Wednesday, July 20, 2011

Everyone Wants Stability

Blue and Green
In discussions of a bicycle's ride quality, one thing that always comes up is stability. We want a bike that is stable and we complain when it is not. Of course the problem with "stability" is that the concept is largely dependent on our skill level and cycling background. Those who are unaccustomed to riding roadbikes will often find them unstable at first, while those who ride roadbikes exclusively will often find upright bikes unstable. This does not mean that either is actually unstable, but rather that the two cyclists are used to radically different means of weight distribution. Similarly, what's "unstable" to one cyclist can be "responsive" to another. It seems that perception of stability has at least as much to do with the person riding the bicycle as it does with the bicycle itself. How useful is it, then, to tell a salesperson or a framebuilder that we want a bicycle that is stable? And how useful is that term in reviews? Clearly we need further qualification.

When I talk to new cyclists who are uncomfortable operating their bikes, instability is often cited as the problem: It can make a bicycle difficult or scary to ride, making the cyclist feel not entirely in control. In the process of teasing out what exactly is meant by this elusive concept, I've identified a number of distinct points that I would like to share, and see what others think: 

Pilen, Balance
Starting from a stop
Some bicycles are described as shaky when starting from a stop, as if the front wheel is wobbly and wants to turn just as the cyclist is trying to get the bike rolling forward. This is a complaint I hear a lot from women about vintage mixtes that came with dropbars, but have been converted to upright bikes and also, interestingly, about classic Dutch bikes. The feeling is sometimes referred to as "light steering" or a "light front end," and has to do with a complicated combination of the bicycle's geometry and the height of the handlebars. With some bikes, I have found that lowering the handlebars helps - in particular when it comes to the mixte conversions - but ultimately it is a matter of getting used to it. Some cyclists do get used to it, but others can't and feel inherently uncomfortable with the bike. 

Cycling at slow speeds
Similar to the above, only extended to cycling at slow speeds: The bike wants to weave (i.e. feels "squirrely" or "twitchy") when the cyclist attempts to ride slowly, making it difficult to control. Aggressive roadbikes are known for this quality, but cyclists report the feeling about some upright bikes as well (albeit often they are upright bikes that are roadbike conversions). One thing I have found useful when riding bicycles like this at slow speeds, is to pedal in slow motion while feathering the brake, instead of coasting. I would be interested to know whether this works for others. 

Pilen Bicycle, Castle Island
Cycling at fast speeds, downhill
When riding at fast speeds, and particularly downhill, some cyclists are alarmed to notice that the font end of their bicycle will begin to vibrate in the region of the stem and handlebars. Assuming that nothing is loose on the bike or mechanically wrong with it, this is known as "shimmy" and there are ongoing debates regarding what causes it, whether it's a problem, and whether it is even a real phenomenon. This is something that a cyclist either gets used to, learns to avoid by abstaining from high speeds on that particular bike, or deals with by getting a different bike. 

Turning
When cyclists describe a bicycle as unstable on turns, they can mean a number of things by this. One type of complaint is that the bike turns too aggressively or, "too much," overreacting to the turn. Another type of complaint is the opposite: that the bike keeps trying to straighten itself while the cyclist is still continuing the turn. Either of these qualities can make turning stressful, with the cyclist struggling to make the bicycle follow the course they would like it to follow. How to deal with this, other than developing handling skills in line with the bicycle's tendencies (or getting a different bike) I cannot say.

Tire and Rock
Rough surfaces
To some cyclists it is important how stable a bicycle feels when going over rough or uneven surfaces. While wide tires play a role, at least to some extent this seems to be also about the bicycle itself - with some bikes seemingly "unfellable" off road or over potholes, while others relatively easy to wipe out on, especially for novices. In the realm of upright city bikes,  there is an increasing number of manufacturers (Pilen, Retrovelo, Urbana) infusing classic transportation bicycles with mountain bike characteristics in a way that works well in this context. Converting an old hardtail mountain bike to an upright bike can work as well. Upright roadbike conversions on the other hand, tend to be problematic in this respect - particularly for beginners. 

Tire width
Whether on smooth or rough surfaces, I have noticed that tire width can have a lot to do with a novice cyclist's perception of a bicycle's stability: Narrow tires are simply more difficult to balance on across a wide range of circumstances. If the bicycle's clearances allow for wider tires, this is an easy way to improve the feeling of a bicycle's stability. 

