Greets, haven't posted here in a while. I'll keep it brief:

I have an '08 Specialized Allez, been riding it for 4 years. It's been okay. Only thing is, it's squirrely as hell. I feel like I can't take my hands off it for a split second without taking a dive. The bike shares Tarmac geometry and is built for twitchy racing maneuvers, which I never need to make. When I get on my old '83 Peugeot, it's like a tank, pretty much steers itself, so I don't think it's me.

I do a lot of long, hilly rides and would like a more stable bike that's a little nicer than an '83 Peugeot. I'm not a racer and have no interest in racing, so that's not a concern.

What are some road bikes that are known for being stable? What makes one road bike feel more stable than another?

I'm not an expert on frame geometry but I know things like wheel base, head tube length, reach, handle bar width can effect the things you mention. When it comes down to it, no matter how many replies you get, testing different bikes and getting fit are going to help you lose that twitchy feeling by finding a bike that is the most comfortable for you and you alone.

OP, try a Secteur or Roubaix.

Longer wheel base and slacker geometry (less steep head tube, more trail to the fork) = less twitchy.

Longer wheelbase and longer chainstays give more straightline stability. But I'm not sure that is your bikes problem. If you watch any Pro Race they can ride for hours without hands on bikes like yours. Not sure what the secret is as my Colnago C50 is scary riding no hands, where my Specialized Tricross with long wheelbase is easy riding no hands.

My Bianchi Veloce is pretty sporty but not a racing machine. It's great on longer rides and quite stable. I've never felt like it was twitchy. It's not made anymore, but I see some similar models still in the lineup. I think you are looking for a description of something like a "sport" bike or "club rider". If the description starts talking about winning races on it, then you may be getting into twitchy territory.

How long is your stem?

Also having a weak core and locking your elbows/leaning on the bars hard will make things feel twitchy.

all else being equal less rake equals more trail equals more stable bike.

It appears that your Allez likely has fork rake of 43-45mm depending on the frame size.

You could switch it out to a fork with 40mm of rake (and the same axel to crown height) and see if you like it better.

Nice short piece on Bike Geometry

https://www.calfeedesign.com/tech-pap...bike-handling/

The reasons that the OP finds his current bike twitchier than his Puegot are likely less trail,steeper head tube angle, and longer wheelbase. I'd be willing to be you the Allez has a steeper head tube, longer wheelbase, and less trail.

As mentioned, I'd guess fit and posture is going to make a bigger difference than frame geometry for the average rider. Get a professional fit, and see if that solves the issue before convincing yourself to get a relaxed fit bike. I have a cyclocross bike that I set up for road, and its more relaxed and comfortable for me as compared to my Madone, but I notice more from the wide tires than anything else!

I've had some bikes where you have to lean pretty far back to get a decent stable no hands ride. The more weight you have on the front wheel, the less stable it will be.

There is a lot to be said for the ride quality of fatter tires. You might want to check out a cross bike and see what you think of the ride; same goes for a touring bike. They may give you the kind of ride you are looking for.

Training wheels? Err uhm.... Stabilizing extensions, that's what the box said when I baught them

Flyweight wheels turn very quickly, and heavy wheels don't.

You could try using a heavier front wheel/tire combination. Even putting Slime inside the front tube.
Your hands might like the comfort of a fatter front tire (at slightly-less-pressure!) and the slime will serve a second purpose too.

I've had twitchy bikes before, and simply got a LONGER stem and made sure the stem was below my handlebar by at least a few inches. say a stem from 100 to 120 is OK, but of course this must mean your reach won't be throw completely out of whack. Then try to put the seat a few inches behind the BB, at a minimum. Maybe even raise the seat very slightly (if you never got a fit that is...i mean like 1/8th inch). Ride this for an hour, and if it feels bad, keep adjusting. my bike does have a relatively long wheelbase. a lower BB is good, but that's harder to change (new bike). gl

Recently I took my girlfriend bike shopping. I have a simple philosophy when it comes to bike buying, which I've often espoused here: ride everything, buy the one you like.

She tried lots of race bikes, but ended up buying a Marinoni Sportivo, because it felt the most 'stable' and controllable to her. Maybe look into something with similar geometry.


https://www.marinoni.qc.ca/Html/Sportivo.html

If you can't ride with your hands off the handlebar, a few millimeters of difference in frame geometry is unlikely going to make of an impact.

The most likely reasons for your lack of stability is because:
a: You're putting too much weight onto your hands.
b: You're not effectively using your core and body weight to control steering.

If you just want a real stable bike that's hill friendly, just get any ole touring bike.

Id recommend the Surly LHT, the Trek 520, the Marin Four Corners, the Fuji Touring, the Raleigh Sojourn, the Jamis Aurora, or perhaps even the Bosanova.

They all have longer wheel bases. Of course, that's to be expected with touring road bikes.

Good Luck!

Thanks everyone! Great info.

The Allez really shouldn't be particularly twitchy. What size are you on? What size stem? How tall are you?