Member Contributer Stray Posted January 16, 2023 Member Contributer Share Posted January 16, 2023 Hello All, I've been working with some engineering types lately to get my 5th gen track bike project finished. Following a phonecall with Mohawk (what a great bloke!) it seems there may be some appetite for aluminium subframes to fit standard 5th gen tails. The subframe design is simple enough to replicate (6th gen is quite complex in comparison, for example) so it might be an idea to do a group buy on these. Just checking if there's enough interest to get the ball rolling with the welder: need 15 confirmed names to start. Not sure what price is yet: depends on numbers I suppose. Material is likely to be a 5000-6000 series aluminium (6065 or 6082, for example). Will update this when I speak to Bob the welder. Bit of info about the welder: he has welded for Norton and Suter (yes, the race bikes), making frames, wheels, swingarms and subframes. His work is outstanding. He welded on McGuinness' IOMTT bike in the late 'teens. He also made a custom Norton for Keanu Reeves along with a whole bunch of other badass stuff. I'll post a few pics of his work when I get home later tonight. If you're interested in a aluminium (aluminum for our American cousins) subframe please reply on this thread with your location and we can see if this thing has legs. Best, Stray Link to comment Share on other sites More sharing options...
Member Contributer WDIV Posted January 16, 2023 Member Contributer Share Posted January 16, 2023 I know the 6th is a little more complex because of the mount points but I'd be in for that LOL Link to comment Share on other sites More sharing options...
Member Contributer bmart Posted January 16, 2023 Member Contributer Share Posted January 16, 2023 Interesting, but what practical problem does it solve other than lightening my wallet more than Biden has already done? Is there is a big weight savings, for instance? Thanks! Link to comment Share on other sites More sharing options...
Member Contributer Tirso Posted January 16, 2023 Member Contributer Share Posted January 16, 2023 passive interest as shipping and exchange rate will probably make it cost prohibited;-( Link to comment Share on other sites More sharing options...
Member Contributer Stray Posted January 16, 2023 Author Member Contributer Share Posted January 16, 2023 2 minutes ago, bmart said: Interesting, but what practical problem does it solve other than lightening my wallet more than Biden has already done? Is there is a big weight savings, for instance? Thanks! Not sure to be fair - haven’t built one yet but I’d expect it to be lighter. The desire for an aluminium (aluminum) subframes has been expressed on the forum a few times. Just checking if there’s appetite. Also, unlike Biden this is wallet lightening you’d be voting for, rather than having it imposed upon you. Link to comment Share on other sites More sharing options...
Member Contributer Mohawk Posted January 16, 2023 Member Contributer Share Posted January 16, 2023 Count me in 👍 Link to comment Share on other sites More sharing options...
Member Contributer Ughandi Posted January 17, 2023 Member Contributer Share Posted January 17, 2023 Count me in as suspiciously curious. I'd likely helicoil all the things to prevent this 200lb monkey from doing dumb things to what will surely be a piece of art. Can anyone smarter than me chime in on conductivity of dissimilar metals for the purpose of grounding the electrical circuit? Link to comment Share on other sites More sharing options...
Member Contributer Stray Posted January 17, 2023 Author Member Contributer Share Posted January 17, 2023 An example of Bob’s work - he made this last week. 2 hours ago, Ughandi said: Count me in as suspiciously curious. I'd likely helicoil all the things to prevent this 200lb monkey from doing dumb things to what will surely be a piece of art. Can anyone smarter than me chime in on conductivity of dissimilar metals for the purpose of grounding the electrical circuit? Thanks for chiming in, Ughandi. Can’t see any issues with conductivity. Loads of bikes have aluminium subframes and aluminium frames with a ground (including the 5th gen). 8 hours ago, Mohawk said: Count me in 👍 This is all your doing Mohawk - you started it! Link to comment Share on other sites More sharing options...
Member Contributer Stray Posted February 5, 2023 Author Member Contributer Share Posted February 5, 2023 I take it there isn’t much interest in this other than Mohawk and Ughandi? Link to comment Share on other sites More sharing options...
Member Contributer ShipFixer Posted February 5, 2023 Member Contributer Share Posted February 5, 2023 On 1/16/2023 at 8:23 PM, Ughandi said: Can anyone smarter than me chime in on conductivity of dissimilar metals for the purpose of grounding the electrical circuit? Aluminum to aluminum is no problem. Its a dissimilar metal "today," so it would reduce the odds of some kind of corrosion due to galvanic potential between the frame and subframe. Vehicles are typically slapped together with little between them other than maybe paint or grease (only maybe) and it works out over the life of the vehicle. In aircraft and MILSPEC land there are requirements for dielectric materials between even sort of related alloys. Could do that here but probably not required. Link to comment Share on other sites More sharing options...
