Hi, I recently replaced my speedo drive (it was cracked) along with the cable, and the speedo now overreads by 25-30%. I'm told that there is only one speedo drive that will fit my bike (p/n ends 51A, I think), but I'm doubtful. Can anyone help? It's a 1995 900SS. Cheers, Humbug
There are two different ones that fit the carb 900ss and variants, it all depends on whether you have the 17mm front axle or the 20mm one. The 17mm front axle is on the early models, but they changed to the 20mm one about the time your bike was built. Maybe there are two different gear ratios for the same axle size?
Not as far as my research leads me to believe......there are two wheel types, two axle types, two speedo drives and one speedo type....neither of the drives are really interchangeable unless someone has fitted incorrect parts to try to get one working.... If Humbug sticks some pics of his drive when removed from the bike, we may be able to see what the problems are, or failing that a close up of the hub and drive when all assembled on the bike might prove useful..... I think I have a spare late wheel drive which can be borrowed to carry out tests.... PS...what profile front tyre is fitted? AL.
I have a spare 'late' drive too, with the larger diameter front axle. When I fitted it to my bike, after swapping a wheel, the speedo over read. If its any use to you, I can let you have all the bits (dead easy to put back together again)
I appreciate everyone's help, and I hope you people can help me figure out the solution. Pics as below.
The later IE Injection drive is a different ratio, used to correct the ratio when fitting superbike forks to an SS? Probably the same part number too, lol
Right...that's the later carby wheel.....Also looks as though you have standard adjustable Showa forks. You have the correct tyre for the 900SS, which as far as I can tell should mean the speedo is pretty spot on at 30mph... I can't really see if it is the later speedo drive, but in your pics I get the impression that it might be the smaller one.....I need to inspect my bike and the spare drive to be sure (bear with me on that.....too late to be rummaging around in boxes)......The fact that I can see in your top pic a glimmer of light metal between the drive and the wheel hub suggests something may be wrong. If it is the smaller drive (the earlier one) somehow cobbled to work in the later wheel, the speedo will read 'faster'. Be handy if your wheel was out of the forks and the hub and the drive 'loose bits' were in a pic. I'll be back tomorrow.... AL.
What a coincidence. Needed to replace mine as it was cracked. Saw one on ebay thought it was the right number from memory 748216 looked exactly the same and 17mm shaft so even though the seller said it was for a 600 (mine is a 92 900ss) I bought it. Got it for peanuts so no too bothered if got wrong one. Looking at my old one tonight number is 748209. Took wheel out 748216 is 19 tooth and 748209 is 18 tooth, (hope I got that the right way round - just looked at tyre size 600ss R17 60 profile 900ss R17 70 profile so think 19 tooth more revs of speedo cable to compensate for small overall diameter wheel of 600ss) can't get at worm gear yet to see number of teeth. If I can will swap worm and wheel and use the new body. My speedo does not look like the one in Humbugs pictures it does not have any recesses on the outer plastic casing it only has one longish torque arm sticking out. Not sure I have answered any question here - only check, check and double check. Cheers Gaz.
Pics? Hub and drive bits.....Sure your front wheel hasn't been changed, I just need to see the hub and the brake disc locating rib. Drives won't interchange regardless of how many teeth they have. AL.
OK....For the later carby wheel the speedo drive part number on the drive body should be 750707... ....it looks as though that is what you have got, but I can't see it clearly in your pics. However, the fact that we can see that light metal in the top pic makes me think there is something adrift and the drive casing isn't close enough to the wheel or it is on the p*ss..... .....to be sure it is completely correct I suggest you whip the wheel out and post some pics of the hub and the drive washer thingy that normally gets left in the hub when you take the drive off. Sorry I can't be more help at this stage. AL.
I really appreciate the response..but I'm stuck, as I don't have paddock stands / jacks to work on the bike. I'll get that number off the drive though later today, and post it here.
Had to lie on the floor to get the number .. 750709. Can anyone figure out what I can do next, without getting the front wheel off?
Buy some stands? If you had a back stand you could ratchet strap the front yokes/frame to the garage roof beams so you could remove the front wheel?
To be sure, take a photo of the oval stamp thing on the wheel spoke and another close-up more at right angles to the hub, but so I can see a few disc bolts. Also can you get one close-up at right angles nearer to the drive and the hub? I want to see the relationship of the drive case curve to the curve of the disc retaining lip. But that number isn't right as far as I am concerned......Yep, I laid on the floor as well, just for you......and scrabbled around in a box, so two drives confirm the number 750707. I reckon you might have an IE speedo drive.......FKsY The only way I can tell is by seeing the drive 'washer' and the hub internal. Craig at MOto Rapido is usually kind enough to answe a few questions, but the 750707 number on the drive body isn't the actual Ducati Part Number by the looks of it....although 750707 must be a Part Number, trust Ducati to give it a different one. AL.
JJust been out for a ride on the bike, more to gauge the inaccuracies as anything else. Took the wife's iphone with co-pilot on it, so allowing for a couple of miles either way, here are the readings: Indicated 30mph = 21mph on GPS Indicated 50mph = 33mph on GPS Indicated 70mph = 47mph on GPS Here are a few more photos. Apologies, forgot a ruler, but my thumb is approx 17mm accross the nail. Cheers Humbug
This is what you are looking for on the spoke..... That also looks like the larger axle, which would tie up with the wheel unless someone has p*ssed around with the bearings etc...... But I am absolutely convinced that is not the correct drive, because that 'white ' metal IMO shouldn't show, and it looks as though the drive is sitting straight against the hub AL
That looks like 11 - 94 to me (when the wheel was made) but as it appears to be a later one (by the disc locating rim) and your axle can't be an 17mm early one by that dimension, it looks as though wheel and axle are correct, and speedo drive isn't. That's supported by three things: 1) The gap and it looks wonky, 2) Wrong number, 3) It doesn't read right. Sorry, unless I can see the drive washer etc, I can't say any more. I think you should go back to the people that fitted it. In the meantime, make yourself a front paddock stand for about £10. AL
Not much help to humbug but some one might find it helpful. Unfortunately for humbug I see no other way than taking the front wheel off to solve the problem. Got worm gear out by knocking the spring pin out with a small nail. Be careful pulling threaded bit out with pliers not to damage thread, maybe reattach cable drive and give it a good waggle. The drive on the left is the original: 748209 17mm spindle 1992 900ss 17" wheel 70mm profile 18 tooth wheel gear (got a little number 1 stamped on it) 10 tooth worm gear. The drive on the Right is said to be off 600ss: 748216 17mm spindle 17" wheel 60mm profile 19 tooth wheel gear (got a little number 4 stamped on it) 10 tooth worm gear. Can't see any difference in worm gear both 10 tooth. So I plan to put old internals in new housing. As said before I think the difference in gear ratio is to compensate for difference in wheel dia but actually don't think they exactly match but not sure what it translates to in MPH. Anyway at least you got a pretty picture out of it. Cheers Gaz