Mixte with Camera Bag, Pannier and Packages
Cycling with a load
Finally, whereas a bicycle might feel perfectly stable unloaded, some notice that introducing weight in the front basket or on the rear rack can disrupt that stability. Most of the time, this happens with a front rather than rear load: the bicycle begins to weave or wobble if the front is overloaded. There can be a myriad of causes for this, and subsequently a myriad of ways to deal with them. Generally speaking, carrying weight lower on the bike (i.e. not mounting a basket on the handlebars) is said to improve stability. But some bicycles are just not intended for a front load no matter what.

Pilen Bicycle, Castle Island
While it might be difficult to express what we mean by stability, breaking it down into specifics can be helpful - both in communicating with others and in gaining more insight into our own preferences. In attempting to understand the nuances of ride quality, it continues to amaze me how the same idea can be echoed by so many people, yet mean something slightly (or even not so slightly) different to each. Does a novice who finds their bicycle unstable need a different bike, or merely wider tires? Could be either.

41 comments:

  1. There's an excellent article that explains "shimmy" in detail and how to deal with it in the late Sheldon Brown's wonderful webpages. It is part of the collection of articles written by the inimitable Jobst Brandt!

    Link: http://www.sheldonbrown.com/brandt/shimmy.html

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  2. I have this issue with my Gazelle that it makes me nervous starting from a stop. It's heavy and when I try to start pushing on the pedal from a standing position it wiggles and its weight makes me feel like I will tip over on it. I acquired another dutch bike, a vintage one with considerdably lower handlebars and a higher seat post (to which i cant tippytoe and have to mount and dismount standing on the pedal) and I don't have this issue at all. It's like day and night. Could it really be that lowering the handlebars might help?

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  3. V, many of the issues that you mention are to a large extent, but not only the by-products of the frames dimensions and/or geometry, but also physical dimensions of the rider themselves. Many people point out issues with mixte or ladies frames, I think the relates to the fact that because of the relatively low standover heights a variety of riders can ride them even though they may not be the correct sized bike for the individual. If a larger person is riding a bike designed for someone smaller, many times it will feel "Squirrelly". Additionally road bikes, mountian and traditional Dutch or English bikes have wildly different geometries which can complicate "converting" them to other uses. You may not see this as much with Mens bikes, because the top tube height kind of limits who can ride it in the first place.

    I find the most helpful thing to solving issues of the sort you are talking about is proper stem length. Most bikes I build for myself go through 2 and sometimes 3 stems till I get one that works properly for me on a particular bike! Sometimes bike manufacturers are not given enough credit, because it's a tricky business to match stem and handlebars to a bike and the intended size of the rider based on bike size itself.

    MASMOJO

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  4. "Does a novice who finds their bicycle unstable need a different bike, or merely wider tires?"

    Could also be he needs to sit on it differently and relax and/or make small hardware adjustments.

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  5. I'm going to agree with Masmojo that fit can also have a huge effect on handling characteristics. geneally, a bike that's too small will feel squirely, too large, hard to steer. This can be especially apparent with kids, as a growing young'n who's been wobbling all over on their too-smal bike suddenly gets a new one and zips off in a straight line.

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  6. As a supplement to your comments on bikes that can suffer from overly-fidgety steering: I have found that upright or flat bars coupled with very short stems will lead to a twitchy front end, particularly on bikes originally designed for use with drop bars. (This is probably why ultra-stable bikes, with long wheelbases and well-raked forks, tend to have stems with very little forward extension. Think of traditional roadstars with one-piece John Bull bar/stem combos & rod brakes. No real forward extension to speak of. This set-up prevents nonresponsive steering while preserving the relaxed ride characteristics afforded by the LWB/comfy fork.)

    Vintage mixtes tend to have dropbars with short stems, and novice riders like to put northroads on them, in an attempt to be cute. Few of these folks swap stems, and the twitchy front end often results.

    -rob

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  7. novice riders like to put northroads on them, in an attempt to be cute

    Come now! Such digs are unnecessary. It seems just as likely they are changing the bars to fit a different style of riding.

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  8. While I think it's pretty obvious that no one puts North Roads on mixte roadbikes "to be cute," it's true that it is not always a good idea. Some bikes are just not intended for upright conversion; they were not designed to handle with the weight off the front. Of course definitions of upright also vary. A long stem with the swept-back bars set fairly low will not be as bolt-upright as a Dutch bike, but should make the converted roadbike more stable.

