grolby

There's no doubt that the smaller wheels won't accelerate faster. You're not spinning a set of wheels up to speed, you're accelerating your butt from zero to that speed. You won't accelerate or climb better because of smaller wheels. They just feel different. You do pay a rolling resistance penalty, but that's pretty small, possibly overcome by potential aero savings. The ride will definitely be harsher, even 26" wheels are noticeably bouncier compared to 700C. But anyway, sniping at technical inaccuracies aside, these are intriguing little bikes! I'm enjoying this thread.

chaadster

i think you are wrong about that. The larger wheel has a larger moment of inertia, and therefore requires more effort to accelerate to a given speed than a smaller one.

Bacciagalupe

I've never noticed anything like that. I have, however, noticed that they're much twitchier at all other speeds, especially on fast descents.


...and the increased rolling resistance of the wider tires almost certainly overwhelms any such effects. It's a wash.

IIRC about 10 years ago, there was this huge push in triathlons for 650 wheels, using all the same arguments -- better aerodynamics, less weight, faster acceleration. It didn't last long, presumably because the results did not match the hype.

Again I'm not saying that mini-velos are bad or inappropriate for riding around SF. And as noted, they can be fun. There just isn't really an advantage to them in terms of performance or utility.

halfspeed

I don't think there's any question about that. What's suspect is the claim that the difference is enough to matter to any significant degree.

chaadster

Well, that's not what Grolby said:
The danger, of course, in getting into a discussion over what "matters" to a "significant degree of difference," is that it's purely subjective, and like arse-ends, everyone has their opinions about what matters and what's significant. The fact is that smaller wheels spin-up faster, and that's something that should be obvious to anyone who has ridden both 20" and 700c wheels, as Grolby noted when he said they feel different. Why he didn't connect the feel with the idea that the wheel is actually performing differently, I don't understand.

grolby

Well, the point is that the difference in moment-of-inertia between different size wheels is essentially irrelevant to the task of applying torque to accelerate a 130 lb (in my case) body and 15-20 lb bike horizontally. That's what you're doing, not spinning up a wheel, really. It might feel different with smaller wheels, but connecting that sensation to an actual increase in acceleration is assuming a lot. It's just me being OCD about technical stuff, like I do, sorry. I apologize for derailing the mini-velo discussion!

On that discussion, I think they look kind of funky, but it could be a fun thing to play around with. Perhaps if I end up in a bigger city at some point in the future, I would consider the option. I probably wouldn't bother with a road-style bike, though - I'm pretty devoted to the 700C machine I already have for that stuff.

juan162

Theres nothing to assume. There's a huge difference in acceleration from a dead stop! My first 2 years were spent on a modified Raleigh Twenty with 406 size wheels. After losing 50lbs, my bike racing brother-in-law finally convinced me that I was missing something and I pony'd up and paid for a 700c bike outfitted with shimano 105 components that easily weighed 6-7 lbs less than my raleigh. From complete stops it took me forever to get to regular cruising speed on the 700c compared to the 406 wheel raleigh. On the other side of the equation, I did appreciate the fact that on my 700c bike I could coast longer and faster than on my raleigh including on decents. It should also be noted that these differences aren't merely perceived. While I didn't do any serious scientific testing (give me a break, I just like riding!), I routinely did the same training routes and would switch from one bike to another for 3-4 weeks before coming to any conclusions. Its also interesting that I ended up posting about the same times on my regular 24 mile loop regardless of what bike I was on. In the end, I recognized the fact that if I wanted to get into racing, I would want a 700c wheel bike but personally preferred the 406 wheel's riding characteristics: quicker acceleration, tighter turns, and slight climbing advantage. I do wish my raleigh weighed less, though!

chaadster

If you're not too long-legged and don't mind sitting upright, a quick bar swap and a supple 1.5" tire could make for a feisty little urban Nano commuter, along these lines:



The owner of this bike, though, if I read the Flickr comments right, uses it for touring, and rode it between Portland and Seattle.

