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#1 |
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Guest
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Hi All, I have a basically new 3 year old NOS Bianchi
Road Bike, with conventional geometry, and one slightly disappointing quality I notice about this bike when I ride it, is that it seems a bit overly sensitive to steering input. It seems like just the slightest input from me at the bars, and this bike is all over the place. I don't dare take my hands off the bars for a second. It does not exhibit as good stability as I wish it would, and wonder what causes this? The bike has never been crashed. The frame from all accounts that I can tell appears straight. I've searched some tech articles, but cannot currently find anything relating to stability when riding? Can anything be done to lessen this "Touchy" effect? I've never had the Headset apart, and while it seems solid, maybe this should be broken down, lubed, and re-adjusted? Or is this more likely another cause, like frame geometry, position of rider on bike, etc? Opinions would be appreciated, Thanks! Mark |
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#2 |
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How long of a stem do you have on the bike? Real short stems
can be very, very twitchy. How high are the handlebars? Short wtems with high bars can also make the handling twitchy. What size bike is it? A bad combination of stem length, bar height, overall frame size can affect handling. One of the reasons to have a well fitting bike. Where is your body weight positioned? Are you way back and have little weight on the bars? Or are you way forward and have too much weight on the bars? Either can cause handling to be not right. How experienced are you at bicycling? Different levels of experience will interpret handling differently. What seems twitchy to you may seem just right to someone else. Just some ideas to think about and look at on your bike. apoman60612@yahoo.com (Mark) wrote in message news:<68236fb6.0407060602.27533845@posting.google.com>... > Hi All, I have a basically new 3 year old NOS Bianchi > Road Bike, with conventional geometry, and one slightly > disappointing quality I notice about this bike when I > ride it, is that it seems a bit overly sensitive to > steering input. > > It seems like just the slightest input from me at the > bars, and this bike is all over the place. I don't dare > take my hands off the bars for a second. > > It does not exhibit as good stability as I wish it would, > and wonder what causes this? The bike has never been > crashed. The frame from all accounts that I can tell > appears straight. > > I've searched some tech articles, but cannot currently > find anything relating to stability when riding? > > Can anything be done to lessen this "Touchy" effect? I've > never had the Headset apart, and while it seems solid, > maybe this should be broken down, lubed, and re-adjusted? > Or is this more likely another cause, like frame geometry, > position of rider on bike, etc? Opinions would be > appreciated, Thanks! Mark |
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#3 |
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apoman60612@yahoo.com (Mark) wrote:
> > I have a basically new 3 year old NOS Bianchi Road Bike, > with conventional geometry, and one slightly disappointing > quality I notice about this bike when I ride it, is that > it seems a bit overly sensitive to steering input. > > Can anything be done to lessen this "Touchy" effect? I Visit your LBS and find out whether the frame and fork are straight, wheels are centered, and headset is running smoothly. If there is nothing wrong with the frame, fork, or headset, fatter tires are a good first resort for adding a smidgen of rolling inertia, gyroscopic stability, steering trail, and ride smoothness. A longer fork is a further measure you can take, but shouldn't be necessary. If you crave a stabler ride, a road racing type bike is probably not for you. If you are previously accustomed to a motorcycle or a balloon-tire cruiser, you should probably just give yourself some time to readjust to the more sensitive equilibrium of a lightweight bicycle. Chalo Colina |
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#4 |
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Hi Russell/all,
So, you are saying that a short Bar Stem Raised quite a bit will cause this effect? This was something I did do recently, was I did raise the handlebar Quill Stem about 1", as I thought it would offer a slightly more comfortable ride. I am not at the stem limit, but probably a 1/2" from it though. Yes, before I did this, it did seem a bit more stable, so, I think you may have found the culprit. The bike is a 57cm, and I'm 5'-8" in height. I have owned about 8-9 road bikes in all, so this isn't my first experience with road bikes, or 700x23 tires I think first thing I'll try, is lowering the Stem 1" once again to see what that does? One other thing I do notice is that the dish/offset on my front wheel seems ever so slightly off to one side. Can this also affect handling? I imagine that it might? I've had the