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  9. I have not ridden a great number of bikes, though I have done quite a few miles, so I found this interesting as I do not have any of the problems you mention here. My bikes must be well set up and suit my riding style. When it comes to turning, I tend to simply lean into the turn if I am going fast enough. Recently I had to do a slower turn which required turning the handlebars and I was alarmed to find that the toe overlap you talked about in an earlier post happened to me, it was a bit of a surprise to me and nearly caused me to fall.

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  10. I never knew that cuteness (or attempts to achieve cuteness) was a bad thing. FWIW, my wife has northroads on her 70s-era mixte, and she thinks they're cute. Lighten up; being tense isn't cute at all.

    As for certain bikes not being "intended" for certain components, well, this can be a factor, but something as simple as a bar-swap can typically be done without dire consequences so long as the user takes the time and effort to make other changes. Some, such as shift/brake lever style & placement, are obvious to most ppl. Others, such as a different length stem to achieve the desired rider position while minimizing any negative changes to weight distribution/overall geo, are less obvious to rookies.

    In all seriousness, I like mixtes, I like northroads, and I like cute cyclists. But, let's be honest, cyclists have forever been obsessed with image, and the past 5 years or so have been dominated by a drive towards cutesy retro/dorky trends. I think that's a good thing, b/c many retro and dorky aspects of cycling are quite practical. I wasn't trying to offend anyone, but I suspect aspirations of cuteness when someone swaps out bars to a more popular style the same day they get the old bike with the stock set-up. (Especially if they don't get it right, and they don't know why it didn't work out.)

    respectfully,
    -rob

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  11. For me stability means that the bicycle can recover from a disturbance (e.g.: a small but sharp move of the handlebars) and tend to go back to a balanced point by itself.
    The shimmy happens when at a certain speed the frequency of oscillations caused by the road equals the resonance frequency of the system (in this case, the bicycle, rider and load).
    It also depends on the type of road and in this case, an irregular pavement may eliminate the shimmy because it will increase the frequency of the road vibrations shifting it away from the resonance frequency.
    The best solution for resonance is to introduce damping: wider tires with a bigger surface in contact with the ground or lowering the front tire pressure will increase friction, damping the oscillations of the system.
    I never experienced this with any of my bikes but in the given example of converting a road bike that was used to front loads to a more upright bike, I would use a front basket instead of a rear rack (if shimmy was present).
    But I am aware of the fact that if a bike was designed to carry load on the back, using a basket can lead to instability.

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  12. What a great topic! I've been thinking a lot about stability, possibly in preparation for buying another (perhaps custom?) bike. There is one more aspect of stability that I think you forgot: Climbing (or sprinting) *out* of the saddle.

    I have a Madone, which, while a little twitchy at low and medium speeds, I find to be /very/ awkward out of the saddle. The front wheel wants to squirm left and right with each pedal stroke while the frame slops side-to-side in the other axis. I feel I have to apply lots of complicated corrections to the bars to counter these actions.

    In contrast, my cross-check really enjoys climbing out of the saddle, and I wonder if being double the weight of the Trek contributes to that. But I'm convinced there's more to it than just the additional inertia.

    V, have you noticed out-of-the-saddle stability quirks with any of your bikes? Particularly the seven?

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  13. I also meant to add, that reducing the pressure in the front tire on my cross-check seems to "calm it down" a bit.

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  14. Looks like that dragon known as toe strike went away...

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  15. Well TCO is a separate issue from stability. But still a dragon.

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  16. rob - I think the interpretation of the "cute" comment was that the swept-back handlebars are put on the bikes for frivolous as opposed to function-driven reasons.

    rubix - Out of the saddle, good point. Interestingly I almost never get into conversations about that aspect. I don't ride out of the saddle much, but the Seven is pretty good at it. Of course, my definition of "good" might be different from yours. I've never tried a Trek Madone, but I ought to just for comparison's sake.

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  17. Pushing down on the pedals steers the bike. The chain is on one side only, you are applying an off-center load. Every time you load the pedal you also apply a counterforce - basically you use the opposite arm & shoulder to keep the bike going straight. Pay attention to this while pedaling slowly, you'll feel it immediately.

