front tires and their effects on wobbling at "high" speeds

Discussion in 'Motorized Bicycle General Discussion' started by tire, Oct 5, 2010.

  1. tire

    tire New Member

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    i would think that a fat, wide, "cruiser" tire of 26x2.125 would provide the most cushion and stability, counteracting wobble to a degree, if nearly negligible. i would assume this because cruiser motorcycles are similarly equipped.

    can i get some experienced guys to comment?

    i'm asking because i was going downhill on my new frame/suspension setup and there was some wobble (or the beginnings of wobble) on my 10 year old mountain bike tires. this could be from improper installation of the suspension (improbable) or the tire itself, or an unbalanced wheel.
     
  2. Nougat

    Nougat New Member

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    If the tire isn't seated in the rim properly, yes, you'll get wheel bounce at higher speeds. I replaced my Walmart front wheel with a wider HD wheel from Husky, and the old tire just would not seat in it. I bought a new tire (Bell, also from Walmart) and it's fine.

    If your tires are that old, replacing them is a good idea, especially if it's wonky.
     
  3. tire

    tire New Member

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    i'll pedal my heavy ass bike to school tomorrow and on the way home test out that hill again with my mountain bike wheel and bell 26x2.125" white wall cruiser tire.
     
  4. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    You may want to balance the tires, new or old. I have always used solder wrapped around the spokes, takes a few minutes per wheel to get them pretty well balanced.
     
  5. Fulltimer

    Fulltimer New Member

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    My local bike shop thinks that if you "True" the rim it is balanced. The 2 terms are not the same though. So, like was stated balance the tire with solder or some people use a self adhesive weight used on golf clubs.

    Terry
     
  6. Nashville Kat

    Nashville Kat Active Member

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    It sounds like the wheel rim may be out of round- a spoked wheel is both trued from side to side and also rounded when assembled or adjusted.

    Cruiser wheels tend to be less trued at retail because they don't need to ride between cliper brakes- which more reveal their true and roundness-

    Regular cruiser tires are fairly knobby, and caused me a lot of unpleasant vibes- when I switched to 1.75 street tread it was both a more pleasant top end, and an easier pedal- I've since gone to a 27 x 1 1/4 wheel with a campy brake.

    I think the heavier the tire, the more likely the tire itself may be unbalanced- I haven't ever really seen that as a problem- in years as a mechanic- but maybe the higher speed of otoring may reveal imperfections in tires.
     

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    #6 Nashville Kat, Oct 6, 2010
    Last edited: Oct 6, 2010
  7. tire

    tire New Member

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    interesting observation today.

    my mountain bike wheels with cruiser tires continued to "sway" going downhill (pedalling) but nothing dangerous.

    under power of the motor, it rode like a little motorcycle, but with no wobble. i'm not sure how this happens, but it seems to feel safer and more steady at a higher speed.
     
  8. Nashville Kat

    Nashville Kat Active Member

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    Sounds then like LOOSE SPOKES- tighten them all evenly a half or quarter turn at a time, until they have a fair amount of tension and that should stop the sway

    also another common problem with bikes bought at department stores
     
  9. tire

    tire New Member

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    i will learn how to tighten spokes then and report back. the mountain bike (using its wheels) may have been purchased at a bike shop around 1999.
     
  10. scotto-

    scotto- Custom 4-Stroke Bike Builder

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    Just a suggestion....get some weebles....they'll wobble, but you won't fall down;)


    Then on the more serious side, I've got really nice 26x2.30 tires that when I let go of the bars, they develop a slight wobble at high speeds, but it never gets past that.....wouldn' really worry about it, just say'n. Cheers.
     
  11. Ted

    Ted New Member

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    front wheel bearings loose or bad, steering head bearings loose or have through time taken a set and want to self center, balls can and will beat little indentations in the race.
     