back wheel trued, and spokes re-tensioned, as it was really quite bad from the factory, with horribly loose spokes. The front wasn't as bad as the back, but for the small fee, and the great work my LBS does, maybe it's time to let them true-tension the front also? The bike has about 600mi on it. My experience with road bikes is not too bad, but was better 20 years ago I'm afraid. Just coming back from a long layoff.Mark russellseaton1@yahoo.com (Russell Seaton) wrote in message news:<e90052be.0407061134.195cdc08@posting.google.com>... > How long of a stem do you have on the bike? Real short > stems can be very, very twitchy. > > How high are the handlebars? Short wtems with high bars > can also make the handling twitchy. > > What size bike is it? A bad combination of stem length, > bar height, overall frame size can affect handling. One of > the reasons to have a well fitting bike. > > Where is your body weight positioned? Are you way back and > have little weight on the bars? Or are you way forward and > have too much weight on the bars? Either can cause > handling to be not right. > > How experienced are you at bicycling? Different levels of > experience will interpret handling differently. What seems > twitchy to you may seem just right to someone else. > > Just some ideas to think about and look at on your bike. |
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#5 |
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apoman60612@yahoo.com (Mark) wrote in message news:<68236fb6.0407070553.50c768c5@posting.google.com>...
> Hi Russell/all, > > So, you are saying that a short Bar Stem Raised quite a > bit will cause this effect? A really short stem raised really high will make handling twitchy. I know someone with a 5cm Nitto Technomic raised to the maximum and the handling is twitchy if hands are off the bars. But with hands on the bars, the bike was ridden across the USA and has ridden many week long rides since. So even not ideal stem height and stem length can be managed well enough. > > This was something I did do recently, was I did raise the > handlebar Quill Stem about 1", as I thought it would offer > a slightly more comfortable ride. > > I am not at the stem limit, but probably a 1/2" from it > though. Yes, before I did this, it did seem a bit more > stable, so, I think you may have found the culprit. You can try lowering it to see what happens. But I have my TTT Synthesis quill stem at its maximum and handling is fine on my 58cm bike. Stem is 12 cm extension. > > The bike is a 57cm, and I'm 5'-8" in height. I have owned > about 8-9 road bikes in all, so this isn't my first > experience with road bikes, or 700x23 tires 57cm frame and 5'8" tall? I would guess you are on about the largest frame you can ride. Just guessing. I am also guessing the stem is not long. And it was raised to get the overall reach closer. You may have a bad combination of slightly too big of a frame, slightly too high of bars, slightly too short of stem, and you being stretched out to your limit trying to hold onto the bars. Are you riding with your hands on the tops a majority of the time because the hoods are quite a stretch? If so then the length of your bike's rudder, so to speak, is only the stem extension length. While riding on the hoods, the bike's rudder length is the combined length of the stem extension and the bar reach. Handling will be twitchier with your hands on the tops instead of further out on the hoods. > > I think first thing I'll try, is lowering the Stem 1" once > again to see what that does? I would guess you will be even more stretched out than you currently are and handling would suffer. > > One other thing I do notice is that the dish/offset on my > front wheel seems ever so slightly off to one side. Can > this also affect handling? I imagine that it might? I've > had the back wheel trued, and spokes re-tensioned, as it > was really quite bad from the factory, with horribly > loose spokes. I doubt if this matters any. I have ridden many wheels that were not true and never noticed any change in handling. I've broken spoes on the back and had the rear wheel wobbling side to side a half inch or more and never noticed a change in handling. Loss of efficiency from having the wheel wobble so much. I currently ride a front wheel that is about 3mm out of dish. Its a boutique wheel and would require a fair amount of effort to dish it so I just ride the wheel. Its true but out of dish 3mm. Seems to ride just fine. > > The front wasn't as bad as the back, but for the small > fee, and the great work my LBS does, maybe it's time to > let them true-tension the front also? The bike has about > 600mi on it. My experience with road bikes is not too bad, > but was better 20 years ago I'm afraid. Just coming back > from a long layoff.Mark Have your LBS true the front wheel too. Can't hurt and might help. I doubt you will notice any difference but its nice to have your bike working well. If its been 20 years since you rode a road bike it could be you aren't bending as well and you need the overall reach to be shorter now. And you may need a shorter reach bike. > > russellseaton1@yahoo.com (Russell Seaton) wrote in message > news:<e90052be.0407061134.195cdc08@posting.google.com>... > > How long of a stem do you have on the bike? Real short > > stems can be very, very twitchy. > > > > How high are the handlebars? Short wtems with high bars > > can also make the handling twitchy. > > > > What size bike is it? A bad combination of stem length, > > bar height, overall frame size can affect handling. One > > of the reasons to have a well fitting bike. > > > > Where is your body weight positioned? Are you way back > > and have little weight on the bars? Or are you way > > forward and have too much weight on the bars? Either can > > cause handling to be not right. > > > > How experienced are you at bicycling? Different levels > > of experience will interpret handling differently. > > What seems twitchy to you may seem just right to > > someone else. > > > > Just some ideas to think about and look at on your bike. |
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#6 |
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Mark wrote:
> Hi Russell/all, > > So, you are saying that a short Bar Stem Raised quite a > bit will cause this effect? > > This was something I did do recently, was I did raise the > handlebar Quill Stem about 1", as I thought it would offer > a slightly more comfortable ride. > > I am not at the stem limit, but probably a 1/2" from it > though. Yes, before I did this, it did seem a bit more > stable, so, I think you may have found the culprit. > > The bike is a 57cm, and I'm 5'-8" in height. I have owned > about 8-9 road bikes in all, so this isn't my first > experience with road bikes, or 700x23 tires > > I think first thing I'll try, is lowering the Stem 1" once > again to see what that does? > > One other thing I do notice is that the dish/offset on my > front wheel seems ever so slightly off to one side. Can > this also affect handling? I imagine that it might? I've > had the back wheel trued, and spokes re-tensioned, as it > was really quite bad from the factory, with horribly > loose spokes. > > The front wasn't as bad as the back, but for the small > fee, and the great work my LBS does, maybe it's time to > let them true-tension the front also? The bike has about > 600mi on it. My experience with road bikes is not too bad, > but was better 20 years ago I'm afraid. Just coming back > from a long layoff.Mark > > Hi, when you lower the stem, if it is hard to reach the hoods, try angling the bars upward. That might help a little, not for stability, but for reach. Life is Good! Jeff |
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#7 |
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russellseaton1@yahoo.com (Russell Seaton) writes:
> A really short stem raised really high will make handling > twitchy. I know someone with a 5cm Nitto Technomic raised > to the maximum and the handling is twitchy if hands are > off the bars. Interesting. I have never really looked into the physics of bike handling, so it is counter-intuitive to me that the stem can affect handling when hands are off the bars. Can someone explain how this works? |
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#8 |
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On 08 Jul 2004 19:55:04 -0500, Jim Smith
<bokonon442news@yahoo.com> wrote: >russellseaton1@yahoo.com (Russell Seaton) writes: > >> A really short stem raised really high will make handling >> twitchy. I know someone with a 5cm Nitto Technomic raised >> to the maximum and the handling is twitchy if hands are >> off the bars. > > >Interesting. I have never really looked into the physics of >bike handling, so it is counter-intuitive to me that the >stem can affect handling when hands are off the bars. Can >someone explain how this works? Dear Jim, Bicycle handling is a dark and bloody mystery, but if the farther the mass of the handlebars is from where things happen, the more likely they are to vibrate, oscillate, and generally make a nuisance of themselves. In a current thread, Rick Onanian confesses that his bicycle is shimmying alarmingly after he reaches 15 mph and lets go of the handlebars. The aero-bars sticking out on the front of his handlebars may be the culprit. Carl Fogel |
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#9 |
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On Thu, 08 Jul 2004 21:39:35 -0600, carlfogel@comcast.net wrote:
>In a current thread, Rick Onanian confesses that his >bicycle is shimmying alarmingly after he reaches 15 mph and >lets go of the handlebars. The aero-bars sticking out on >the front of his handlebars may be the culprit. Or, it could be the tall stem, as implicated here. Or, a combination of both. Or, the any combination of those issues with other issues... My question was just if the troubleshooting of said shimmy works the same way as the troubleshooting of high-speed shimmy, which has been discussed to death here, and which I can find oodles of information on with google groups. The non-resounding answer was "yes". -- Rick Onanian |
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#10 |
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carlfogel@comcast.net wrote in message news:<8k4se0l4k26h1e3019lq3j94harcdl7jdv@4ax.com>...