    If you lift the pedals rather than push on them pedaling force pulls the bike vertical. Powerstroke and steering counterforce are the same stroke. Much less energy expended on keeping the bike going straight.

    Works on upright bikes as well. Just drag the pedal back from 5 o'clock to 9 o'clock. Even just unweight the pedal as it comes up.

    I got hit by a car yesterday. Traffic cop directed a car right at me. You can't think in those situations, you don't steer. Lifted the pedals from habit, hard, the bike pulled upright and regained inherent stability. Pushing on the pedals would've steered the bike right into the ground.

    Bikes are way more stable than anyone imagines. Loss of stability can be from bad design, just as often it's the cyclist working against the cycle.

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  18. I never could make friends with a bike that had quick steering due to an odd headset angle.

    Headset angle is so critical but so hard to judge with the naked eye to how a bike rides and handles.

    This is why I prefer the relaxed geometry of the American Cruiser. I have a really good idea how the Cruiser will handle so I will hop on one in a heart beat for a nice ride loaded or not.

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  19. LadyEnoki - Yes, I'd say lowering the handlebars could help! What is the other Dutch bike you mentioned?

    Walt - Do you know what the angles are on your cruiser? Wheelbase, chainstay length, etc? Just curious.

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  20. Interesting post! I’m doing the "pedaling while braking trick" too when I have to go (very) slow (and don’t want to dismount). But I have never perceived my bike as instable.

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  21. The presence or not of a front suspension.
    It's silly, but it tooks me months to figure. Smoothes out the road irregularities but requires permanent control.

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  22. This is a very helpful analysis. It explains why I feel sort of all-left-feet when riding my road bike in slower situations such as on MUPs. It's not bad, just a little awkward at slower speeds. I haven't experienced shimmy on any of my bikes, thank goodness.

    The biggest challenge to stability for me is riding with a kid behind on a trailer bike - especially if he's pretending to be driving a race car. Or a bat-mobile. I find I need albatross (on the mixte) or moustache bars (on the roadbike) for the extra leverage. My brother put moustache bars on his tandem for the same reason. He usually rides with two kids - one on the tandem and one on the trailer bike behind. He found that drop bars were just too narrow and didn't provide enough leverage to keep the "bike train" on track, even though he's a very strong and experienced cyclist.

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  23. The Raleigh Sprite 27 Mixte came standard with North Road bars. Using that as a model, I recently put Soma Oxford bars on my girlfriend's Raleigh Super Course Mk II Mixte- That bike is now a wonderful commuter bike- comfortable, nimble, and light. I've also got swept back bars (VO Left Bank) on my Super Course, which originally shipped with Maes drops. Much, much better ride now as well. I commute ~20 miles a day, and I find it to be very comfortable and stable.

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  24. Hmm, vintage mixtes with North Road bars. I bought a vintage mixte two years ago and swapped the drop bars for upright North Road-style bars, not to be cute but because I found the steering and handling terrifying with the drop bars. I had never ridden a bike with drop bars before and it felt mightily unstable for this little black duck. The North Road-type bars worked much better for me. It's possible many novice riders like me who buy a vintage mixte swap the bars to create a more upright position and more stability for themselves, regardless of what bars and stem the geometry is suited for. When I swapped the bars I didn't swap the stem; I probably should have.

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  25. Excellent break-down of all the potential stability issues. You make a really good point about how stability means different things to different people, depending on where they're coming from. To me any bike with drop bars is scarily unstable, meanwhile I would describe my Dutch bike as the most stable beast out there. But often when someone tries to ride my Dutch bike for the first time, their steering is all over the place and feels unstable simply because they're not used to it.

    Any issue I have with instability now, when dealing with the bikes I own, comes from carrying loads. A heavy front load can make me feel unstable. My only solution has been to try to weigh cargo to the back as much as possible, which does not affect steering.

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  26. "Traffic cop directed a car right at me."

    That happened to me once as well. I couldn't believe it, and it is even more disturbing to hear that such a thing is not as rare as I thought.

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  27. Thanks for this post. My one point of frustration with my Raleigh 3-spd is that it feels "unstable" and this is a helpful discussion in nailing down the cause. It would describe it as generally over-responsive and wobbly when starting from a stop. Interestingly, when I have a heavy load (in the rear folding basket, or even just in my backpack) it tends to feel MORE stable! I might play with the handlebars or the tires.

