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-   -   Unstable when no hands on bars (https://www.bikeforums.net/general-cycling-discussion/1203894-unstable-when-no-hands-bars.html)

Holm 06-07-20 10:56 AM

Unstable when no hands on bars
 
Im wondering if there is an explantion to this or the bike just has a weird geometry.

When i ride my bike its like the front wheel drags me off course (both left and right). It nearly impossible to ride no hands. when i let go of the bars the bike just wanna go left or rigt and tip over.

Headset i a hope, its not too tight and no slack. Bearings put in correct (checked thrice)

Tires are michelin slicks on miche rims

Frame fits me and reach is same as my other bikes.

Whats happening?

rosefarts 06-07-20 12:07 PM


Originally Posted by Holm (Post 21520173)
Im wondering if there is an explantion to this or the bike just has a weird geometry.

When i ride my bike its like the front wheel drags me off course (both left and right). It nearly impossible to ride no hands. when i let go of the bars the bike just wanna go left or rigt and tip over.

Headset i a hope, its not too tight and no slack. Bearings put in correct (checked thrice)

Tires are michelin slicks on miche rims

Frame fits me and reach is same as my other bikes.

Whats happening?

Inner ear infection?

79pmooney 06-07-20 12:59 PM

It could be a lot of things, Headset adjustment (or alignment), structural (cracks starting) or a number of other causes or simply "quick steering"" geometry, To make bikes steer quicker, one can 1) steepen the headtube and fork, 2) increase the fork rake (not intuitive but trust me) or 3) shorten the overall wheelbase (this has much less dramatic effect). A lighter front wheel, especially rims and tire/tube will also speed up steering.

1) and 2) are tightly linked and can have a dramatic effect with small changes.

I raced a bike with a 75 degree headtube angle. Largish frame. It had the same fork as the smaller frames of that model that came with more "normal" headtube angles. By modern standards, a lot of rake. The steering was so quick I could not comfortably ride no-hands the first month and a half of the season but as my riding got smother and I trusted the bike more, I found I could ride it no-hands anytime and in fact loved that I could steer around stuff easily no-hands. Now on that bike, a less than perfect headset flat out didn't work! My Peter Mooney is a far more forgiving bike (shallower head tube and less fork rake) and I rode the Campy HS that Peter installed for about 25,000 miles. It was pretty beat up wen I replaced it! Same headset in my racing bike was usable for less than 6000 miles.

Try parking a bike you like against a wall. Park this bike beside leaning on it so the handlebar tops line up. Step back and look at the two. Steeper fork? More fork rake? Could well be the answer. A fork with less rake (or having a framebuilder straightening a steel fork a little will slow the steering. (Probably need a paint job after. Straightening a fork is bending cold hard steel. Not a gentle operation. But it is how that fork got raked n the first place.)

Ben

Gresp15C 06-07-20 02:11 PM

Every time I've had a bike that pulled to one side, it was due to frame alignment. Folks have blogged on techniques for checking frame alignment that don't require any special tools. If it turns out that your frame or fork are crooked, then of course you have to decide if that's a problem you want to tackle on your own.

J.C. Koto 06-07-20 02:15 PM

Also check that your wheels are properly centered in the dropouts and secured, which is a pretty good idea to check anyway whenever the bike handling is getting squirrely for some reason.

50PlusCycling 06-07-20 05:54 PM

It can be a lot of things. The most common problem is a misalignment somewhere; perhaps the fork isn't straight, and the front wheel is not perpendicular to the road or the bike frame. A misalignment of the rear wheel can also cause the bike to track incorrectly, and force the front wheel out of alignment as it compensates. A bent steering tube or loose headset can also be the culprit.

semroc 06-07-20 06:45 PM

I just had all three of my road bike frame, and fork checked and realigned. All were out of alignment. All were slightly squirrely before, now track straight with no hands. It's a little stressful holding your bike with everything you got while a mechanic straightens your frame. But very much worth it. Make sure you go to a top notch mechanic. Good luck.

Flip Flop Rider 06-07-20 07:05 PM

road slanted

veganbikes 06-07-20 07:20 PM

Of course something designed to move is more unstable when not being held to stabilize it. My water just drops on the floor when I don't use a cup.

My top recommendation is to use your hands so you can steer the bike and keep it stabilized.

Holm 06-08-20 04:44 AM

Thanks for the advice. I think I need to check the steerer tube alignment.... Everything else looks good.

Thanks a bunch

Holm

Kapusta 06-08-20 04:50 AM

Some bikes are more stable no-handed than others. What kind of bike is this?

Holm 06-08-20 04:56 AM


Originally Posted by Kapusta (Post 21521453)
Some bikes are more stable no-handed than others. What kind of bike is this?

Its a steel bike. I thought in the beginning that it was just me noticing the difference between this bike and my other bike but its so crazy its beyond "twitchy" or "loose" or anything. This badboy is a hazard at high AND low speeds now. When I corner downhill the bike is hard to keep in a straight line and in low speeds it tips over momentarily as I let go of the handlebars.

Im now in search for a good tutorial to see if the headtube is misaligned. Too bad as its a pretty sweet steel frame. Also sent the manufacturer a request what to do..

Kapusta 06-08-20 05:12 AM


Originally Posted by Holm (Post 21521459)
Its a steel bike. I thought in the beginning that it was just me noticing the difference between this bike and my other bike but its so crazy its beyond "twitchy" or "loose" or anything. This badboy is a hazard at high AND low speeds now. When I corner downhill the bike is hard to keep in a straight line and in low speeds it tips over momentarily as I let go of the handlebars.

