The Chainlink

I don't like how slopey top tubes look.  But, I see them everywhere these days.  Why do they exist?  Does anyone actually think they look cool? (I KNOW THATS PROBABLY NOT THE POINT, I'm guessing they have some practical value)  It seems they were not used on the top tubes of the eighties and nineties.  I have four frames of the eighties and all top tubes are parallel to the floor.  So what's the deal with these things yall? 

Views: 3291

Reply to This

Replies to This Discussion

Yea I have been looking at that one. It is my first choice

Kelvin Mulcky said:

The Soma Stayan is lugged.

There is just so much bad info here I don't even know where to start...

Slopping top tubes and compact geometry have several reasons, but the biggest one is stiffness of the frame.  Smaller triangles and shorter tubes translate into less flex in a frame which means there is less waste turning power from the rider into forward motion.  I don't really know what proof of this some of you are looking for because it seems like pretty common sense to me...

Fit does have a little to do with it but mostly because the taller head tube allows for a higher bar position without a super tall stem of having the steer tube being super long which is not only not vert stiff but hard on headsets.  It's easier to be able to get that high bar position on a bike with a quill stem than it is on a threadless stem which is one of the reasons top tubes started to slope more on newer bikes.

As for some kind of cost slashing conspiracy with the manufactures that is just pure nonsense.  

If compact geometry allowed manufactures to get the proper fit with fewer frame sizes why do they all still make frames in 2cm increments?  Yes, cheap hybrids and low end bikes often come in fewer sizes but that has less to do with the manufactures trying to save money and more to do with those bikes, and customers, not being as fit sensitive

If there was a benifit to traditional horizontal top tubes do you think all the pros would be riding compact frames?

This is just completely wrong information.  

Bikes with sloping top tubes are usually sized by effective seat tube or top tube length; if you ride a 56 in a horizontal top tube that should size out to a 56 in a compact geometry frame.  You may experience some (or a lot depending on the manufacturers) size variation between manufactures but if you are seeing a size difference of that much you are not properly fit on one end of the spectrum.

Lanterne Rouge said:

Sizing is much different on sloping top tubes as well. Whereas I ride a 57-58 cm on a traditional frame, I have rode 52-54 cm on a compact frame, with no issues whatsoever. 

That person was an idiot.

Yes, there are several benefits to having a 650 bike if you are a smaller rider but Surly, and several others, so a very good job of making a decent handling and well fit bike for smaller people with a 700 wheel. 

It is also true that there is a body shape difference between men and women but outside of truly weird shaped people the differences can easily be compensated for with stem length and such.


Jennifer on the lake said:

Mostly just to vent, because my arm hurts and why not: I still recall the scathing mansplanation I received when I showed up to some event with my brand new 50cm Cross-Check, all about how I really ought have held out and invested more money (as though I had any more to spare at the time, or ever, but nevermind that) for a custom job with 650b wheels and a shorter, perfectly horizontal top tube, because it would have fit me so much better due to women having shorter arms or something. Well, that didn't stop me from feeling exceedingly proud of my new bike, for which I had been saving for a number of years and had performed something resembling research on before I decided on that model. I honestly didn't care that it cost "only" $1000, and for that money I was limited to a "men's" bike with slightly sloping top tube and other strange proportions that might not be aesthetically pleasing, and that for all I was sized at the local LBS by experts, it was still something that they already had on hand and ready to go. If a limited number of frame sizes with odd proportions is how manufacturers can keep costs down to levels that people are able/willing to pay, then what's the huge harm in it?

The weight difference between a quality steel bike and an aluminum bike is very small at best.  In fact the aluminum bike can sometimes weigh more.  There is also a huge difference in the ride quality which is why most purpose built and designed touring bikes are steel.

Zidaane said:

I don't think I'd ever use a steel bike for long distance. A loaded Aluminum bike can be 250lbs with rider, gear and water. I could barely get that up a hill. I would say I'd rather be on a steel bike going downhill with that weight then an aluminum bike. I was deathly afraid of a speed wobble at 40mph+.

Deet 4.5mi said:

I am in the process of building up a new bike and am looking for a lugged non slopey top tube model, in steel.  I have been focusing on Soma and Velorange. Any other suggestions. This will be a long distance bike.

My current bike is a slopping top tube and it is fine. But I really like the look of the non slope type so I am hunting around.

This was best answer so far. I think compact frames are great ergonomically for upright sprint riding. That's why the pros use them. They are never comfortable sitting down as they are longer and the seat to bar height is a compromise. A straight tube top will always be perfect sitting down but you get no additional leverage standing up. The longer frame and higher bar of a compact frame give you additional torque to put into your sprint or even maneuvering your bike. It depends what kind of riding you are doing: Ignorable points-

  • A compact frame for touring is not practical. I like a compact frame in car traffic or when I know I'll stand up most of the time. A straight top tube is best for casual or longer rides. Unless you're the weird guy that needs to pass people touring...
  • No one on a straight tube would keep up with me in car traffic when I'm on a compact frame. There's that. Do you want to be comfy and look cool or ride something that's a hundred times more nimble and quicker than car traffic. I'm saying this from the experience of biking a lot on old steel bikes in the city at night during rush hour. I know the difference and there's a compromise. I would not get crazy on a steel frame like I still do on a compact.
  • I do not ever get the stiffness debate. I haven't hit a pebble or bump in the road in 30 years to even care. Kidding but really not. Where is this jarring ride people complain about? I could not tell you the diff between aluminum and steel. Carbon maybe. Give me a carbon seat post and forks and I'm OK with aluminum. When I'm on an old steel bike I want to feel rumbles.


