Guest goldVFR Posted November 9, 2007 Share Posted November 9, 2007 I remember reading that the VFR uses the engine as "a stressed member of the frame" or something like that. Or maybe that wasn't the VFR. Anyway, I have couple questions about motorcyle frames: - Is there anything unique about the VFR frame, how does it compare to say the frames found in slightly older CBRs, 954 etc? - How different are the frames of the latest supersports? is an 08 CBR1000RR frame all that different than an 08 CBR600RR frame? - I know the newer FZ1's have Aluminum frames whereas the older ones have steel frames. How does the VFR frame compare to either of those? - 5th gen vs 6th gen. I assume the have identical frames, no? Link to comment Share on other sites More sharing options...
Earthshake Posted November 9, 2007 Share Posted November 9, 2007 I think you need a doctorate to begin to understand frame design, and I am certainly not qualified to give an educated response. However, it seems to me that the choice of steel vs. aluminum has as much to do with weight and manufacturing complexity as anything. There are many excellent handling bikes (read Ducati) that continue to use a steel trellis frame. The Japanese seem to favor aluminum. Using engines as stressed members is another way to reduce weight and have one element of the bike perform multiple functions. As engines became more powerful and tires more competent, it was necessary to better understand the dynamics of handling and the part that frames play in that role. It used to be a case of simply making the frame stiffer to achieve the desired results. Nowadays, bikes are generally so darn good that it is a matter of designing a frame to exhibit a controlled flex so the rider gets adequate feedback and can tell when the machine is nearing its handling limits. It's no easy task but I am glad that there are people out there that understand how rider, road and machine interact. Fortunately, we have progressed way beyond the 1970's and 80's when frames were an afterthought and mainly used to hold everything else together. If you ever rode a two-stroke Kawasaki triple you know what I mean. Link to comment Share on other sites More sharing options...
Darth Bling Posted November 9, 2007 Share Posted November 9, 2007 I remember reading that the VFR uses the engine as "a stressed member of the frame" or something like that. Or maybe that wasn't the VFR. Anyway, I have couple questions about motorcyle frames: - Is there anything unique about the VFR frame, how does it compare to say the frames found in slightly older CBRs, 954 etc? Not really. All of Honda's lastest bike frames from the late 90s and early 00s are similar. And, many other manufacturers have been using the "engine as a stress member" idea for a while. The frames in the 954 is not quite the same as the VFR frame, but it's close. Below are some pictures of different Honda frames. - How different are the frames of the latest supersports? is an 08 CBR1000RR frame all that different than an 08 CBR600RR frame? If the 04-05 CBR1000RR vs the 03-04 CBR600RR is any indication, then no. They're probably pretty similar. :goofy: - I know the newer FZ1's have Aluminum frames whereas the older ones have steel frames. How does the VFR frame compare to either of those? The VFR has an aluminum frame. - 5th gen vs 6th gen. I assume the have identical frames, no? No. The 6th Gen frame is thicker. Link to comment Share on other sites More sharing options...
Darth Bling Posted November 9, 2007 Share Posted November 9, 2007 And the pictures of the frames as promised: CBR929 CBR954 CBR1000RR (04-05) CBR600RR (03-04) VFR 6th Gen VFR 5th Gen VTR1000 Link to comment Share on other sites More sharing options...
Guest Posted November 10, 2007 Share Posted November 10, 2007 Thanks this is helpful. So the VFR has an Aluminum VFR. I have also heard references to Aluminum alloy. Alloy= mixture of metals and it makes sense that no frame is going to be pure Aluminum. It probably has some steel in it. There must be some kind of weight / strength / flex tradeoff that they use to determine how much of different metals to use. Link to comment Share on other sites More sharing options...
Member Contributer Dutchy Posted November 10, 2007 Member Contributer Share Posted November 10, 2007 The VFR was the 1st production bike to sport such a frame back in the olden days (I believe...) Link to comment Share on other sites More sharing options...
Member Contributer fallzboater Posted November 10, 2007 Member Contributer Share Posted November 10, 2007 Thanks this is helpful.So the VFR has an Aluminum VFR. I have also heard references to Aluminum alloy. Alloy= mixture of metals and it makes sense that no frame is going to be pure Aluminum. It probably has some steel in it. There must be some kind of weight / strength / flex tradeoff that they use to determine how much of different metals to use. Chrome-moly steels are alloys of iron and chromium, molybdenum, silicon, vanadium, etc. Aluminum alloys are aluminum with typically less than 1% each copper, chromium, magnesium, zinc, iron, etc. Honda started using extruded aluminum for frame spars back in the mid to late '80s (VFR, Hawk GT), joining cast aluminum headstocks, swingarm pivots, and motor mounts. The trend seems to be towards less use of extrusions and more use of cast and hydro-formed sections. These allow much more complex geometries for packaging, tuned flex characteristics, etc. So, the current VFR frame is relatively low-tech compared to the latest super-sport bikes. Compare the CBR1000RR (04-05) frame drawing to the VFR ones, above. Trellis steel frames are obviously still a viable construction method, using relatively inexpensive material and low tooling costs, but labor-intensive. Damn sexy, too. Makes sense for high end lower production bikes (Ducati, KTM, BMW HP2). Link to comment Share on other sites More sharing options...
Beck Posted November 10, 2007 Share Posted November 10, 2007 Most aluminuim sportbike frames are either made with extruded spar pieces or aluminuim formed plates welded together with cast heastocks and swingarm pivot/rear engine mounting plates. Not to mention, a lot of sportbikes now also use high pressure diecast peices to make up their rear subframes, a development from the last few years that the VFR is still to employ. The VFR still has welded steel tube rear subframes. Not bad, but heavy. I think, unfortunately, along with the suspension, Honda still uses it as a part to skimp on to be able to sell the VFR at the prices they're at. Beck 95 VFR Link to comment Share on other sites More sharing options...
VFR4Lee Posted November 11, 2007 Share Posted November 11, 2007 Sportbike performance - Kevin Cameron You might check this out. Kevin Cameron also has a column in Cycle World. He makes some very technical stuff understandable. :thumbsup: Link to comment Share on other sites More sharing options...
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