, lose weight, get fitter, etc, etc.

However, thought the power transfer might be more efficient, the weight reduced, the aerodynamics might be better, tyres thinner, less rolling resistance.

In the same way as I am a fair bit faster on my Roadrat, on the road, than on my full susser, I thought I might be an order of 3-4 mph quicker on a road bike, designed to travel quickly, on the road.

and on one straight where I would be doing 20mph on one bike, on this one, it's 16.

The wind? Were you more tired? Brakes rubbing?

[i]However, thought the power transfer might be more efficient, the weight reduced, the aerodynamics might be better, tyres thinner, less rolling resistance.[/i]

All these things are real, but ....

...as with 'lighter wheels', as with a 'carbon frame', as with 'deep section rims', as with 'energy drink', as with 'race tyres', as with a 'super light bike', the basic issue of moving you still remains.

The reason I am so sceptical of all the 'Oooh, I got some lighter wheels and now my bike flies like the wind' posts is because it's just not true.

People think that losing a few hundred grammes will make their bike soooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo much faster, and it is demonstrably cobblers.

...as with 'lighter wheels', as with a 'carbon frame', as with 'deep section rims', as with 'energy drink', as with 'race tyres', as with a 'super light bike', the basic issue of moving you still remains.

😯

...nooooooooooooooooo!!!

It definitely [i]feels[/i] faster when out of the saddle and climbing but I guess in between times, on less hilly sections, I still tend to plateau and rein it in at approximately the same level of effort at which my legs muscles start to ping and ache or I get uncomfortably short of breath. Why try to crash through the pain barrier when shopping for a new bike or lighter bits is so much more fun? 😛

Yes but if you put the engine on one bike and it does 20mph and the engine on another and it can only (painfully) do 16, then I'd want to kno why

5mm of crank length variation IS noticable but for me not much and only when really trying to crank too high a gear up a hill. I had 165s on my MTB and switched to 175s which really helped up the steep bits. But for a high speed road bike situation I can't really see it unless you're operating at your absolute max torque. If you're saying you can manage 20 on a MTB and 16 on your road bike I think you've got a serious setup issue, not a crank length issue. My road bike is notably easier to keep at 20+ than my mtb with slicks now that I have it set up right, but I thin that's primarily from the tiny tyres. The cranks on my road bike are 170s, MTB are 175s.

Yeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeessssssssssssssssssssssssssss.

When I started road riding/racing, my bike weighed 21 lbs. A 'light' bike weighed 18-19 lbs. Bikes now weigh 15-16 lbs.

A huge difference of about 4-5 lbs.

Is anyone actually riding faster because of this astonishing drop in weight?

Everyone has drunk deep from the fountain of shiny thing make it all better, but it's still not about the bike.

[i]Why try to crash through the pain barrier when shopping for a new bike or lighter bits is so much more fun?[/i]

Because you are weak.

crikey, rule #4.

Rule #5 for you, young Skywalker.

You [i]can[/i] be a total hard man [i]and[/i] ride a fantastic bike.

Perfect example:

[img] [/img]

1.5mph gain is huge.

i.e at the end of an hour you'll be 1.5 miles further ahead. Or one lap ahead in cross, possibly two or three in a crit.

Aaaah.....

Only if you are doing a time trial, I would say.

In a crit, or in any other mass start event, tactics play a greater role than aerodynamics, than speed, even than power. It's a mind game.

4mph slower on a road bike over a hybrid on the same stretch of road?

It just doesn't sound plausible. What did you buy? Something made from welded scaffold poles?

oldgit - Member
1.5mph gain is huge.

i.e at the end of an hour you'll be 1.5 miles further ahead. Or one lap ahead in cross, possibly two or three in a crit.

I was thinking that, it'd knock over a minute of my PB for a 10 mile TT. Typically you I'm looking for seconds over that distance.

Only if you are doing a time trial, I would say

Indeed. Or just riding on your tod.

'for a given amount of effort' if you are expecting either a wattage or a perceived effort to give you a certain speed then it's never that simple

road riding is all about laying down a set effort for long periods, so you need to get to get the fit sorted and then ride the bike lots more

Had a few thoughts...are you using the same pedal system between bikes? Is your saddle height the same between the two bikes (n.b. can of worms opened...different crank length = different saddle height)? Both of these things will affect your 'feel' of the bike and your sensation of power delivery to the pedal.

Like I say, just thoughts...

It boils down to this.buying things doesn't automatically make you faster.

you say you don't ride it much,ride it more.Was off the road bike for a month,had my usual ride today.
felt like shit.You can't buy your way out of it.you can ride your way out of it.
and get a fit done.

How much tangible difference and useful feedback and data does a fit generate?

Does the fact that fits are generally done by bike shops mean you end up getting advice like "see this stem and these cranks here, or that bike over there, that we need to shift stock of, you could be doing one of those..."?

well,it's a really good starting point.made a lot of difference for me.

The shop I went to wasn't like that,they charged me for the fit,I then got a stem off crc.
but it is a fairly precise starting point.you still tweak a bit.and lowered the stem as I got fitter.
Basically it saved me lot of time,hassle and frustration.

want to get a fit done at the mapei clinic over in varese,it's not that dear.bit of a hassle tho.

I've spent some time tinkering with the set up, and have lowered the bars by flipping the stem, and it has made a hell of a difference.

Previous times on commute:
01:22:57, 01:19:01, 01:21:14

New set up:
01:12:46