Fixed Gear Climbing

[Cycling Badger]

I was watching a GCN video yesterday where the presenters were doing an “experiment” on climbing.
In the video Dan was explaining why weight and gravity have such impact when going uphill.
He stated that at the dead points in the crank rotation forward momentum is reduced and gravity drags the bike back.
My thought was it therefore must be quicker to climb seated and with concerted effort to circle the feet, not stamp of the pedals.

I then read a comment in this forum (and I think I’ve read similar others)

Fixies get uphill in a most astounding fashion

@rogerzilla from thread

To the point of the post …

I hypothesise that fixed gear bikes encourage a smother more continual power delivery, reducing the span of the dead points in the crank revolutions.
This has the consequence of reducing the yo-yo effect of gravity and forward propulsion.

Just a thought exercise, interested in views of others in the forum?
Does anyone have any experimental evidence to support or refute the hypothesis?

 

[rogerzilla]

Fixie riders call it the flywheel effect, although it's your own momentum rather than a true flywheel.

If you ride fixed all winter and then get back on a bike with a freewheel, you'll probably find you've forgotten to pedal in circles, evidenced by clanking freehub pawls when you get out of the saddle up hills.

 

[ColinJ]

I have ridden with forum members who used fixed up 20% climbs!

In one case, including a track stand on the steepest ramp so as to enjoy the views!!

I can definitely vouch for the opposite - singlespeed grinding to a halt above 10%. The only thing that I found to help was to adopt a ridiculous pedal stroke to get over the deadspots - bum way back, arms outstretched, and forcing the cranks round from behind rather than trying to do it from above.

 

[Dogtrousers]

There's something going on with climbing on fixed, but I can't fully explain it. It's it's more doable than I expected it, but at the same time it's hard work. My little fixed gear outings have something of the feeling of going for a run, rather than just a ride.

I think it's a combination of a) the mechanics of it and the "flywheel effect" that @rogerzilla mentions and b) the fact that it "keeps you honest", you can't be lazy and just knock it down a few gears and engage trundle mode.

I wouldn't agree that they go up in an "astounding fashion" but it's definitely something quite different to climbing with gears. I personally have a gradient limit of about 9 or 10% where I just grind to a halt @ColinJ stylee.

 

[ivegotabike]

The Monsal Hill Climb record, that has stood since 1981, was set on a fixed gear bike

Here is a photo from the Monsal Hill Climb website "Malcolm Elliott during his record breaking ride in 1981 – 1:14.2!!"

https://www.monsalhillclimb.com/wp-content/uploads/2016/09/malcolm_elliot_1981.jpg

 

[fossyant]

I could get up most climbs on my fixed, not always pretty, but they do climb well.

 

[mickle]

My mate Clive geared his fixed wheel for commuting in Bristol. Which included a trip up Park Street in the am and down Park Street in the pm. I think he geared it around 62"

Boy could he spin!

 

[N0bodyOfTheGoat]

Limited gearing certainly puts you in an aggressive mindset to climb a hill, if you have no plan to dismount part way up it. With gearing, within reason, you have the option to make the climb easier.

It certainly made my commute home more fun towards the end of my fatbike's life, rear mech cable had sheared and I was having to use the default rear fat wheel with 4" Jumbo Jim, because the pawls on my FatNotFat 29er rear stopped engaging. Just before I reached home, I had a 0.5 mile steady ~5% climb, a short recovery and then a rampy 0.25 mile climb that hit ~13%.

 

[a.twiddler]

Not ridden fixed, but since all the bikes of my youth were single speed I can imagine the exaggerated ankling needed to keep going on hills to avoid submitting to the dreaded getting-off and pushing. This does keep the pushing of the pedal from behind near the the top of the stroke as much as possible. It must be remembered that a) in those years I lived in North Devon then South Wales b) I'd never heard of toeclips let alone fancy whiz bang clip in pedals so it was all down to friction and none of that there pulling up on the pedal.

 

[Ian H]

Seated is definitely more efficient, but there comes a point when dancing on the pedals is the only way. I have certain hills where I know I'm fit when I can ride them seated.

 

[Ming the Merciless]

Not ridden fixed, but since all the bikes of my youth were single speed I can imagine the exaggerated ankling needed to keep going on hills to avoid submitting to the dreaded getting-off and pushing.

Seeing fixed riders on audax; they will tack across the road when it gets very steep.

 

[Ian H]

When I'm on fixed, a friend of mine likes to drop behind on steep descents so she can laugh at my Keystone-Cops-style comedy cadence.

 

[Sharky]

With fixed and single speed, a rider develops a wider cadence range. A geared rider will just change down to retain the same cadence.

So on encountering a climb, the fixed/SS rider is more comfortable on the same gear, just reducing cadence and using various techniques to get up the hill.

 

[Cycling Badger]

Thanks for all the replies.

I can't imagine tackling an Audax on a fixed gear - chapeaux to everyone who's ever managed to achieve this.

I'm going to distinguish between s/s and fixie when it comes to climbing. I more often cycle s/s than fix - but even then it's not the most used of bikes. I could give the many virtues of s/s, but for the propose of this hypothesis as both gear and s/s bikes have freewheels I consider them to be the same. On fixie I don't find it easy to allow the pedals to spin relaxed legs. I therefore need to keep some pressure on the pedals. Hence my assertion the dead spot in crank rotation is smaller.

I think I'm going to have to do some "experiments" - not sure they'll be that scientific but might give some insight.

I have two wheels for my bike one fixed, one s/s and both have same size rear sprocket.
I'm going to fit a cadence centre to the cranks, use similar tyre types (32mm road tyres I think)
Heart rate monitor to give a measure of effort.
Then collect three sets of data per configuration over the following:
- Short 100m ramp that has a nice gentle downhill run into it
- 85km local loop over mixed surfaces, no major hills and around 600m of climbing (so mostly ramps)
- Local hill climb which I think is 100m climb over 1km with pitches at ~14%
(I know that's considered a ramp in some parts - not even sure I can make it up that on s/s)

Can't control the external variables, but will try for some consistency in weather.

My alternative is that someone from GCN is reading this, do a video and save me all of the effort.

 

[fossyant]

Riding fixed is also good for strengthening hamstrings. I used to get a left hamstring strain following a silly running injury that was a niggle for years. Commuted on fixed for a number of years, and no more hamstring injury. Hasn't come back either. I sold the bike about 5 years ago as I wasn't proposing to commute again (got spine broken). I'm back commuting but use an old 90's MTB, so can mix my route up to avoid the worse of the traffic. I do miss that bike.