TiHabanero

Racing in the 80's chain stays were thought to be better when shorter. Shorter means stiffer, which means faster in acceleration, and crisper handling in crits. The stays on my race bike were 41cm. Some race buddies had 40.5 stays. When I designed my first frame in 2000 I wanted more room for a 28mm tire and used 42.5cm stays. After 10 years I replaced the rear end with chain stays at 43cm. Two years ago I built a touring frame with long stays at 47cm to fit fenders, 38mm tires and big panniers.

Been riding the long chain stay bike for 2 years, and this spring I moved all the parts to a 1984 Miyata 1000, a well respected touring bike. This week I moved those parts back to the 47cm chain stay bike to have a direct comparison to a more mainstream 45cm chain stay design. Without a doubt I really like the longer chain stays. I like the way the rear wheel rolls over bumps and how smooth it feels. Keep in mind this is a touring bike, however I feel the long stays are not a hinderance when tempo riding down the road. Same with seated climbing. Only on steep hills when I must stand to accelerate do I feel any noticeable flex.

No question I prefer longer stays. 41 stays are a thing of the past. My daily rider has the 43 stays and does everything perfectly. I can't flex it and I am 230 pounds. Longer stays are here to stay. Raise a glass to longer chain stays!

mstateglfr 

The road frame I built in a class a few years ago has 430mm stays. I think my gravel bike also has 430mm stays.
My main backup road bike was made in '89 and I think the stays are 415mm.

I can't tell the difference between them when it comes to rear end characteristics, especially since different sized tires are on each..
The backup road bike barely clears a 25mm gp5k tire and thats basically the only thing thing that is noticably different.

I imagine I'll be happy with the 430mm stays for years to come.

chaadster

Chainstay length is less about tire clearance these days than it is about overall feel of the bike. Shaping and construction technology allow comparatively short stays with huge tire capacity.

As for short vs. long stays, then, it’s simply about what kind of ride characteristics you want. It’s well-known that longer wheelbases smooth out bumps better, just as it is that short wheelbases change direction more quickly and crisply. Do you want or the other? Something in-between?

Personally, for a sporting road bike, short stays are a must. My favorite road bikes, from a handling perspective, both have 405mm c-stays. I have a 420mm stay bike which has noticeably more comfort and stability (at the expense of crispness), and 426mm and 444mm stay bikes which make gravel riding better. It may coincidence that the 405 stay bikes are my favorites because all the geometry elements are different, but between the two 405s, the shorter wheelbased and steeper head tubed one is my absolute favorite handler because it feels so responsive to subtle weight shifts— it steers from the hips— so I think it’s to do with weight balance, and having the rear tire tucked in underneath me is the most rewarding placement.

The 426mm stays bike, by the way, is titanium and will take 700x45c rubber.

TiHabanero

"I imagine I'll be happy with the 430mm stays for years to come."

Exactly my sentiments when I put longer stays on my bike, but now after riding the long 47cm stays I am thinking that perhaps I just like that really long back end and it is the ticket for me. Believe me when I say there is a difference in the way the bike rolls over bumps with chain stays that are 4cm longer.

The fun thing is that we all have what we consider the perfect bike, and then something comes along that rings a bell and wakes up our senses to consider something rather unconventional. Life is fun!

donoharm

Here here!

mstateglfr 

how I phrased that was bad. I meant to say I csnt see myself buying a bike with 415 chainstays. It was agreeing with your comment.
my commute/touring bike is set at 445mm right now and it's also a blast.

Really no desire to have short stays. <--hopefully better worded than my earlier comment.

Kimmo 

Your preference may also depend on whether you want that aspect of your bike to resemble a 1903 model.

chaadster

Like the long wheelbase sedan compared to the short wheelbase sports car; t’s a classic analogue to 1970 Cadillac vs. 1970 Porsche. Do you want more plush, luxurious, ride characteristics, or do you want something more responsive and fun to manipulate?

TiHabanero

Chaadster, your bringing up the 70's Caddy is exactly correct, and I told my wife that it is like riding a Cadillac vs. a Porsche. I much prefer the Caddy over the Porsche these days. Simply tapping out a tempo through the countryside is what I do now vs. ramping it up and down between road signs. I don't race anymore and don't pretend to be a boy-racer and have no need for racer-like handling. Steady riding and stability on wheels is my thing now.

Kimmo 

Ears, noses and chainstays grow with age, it seems

Chandne

I prefer nimble bikes so I tend to prefer shorter chainstays in all my riding disciplines. However, I give up (especially mountain bikes) some or a lot of rear stability on fast and rough downhills...no doubt about that. The longer chain stays help a lot in that regard, regardless of head tube angle. I know riders who like the opposite, mainly for the stability. I think I prefer shorter chain stays because I am a mountain biker. On technical/rocky and twisty climbs, I find the bikes to be more nimble and fun.

MoAlpha

Apples to oranges perhaps, but I have a carbon road bike with 405 mm chain stays and a Ti CX/commuter (currently on road tires) with 435 mm stays. The stability and handling differences are obvious, but I keep interrogating my butt about the comfort experience and the answer is equivocal and might even favor the road bike.

79pmooney

There are other issues that chainstay length affects for some of us. 1) weight balance over the wheels. On a bike that fits me properly, long chainstays mean not enough weight on the rear wheel for good traction on bumpy downhill turns unless the front center is very long. 2) some of up climb out of the saddle and come far forward as we do. Long chainstays mean the rear wheel slips on steep hills and any loose sand or gravel (or oil and sometimes even water).

All the bikes I have ever owned that were both super secure feeling on fast, curvy descents and sure footed up steep stuff have had short chainstays. (The bike I raced was a dream on both counts. 39cm.)

Now, short chainstay bikes have their challenges. My race bike had horizontal dropouts. Wheels with training sew-ups were the biggest I could get in with the tires inflated. Hit the seat tube paint on insertion - always. (Good clinchers didn't exist yet so that wasn't an issue.) A mid -80s Univega I loved could barely take 25c tires because everything was so close. On my two TiCycles customs, I spec'd steep seat tubes, 74 and 75 degrees. 74 and vertical dropouts so 28c tires fit. 75 on my fix gear so the two inch travel dropout was as far forward as possible to keep the wheel as far forward as possible using the tiny downhill cog. That meant the wheel was VERY far forward running the 24! (25c was the design tire size. They work just fine but clearances are 1990 race close in low gear. A true real wheel is a must. Tire traction on mediocre roads and steep hill is excellent, even honking in a huge gear - remember fix gear.)

Now, if you run the steep seat tube angles to get tire clearance, that raises another issue - seat position. Both of those bikes use custom seatposts with massive setback. (60mm)

And as for comfort on rough roads? Well, ti is wonderful.

DaveSSS 

410mm and 415mm stays are common on disc brake road frames like my Cinelli superstar.