Sancycles

My SAAB Minivelo. Dec. 3, 2012

bjorke

Mini's come in various sizes. I like mine for being a mini -- I like my Friday too, but the little Soma is awesome in congested traffic. It fits fine.

That Saab looks like a sweet bike!

thugpipe

I just found this thread and I would love to put my 2 cents in. I am a big mini velo fan I own 3, a mercier nano, a dahon silvertip, and a origin 8 bully and these bikes are super fun in the city but as for acceleration I really don't think that they get up to speed any faster for any reason other than gearing. The smaller wheels have more mechaincal advantage than a larger wheeled bike and I have found that unless you have some crazy huge Chainring you are going to have a slightly offset gear range from a 700c road bike so the bike will have more torque and a tighter range and it will accelerate faster but you don't get the taller gears in the range so you can't hit quite the same top speeds. I am sporting a 55t chainring on my minis and I max out at just under 100 gear inches where as my 700c road bike has a 52t chainring and it maxes out at closer to 125 gear inches I think it is 99.9% gearing. On the low end my minis get like 36 gear inchs whereas my 700c bike gets only 49 gear inches of course the mini seems to accelerate easier your whole range is offset towards the low end. In order to have an apples to apples comparison the bikes would have to be geared the same and the only way to do that is to put a 69T chainring on the mini (good luck finding that) and i bet you would find the two bikes behaving very similarly baring any drastic geometry differences.

As to the twitchy handeling, once acclimated to the bike you compensate and it feels fine.

One of the best advantages of the small wheels is they are strong I'm 5'7" and 190lbs I like to jump off curbs at speed i need a strong wheel. Also addressing size the small wheel make the bike significantly smaller even though you may only reduce the length of a bike by like 10" don't discount the significance of the wheel height on the perception of bulk of the bike. Here is my latest project mini velo, you can't see the derailleur in this shot but its there, still much to be done.

Bacciagalupe

The MA of the wheel is offset by the higher gearing.

Small wheels accelerate a bit faster because they have less rotational inertia. However, they also have more rolling resistance. In addition, the smaller wheels usually require some type of compromise to get comfort on the same level as a larger wheel, e.g. wider tires.

In terms of performance, it's pretty much a wash.


For you, perhaps.

I found the handling to be excellent on some bikes and in some situations (e.g. a loaded bike), and detrimental in others (e.g. club rides).


True, but on a larger wheeled bike, that same impact would be far less jarring.


Having owned both 20" and 700c bikes in a small apartment, I'll discount it. The difference in space savings for a mini-velo is very small.

A well-designed folder, in contrast, makes the bike much easier to store in a tight space.

tds101 

I pulled my Lombardo Power 2000 out to take a springtime spin the other day. It was fun, but I realized I need to get some disk brakes on it & do a better job of fenderizing it. It's also not the fastest thing out there (slowest 21 speed I've ever ridden!!!),...my Puma Nevis 8 speed toasts it. It should be the other way around IMO. Eventually I'll take care of that as well,...but the disk brakes are priority #1.

Still, I hope all of you are enjoying some warm weather & riding to be happy!!!

PS: The origin 8 bully is fantastic!!! I wish it was still available,...sweet ride.

thugpipe

If you are serious about putting on discs be prepared to lay down some dough. Between the wheels and the calipers/discs on my bully alone it cost me about $500 mostly in the wheels because I had to have them laced up(20" disc wheel sets don't exist as such I have found). Does the lombardo power 2000 have disc caliper mounts? I stumbled upon the Bully at a LBS and picked it up cheap but I ended up replacing every part on the bike but the frame and the fork. Good luck on the disc brake conversion!

chaadster

That's pretty nice! Do you know who actually made it for Saab? Is that frame available under a different brand name?

tds101 

I'm going to hold off on the disk brakes for now, considering I'm not about to spend $500 on 'em ATM (thanks for the warning!!!). I'll just get some koolstops and deal with it,...