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  28. Having read through this post I agree with ''anonymous''There are different bikes designed for different purposes. MTB off road, road race, TT, triathlon, city commuter, tourers, load carriers etc. Geometry on all these are totally different and one should choose a bike for what it was originally designed for. Bike fit is important and should be undertaken by an expert making sure frame size, geometry, crank length, stem size and bar width is suited to the individual.Shimmy is normally found on cheap poorly designed bikes or poorly set up bikes. TDF riders hurtle down mountain roads at 100 kilo per hr without problems. Basically - buy a bike designed with the geometry and components for what one needs from a bike, get an ''expert'' to do the fit and learn the basics of correct pedaling, cadence and gearing, riding, steering and braking -- then all these problems sighted in this post will be elevated,

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  29. Pilen bicycles have a steering damper:

    http://www.pilencykel.se/site/sites/default/files/2011_05_06_1357.jpg
    http://farm4.static.flickr.com/3533/5770109467_4ed31cb16a_o.jpg

    Has anyone tested how this affects or improves stability?

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  30. My new beater is a 79 peugeot mixte 10 speed that came with original Phillipe porteur bars. I could just not get used to them, kept smacking my knees and steering was too responsive for slower city riding. I put north roads on her and 700cX37 tires. If I was going to keep it "cute" I would have kept the porteurs which looked lovely.

    So why don't I just buy a true city bike instead of mixtes? Because most city bikes I find too heavy, too tall off the ground, too ugly as sin... The traditional oma fiets looks lovely but is often slow and cumbersome. I can't keep up with my husband and two teenage boys on an oma fiets!

    I have noticed that the Peugeot feels like driving an old Chevette. The carbolite frame is comfortable, light enough.. but wow.. it's like pedalling a tin can! While that seems kinda bad, it also is kinda joyful and reminds me of being a 8 year old kid again on a cheap old Murry. It is flexy and springy and lively with a personality of it's own. I'd love to see a discussion from you Veloria on the different types of steel. My 531 Reynolds is so much lighter, but doesn't have the same feel as carbolite. I'm sure design has something to do with it, but metal quality can't be discounted either.

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  31. Coming from a motorcycling background, I've learned that many riders -- even very experienced riders -- don't understand (or aren't aware of) countersteering. I suspect that the same may be true for bicyclists. You might think that you turn your bike by shifting your weight, but in fact the *only* way to initiate a turn on any two-wheeled vehicle moving at a speed faster than a crawl is to countersteer: you "turn" the bars left in order to cause the bike to lean (and turn) to the right. It's really not "turning" the bars; it's just applying pressure -- counterintuitive, but fact:

    http://socrates.berkeley.edu/~fajans/Teaching/Steering.htm

    I bring this up because I wonder if some stability issues might be caused by unconscious countersteering; i.e., pulling unevenly on the bars, "steering" the bike when you don't want to. Anyone have thoughts on this?

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  32. Velouria - my other one is one I cannot find any information on. It's a 1968 Spitz dutch bike from England. It says that it's made in England but the decals on the bike cover it in little Dutch flags. I'd say it weighs 30-35lbs. It could be a combination of lighter weight and lower handlebars that make it more easy for me to control than my heavier Gazelle. I'm even sure about geometry because the stem height is higher on the Spitz than on the Gazelle. I am actually hoping that by riding the Spitz more in the manner that involves straddling the bike and then pushing up on one peddle rather than trying to tippytoe with one foot while the butt is still on the seat, will maybe teach me better to be able to do this on the Gazelle. It seems very natural on the Spitz but unnatural on the Gazelle. The seat on the Spitz is pushed down all the way it can be and it's still higher than the Gazelle's. I was afraid to initially try this other way of mounting a bike with my harrowing experiences on the Gazelle but it really surprised me how naturally it came. I took to trying it on the Gazelle after riding the Spitz for a while and I seemed to be able to do it more than previously. The handlebars on the Spitz are not only shorter but they are narrower too. I sometimes wonder if it's also the width and "largeness" of the handlebars that could make it harder to grip when starting from a stop that would make the front wheel wobble more. I am about 5'2 and the Gazelle stem height is 51cm. I haven't measured the Spitz since it's in the shop waiting for new Schwalbe Delta Cruiser tires in creme :) Does a hub dynamo make the front wheel heavier than a non hub? The Spitz has only a drum brake on the front wheel.

