How much different can frames with the same geometry feel?

[PurpleFrog]

So GT made 900 different models with the same geometry - some from one sort of aluminium, some from another, some from steel made by Zen monks, others from fossilized mammoth bones and a few from a composite material made out of pressed ferns. Kona wasn't quite as willing to experiment, but they were out there, and Spesh made Stumpjumpers out of that weird metal matrix stuff as well as alu and steel. And of course the designers often varied tube diameters to get the best out of these materials.

What I'm wondering is how different do these bikes feel? Do a Zaskar and a Psyclone, to take what might be the most extreme comparison, feel very different? Do they handle differently? Or does the geometry really set the handling and feel?

 

[jimo746]

very different.

frame material is a BIG part of how it feels or rides, geometry has more to do with handling, and then the controls/contact points ie stem/bars/saddle can also make a big difference.

 

[M-Power]

Re:

A great question.

Having ridden three bikes with the same geo, and construction materials but different welding, they can feel amazingly different. The thinner and better the tig welds the better the bike feels imo. A brazed frame also feels less lively than a neat tig welds job. Not tried a glued together frame for comparison though.

 

[barry2017]

It's all very subjective.

Tyres make an enormous difference, and of course, the setup of all the contact points. Both of them are as important (if not more so) than the materials a bike is made of.

There have been a few experiments like this one:

http://www.bgcycles.com/new-page-1/

That example is road frames, but it's been replicated with other types of bike. It shows that even very knowledgeable/experienced cyclists tend to pick average bike frames over ones built with more esoteric materials.

 

[M-Power]

It's all very subjective.

Tyres make an enormous difference, and of course, the setup of all the contact points. Both of them are as important (if not more so) than the materials a bike is made of.

There have been a few experiments like this one:

http://www.bgcycles.com/new-page-1/

That example is road frames, but it's been replicated with other types of bike. It shows that even very knowledgeable/experienced cyclists tend to pick average bike frames over ones built with more esoteric materials.

Thanks for that interesting read.

 

[legrandefromage]

I had a 96 Avalanche next to a 93 Zaskar and the two couldnt be more different. riding both to work really showed up how dead feeling the Avalanche was.

The best frames that I have ridden have been from Saracen, mid range but just right for myself.

 

[FluffyChicken]

Re:

Simple solution here, buy 3 of them top Ti, Top Alu and Top Steel from the same year GT or Kona should be easy to do this with. Cannot afford the To then get a shire steel frame or shite alu frame in its place.

Bud them up with the same parts and go and have fun.

You cannot go to far shire though as they often altered the setup for casual slower riding comfort and stability.

 

[PurpleFrog]

I had a 96 Avalanche next to a 93 Zaskar and the two couldnt be more different. riding both to work really showed up how dead feeling the Avalanche was.

That's very interesting and unexpected given that they're both alu bikes with same geometry and tube diameters - but it ties in with chris's link where two steel frames looked the same but felt very different because of tubing profile.

Could you say some more about the feeling differed?

 

[legrandefromage]

the original Zaskar frame was very stiff and did a good job of propelling you along without waste via wobbly frames etc. It was handbuilt in the US somewhere. 6061 T6 heat treated.

The Avalanche is from Taiwan. It is prettier to look at weld wise and is made from 7005 series aluminium.

The avalanche had no go, no twang, no feeling of propelling you along. It was using a set of forks that I'd used with the Zaskar for years previously and had decent M570 series LX and other good quality parts to mirror the Zaskar. At the time, the Zaskar was still wearing its old M730 XT and had steel GT forks.

The little test climb was a road between Ellington and Grafham - its where I found that quite a few bikes that I had at the time werent very good at stomping up steep gradients.

 

[PurpleFrog]

the original Zaskar frame was very stiff and did a good job of propelling you along without waste via wobbly frames etc. It was handbuilt in the US somewhere. 6061 T6 heat treated.

The Avalanche is from Taiwan. It is prettier to look at weld wise and is made from 7005 series aluminium.

The avalanche had no go, no twang, no feeling of propelling you along. It was using a set of forks that I'd used with the Zaskar for years previously and had decent M570 series LX and other good quality parts to mirror the Zaskar. At the time, the Zaskar was still wearing its old M730 XT and had steel GT forks.

The little test climb was a road between Ellington and Grafham - its where I found that quite a few bikes that I had at the time werent very good at stomping up steep gradients.

That's my impression of the Zkr compared to every other bike I've ridden - there's a feeling of a bit of boost. I suspect it's not just because the frame is taut but because it planes well:

http://janheine.wordpress.com/2011/02/2 ... stiffness/

..Unless a frame is infinitely taut, it will absorb some energy from the peak moment pedal stroke. Planing is a frame's ability to return this energy during the weaker part of the stroke as it functions as a spring.

You should probably pat yourself on the back over realizing that your hill was a good way for testing for frame "boost" - it's what Heine did too, and he was a NASA Fellow.