Now, I just ordered a set of Maxxis M-Tread tires. I had a blowout riding last night and was PISSED!!! I'll just replace my tubes (turns out they're old and deteriorated) and wait for my tires to arrive. I'm lucky I didn't go OTB!!!

thugpipe

Yea its a lot to drop but I really wanted a bike exactly like this for a while now: mini velo, Cr-Mo frame, discs.

Might I also suggest considering the Maxxis Hookworn tires, I have the 20"x 1.95s and they are great! I have them on 24mm wide rims which give them a very round profile and when pumped up to 100psi they roll very fast and are SUPER grippy. I haven't tested their rain performance yet but in the dry I can lay the bike to the ground in a turn and take it at speed if you are so inclined.

tds101 

Yeah, I hear you. I'll eventually go disk myself,...but with a wife & kids I'll hold off for a bit.

Now, I'll see how the M-Treads work for me, as I occasionally ride a bike path in Alley Pond park by my house. I need a little more tread for some of it. It's kinda neglected in areas,...but still a fun ride. Even if they are more of a street tire,...I'm not doing a "bmx"!!! They should be adequate. And if I ever drop the weight I'll go with thinner tires. 230lbs is a lot to carry on a minivelo.

thugpipe

well there is a guy in another thread who found a line on cheaper 20" disc wheels $115 for a front and $120 for the rear https://www.calhouncycle.com/productc...idproduct=1695 you know for when you can afford it 3:-)

heres mine after a few more $

tds101 

Thanks!!! I'll keep this in mind when I finally upgrade,...

ttakata73

Wheel size makes a huge difference to me because I run singlespeeds.
I have a Dahon Mantis rolling on 16" tires with a 12t/60T setup=80.5 gear inches.
I also have a Volume Thrasher rolling on 700x38c with a 16t/44t setup=75.6 gear inches.

From a stop, the Mantis feels stable in just a 1-2 pedal strokes since the wheels spin up and achieve stability faster.
The Thrasher feels clumsy and wobbly the first 2-3 pedal strokes because it takes a lot longer for the wheels to gain gyroscopic stability.
I feel like I can go to a 65t chainring on my Mantis because it still tops out too slow for my likes, but I don't want to increase my Thrasher's gearing because it takes too long to get going as it is.

Bottom line, I find it takes less effort to get up to speed/stability with smaller wheels and that is a noticeable advantage.
If you stop and start a lot, then you will appreciate smaller wheels.
You can ride slower among people and not fear you will run over them.
Also, other pedestrians walking are not/less intimidated by a bike with small wheels.
If you can't adjust to the twitchyness of a small tire, there might be something wrong with your inner ear.
I even have a folding bike with 14" tires and I got used to it in less than a minute.
Rollerblades are twitchy, not bicycles.

I am far more confident jumping off a 2' drop on my 20" BMX than my 29" Thrasher (never even tried but youtube says it can handle it) because the wheels must be stronger.
To think smaller wheels have no advantages is silly to me.

If you look at go karts, F1, and drag cars, they have small wheels because acceleration/deceleration is the priority.
The only reason why civilian sports cars of the last 20 years have big wheels is styling.
Big wheels look cool, show big brakes, and they sell cars.
If no one cared how cars looked, cars would likely have smaller wheels and inboard disc brakes.

If the UCI never banned small wheels in cycle racing, I think many road race bikes would have smaller wheels today.
Just my opinions, I could be wrong.

When I was a kid I rode a 700c Fuji Espree all over the place.
I even jumped a golf course sand trap with it and landed so hard the front brake fell off.
I wandered off to MTB, BMX, singlespeed, and folding bikes the last few decades but am getting the urge for a road bike again.
Still, I can't see myself getting a regular 700c road bike until after I build up a titanium minivelo.

banerjek

Of course. Most 'bents have smaller wheels....

echotraveler

MOULTON!! me want a new one!!

BOOM!

chaadster

Überoberaffentittengeil!

7up

Here's my MiniVelo