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  33. The recent research on self-stable bicycles (you may have seen the media reports of a self-stable bicycle with zero trail and no gyroscopic effect, if not, see http://bicycle.tudelft.nl/stablebicycle/) show how complex this subject really is. You've done a good job of explaining the user's perception and the relationship with bicycle and load issues.

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  34. "...but wow.. it's like pedalling a tin can! ...It is flexy and springy and lively with a personality of it's own. I'd love to see a discussion from you Veloria on the different types of steel."

    Sigh... It will probably be years before I can comfortably delve into that kind of discussion. I know what you mean about the "tin can" feeling though - most vintage roadbikes I've ridden have had quite a harsh ride quality.

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  35. Dottie & LadyEnoki - This initial feeling about a Dutch bike's instability when starting is one reason I decided to buy a Pashley and not a Gazelle when I was looking for my first bike. After obsessing about the Gazelle, I test rode it and found the slow speed handling just bizarre. The Pashley, in comparison, was "normal" in that respect - i.e. very stable and did not want to weave. A year later, in Austria a friend lent me a Dutch style bike and I had no choice but to get used to the light front end. And I got used to it very quickly, realising that I loved the overall handling of the bike considerably more than that of the Pashley. Same with the vintage Gazelle I now own.

    Interesting about the Spitz bike, I will look it up. No, I don't think the dynamo hub should make any difference what so ever in front end stability. But it just seems like a very different bike overall, even judging by weight alone.

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  36. Velouria - I love the handling of the Gazelle, there's no doubt about it. I also love how all of the weight is all on the butt and zero on the arms so I always feel like I'm floating by. In the rain I ride around with an umbrella in my hand and no problems. I can't do this on my 20" folding bike because I can barely control the handling. So you can't ride smaller bikes so casually! I guess it's just something I have to persevere through as far as mount/dismount goes with the Gazelle. The handling of the Spitz seemed fine and I think better than the Gazelle at slow speeds. If the Gazelle is a big behemoth 4 door Cadillac, then the Spitz is more like a smaller coupe.

    Let me know if you find anything when you look it up. I am curious as well. It seems like its a low end cheaper version of a the real heavy dutch bike. It's a 3 speed with a Sturmey Archer shifter and has drum brakes in the hub. I got it for 50 bucks locally here and it was decent (dirty but not really rusty). It has a fully enclosed chainguard, plastic skirt guards (one was chipped and finally just broke off), and an air pump attached to the lower loop frame. It used to have a bottle dynamo system but is missing the bottle and the headlight though oddly the rear light is still there. The lady who had it never rode it so whoever previously owned it lovingly replaced the rear rack reflector with some sort of LED lighted reflector. It has a weird O-lock in that there is no key and its just metal. It has a lever and to release it, you have to know to push the lever in. It took me 15 minutes of almost breaking it to figure that out. Other than the awful knobby gumwall tires that were on it and the light, it's all original. The shifter wasn't working well and the tires and tubes needed replacing so its in the shop for now. I will eventually put back in the bottle dynamo system when I can afford it better. Do you have a bottle that you are looking to sell? I'll check your marketplace.

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  37. First I commuted on an upright mountain bike.

    Then I got a road bike and with more weight distributed over the front end, I said "wow this is stable!"

    Then I made it fixed gear and modulated my lower speeds with my body and I said "this is even MORE stable!"

    Then I got a Raleigh Sports and now I'm back to square one. Dang light front ends.

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  38. Funny timing, this just came up for me. I converted my 1983 Trek 760 steel frame bike to handle commuting, adding a rear rack, 700Cx28mm tires (max size) and wider range gearing. The 760 is a racing-geometry frame, very nimble and responsive. I found the instability with a load on the rack unsettling. When I stood up to pedal, the normal tendency to sway was exaggerated, and I had to be very conscious of keeping centered. The 28mm tires helped a little, but were still a bit harsh on the rough pavement. Most importantly, road bumps would cause the front end to be a bit unpredictable unless I was focusing on control.

    Instead of trying to tune the bike, I found a vintage (1988) Schwinn Voyageur touring bike on CL, and it is much better at loaded riding than the Trek is. I put 35mm tires on, and all the complaints I had regarding the handling were gone. Also, standing up is easier, too. Much more relaxing commute - my only problem is the Biopace chainrings that were installed. Not too happy about those, but it's more of a nuisance, not a major issue.

