TheGreaseMonkey Posted October 18, 2023 Share Posted October 18, 2023 Despite many hours scouring the internet I can't find any mention of the OEM dog bone length for the 4th gen VFR750 (94-97). If anyone has this info handy at all it would be greatly appreciated. I'm just after an eye-to-eye length measurement (or overall length measurement), and if possible a width measurement. I'm pretty sure width is fairly standard for this style of dog bone but extra information can't hurt. Cheers. 😉 Quote Link to comment Share on other sites More sharing options...
Member Contributer Dutchy Posted October 18, 2023 Member Contributer Share Posted October 18, 2023 Dark here now (my bikes live outside), will crawl under the bike in the morning Quote Link to comment Share on other sites More sharing options...
Member Contributer Dutchy Posted October 19, 2023 Member Contributer Share Posted October 19, 2023 @TheGreaseMonkey The rains finally subsided... Centimetres, not inches Quote Link to comment Share on other sites More sharing options...
SEBSPEED Posted October 19, 2023 Share Posted October 19, 2023 Referencing data I collected for my 2005 build, but it may be of some help: My stock 6g dogbone was spaced 115mm center to center. I replaced it with a CBR600F3 dogbone which was otherwise equal, but spaced at 110mm. The 5mm difference resulted in a swingarm angle change of -1.7 degrees. I have drawn up a couple new versions and will be machining a few new parts with even smaller spacing over this winter. I am making this effort to further increase my swingarm droop to combat rear suspension squat under acceleration. Quote Link to comment Share on other sites More sharing options...
TheGreaseMonkey Posted October 20, 2023 Author Share Posted October 20, 2023 @Dutchy Woo hoo, thanks mate, you're a legend. Front end of the tape is in a great spot and I reckon with the back end on the bolt thread that would be pretty bloody close to 110mm for length and 36mm for width. @SEBSPEED Extra reference data is always handy! You're measurements on 6th gen matches what I found somewhere online, 115mm for length. Not sure where I got it but my notes also say 35mm for width on the 6th gen. Interesting the length of the F3 dogbone is the same as what Dutchy got for the 4th gen at 110mm. Good to know for parts interchangeability. I'll be pulling my XX dogbone out this weekend so will post up the results (as above, extra reference data is always handy!) Quote Link to comment Share on other sites More sharing options...
SEBSPEED Posted October 21, 2023 Share Posted October 21, 2023 Worth noting, the width of the dogbone is less important than the width(length) of the steel bushes that ride in the bearings. The bushes are what set the spacing of the link plates. The aluminum dogbone just carries the bearings and sets the spacing. Quote Link to comment Share on other sites More sharing options...
TheGreaseMonkey Posted October 22, 2023 Author Share Posted October 22, 2023 So it turns out the XX dogbone is also 110mm length and the width is 36mm. 22 hours ago, SEBSPEED said: Worth noting, the width of the dogbone is less important than the width(length) of the steel bushes that ride in the bearings. The bushes are what set the spacing of the link plates. The aluminum dogbone just carries the bearings and sets the spacing. Good point on the bushes/collars SEBSPEED. I went back and took another measurement at 39mm for the collar width and it takes an M10 bolt. Interestingly, although these bikes share the same dogbone dust seal part number the VFR uses a different bearing part number, and the F3 uses a different collar part number. Makes me wonder what the difference is between the XX and VFR needle bearing when the dogbones have the same dimensions, dust seals and collar. 1 Quote Link to comment Share on other sites More sharing options...
Member Contributer JZH Posted January 2 Member Contributer Share Posted January 2 Slightly off-topic, but I was wondering recently if anyone has managed to replace the VFR dogbone with something derived from threaded rod-ends? They are available in various strengths and grades, and could conceivably be used to allow adjustability (within a range). Would need appropriate spacers, because they are very narrow. Might not be enough length to use right/left threads with a stainless steel turnbuckle, but there would almost certainly be enough room for something which could be easily adjusted after popping out one of the bolts. 10mm ID rod ends would slide over the existing dogbone bolts, but larger ones could be used with a sleeve of some sort. Is there an otherwise-obvious reason why this wouldn't work?! Ciao, JZH Quote Link to comment Share on other sites More sharing options...
Member Contributer bmart Posted January 2 Member Contributer Share Posted January 2 I would ask...why? Quote Link to comment Share on other sites More sharing options...
Member Contributer Captain 80s Posted January 2 Member Contributer Share Posted January 2 Quote Link to comment Share on other sites More sharing options...
Member Contributer Duc2V4 Posted January 2 Member Contributer Share Posted January 2 If memory serves me correctly, a former member ('Recalcitrance') had one of the adjustable type dog bones and it broke while she was riding home. Fortunately, she came out OK but did stop traffic on the '101' freeway for a spell. I do recall her posting about it, but this was before the server had to be rebuilt, so not sure if the post was recovered. I suppose if one was to use an adjustable dog bone to figure out their preferred length and then have someone like Seb build a solid unit with the measurements that worked, I definitely see that as viable. Personally, I'd be worried the same issue that happened to Recalcitrance could/would happen to me, especially if I was doing aggressive track or canyon riding. All that said, I would have to reach out to her and ask if she recalls who made the one that she had, as to avoid them as a possible supplier. Quote Link to comment Share on other sites More sharing options...
Member Contributer Captain 80s Posted January 2 Member Contributer Share Posted January 2 16 minutes ago, Duc2V4 said: . I suppose if one was to use an adjustable dog bone to figure out their preferred length and then have someone like Seb build a solid unit with the measurements that worked, I definitely see that as viable. I would never run one. Well, not a generic one. But as a tool to determine a set up I could see it being useful. Quote Link to comment Share on other sites More sharing options...
Member Contributer Mohawk Posted January 2 Member Contributer Share Posted January 2 You need to understand the loads through the part. It's what holds the swingarm & suspension parts in place & is the leverage point for all of it as well as the connection to the frame. Due to the leverage ratios it can have quite a load through it. The adjustable units would need to be doubled up IMO to be able to take the load without any worry. Quote Link to comment Share on other sites More sharing options...
Member Contributer JZH Posted January 3 Member Contributer Share Posted January 3 On 1/2/2024 at 6:58 PM, Mohawk said: You need to understand the loads through the part. It's what holds the swingarm & suspension parts in place & is the leverage point for all of it as well as the connection to the frame. Due to the leverage ratios it can have quite a load through it. The adjustable units would need to be doubled up IMO to be able to take the load without any worry. Indeed, but I'm probably not (certainly not!) the first person to think of this (although the reported Recalcitrance experience is a little worrying). Adjustability adds complexity, expense and weight, but could greatly assist determining the ideal dogbone length. So could acquiring a few Honda dogbones in various lengths--which would probably work out cheaper than buying high-strength rod ends... Okay, it was just a thought! Let's get some more dogbone measurements. I'll see what I can find in the shed (I'm pretty sure I have ended up with a few, given that I have about six different Honda swing arms tucked away). Ciao, JZH Quote Link to comment Share on other sites More sharing options...
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