Hey! Bike Shop Guy said:

There is just so much bad info here I don't even know where to start...

Slopping top tubes and compact geometry have several reasons, but the biggest one is stiffness of the frame.  Smaller triangles and shorter tubes translate into less flex in a frame which means there is less waste turning power from the rider into forward motion.  I don't really know what proof of this some of you are looking for because it seems like pretty common sense to me...

Fit does have a little to do with it but mostly because the taller head tube allows for a higher bar position without a super tall stem of having the steer tube being super long which is not only not vert stiff but hard on headsets.  It's easier to be able to get that high bar position on a bike with a quill stem than it is on a threadless stem which is one of the reasons top tubes started to slope more on newer bikes.

As for some kind of cost slashing conspiracy with the manufactures that is just pure nonsense.  

If compact geometry allowed manufactures to get the proper fit with fewer frame sizes why do they all still make frames in 2cm increments?  Yes, cheap hybrids and low end bikes often come in fewer sizes but that has less to do with the manufactures trying to save money and more to do with those bikes, and customers, not being as fit sensitive

If there was a benifit to traditional horizontal top tubes do you think all the pros would be riding compact frames?

Slopping top tubes are nice on loaded touring bikes because they make it easier to get a leg over a loaded bike.  The Trek 520 and Soma Saga (and some tour bikes I can't think of at this second) have slopping top tubes and fit racks quite well.

You have a preference which is based on looks, and that's fine I prefer a traditional top tube appearance wise myself., but stop trying to justify when there are legit performance reasons for the slopping top tube.

Jeff Schneider said:

Of course, the needs of racers, tourists and randonneurs might be different.  As a tourist riding at a moderate pace with some gear, I really don't care what frame geometry a racer uses.  A compact frame is awkward for fitting racks and carrying gear IMO.

I can believe the stiffness argument (to a point), but I also know that even racing has fashions, like tire width going mostly to 23mm then mostly back to 25mm...and of course, even the desirability of frame stiffness beyond a certain point is questioned (see BQ).

As for bikes sold to recreational riders, I am willing to bet that superior stiffness is not the main reason for the compact frame.  I think it's much more likely that it's used to make fitting riders of different sizes easier (which is not a bad thing).  I'm sure you are right that the threadless stem encourages compact geometry, too.

So, while compact geometry may have benefits for some, it may have none (or even be disadvantageous) for others.  For most, it probably doesn't matter either way.



Hey! Bike Shop Guy said:

There is just so much bad info here I don't even know where to start...

Slopping top tubes and compact geometry have several reasons, but the biggest one is stiffness of the frame.  Smaller triangles and shorter tubes translate into less flex in a frame which means there is less waste turning power from the rider into forward motion.  I don't really know what proof of this some of you are looking for because it seems like pretty common sense to me...

Fit does have a little to do with it but mostly because the taller head tube allows for a higher bar position without a super tall stem of having the steer tube being super long which is not only not vert stiff but hard on headsets.  It's easier to be able to get that high bar position on a bike with a quill stem than it is on a threadless stem which is one of the reasons top tubes started to slope more on newer bikes.

As for some kind of cost slashing conspiracy with the manufactures that is just pure nonsense.  

If compact geometry allowed manufactures to get the proper fit with fewer frame sizes why do they all still make frames in 2cm increments?  Yes, cheap hybrids and low end bikes often come in fewer sizes but that has less to do with the manufactures trying to save money and more to do with those bikes, and customers, not being as fit sensitive

If there was a benifit to traditional horizontal top tubes do you think all the pros would be riding compact frames?

For the most part, pros ride what their sponsors tell them to ride.

Hey! Bike Shop Guy said:

If there was a benifit to traditional horizontal top tubes do you think all the pros would be riding compact frames?

besides, what's good for the pros is not necessarily good for me, is it?

Skip Montanaro 12mi said:

For the most part, pros ride what their sponsors tell them to ride.

Hey! Bike Shop Guy said:

If there was a benifit to traditional horizontal top tubes do you think all the pros would be riding compact frames?

Not much if any slope to the LHT:

Gearing, wheelbase, and tire thickness are all bigger factors, though.

Interesting thread. I don't have one but I always associated a slopey tube with plush bikes.

http://www.bikeradar.com/us/road/gear/article/the-best-endurance-ro...

These bikes make sense to me, an overweight guy over 50 with short arms. You can ride all day at a decent pace without feeling it in your lower back. Plush bikes generally have a slopey tube.  It seems less about aesthetics than about ergonomics. I like my current, non- plush road bike but when I am ready to replace it I will likely go this route.

RSS

© 2008-2016   The Chainlink Community, L.L.C.   Powered by

Disclaimer  |  Report an Issue  |  Terms of Service