> On 08 Jul 2004 19:55:04 -0500, Jim Smith > <bokonon442news@yahoo.com> wrote: > > >russellseaton1@yahoo.com (Russell Seaton) writes: > > > >> A really short stem raised really high will make > >> handling twitchy. I know someone with a 5cm Nitto > >> Technomic raised to the maximum and the handling is > >> twitchy if hands are off the bars. > > > > > >Interesting. I have never really looked into the physics > >of bike handling, so it is counter-intuitive to me that > >the stem can affect handling when hands are off the bars. > >Can someone explain how this works? > > Dear Jim, > > Bicycle handling is a dark and bloody mystery, but if the > farther the mass of the handlebars is from where things > happen, the more likely they are to vibrate, oscillate, > and generally make a nuisance of themselves. > > In a current thread, Rick Onanian confesses that his > bicycle is shimmying alarmingly after he reaches 15 mph > and lets go of the handlebars. The aero-bars sticking out > on the front of his handlebars may be the culprit. > > Carl Fogel Hi Carl/All; Two days ago, after starting this thread, I decided to remove front Mavic wheel, and take it in to the LBS to be trued/re-tensioned. While this was being done, I came home and removed Fork for Headset Bearing Re-Lube, and adjustment, and did lower the Quill Stem about 1/2" (Almost back to where it originally was, which was very low). It is a bit better now, but still is not as stable as I wish it would be. It was beneficial going over the Headset, as Lube was virtually non-existant, and dried out. Luckily, it appears no apparent damage has occured, and this strengthens my thoughts even more about how factory built bikes essentially need a complete teardown/lube from day 2. I pray my BB doesn't look that way. While I didn't buy the bike from the LBS, I asked the LBS owner if I could bring the bike in, and help me check over bike fit adjustments for myself. I'm thinking also, that possibly, my saddle fore/aft position may be off slightly, and this could be affecting balance weight between the front/rear wheels? They'll know for sure. Mark |
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#11 |
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Jim Smith <bokonon442news@yahoo.com> wrote in message news:<87eknmdmon.fsf@yahoo.com>...
> russellseaton1@yahoo.com (Russell Seaton) writes: > > > A really short stem raised really high will make > > handling twitchy. I know someone with a 5cm Nitto > > Technomic raised to the maximum and the handling is > > twitchy if hands are off the bars. > > > Interesting. I have never really looked into the physics > of bike handling, so it is counter-intuitive to me that > the stem can affect handling when hands are off the bars. > Can someone explain how this works? The bike I know has the bars very, very high. A Nitto Technomic at the maximum line. A 5cm extension. And the frame is a 47cm or something. So even with the hands off the bars, the weight of the bars and brakes are very high on a very, very short stem. Any minor undulation in the road. Any blade of grass on the road. And all of that bar/shifter weight way up there will move and affect handling. To test your intuition, take the bars and stem completely off a bike and try riding it. No handed of course. I bet you will discover that the bike needs a certain amount of weight at a certain height and forward extension to ride stable. With no weight to balance the front wheel and fork, handling would not be good. Somewhat similar to the bike I am thinking of. All of the weight is directly above the steerer and is very high. The natural stability of the bike is affected. |
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#12 |
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apoman60612@yahoo.com (Mark) wrote in message news:<68236fb6.0407070553.50c768c5@posting.google.com>...
