The Road Razor. Suggestions

new cranks fitted.

The 700c now weighs 10.8 pounds - complete with front and rear lights and computer.

Compared to my Nimbus 20 in standard trim which weighs 11.4 pounds and my Pashley 26 inch MUni that weighs a massive 15.4 pounds.

Next project? Lighter wheel (expensive) or perhaps pedals.

I use pinned platforms. These are heavy, but spread the load and give good grip.

Any suggestions for light grippy pedals suitable for road and easy cross country? As rotating weight, the pedals must be quite important.

I use the Odyssey plastic “pinned” pedals on my touring uni ($11 from I think they go well with a fairly grippy shoe, like a trail runner or sand shoe; the shoe’s grippiness makes up for the lack of real pins, and it’s still possible to move your foot around on the pedal. (The same shoes on my MUni aren’t as good because they have a tendency to get stuck in the wrong position).

They’re listed at 400 grams.

What length of cranks do you use? :slight_smile:

I have the standard 125mm on my 29er… But i’ll order a new pair in just a few days, but i don’t know what length i want…
114, 110, 100 or 89mm…
I’m a decent rider, have the balance to glide, and havent any problems with the 125mm, but they aren’t fast enough! :wink:

Go tubeless?
Do you need all of those spokes?
Drill out the rim (if it’s double walled)?

There is a danger here that you turn into the unicyclist version of bikers who buy £100 worth of titanium bolts to save 2.1g. So: Haircut? Ride in sandles not shoes?

We have to go for another ride sometime - I want to see this anti-beast of a unicycle.


You could get titanium pedal axles and magnesium pedal bodies.

I saw some onza titanium pedal axles on ebay a while back, think they went for about a tenner.

I don’t think magnesium pedals are too expensive either, ones with just a basic platform shape, nowt too fancy. They probably come with steel/cromo axles but stick titanium ones in. Super light and quite strong too!


Re: The Road Razor. Suggestions

“tholub” <> wrote in message
> I use the Odyssey plastic “pinned” pedals on my touring uni ($11 from
> I think they go well with a fairly grippy shoe, like a
> trail runner or sand shoe; the shoe’s grippiness makes up for the lack
> of real pins, and it’s still possible to move your foot around on the
> pedal. (The same shoes on my MUni aren’t as good because they have a
> tendency to get stuck in the wrong position).

It only just occurred to me, after reading that, that not only are pedals
rotating weight, but so are the shoes, the whole mass of which is rotating
at maximum radius. ( and so are my feet, but I don’t think I could do much
about that ) . I’ll rethink shoes the next time I buy some and will
carefully consider their suitability. By then I might even be good enough
for it to matter.


102 mm.

I ran 110s on it for a long time and, to be honest, they are noticeably more versatile, but, hey, a 29 inch tyre would be too.

I have ridden the 29 on 89s. For mounting and smooth riding, it’s OK. First patch of gravel: face into gravel, gravel into face, face/gravel interface.

125s are just like soooooooooooooooooooo long.:wink:

You are, of course, totally correct. And your point is… ? :wink:

Not much hair left to cut, though. I’m down to a 1/2 at the back and sides.

Re: The Road Razor. Suggestions

Not so.

Rotating weight ‘actually’ matters when it comes to wheels, where the weight is being spun around at fast bike wheel speed. (how many RPM’s would a ‘fast’ bike wheel go?)

Even though your pedals are going in a circle, it’s only really ‘moving weight’

The cranks and pedals go round at exactly the same number of rpm as the wheel, except on geared unis.

I’m riding at speeds of 10 - 13 mph, maybe a little faster. That’s oveer 100 rpm, and sometimes almost twice that for short bursts. On a bicycle I’d be riding at speeds of 15 to 20 mph, maybe a little faster.

However, on a bicycle, because of gearing, the cranks and pedals would be going round much more slowly than the wheel. I used to ride a bicycle with a 27 inch wheel and my typical cruising gear was around 70 inches. Therefore at any given wheel speed, the pedals are traveling about 2.5 times as far. Therefore the weight of the pedals is more significant than it is on a bicycle.

In fact, it’s not speed that’s the important thing, but acceleration and stability. The lighter a thing is, the easier it is to accelerate or slow down. (Technically, slowing down is a form of acceleration.) Also, the offset weight of the pedals and cranks (and shoes, feet and legs) is part of what sets up a side to side wobble in a unicycle wheel. On a bicycle, the cranks and pedals are completely isolated from the wheel that steers the machine.