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  39. Thinking about geometry and handling characteristics, I was trying to decide which of my bikes is thoroughly stable without sacrificing too much of the responsive characteristics that I find enjoyable. I think the jack-of-all trades in my stable is an '88 Miyata Terra Runner.
    The bike is a 19.5" frame, measure center-to-top. It's got some old-school mtb geo; fairly relaxed head/seat tube angles (71/73degrees, respectively), fairly long chainstays (435mm), and 50mm fork offset contribute to a decent amount of stability. However, I think the stability is counteracted by the BB height of a whopping 305mm and a fairly short reach on the stem. (In an attempt to be cute, i swapped out the original black nitto quill and flatbar for a vintage chromed bullmoose bar, but the bar height and reach wasn't altered much.) In truth, I wanted something a l'il wider, with a l'il more sweep, and the bullmoose filled that order while epitomizing the 80s mtb era in style. The result is a bike that has a lot of stability in straightaways, but which responds well to steering input due to a high center of gravity and a rearward weight bias.

    The bike fits me very well when riding it, but it's showing far more post than any of my bikes, with the exception of my NORBA-geo Kona hardtail. Despite the long wheelbase and fairly high standover, the bike looks TINY leaned up against a tree, almost like a bike for a preteen rather than a 5'11" fat guy. But, it feels right while riding, which is the most important consideration.

    from the catalog: http://4.bp.blogspot.com/_whtVpXkKwlQ/R1w8JDQppyI/AAAAAAAAAX0/3F9qlyWNUgw/s1600-h/img164.jpg
    -rob

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  40. Charlie Blaum

    Yes.
    The difference between motorcycles and bicycles being that the bicycle has a great deal less mass. The rider outmasses the bike 3-1, 5-1, 10-1.Narrower tires don't help. Don't forget weight distribution towards the front wheel.

    Weight swinging around on the bicycle does initiate steering and countersteeering. The bike leans all the time, steering is totally undamped. Just scan the comments above and look at all the things people expect their bike to do. Does a purse or package tossed in a wicker basket strapped to the handlebars exert steering pressure? I think so. Where is the pressure going when a rider wears a backpack?

    I had the great good fortune to grow up riding with old gents who were veterans of 6 day racing in the 1930s, possibly the most intense era of competition the sport has seen. I had no idea. They were just nice old guys. They sat STILL on the bike. They were centered. They were massively calm. Turns were initiated with tiny gestures. Nothing took them off the straightest of lines. By comparison modern racers continuously fidget and ordinary riders are just manic. For the smallest idea of how riders used to sit on a bike, YouTube has plenty of Fausto Coppi and Eddy Merckx vids. They float through a dream compared to the tense ratcheting of what's on today's Tour de France.

    The steering geometry of the bike and the tires have to soak up all sorts of inputs and actual abuse. Fat tires even out a lot. There's a reason the Schwinn family put America on balloon tires, a reason "mountain" bikes are so popular.

    Smart motorcyclists spend some time in class learning to ride. Cyclists mostly think they learned what there is to know when they learned to balance, age 5 or 6. Just to sit on a bicycle is something you learn, same as a yoga posture or a ballet pose.
    Sadly, we have few riding masters. And everyone wants to solve their problems by doing things to the machine, getting involved in mechanical minutiae.

    I think it's a wonder the bikes keep working as well as they do. Only thing I know to do, that someone might listen to, is tell them to ride down a flat quiet street, slowly, and feel everything they're doing to keep the bike on track. Then think about that.

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  41. I am in the "fit" camp. I have found that a bike that fits does more for my stability, and confidence riding it, than anything else. I think it has to do with the way your body is balanced over the bike.

    As for conversions: I have seen track bikes (real ones) with "ape hanger" bars on them. I don't know how in the world anyone, no matter, how skilled, can ride such a setup. I'm not being a purist, now: I have ridden enough to know that the two are more-or-less mutually exclusive. On the other hand, mountain and city bikes can be fairly stable with dropped bars and road stems. I actually had a bike set up that way for a time and took it on a cycle-camping trip. The bike handled well with the load I had on it, and I had the benefit of the extra positions the dropped bars afforded.

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