To bridge or not to bridge, that's the chainstay question

[Amaro Bikes]

Well, the post title says it all, but...

¿What's your own personal opinion on road frame chainstay bridges?
Absolute must for performance? fatigue risers?

Yes? no? wtf?

talk to me

[e-RICHIE]

Traditionally, they are (were) there for bracing a fender. Then, the multi-use unit morphed in a racing machine (late 1960s and through the 10 speed bicycle boom in the early 1970s). The brace was never questioned as for its being there, unused. Folks say it adds strength. I don't believe it as something that a human being can discern. I got used to the aesthetic element of a lapped bridge on a 22.2mm round stay so my bicycles had them. When I switched to oval stays in the late 1990s, I ceased brazing them in atmo.

[Amaro Bikes]

Seems that, once again, think don't follow applies

Thanks

[Todd Mosley]

My powertap hub can discern no meaningful difference in peak watts on bridgeless bike vs a bike w/ a bridge.

[Pi Guy]

Here is a thread with contributions from eRichie, Curt Goodrich, Dave Anderson, and Frank the Welder:

http://www.velocipedesalon.com/forum...dge-27065.html

[Amaro Bikes]

Here is a thread with contributions from eRichie, Curt Goodrich, Dave Anderson, and Frank the Welder:

http://www.velocipedesalon.com/forum...dge-27065.html

Sorry for not having do the homewrok first, lazy me, guilty on all charges.

[Pi Guy]

Sorry for not having do the homewrok first, lazy me, guilty on all charges.

No worries, I just remembered it because I participated in that thread a little. I wasn't trying to call you out. I think it's a neat topic. I also think it's interesting that FTW takes a different stance than the other framebuilding heavy weights in that thread.

[David Tollefson]

In my very limited building life (barely a fetus compared to the mature builders here), I've only added a chanistay bridge with a fender mount.

[Will Neide]

I didn't notice a difference without chain AND seat stays. That was a thru axle rear end. Very limited sample size though.

[crumpton]

in the ANSI frame stiffness test protocol RFC-0U812 (squeeze the unsupported dropouts towards each other) it scores higher marks with a bridge than without.

seriously, the trapezoid is completed by the rear hub.

[Will Neide]

in the ANSI frame stiffness test protocol RFC-0U812 (squeeze the unsupported dropouts towards each other) it scores higher marks with a bridge than without.

seriously, the trapezoid is completed by the rear hub.

I don't completely understand the ANSI rationale for testing a frame without an integral part of the system (hub or axle).

[crumpton]

I don't completely understand the ANSI rationale for testing a frame without an integral part of the system (hub or axle).

because it was a joke. just assumed the second sentence cleared that up.

[Will Neide]

because it was a joke. just assumed the second sentence cleared that up.

Gotchya....just realized the OU812.

[Peter Polack]

I wanna tell you bout my good thing
I ain't disclosing no names but--
He sure is a good friend and!
I ain't gonna tell you where he comes from, no!
If I tell you you wont come again! Hey!
I ain't gonna tell you nothin but I do will, but I know, yeah!
I should do but I know now let me tell you bout my girl:
Open up a newspaper and what do I see? Ahh, ah
See my girl, ah, looking at me
Ooh, And when she walks, Ooh, lemme tell ya:
She walks and when she talks, she talks and
When she looks at me in the eye
She's my baby lord I wanna make her mine
Tell me baby what you want me to do!
You want me to love you, love some other man too?
Ain't gonna call me Mr. pitiful, no!
I don't need no respect from nobody...

I ain't gonna tell you nothing I ain't gonna no more, no!
She's my baby let me tell you that I love her so and
And! She's the woman I really wanna love
And let me tell you more, oooh!
She's my baby she lives next door
She's the one a woman the one a woman that I know.
I ain't gonna... tell you one thing that you really ought to know ooh!
She's my lover baby and I love her so and
She's the one that really makes me whirl and twirl!
And she's the kind of lover that makes me me fill the whole world and
She's the one who really makes me jump and shout, ooh!
She's the kind of girl--I know what it's all about!
Take it take it

Excuse me
Oh will you excuse me
I'm just trying to find the bridge... Has anybody seen the bridge?

(Have you seen the bridge?)
I ain't seen the bridge!

(Where's that confounded bridge?)

The Crunge-Led Zeppelin

[Dazza]

I like bridges
I don't really care if they do anything or not
I have rediscovered my like for bridges

[edoz]

I'm like most, I only put them in for fender mounts.

[duanedr]

I like bridges I don't really care if they do anything or not

When you do them as nicely as those, i'm sure customers appreciate them as well - whether they do anything or not!

[mmoore]

How about seat stay bridges for disc bikes?

Seat stays can be quite a bit longer and are usually quite a bit smaller, is there a benefit for the stays in a disc bike? or is it just carried over from caliper brake frames?

M

[Will Neide]

How about seat stay bridges for disc bikes?

Seat stays can be quite a bit longer and are usually quite a bit smaller, is there a benefit for the stays in a disc bike? or is it just carried over from caliper brake frames?

M

I built two fairly identical MTB's. One with chain and seat stay braces and a quick release axle. The other without seat and chainstay braces and a thru axle. I, and a few other riders couldn't tell a difference. Both used the same chain and seat stays and both had chainstay mounted brake calipers (rocker dropouts......both were singlespeeds). Not a definitive answer to anything, but I felt pretty convinced given the size of the riders (150-175lbs) on rigid mtbs that the seat stay bridge was/is a carryover from caliper/canti/v-brakes.

With that said, I like the look of the seatstay brace, and still add it on most bikes.

[emanuel]

I always thought chstay bridges come from very old (1920s and before) frames where the chainstays came out straight then bent outwards, like many bmx frames have.
I remembered reading this Waltworks Bicycles: Random musings: do bridges matter?
I also remember everyone who had met the founder of my old shop saying he used to call the ch.stay bridge a rin-deboli, rather than rinforzo.
Ie. it makes it weaker (debole) rather than stronger (rinforzo).