Member Contributer Dangeruss Posted February 6, 2023 Member Contributer Share Posted February 6, 2023 Curious what sort of bodywork you are thinking of, stock 5th Gen? I've always thought the 5th Gen looked a bit 'full figured' aft of the tank, and always been a big fan of the RC51. I bought all the bits for an RC51 tail and mocked it up on the bike to get the right position. I measured the distance to the frame mounting points and then made a jig to hold the stock tail and added the offset to mount the RC51 tail in the correct orientation. This allowed me to bolt up the RC51 subframe and modify one leg at a time to fit the VFR, so I now have an RC51 rear with an integral hanger for a high mount silencer and hidden trunk release that bolts right onto my 5th gen. I'll try to get some pictures up this week so it makes more sense. Heres a pic of it on the jig before the subframe was complete, you can see the lower VFR holes that I have to extend the bottom mounts to. Link to comment Share on other sites More sharing options...
Member Contributer Ughandi Posted February 6, 2023 Member Contributer Share Posted February 6, 2023 On 2/4/2023 at 8:33 PM, Stray said: I take it there isn’t much interest in this other than Mohawk and Ughandi? Sounds like the cost per unit is about to go waaaaay up! lol Not to contribute to 'scope creep' here, but wouldn't it be a good move to slightly increase the box-section size for stiffness & strength purposes (such as the next 'off-the-shelf' size up from factory)? On 1/16/2023 at 6:40 AM, Stray said: he has welded for Norton and Suter I dont know how my eyes glossed over this on my first read- This guy has serious credentials!! Now I REALLY want one! On 2/4/2023 at 11:41 PM, ShipFixer said: Aluminum to aluminum is no problem. Its a dissimilar metal "today," so it would reduce the odds of some kind of corrosion due to galvanic potential between the frame and subframe. TL;DR - It's going to be a non-issue. Got it. Link to comment Share on other sites More sharing options...
Member Contributer Ziffer Posted February 6, 2023 Member Contributer Share Posted February 6, 2023 I've thought about getting an aluminum subframe built (and a front fairing support). So I like the idea, but, after shipping, I could probably get a custom one built over here. Still, depending on price, I could be interested. Link to comment Share on other sites More sharing options...
Member Contributer Ziffer Posted February 6, 2023 Member Contributer Share Posted February 6, 2023 20 hours ago, Dangeruss said: Curious what sort of bodywork you are thinking of, stock 5th Gen? I've always thought the 5th Gen looked a bit 'full figured' aft of the tank, and always been a big fan of the RC51. I bought all the bits for an RC51 tail and mocked it up on the bike to get the right position. I measured the distance to the frame mounting points and then made a jig to hold the stock tail and added the offset to mount the RC51 tail in the correct orientation. This allowed me to bolt up the RC51 subframe and modify one leg at a time to fit the VFR, so I now have an RC51 rear with an integral hanger for a high mount silencer and hidden trunk release that bolts right onto my 5th gen. I'll try to get some pictures up this week so it makes more sense. Heres a pic of it on the jig before the subframe was complete, you can see the lower VFR holes that I have to extend the bottom mounts to. Same here. I've never been a big fan of the 5th gen VFR tail and light (although it's gown on me a little bit). I prefer the thinner/sleeker/sharper look. I've been looking at that, trying to figure out what to do about it. The RC51 tail looks good. Let's see a pic with it on the bike. Link to comment Share on other sites More sharing options...
Member Contributer Ziffer Posted February 6, 2023 Member Contributer Share Posted February 6, 2023 On 1/16/2023 at 11:57 AM, Stray said: Also, unlike Biden this is wallet lightening you’d be voting for, rather than having it imposed upon you. LOL ... Link to comment Share on other sites More sharing options...
Member Contributer Dangeruss Posted February 7, 2023 Member Contributer Share Posted February 7, 2023 3 hours ago, Ziffer said: Same here. I've never been a big fan of the 5th gen VFR tail and light (although it's gown on me a little bit). I prefer the thinner/sleeker/sharper look. I've been looking at that, trying to figure out what to do about it. The RC51 tail looks good. Let's see a pic with it on the bike. I got carried away cleaning the bike and currently the largest part is the engine, as it goes back together I will post pics. Link to comment Share on other sites More sharing options...
Member Contributer bmart Posted February 7, 2023 Member Contributer Share Posted February 7, 2023 Mine always get cleaned right after the next owner buys it! 🤣 Link to comment Share on other sites More sharing options...
