Geok

I see the key basis of speed difference is in upright position of folding bike rider. The stock complectation, the stem and width of handlebar - all of these factors create poor aerodynamic posture of rider. That's why I cutted up the stem for 2"1/4, added massive bar ends so elbows are almost on grips, also added toeclips.
Of course, I could set up some Duranos or Kojaks for having 700x28c analoge, but with harsh roads I have here it's better to stay with 20x1.5+.

sreten

Hi,

Worrying about the wheel bearings, crank and pedals robbing
power seems a bit OTT. AS long as they spin freely they'll
make next to no difference.

Poor tyres that don't roll will constantly slow you down, mine
did, and new tyres made a big difference to cruising speeds.
At high speeds the limitations of folder geometry can limit
your maximum power and and a good aerodynamic position.

Good rolling tyres IMO are the main factor.

If you really want to fly, get serious :



Tight cornering might be a problem ,

rgds, sreten.

fietsbob

There was a Moulton Team in the RAAM that started in SanFrancicso, when I lived there.

BassNotBass

OTT? Hubs and bottom brackets that apparently 'spin freely' but are actually far too tight rob quite a bit of energy. I've even had people come into the shop with toasted cartridge bearings and they didn't even realize it because everything 'spun freely'.

sreten

Hi,

I don't understand your language, "far too tight" and "spin
freely" don't go together in my book. "Too tight" and "binding"
I understand. Still rideable, but they won't last very long.

TBH I don't know the result of running overtight bearing,
you get a binding effect each rotation which is not good,
but I don't know what that turns into longer term.

I can only check mine at effectively no real loads compared
to riding the bike, I just look for very little play and no
apparent stiction or binding. Too much play is bad,
stiction or binding a lot worse, both is terminal AFAIK.

rgds, sreten.

BassNotBass

Maybe you should explain what you mean with 'spin freely'... that certainly is a very vague term and is open to varied interpretations. I assume that your response "Worrying about the wheel bearings, crank and pedals robbing power seems a bit OTT" was to something posted in this thread, maybe you could clarify what you were responding to which you thought was OTT.

sreten

Hi,

In retrospect you are of course right, I meant they shouldn't affect your
speed usually, usually being they are well adjusted, if they are not well
adjusted to the extent they affect your speed, something is very wrong.

The way you put it seemed to me implied adjustments affected speed,
but I guess you really meant if they are wrong, they will slow you down.

I don't think proper adjustments of bearings affect speed much at all.
What I thought was OTT is the idea that the normal adjustment range
of bearings would affect your speed, but that is not what you meant.

For sure any problems in those areas will have an effect.

But faults aren't really the subject of this thread ?

rgds, sreten.

roka

I find that I average about the same average speed (14 - 15 mph) on my Brompton as on my Giant hybrid.I keep both in good condition and ALWAYS check the tire pressure before heading out.

Sixty Fiver

Halfway through a century over the rolling hills we have here... I was not out to push things very hard and slowed down to see the sights but also met up with some riders along the way who were pushing a pace of 35-40 kmh and I had no trouble keeping up.

And yes...flat tyres suck.



After the flat I had some issues with my pump which just would not work to give me enough psi so it slowed me down until I found a filling station and could get those Comets back up to 100 psi.



Forrest has gotten faster after some upgrades to the drivetrain which gives me a slightly higher top gear... now I spin out at 55 kmh which is good for a touring folder.



On group rides I have even laid waste to folks riding "real" bikes who were unprepared to have me blow by them and then be frustrated because it is really hard to get a good pull off a skinny guy on a little bike that sometimes thinks it is a racing bike and not a tourer.

I can't wait to build up a more race oriented folder / small wheeler... my new Moulton is an all rounder while I am looking at my Dawes or my yet to be built up Moulton to dedicate to more pure speed and less utilitarian / touring purposes.

I have something like this in mind for the other Moulton...

Sixty Fiver

All things being equal a performance oriented folder or small wheeled bike benefits from reduced drag and lighter wheels so can be very competitive against full sized bicycles... as a rider you need to be able to be in the same position as you would be on a road bike to make good comparisons because as soon as you are sitting up the advantages get lost pretty quickly.

The most important factor in gaining speed is reducing wind resistance... weight plays a very small role unless you are climbing mountains.

Ozonation

Hey Sixty Fiver... are you in Alberta? I did a double take looking at the Ukrainian Village sign. And is the ravingbikefiend.com your blog? I recognize that skyline... I grew up for 20 years in Edmonton!

By the way, your reconditioned folding Raleighs are just awesome. We just had a local "urban" cycling shop open up, and they have a lot of Raleighs - no folders, but I'll keep an eye out for them.

Sixty Fiver

Yes and yes.

And thank you.

The Ukrainian Heritage Village is one of my favourite places to visit.

...

I should have pointed out that when I did the first century on my folder it was at the end of a week when I had been riding 100km every day to go back and forth to the frame shop (on my folder) which is on the other side of the village and then ran other errands locally.

I did this to set an example that not only can small wheeled bicycles be quick, but that they are well suited for long distance riding over extended periods... 700 plus km a week is some good mileage to be laying down and a bike needs to be very comfortable to do that.

I have ridden that folder an incredible number of miles in the past 5 years and found myself preferring it to my touring bike for shorter trips where I might ride 300km over a weekend but not have to carry that much because I had accommodations waiting.

Ozonation

Very cool... I miss the River Valley bike paths. My Dad used to take us out to Rundle Park when we were kids, and we'd cycle to the High Level Bridge and back: back in the late 70s and early 80s, that was about as far as you could go.

Last year, I had a conference back in Edmonton, and I had the Brompton - well, why not for old times sake? On the afternoon after the last session, I ditched the tie and blazer, unfolded the Brompton, and headed down into the River Valley and away I went back up towards the old neigbourhood in the northeast end of town. Brought back a lot of memories... and some inclines that I had forgotten about! The Brompton was more than capable... amazing what 6 well spaced gears can do. The rider... well, I'm in pretty good shape, but I don't have the legs I had when I was 16 that's for sure...

badmother

Yay sixty Old steel is the way to go. Missing your postings in the folder forums. I guess you had enough of the dogfights around here..

bhkyte

Release your inner pigeon !!!!!!

Sixty Fiver

Dogfights ?

What have I been missing ?

badmother

smallwheeler

hahahahahaha!

cplager

If you really want to see how fast small wheeled bikes can go:



Sam Whittingham has the world record at just over 82 mph.

I'm not sure what size the wheels are, but the are smaller than 700c by a noticeable amount.

If you want to faster, there are a lot of things you can do.

If you want to go fast, aero is everything.

sreten

Hi,

Graham Obree is making a serious (headfirst)
attempt to break the 100mph barrier it seems.



rgds, sreten.

BassNotBass

let's not forget

cplager

I like Graham, and like his out-of-the-box thinking, but so far I haven't yet been impressed by this attempt. I haven't seen or read anything suggesting he's taken that bike over 20 mph yet...

But, yes, it has small wheel.

sreten

Hi,

Yes. Though he can probably still do 20mph in a bathtub
fitted with wheels, 100mph is a huge jump from 82mph.

rgds, sreten.

MEversbergII

Good googly moogly, how does that Obree guy start on his bike? Do they just lock him in there and roll him down a hill?

M.

cplager

For many (most?) of the two-wheeled bikes going for speed records, they need to be held at start.

So, basically, as you said.