> > The bike is a 57cm, and I'm 5'-8" in height. I have owned > about 8-9 road bikes in all, so this isn't my first > experience with road bikes, or 700x23 tires From this alone it sounds like you should be riding a 48-53 frame, depending upon the top tube length. Why are you riding a bike this large? |
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#13 |
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Hi Steven, But from this alone, why would this give a bike
instability? Why would there be a difference in stability if the bike was 48cm, or 61cm? (Provided saddle height was adjusted so I could reach the pedals?) In fact, wouldn't a larger frame, which generally also has a longer wheelbase be more stable at straight line speed? I have on occasion ridden road bikes that were way too large for me (60-61cm), yet they exhibited super stability, where I could ride hands free for miles if I chose. Mark stevenwoo@gmail.com (Woogoogle) wrote in message news:<4011b2ad.0407091159.58de1941@posting.google.com>... > apoman60612@yahoo.com (Mark) wrote in message > news:<68236fb6.0407070553.50c768c5@posting.google.com>... > > > > The bike is a 57cm, and I'm 5'-8" in height. I have > > owned about 8-9 road bikes in all, so this isn't my > > first experience with road bikes, or 700x23 tires > > From this alone it sounds like you should be riding a 48- > 53 frame, depending upon the top tube length. Why are you > riding a bike this large? |
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#14 |
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apoman60612@yahoo.com (Mark) wrote in message news:<68236fb6.0407091929.73e163ae@posting.google.com>...
> Hi Steven, But from this alone, why would this give a bike > instability? > > Why would there be a difference in stability if the bike > was 48cm, or 61cm? (Provided saddle height was adjusted so > I could reach the pedals?) Because to fit a big frame, you will have to move the saddle way forward, and put on a super short stem so you can reach the bars. Frame fit means reach to the bars too. And as I stated above, a super short stem, to make it possible for you to reach the bars, will be twitchy. If you are so stretched out to get your hands on the bars, you will likely not have the best control of the bike. > > In fact, wouldn't a larger frame, which generally also has > a longer wheelbase be more stable at straight line speed? > > I have on occasion ridden road bikes that were way too > large for me (60-61cm), yet they exhibited super > stability, where I could ride hands free for miles if I > chose. Mark > > stevenwoo@gmail.com (Woogoogle) wrote in message > news:<4011b2ad.0407091159.58de1941@posting.google.com>... > > apoman60612@yahoo.com (Mark) wrote in message news:<682- > > 36fb6.0407070553.50c768c5@posting.google.com>... > > > > > > The bike is a 57cm, and I'm 5'-8" in height. I have > > > owned about 8-9 road bikes in all, so this isn't my > > > first experience with road bikes, or 700x23 tires > > > > From this alone it sounds like you should be riding a > > 48-53 frame, depending upon the top tube length. Why are > > you riding a bike this large? |
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#15 |
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Hi Folks, I wish to deeply thank all of you who have given
me good advice, and things to consider, and check, You have all helped me greatly, and I have solved the problem. It was indeed the Stock Handlebar Quill Stem (90mm long) that I had adjusted a bit too high. At first, I thought the slight raising of the Stem would be a benefit to a slightly more comfortable ride, and that it would look a bit nicer too. Little did I know by doing this, that this would destroy the straight-line stability of the bike. I'm back to where is was, and thinking now about how other bikes are (looking at the pro's bikes on TV lately), nobody has stems sticking up really high, (Even though they're mostly Threadless Stems) and now I understand the reason behind this. Taking a 20 mi ride earlier this evening, the bike tracks like it's on rails, and I'm very happy with the results, and how it rides now. Thank you all again for teaching me, and helping me understand some bike basics, which I've seem to forgotten. Also too many thanks to the poster for the thought about perhaps slightly raising my Brake Levers on the bars for a bit better comfort when holding by the brake Lever Hoods. I see just about 100% of the TDF pros have thier levers placed quite high on the bars, ans I can imagine that there is better fuction/comfort with them this way. I'll probably raise mine a bit next time I do a Bar Tape Change. Mark |
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