Member Contributer Stray Posted February 8, 2023 Author Member Contributer Share Posted February 8, 2023 Dangeruss, I’m very interested to see the RC51 tail on your VFR. That RC51 is the best looking sports bike Honda have ever produced, in my opinion! What material are you making the subframe out of? Ughandi, upsizing the subframe is easy but you’d have to ask why. The main point of getting an aluminium subframe is to make it lighter. Holding an up spec aluminium subframe that’s as heavy as the stock one defeats the purpose. In fact, if you’re solo riding you could probably down-spec the tubes to lose even more weight. Mohawk likes to take a passenger so his needs to be strong as stock. What about you? Passenger or solo? And yes, the guy welded frames for Norton and Suter. He built McGuiness’s TT bike from scratch when he raced for Norton, including the frame & wheels. Ducati flew him out to Switzerland to build their subframes in the 2010’s. He can weld. Link to comment Share on other sites More sharing options...
Member Contributer Ughandi Posted February 8, 2023 Member Contributer Share Posted February 8, 2023 2 hours ago, Stray said: Ughandi, upsizing the subframe is easy but you’d have to ask why. The main point of getting an aluminium subframe is to make it lighter. Holding an up spec aluminium subframe that’s as heavy as the stock one defeats the purpose. I don't ride with the rear pegs... if a lady wants to ride, she can get her own dang bike!! (or get on my Buell... since it's the only one running at this moment...) ... so you're probably correct that I wouldn't need it beefed up... but I'd prefer the rigidity of a size up over the extra 2lb weight savings of keeping the OG dimensions, for peace of mind more than anything... That big tail section on the 5th gens makes for a very large moment arm, and considering my history of mounting motorcycles in silly ways, I cannot trust the 200 lb gorilla that is typing this message to not try to break it somehow. Link to comment Share on other sites More sharing options...
Member Contributer Ughandi Posted February 8, 2023 Member Contributer Share Posted February 8, 2023 2 hours ago, Stray said: And yes, the guy welded frames for Norton and Suter. He built McGuiness’s TT bike from scratch when he raced for Norton, including the frame & wheels. Ducati flew him out to Switzerland to build their subframes in the 2010’s. Such supreme experience. Just the kinda guy you want to learn from (and build subframes for a niche motorcycle). Link to comment Share on other sites More sharing options...
Member Contributer adkfinn Posted February 8, 2023 Member Contributer Share Posted February 8, 2023 I'm interested, but participation will end up price dependent. VT, USA Also - FWIW - A reference weight I found for the stock subframe is 6lb 14oz ( https://www.vfrdiscussion.com/index.php?/forums/topic/79095-5th-gen-subframe-weight-needed/ ) Using that info, generic material densities of 490lb/ft3 for steel and 170lb/ft3 for aluminum ( https://mojobob.com/roleplay/weight_chart.html ), some silly assumptions about the volume of the stock part and the custom part being the same (unrealistic I know, but what volume scaling factor would you suggest?), and some rough math: (6.875lb/490lb/ft3)(170lb/ft3) or 2.39lbs I'd round a bit up to be conservative and say ~ 2.5lb is probably a decent rough estimate of weight. ( I think... someone much smarter than me can feel free to chime in here. Please correct where I've gone wrong, does this seem a bit low? ) Overall - If the above is correct, I'd guess this would represent around a 4.3lb savings over the stock part Link to comment Share on other sites More sharing options...
Member Contributer Mohawk Posted February 8, 2023 Member Contributer Share Posted February 8, 2023 A couple of Kg out of the rear end is never a bad thing. Lets hope it comes off. I know Stray has a couple of stock ones so he can confirm the weights. Link to comment Share on other sites More sharing options...
Member Contributer Wald Posted February 8, 2023 Member Contributer Share Posted February 8, 2023 There is an alternative to this. Drink less beer and eat less pizza for few weeks. The total weight (rider and bike) saving will be the same. LOL! Link to comment Share on other sites More sharing options...
VFR750F3 Posted February 8, 2023 Share Posted February 8, 2023 To really make this bike fun we have to get rid of a lot of weight. 425pds would be the ideal weight. It is a long and expensive process unfortunately. It is so sad that Honda could not produce a lightweight VFR with 170HP. Link to comment Share on other sites More sharing options...
Member Contributer bmart Posted February 9, 2023 Member Contributer Share Posted February 9, 2023 Really? I've never felt like that about my VFRs. Link to comment Share on other sites More sharing options...
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