My roadie has started acting "squirrley" of late. It seems really twitchy and this morning threw me off at a normal stop. Reynolds 853

I checked the threaded head set and it is tight and there isn't any creaking coming from the bearings. The wheels are straight and true. The lacing to tight. The tires are at 115psi front and rear. No dent, dings, or cracks in the frame. The fork is old and carbon, a Look from 1997. The bars are straight and solid. The hoods are a little rocked up but they work for me. The hoods used to be a little more rocked down, but I brought them up a little for comfort about 3 days ago.

Color me confused. My bike just seems possessed. Sorta like it wants to go anywhere but where I point it. Kinda scary at 30 mph.

odd... double check that there are no cracks in the frame and that the carbon fork has not come unbonded. Pull on the wheels and see if there is any movement at any joints.
Did the squirlley feeling begin around the same time as your brake lever adjustment?

Also check if the fork is bent at all... I bent a mtb fork once - bent it straight out so it increased the rake by 2" or so - and damn that bike was hard to ride.

How old are you? Are you in good health? Blood pressure? Do you have a family history of stroke?

Just covering all the bases

The feeling started before the adjustment it's just gotten worse lately. I checked the frame, fork, wheels, everything. Nothing of note.

It almost feels like I am hitting a really hard left to right wind that is moving the bike of its track. My wheels are 27mm with bladed spokes. I have driven through driving, 15 - 20 mph, left to right winds with out this problem.

Since the fork is carbon I would doubt it would bend, but I'll look at it.

Good general health. Eating normally, no problems or signs of stroke, heart, or other mechanical problems.

My co-worker suggested having the bike exorcised.

I was told several months ago that the rear triangle was 4mm out of square, but it wasn't causing any problems so I left it. Also the LBS that told me this specializes in BS.

I will rock the brakes back down tonight and see if that helps tomorrow.

It's possible that something is loose or a joint is flexing more than normal. Here are a few things to check

Check the headset by aplying the front brake and rocking the bike forward and back. Watch or listen for any movement of the fork at the lower HS bearing.

Do a horizontal stress test by holding the bike up and leaning it away from you, while you press one foot into the base of the crank. Watch for hints of excess flex which might show up with rim movement at the brake shoes.

Check that not only are the rims true, but that the tire centerline is true also. If your tires have a raised center ridge it can feel squirrelly if the point of contact moves on and off the ridge.

Lower tire pressure to 95-100psi which will increase tracking forces slightly.

Check that the rear wheel is square and centered by placing a straight edge against across rim on a secant, and noting where it meets the seat tube. Do this at the same height from both sides, and at the top and bottom of the rim, (all four must meet the tube the same amount off center)

Check the bottom bracket for a failed join. Hold the bike by the bar and seat, lean it away from you, squat down & put your knee against the crank where it goes into the bottom bracket. Push gently. You should feel a little flex, then the frame should spring back when you release it. Watch the tubes where they enter the BB for movement in and out.

Long shot, but easy to check.

You beat me to it, Francis, but only by a moment! (And, of course, you are much more thorough.)

In Bike Shop saturated Portland you should have a choice of places
to look, in person, at your bike.

This is a simple one to check: make sure the wheels are firmly seated in the dropouts. Loosen the QR, put some weight on the bike and tighten it up. Do this on the rear too, unless you have horizontal dropouts. If that's the case make sure the wheel is centered between the chainstays.

If all else fails, take it to a competent shop and have them inspect it.

A headset that's a little too tight will cause the bike to behave badly also.

If you lean the bike from side-to-side the front wheel should flop side-to-side too.

I'll check the head set, the tires and the bb shell. I am hesitant to take it to a shop 'cause it will be like a car at a mechanic.

Well it does this and then you take it in and it never does that thing again. I know that the QRs are not very good I am working to replace them, but they are seated tight. I will recheck them.

@FB: could you explain this a little more:
Check that the rear wheel is square and centered by placing a straight edge against across rim on a secant, and noting where it meets the seat tube. Do this at the same height from both sides, and at the top and bottom of the rim, (all four must meet the tube the same amount off center)
Thanks

i_l_c, I have one roadie with steep geometry and while it's usually very neutral and stable at speed there have been some things that show similar problems to what you wrote. Two were headset related, notchiness caused by a worn lower bearing race, IIRC and when I adjusted the new headset too tightly. I run my road tires at ~85% of max pressure on all of my road bikes, but there are a couple of brands/models I've tried on this particular bike that just made it twitchy anyhow. Tire wear may also cause a similar problem, I suppose.

Brad

PS An afterthought... Since my bike's issues were way back in the early '90s there might've been a tire size issue, ie. too narrow. Possibly not, but I thought I should throw that in.

I checked the headset and loosened it a little, I rotated the hoods back down, checked the flex of the BB and did see any cracks or abnormal flex.

Checked the wheels and tires. I deflated the tires and reinflated them. Checked the QRs and rode to work.

I think it was blood sugar. I was riding in this morning and did not notice anything odd. When I got home last night I felt a little dizzy. It went away as soon as I ate some sugar and some food.

I eat before my rides. In the morning my last breakfast is Greek Yogurt with protein power, old fashioned oats, and honey. Leaving from work its oatmeal usually 2 servings with some kind of sweetener. If my BP or glucose levels are dropping mid-ride that could be problematic.

Thanks for the replies.

It could have been the headset being too tight. If it doesn't move freely, or "indexes" because of indented races, it will take a more significant amount of lean for the bicycle to correct itself making it feel wobblier.

i_l_c, The blood sugar puts the bike in a much less important dimmer light... take care of yourself!

Brad