Im now in search for a good tutorial to see if the headtube is misaligned. Too bad as its a pretty sweet steel frame. Also sent the manufacturer a request what to do..

“Steel” doss not give much helpful info, but I’ll just assume you are not interested in knowing if the bike is less stable as a byproduct of design.

I would look more at the headset. Make sure the head tube faces are aligned, and also that the cups are in straight. The slightest misalignment can cause just enough binding to keep the wheel from freely turning where it wants to go. This was an issue with my Soma Fog Cutter.... the solution was getting the head tube faced. Most new frames don’t need this anymore, but occasionally one slips through Quality Control (who were apparently asleep on the job when my frame rolled past).

Holm 06-08-20 05:28 AM


Originally Posted by Kapusta (Post 21521474)
but I’ll just assume you are not interested in knowing if the bike is less stable as a byproduct of design.

Im just looking for the cause of the error. I know bad steering when I see one. This is not a design issue.

Miele Man 06-08-20 05:32 AM


Originally Posted by Holm (Post 21521459)
Its a steel bike. I thought in the beginning that it was just me noticing the difference between this bike and my other bike but its so crazy its beyond "twitchy" or "loose" or anything. This badboy is a hazard at high AND low speeds now. When I corner downhill the bike is hard to keep in a straight line and in low speeds it tips over momentarily as I let go of the handlebars.

Im now in search for a good tutorial to see if the headtube is misaligned. Too bad as its a pretty sweet steel frame. Also sent the manufacturer a request what to do..

You can check the headtube allignment by removing the front fork and inserting a log straight rod -alluminium, steel or wood. Remove the seatpost and do the same there. Then look at the bike from the very front. The long rods will show whether the headtube lines up perfectly with the seatube.

Oh, bad no hands riding can be a result of a slightly bent front fork. The fork legs can be either pushed to one side or one fork leg can be slightly behind the other. I'd get the front fork checked for alignment too.

Good luck and cheers

Another method that might show up any poor alignment issues is this.

Find or create a small wet area on pavement, ride the bike straight through that wet spot and then go back and see if there are one or two tire tracks. If there are two tire tracks and you rode straight through the we spot then it means something is out of alignment.

Holm 06-08-20 05:55 AM

Thanks for the tip. Miele Man

_ForceD_ 06-08-20 08:01 AM

I had this same exact issue after a complete rebuild of a bike. Turned out that I had unknowingly inverted the upper and lower bearing cups for the headset. On this particular bike, like most bikes, the two cups are only slightly different. Or should I say that looking at the two of them it would appear that it doesn't matter which cup goes on the top or bottom.
But it does matter, and it's enough that if they're installed in the wrong side it will afffect bearing adjustment, and cause this imbalance like you're having. Once I re-installed them properly the bike tracked straight as it should.

Dan

rosefarts 06-08-20 08:13 AM

I'll give you a more serious answer.

Possibility 1. Something up with the fork. I just went through this. I had a Hylix carbon from eBay. It had some integrated race that the bearing sat directly on. No amount of bearing swaps and adjustment could get it right. On a stand, I had it where it seemed ok but offered me the most terrifying ride I've ever had. Forget sitting up, I couldn't even let go long enough to take a drink. This was on the best handling and most stable bike I've owned. It turns out that the fork just sucks, and that integrated race causes really fine but uneven drag, causing the bike to track weird. I put the steel fork back on, and I've got my 60mph bike back.

Possibility 2. Cable too tight or too long that's actually causing it to push the handlebar off neutral. Seems odd but I've seen it.

Possibility 3. A crooked seat.

Most everything else mentioned could be true too. I don't think it's an alignment issue, since most of us rode Huffys and other junk all over the neighborhood without hands.

livedarklions 06-08-20 08:22 AM

Steel bike? The magnetic North Pole is shifting around a lot right now. Just sayin'.

Paul Barnard 06-08-20 08:50 AM


Originally Posted by Holm (Post 21521459)
When I corner downhill the bike is hard to keep in a straight line

.

Going in a straight line around a corner is often called a crash.

fietsbob 06-08-20 09:01 AM


Originally Posted by Flip Flop Rider (Post 21520976)
road slanted

Roads are crowned for draining water ..

Holm 06-08-20 09:49 AM


Originally Posted by Paul Barnard (Post 21521751)
Going in a straight line around a corner is often called a crash.

:D yes! Lost in translation here. :D:D i dont know how to explain? Holding a steady curve/line,?!?

Phil_gretz 06-08-20 10:05 AM

The OP is being purposely vague about the type of bicycle. Is it a threaded or threadless steerer tube? If threaded, I'd say that he shouldn't discount the too-tight headset as a cause...

taco2ewsday 06-08-20 10:09 AM


Originally Posted by Holm (Post 21521485)
Im just looking for the cause of the error. I know bad steering when I see one. This is not a design issue.

Design could be things such as frame geometry, if it's a race type frame it could be 'twitchy' as opposed to a more laid back endurance or touring frame.

u235 06-08-20 10:18 AM


Originally Posted by Phil_gretz (Post 21521891)
The OP is being purposely vague about the type of bicycle. Is it a threaded or threadless steerer tube? If threaded, I'd say that he shouldn't discount the too-tight headset as a cause...

I was browsing through the comments and about to ask that myself. I think it was mentioned earlier but seemed to be glossed over. Check the tightness and movement of the headset. Pick up the bike with the back higher or lean it front down a little on a stand, turn the wheel and let go and notice how easy or if it goes back to straight. That is obviously not a scientific test but even with a slight down angle, the bars should freely return close to center on their own. Even a threadless can be too tight and cause issues with no hands.


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