and a smoother ride . . . YMMV The chain on my VFR was really clapped out. I've always been curious about how much power is lost. So I replaced the chain and sprockets at my local shop so we could do before and after dyno runs. I got the .drf files but couldn't (or didn't try hard enough) download the DynoJet software and convert them to something viewable. I did get one in .bmp as seen below. Note the jagged trace of the before run. Yes you can feel that when riding the bike, almost like there's something wrong with the engine. On this printout the difference is only 1 HP but that's because the highest spike gets tagged as "max power". Once normalized (lines smoothed out) the difference is 75 vs 78 HP. Sorry about not being able to format the other files, and also not getting a good closeup of the old chain (it was shamefully bad) VIDEOS VFR Chain :: 100_3648.flv video by wkdbld - Photobucket VFR Chain :: 100_3643.flv video by wkdbld - Photobucket
I can only imagine how much more power you could get by dumping some Slick50 in there. :bs: Nice bike BTW!! Regards, Rollin
That's interesting...and I believe it. Some very successful club racer friends of mine alway run non o-ring chains on their racebikes because the difference in rolling resistance can actually be seen on the dyno.
I've heard about that. It would be nice to see some hard data. Another test I'd like to see is before and after dyno runs on a 530 to 520 conversion.
I'm going to have to go on record here as saying that's one of the most beautiful VFRs I've seen. Very nice! And congrats on the positive maintenance results, too.
Thanks! I've put stupid money into it but she's a keeper. Yeah I was expecting 2-3 hp based on comments heard over the years. The surprise for me was seeing the jagged graph.
I'm not surprised at the jagged graph either. A few years ago I picked up a well maintained 91 VFR with 18K...original chain and sprockets but I considered them good runnable shape, that is no sideplates that were 'kinky' , and a VERY slight tight spot (which I consider pretty normal for that many miles). One thing I noticed after having the bike for awhile was a barely perceptible cyclical growl at highway speeds. It wasn't that bad but it annoyed me nontheless. I suspected it was the chain/sprockets...and lo and behold it was. When I replaced them with new it went away completely. The bike felt like it was new!! A simple but real significant improvement in all ways.
WKDBLD- Hello fellow .net member! Saw your thread on .net Love the bike! <----VFR- Matt on dcsportbikes.net
I believe it I remember when I got rid of the old nasty chain that came on my 86 it was a huge difference. But I think the 520 and the -1 tooth on the front helped too. But I felt big difference just spinning the wheel by hand.
nice bike!! and I noticed the same smoothening out of the bike when I replaced the 22yo, 20K mile original chain last summer on my '86... Any mods to the bike for performance? I've been looking for dyno charts on the 700s for ages (so THANKS!!!). Can you e-mail them to me? my username is my address at gmail.com
Howdy WKDBLD; Yes, very fine looking machine. I have a few questions about your before and after tests. Did you use the same # of teeth on the pinion and sprocket from before and after? I believe you stated that the chain size was the same as before and after,but I know there have been claims that smaller lighter chains show improved power.Also were both chain set ups lubed similarily? I am pretty sure ,at least by seat of the pants feel,that a well lubed chain adds a little power,now the $64 question is how much. eddie
Small resurrection for an older thread, but I (very roughly) back-converted the torque curve from the HP curves. If I was PM'd and sent the original bin files, I can probably disassemble them into more accurate data. This was just from eyeballing the hp vs. road-speed graph, and assuming that it ended at the redline for the bike. I wouldn't trust the numbers much, but it gives an idea of torque, and matches my butt-dyno's measurements fairly well, especially the lift in torque at 6-8K, and the taper down after that (although my bike feels like it tapers less, but I know that's hard to feel subjectively from my other vehicles).
