ridingfixed

I recently found a bike on pedalroom with a wishbone seat stay, the first I'd seen, and fell in love.
I was wondering why builders more or less stopped building with them (granted they were never popular in the first place from what I can tell), but I think they are beautiful.
What can you guys tell me?

zukahn1 

On build and true wishbones are harder to produce and in most cases less structualy sound than traditional chain stays. On a wishbone you have one joint that needs to be perfect holding about 2 thirds the weight under load while with a balanced two stay the joints only need to hold a 3 or less of the bikes total wieght. Basicaly while cool looking wishbones are a design that costs 2 times as much on mid level or lesser bike if properly made to make.

Scooper

The problem with the wishbone or monostay seatstay is that it adds vertical stiffness while at the same time increasing lateral compliance. Separate seat stays terminating on each side of the seat lug add lateral stiffness in the rear triangle compared to a monostay because of the cantilever action (one stay in tension while the other is in compression) of the two stays when there are lateral loads on the bike. Likewise, the two separate smaller diameter seat stays allow a little more flex vertically in the rear triangle than a larger diameter monostay.

Vertical compliance and lateral stiffness are desirable in a road bike, and a wishbone stay is stiff vertically and flexy laterally - just the opposite of what's desired.

Wildwood 

My only ti frame, so I have no real basis of comparison.

ridingfixed

wow okay that makes a lot of sense.. I still wish i could ride one to see what it's like.

ridingfixed

so you're saying that i would never see a top of the line build with a wishbone?

gaucho777 

Not arguing with Scooper, but this Cooper is still pretty dreamy.

Wildwood 

Merlin Extralight had wishbone seatstays for a few years and was a pretty high-end frame (to say the least).

zukahn1 

There have actually been a lot of high end Titianium, mixed hard alloy and one piece carbon fiber frames that use a a basically wishbone frame about half of the top of the line current road bikes sold use some form of the more costly wishbone design.

Chombi

Vitus made one in the form of their 787 Futural model aluminum bike in the mid or later 80's
I always found it strange that Vitus did not make that many of the 787's compared to the huge numbers they made of the 979's with the more conventional seat stays.
I haven't heard of structural issues with the wishbone stayed 787's, so that might not be the reason, so it's either they were actually harder to manufacture, or the wishbone stay did result in a less comfortable ride, so Vitus did not bother to extend the bike's manufacture duration...... but the wishbone stay design did look really cool on the 787's as a new alternative to the standard seat stay design....

non-fixie 

Haven't ridden it yet, but it looks great, I think:

zukahn1 

Lets see the whole bike I wan't to see if it is a super rare Vitus with double sucuicide forks don't knock me I didn't name them If I had one I would ride it just like any other bike. It would have a C&V cool factor of about 10.

Chombi

Vitus bike with a "double suicide fork"?? Which Vitus bike could that be???
You might be thinking of Teledyne Titans or Vsicounts....
Those are the only marques I heard that had bikes with "Death forks"

JohnDThompson 

No, Strawberry out in Portland is famous for theirs. They even sell kits for other builders:

https://www.torchandfile.com/8195-Wis...Kits_c_13.html

rando_couche

AFAIK, there's no functional reason for wishbone stays on a road bike, but they DO give the builder a place to show off design and construction skills. Just like a lot of "features" on boutique frames.

SP
OC, OR

SJX426 

I would really like to experience a Strawberry:

Vonruden

My wishbone came true and I will be building up this one.

CV-6 

'

I don't think that is what he is saying at all. He has pointed out the drawbacks to the wishbone. Nothing more. Gazelle and Zunow both had models with wishbones stays.

Saguaro

Wow, dream come true is right! That's just awesome. What a paint job! And the lug work, perfection. I would'nt care much about "increased lateral compliance" on this one

Sixty Fiver

Proctor / Townsend used wishbone stays here for a time along with R753 tubesets... I believe the wishbone stays came from Strawberry and might have to ask Anthony if he ever dealt with those Canucks in Edmonton.

It is a wonderful bike to ride, as a lighter rider I don't find that there is much flex in this frame at all and it climbs like a goat.

surreal

Wishbone seatstays just plain look hott... some builders still offer them on current-production frames... cheapies like on-one, boutique customs like Sycip... I can see how it might have an effect on production costs, and I was told to avoid building an mtb around a wishbone frame b/c I weight\ a lot.

Whataver, VonRuden's Zunow is about as hott as things get. Even if I don't own any**, I appreciate the wishbone stays....

-Rob

**ps-not sure if looptails count....

Sixty Fiver

I have a new build in the works, if the customer wants it I have a wishbone stay for the rear...

Scooper

Yes, exactly; that's all I was saying.

BTW, wishbone seat stay configurations have been around for a very long time. Here's a 1900 advertisement. $15.90 as shown.

ThermionicScott 

AFAIK, this bike doesn't count has having wishbone stays. Yeah, they're "manipulated", but not wishbones.

non-fixie 

This is the bike, just after I picked it up, near Kortrijk in Belgium. It's currently residing in the attic, full of WD40, as the bar stem is stuck. It's a bit outside my comfort zone size-wise, but I couldn't resist. It's a Martelly, built by Martens, one of the underrated Belgian frame builders.