Road bikes with sloping top tubes

[Amaro Bikes]

Never a sloping top tube or never let a client decide such a thing?

If the latter: why not?

I mean never let the client decide, at least in my case, I think is the builder the one in charge on what goes where and making decissions on the bicycle design.
Of course each one can have their own perspective on that matter and I have nothing against builders who feel more confortable being a tool for customers to build their own vision (customer's), this is a free world, but I'm on the opposite side of the mirror, were customer's decission is to choose their favourite builder, not to design the bicycle. They tell me their story and preferences, I build an Amaro for them.

Cheers

[Blakey]

Agreed atmo.
God forbid others may follow suite and wreck the conversation about sloping top tubes atmo.

Like Daza pointed out, Pipe is dimensioned off of the inside dimension because it has something flowing through it and that's the dimension that matters. The pipe size (ID) stays constant even as wall thickness (also referred to as "schedule" IE sch 40, 80, 120 and so on) increases. That keeps the flow constant regardless of wall. Tube on the other hand is tooled and dimensioned off of the OD and the ID is what changes with wall thickness. You use the term pipe on a somewhat regular basis and it incorrectly describes what you're talking about. Others are following suite and I figured I would attempt to straighten it out before people start thinking the two terms are interchangeable.

Without wishing to continue the derailment much further, a quick correction, pipe has a standard OD, so that fittings such as flanges, tees, supports etc only have to fit one diameter per NPS/DN and mixing schedules can be accomplished where required and allowable. The ID decreases with increasing schedule. Pipe with a NPS in STD schedule will have an ID closest to the NPS figure.

Same applies to lugs, otherwise a 1/.8/1 tube would need a different lug than a .7/.4/.7.

/derail, back to the sloping TTs.

[e-RICHIE]

Without wishing to continue <cut>.

http://www.velocipedesalon.com/forum...rum-36866.html

Thanks

[Mark Kelly]

I mean never let the client decide, at least in my case, I think is the builder the one in charge on what goes where and making decissions on the bicycle design.

Thanks for the answer; I thought that's what you meant and I'm mostly in agreement. There are many things I won't change; we all draw the line somewhere and for me top tube slope is on the client side of that line.

[dgaddis]

I'm a piping engineer, Blakey is mostly right.

Pipe OD is constant regardless of schedule (thickness). For socketweld fittings this means a 2" elbow will work with any schedule 2" pipe.

For buttweld fittings however, they are available in different schedules to match both the ID and OD of the pipe. Depending on the process fluid it may not matter that the IDs match perfectly, but for some systems it does mater. Any system with biological fluids for example, food and beverage industry, pharmaceuticals, etc, you don't want crevices and nooks and crannies for stuff to get stuck on inside the pipe.

My Zukas has a sloping top tube.

[Gattonero]

My 2 cents:

I'm 1.78mt (5.9"?) with 82.5cm inseam.
Not easy to make a road frame with lever top tube, that is pleasing to the eye: there will be less than 15cm of seatpost sticking out.
That is ok and coherent with "classic" bikes, but not really nice to see in a modern bike.
For example, Dario had to lower the top tube on my custom MxxxxxO. The 14.5cm head tube, in fact, is the correct size for my riding position

[mmoore]

i like seeing both aesthetically, but like sloping TT for my bikes.

(with straight blade for road or suspension forks for mtb's)

[shand]

If this distinction is one misapplied in the construction of a bicycle there are larger issues at play than the angle of the offending top pipe.

I call them all pubes. Seems to be the best of both worlds.

[steve garro]

well, yeah, but you probably would never order a pipe bender. Is there such a thing? I have, on 2 separate occasions, ordered 3" pipe clamps only to find out that they are some random (much larger) size that fits a 3" pipe. Grrr.

Yes, of course there is.

My large radius bender has both available, and if you order new dies they ask pipe or tube?

Sorry to be persistent, I'm the son of a Boilerman.

My top tubes go where the client's geometry says they should go.

And most are curved……………rolled in dies made for TUBING not the ones for PIPE

http://www.pro-tools.com/pages/choos...r-large-radius
- Garro.

[Jonathan]

My top tubes go where the client's geometry says they should go.

And most are curved...
- Garro.

My favorite answer in the bunch.

Jaysus people, get outdoors and do something.

[zank]

Yeah, put that in your pipe and smoke it.

[steve garro]

Yeah, put that in your pipe and smoke it.

You can make a pipe out of tubing……..mind blown……..

- Garro.

[Dave Thompson]

Pot pipes (and pot tubes) are legal in Washington!

[mmoore]

I like my sloping top tubes LONG.

20150524_152057.jpg


Sorry, was a good chance for me to show this again. Im excited as a kid on christmas eve now that ive finished the frame.

[progetto]

So where does a cylinder fit into all of this?

I call them all pubes. Seems to be the best of both worlds.

[Jeffrey Borisch]

I heard Bartali smuggled documents in his tubes, which is kind of like transporting a substance, which would also make them pipes.

Everyone is right.

[hmbatrail]

Did anyone, ANYONE, legitimately think that Richard was using "pipes" to build frames? Anyone at all think that? Me either. So the point of bringing it up and making this thread into something of a shit show was???

Honestly, do you think any builder is out there building with schedule 40 black iron or some silly shit when they use the term pipe? So we can agree that, while technically incorrect, the terms pipes and tubes can and will be used interchangeably. Then we can we stop the pedantry wheels from turning anymore? Goddamn folks. A little perspective can go a long way.

[suhacycles]

The next question is how people feel about level top tubes for cross bikes?

Ever done a CX race and try shouldering a frame with a highly sloped TT? Level TT bikes are better here. I also think the bike feels more balanced in your hand when you do a quick grab and lift like when running over barriers.

Hey, build a level TT bike and see for yourself. Maybe try an extended HT like Dario to get the main triangle a little smaller. The last two road frames I built have almost identical geometry minus the TT slope and I can't really say that the sloped TT one feels stiffer or smoother...

BTW, I take it you also enjoy riding around Umstead Park on your road/cx machine? =)

-Hansen Su

[febikes]

Ever done a CX race and try shouldering a frame with a highly sloped TT? Level TT bikes are better here. I also think the bike feels more balanced in your hand when you do a quick grab and lift like when running over barriers.

I call BS on the shouldering thing. My background is single speed mountain bike racing. We get off and run up climbs plenty with sloping top tubes. Also, last year at one of the big local cyclocross races one of my sponsored riders won using one of my mountain bikes. I just don't see level top tubes as making shouldering any easier. With level TT, the bike sits lower on the back while shouldering. With sloping TT the bike sits a little higher on the back while shouldering. Also a CX bike with more mountain style geometry allows the rider to get over more stuff without getting off the bike. Running with a bike that has a sloping top tube is just as fast as running with a level TT bike.

Hey, build a level TT bike and see for yourself. Maybe try an extended HT like Dario to get the main triangle a little smaller. The last two road frames I built have almost identical geometry minus the TT slope and I can't really say that the sloped TT one feels stiffer or smoother...

I have done that and level TT really totally fails with my riding style. I pedal knees in so my knee can brush the top tube occasionally when pedaling if the TT is not low enough. This is an issue with road bikes even when they have a slight slope. For my bike I went with maximal slope partly to get the top tube out of the way of my knees inward pedaling style.

BTW, I take it you also enjoy riding around Umstead Park on your road/cx machine? =)

Ya, Umstead is totally awesome.

[zank]

The best part about building your own stuff is that you can make it exactly how you want it.