  12. reb1

    reb1 New Member

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    When I build a wheel I use dial indicators. On my wheels I can true them within .003 TIR from side to side and the hub centered in the rim .005 TIR. The tire needs to be seated and straight also. Some tires will fit and be quite straight and others will not. Something as simple as a wheel reflector can cause the bike to shake at higher speeds. If you are using wheel reflectors it may help to place them directly opposite the valve stem. Weight in front of the handlebars can also cause this. An imbalance can cause the bicycle to shake violently at certain speeds. If this happens it can cause you to be startled. You can stop this by placing one hand or your nee against the top tube of the bicycle. Just remember the speed that it starts to happen also. There are different theories and discussions on what causes this.
    I purchased my wife a rather expensive MTB the week we were married. I had ordered it and the shop let me assemble it also. The front wheel had come in with shipping damage and we had replaced it with the front wheel of a larger framed bicycle of the same model. The wife and I went for a ride up a canyon and on the way back down her bicycle started violently shaking. Her screaming clued me into the situation. I came up next to her and grabbed the top tube and coaxed her to slow down. I and the owner had looked over it quite carefully and had seen no other damage but it had to be something with the fork or frame. He had another one of the same size airmailed in and we assembled it and the new one was fine going down hill at speed.
     
  13. 42blue15

    42blue15 New Member

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    If a front wheel wobbled going fast, I would suspect a few things-
    wheel bearings?
    headset bearings?
    bent rim?
    bent or cracked forks? (look closely for cracks in the corners where the welds are)
    cracked frame? (likely near the head tube, but maybe where the top and down tubes meet the seat tube)
    oddly customized forks? (forks modified so that they lack the proper rake and trail)

    If you are using knobby tires that could cause some instability too, but not usually wobbling.

    -------

    It is possible that a tire could suffer a manufacturing defect that caused it to have its weight distributed unevenly, but generally speaking, bicycle wheels and tires don't need balancing. At all. Ever. At any price level. From any manufacturer. In any country.

    Bike shops randomly stuck reflectors into the wheel spokes of hundreds of thousands of bicycles for decades, and nobody ever said that the reflectors caused any imbalance problems by being there.
    ~
     
  14. bairdco

    bairdco a guy who makes cool bikes

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    i don't believe in balancing bicycle tires either, but i've argued that on too many other threads to re-type it here.

    most of the causes have been posted already, but another thing that causes a sketchy bike is handlebar position, or more importantly, hand position.

    if your hands are forward or inline with the front axle it can make a bike difficult to ride. it completely upsets the geometry of the bike. that's why apehangers are outlawed or regulated on motorcycles (in most cities.)

    it's also why the "poorman's boardtracker" with upside down handlebars is so uncomfortable to ride.

    a few other things i forgot:

    innertubes can create a lump in a tire, making them uneven. a lot of tires these days are bigger, like 2.3's, and a 2.125 tube can't fill the space. i know this from personal experience. usually the area around the valve stem, where the rubber's thicker, can't pump up to fill the tire.

    and some tires just suck. i've got a set of Duro whitewalls that are totally out of round. the whitewall's are uneven, too, and it makes me dizzy watching them spin around all crooked.
     
    #14 bairdco, Oct 8, 2010
    Last edited: Oct 8, 2010
  15. Lance Portnoff

    Lance Portnoff New Member

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    whatever it is u want to get fixed!
     
  16. Ted

    Ted New Member

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    whatever it is u want to get fixed!
    ===========================================
    Brilliant,,,,,and a big help too.
     
  17. Nashville Kat

    Nashville Kat Active Member

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    If you tighten the spokes or true or round the wheel- don't waste time or damage the nipples with a crescent wrench- get a spoke wrench that fits-

    yes it could also be the bearing cones, or loose headset- they should be tight and no wobble, but no resistence or grind- but the wheel should come to a stop with the weight of the valve taking it to the bottom after a spin.
     
  18. WildAlaskan

    WildAlaskan New Member

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    wow i have a bike at least fiften years old with original tires im sure the tube is been changed but i have absolutly no wobble just a slight vibration

    i like to let my hands off the handlebars reach down underneath the top tube grab the throttle cable and pull it riding with no hands its alot more comfortable that leaning over all the time grasping the handlebars

    i think the bike was a high quality bike its an american made huffy its really old though but still fun
     
  19. scotto-

    scotto- Custom 4-Stroke Bike Builder

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    If you want your wheels balanced and don't mind a little extra un-sprung weight....put slime in your tubes. A little less worry of flats as well.
     
    #19 scotto-, Oct 9, 2010
    Last edited: Oct 9, 2010
  20. 2door

    2door Moderator
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    Check your bearings too. You could be experiencing wheel wobble due to improperly adjusted bearings/cone nuts. If not sure about what is correct check with your local bike shop or do some on-line research regarding bicycle wheel bearings.
    Tom
     

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