It is therefore abundantly clear that the weight of pedals on a unicycle will make a difference to acceleration, braking and directional stability.

Re: The Road Razor. Suggestions

I am using these
on my 29" for road and trails in the woods though they are not as large as pinned pedals they fit perfectly well.
(ah I use 152mm cranks so the feeling might be different)

I use azonic fusion magnesium pedals

They weigh 470g the pair according to this page

Or you could try to get hold of some old lightweight road pedals and use them with half toeclips. That might save you some weight.

Other things you could probably save weight on - get an aluminium seat post, cf base, remove half the padding from the seat, cut down the seat post so that the amount of post in the frame is exactly the minimum insertion amount (8 cm on the post I’ve got here), super lightweight tyre + one of those silly roadie tubes. I don’t think tubeless saves you much over a posh roadie tyre + tube.


And be having the same relatively minimal effect of rotational weight from your pedals. Rotational weight is a good thing to consider when getting rims (not unicycle rims, as they don’t spin faster than you pedal) but I doubt makes any difference, a noticable one, anyways.

but please, buy away! Get that thing as light as possible, you’re on a mission!

drill anythin that can be drilled!

I know for a fact it makes a difference because I’ve experienced the difference. A simple change from a cheap heavy 35 mm tyre to a mid priced light 28 mm tyre made the uni noticeably more responsive to pedal input.

One error in my earlier post: a direct comparison between rpm for pedals on bicycles and unis should also take into account crank length. I omitted that.

The cranks and pedals move with the wheel. From a physics point of view, they are part of the wheel, and part of its rotating mass. The laws of phyisics (which we all agree, ye cannae change) do not recognise one part as a wheel and one part as a pedal. They recognise masses, velocities and forces.

The further the mass is from the centre of rotation, the more its effect on acceleration or deceleration.

The further the mass from the central plane of the wheel ( the higher the Q factor) the greater the effect of the weight of the pedals and cranks on directional stability.

If you don’t believe me, stand your uni upside down on the seat, then spin the wheel by hand then stop it by hand. Now remove the pedals and do the same. the wheel will be easier to start, and easier to stop. No pedals at all is, if you like, the lightest pedals possible (for the purposes of this simple experiment).

Now for directional stability. Hold the uni by the saddle and lift it. Now spin the wheel. Feel how the uni rocks from side to side. Now remove the pedals and do the same. It will rock less.

The effect might be slight, but it is there.

I don’t expect these improvements to make my unicycle faster. They might even make it slightly more difficult to ride (reduced flywheel effect) but they will make it more elegant.

If you’re worried about pedal wieght, either get something light and cheap like the twisted PC’s or something light and grippy like specialized lowpros or shimano dx’s.

Not worried about pedal weight. Just interested.

As it happens, I followed a couple of the links posted in this thread, and found that the pinned platforms I have compare very favourable (in terms of weight) with some of the very expensive similar ones advertised. No doubt there are other differences than weight, of course.

It is clear to me that lighter pedals will make some difference. How much is a question of degree. There is even an argument for having a big rotating weight if you want to do distance. The Coker “autopilot” is legendary.

The weight of the rim and tyre will make most difference. The spokes will make a bit. the pedals will make some, and the cranks a bit less. The uni is perfectly rideable as it is, so I’m only looking at it as a project anyway - a bit of fun. “Common sense” says put a wider rim on, a Big Apple 29, and 110 mm cranks. But if we were all into common sense, we’d buy bicycles or bus passes.

Maybe it’s all an elaborate plan to avoid doing hops and drops! :wink:

We must all follow our own demons.

Especially if they’re tempting us with light weight pedals.

Demons are a bugger for that.:wink:

Re: The Road Razor. Suggestions

I would reccomend metal MTB-style pedals, with the spiked cage that surrounds the spindle. These are a lot lighter than platforms, and provide better grip. They are not very nice to your shins, but if you’re just road riding and wearing shin armor you should be ok.

These are really nice, and weigh just a tidge over 15 oz. These are mini pedals, but weigh even less than the ti version of the other pedals. I had them on my MTB for a while, and they were pretty nice. I don’t know if the small size will be a problem on a uni though.