I appreciate this should perhaps be in 998 section but I thought some previous owners or other forum members might have some thoughts on this... Re: 15mm offset brake discs / Ohlins forks. My front wheel in the picture has 10mm off set discs and while everything says they should be 15mm offsets they would not fit or so it appears. I do have clearance at the moment and the wheel free wheels but... I do have another issue: It seems the front wheel wants to shift to right (looking from the front) 2mm... I think I can obtain this but not sure I want to because it does not appear to be the norm. (we had to center the AP calipers on the race cars to reduce drag and friction etc so this is not something I am unfamiliar with, I did not expect to have to do as I was not told when I asked when buying the parts.. I was told they would bolt straight in so never checked them) Now I do not know why I do not need 15mm discs? or do I and I am missing some obvious. I have 1mm clearance on the left side of my discs in the calipers (to the casting) on both calipers and 3 to 4mm max on the right hand side on both calipers.. At the moment the wheel free wheels but this indicates it is not centralised. This is not as simple as slacken the bolts and pump the brakes. It does not want to move over for some reason.. I have not had time to remove the spindle completely and inspect carefully but have backed everything off and tried to move the wheel.... If the wheel moves to the right in the bike, 1.5mm I will have 2.5mm clearance on both sides of both discs in both calipers so this seems like the issue. I have no tensions on the forks, they seem to measure parallel where possible to measure. The the bottom of the forks (foot) measured to the wheel hub or disc face also seems to suggest the front wheel needs to move over. I assume the discs are the same distance from the center of the front wheel and therefore should measure the same from the inside of the foot leg foot. I have the same clearance between the speedo drive and the fork leg where this diagram shows a washer? See NO.2. I would need to remove this and effectively put it on the other side of the wheel and my discs would center in the calipers and all measurement would appear correct (with 10mm off set discs) It all just seems a little odd... something is not right to be adding or moving spacers (it's not a custom build) all the parts look unmolested so why won't 15mm discs fit?. I assume my front wheel is stock width, which I believe it is (as it was fine in the showa forks) and this is an FE/R set up, then it should need R discs? but at the moment the calipers would be locked solid if they even went on with 15mm off set discs because I don't have those kind of clearances. These forks are marked: on the inside of fork legs: FG8851 2003.10.25 and FG8851 2003.10.26 So what do you think? I tried taking photos of the calipers but the angles and light made it hard to see. I slid a metal rule in the gaps (like feeler gauges) to measure the clearances.
Where did you get the information that your bike had 15mm off set discs originally ? To my knowledge that off set was specific to the 748R, 998R and 1098R, not any other bike, Ohlins forks or not. Hopefully one of the usual suspects will have a definitive answer. Andy
:Facepalm: Missed that one essential paragraph. So slightly different question, did your set up include the R triple clamp and top yoke ? Not sure the FE had 15mm off set. I'm going to learn something from this. Andy
Did I say it had 15mm offsets orginally? if it reads that way my mistake sorry. It had showa forks in... so 10mm offsets. It now has ohlins forks as above... and should need from what I understand 15mm offset discs??? However these will not fit with the clearances I have and 10mm look like they do. However I seem to have a front wheel that looks like it may need to move, even thought this is restricted by the washer and speedo drive. If I remove the washer - if there should be one there it might move over but it is stubborn. I need to have the wheel out but it's a bit odd.
Andy I had the correct bottom yoke as advised I believe it was a FE bottom yoke, keeps the same top yoke... I asked the questions at the time but very valid comment. If the FE has 10mm offsets (that would explain this) I will check my receipts now to make sure if it has that info.
So we need an answer to the second question, is there a difference between the Showa and Ohlins triple clamp and top yoke. Mmmm, I'm going to get a beer from the hotel bar and wait a learened answer. Andy
I think you should be able to run the standard 10mm disk. Can I ask why you are thinking you need the 15mm offset disk?
Not really all the standard road superbikes from 748 thru to 1198 use pretty much the same geometry, yokes with a 205mm pitch centre to centre of the forks and a 36mm offset to the steering stem (the 749R is a special case in that the offset is adjustable 30mm or 36mm IIRC but that's done with an eccentric sleeve) the top yokes fork diameters are all 53mm, the bottom yokes for Showas are 53mm and 56mm for Ohlins
If they were 15mm offset forks then the 10mm offset discs wouldn't fit, 5mm (per side) is way too much to make it fit. If the spacings of the 10mm is good and the only issue is that the wheel is slightly off-centre then you just need to alter the spacer on the speedo drive side (if using the 916/998 'stepped' spindle). I fitted 15mm offset (1198R Ohlins) forks to my 916 and needed to move the wheel about 1mm to the left get the discs to sit dead centre in the calipers, I did this by removing material from the speedo side spacer (no speedo drive as using digital dash) and making a correspondingly thicker spacer for the other side - 1198 spindle has spacer on that side rather than a 'stepped' spindle. The 998 spindle will seat up to the wheel but only pull through the forks by the amount allowed by the speedo drive/spacer...
Dukedesmo, I agree with the above. I may even ditch the speedo drive and make a spacer / machine the one inside the speedo drive down and add one to the other side. I was trying to keep the stock clocks but was considering putting something else in.. Just seems odd when others have carried out this conversion to this bike - googled (ducati owners) state the 15mm off set discs are needed (a must) which suggests the fork leg feet, showa to Ohlins must be different or the mounting for the calipers. It's not as if my calipers, or forks have been milled on either sets of forks. As I said I never measured it because when I bought the bits from Ducati Parts, they said they would all bolt straight in.. Still not quite sure, as it uses the same top yoke - therefore these forks are the same center to center as the previous, why the front wheel would be off center, obviously there is some slight difference (which I can get around as you say).
If the speedo drive is putting the wheel off centre you can take 1.5mm-2mm off the fork side of it off without it collapsing.(25mm axle type speedo drive). I had to do that when fitting usd showas to a 907 to centralise the wheel.
The above should read, edit: (sorry it won't let me) Dukedesmo, I agree with the above. I may even ditch the speedo drive and make a spacer / machine the one inside the speedo drive down this will allow the stock spindle that acts as a spacer on the other side of the wheel to slide through 2 mm, pushing the wheel over to make up for it... thus allowing the wheel to center. And - having just had a quick look, the end of the spindle on the left will finish flush as I assume it should, so that works for me.... I was trying to keep the stock clocks but was considering putting something else in.. That speedo drive must be worth 0.25 HP ( joking) I will see when I get more time to look at it. Just seems odd when others have carried out this conversion to this bike - googled (ducati owners fork swaps for this conversion) state the 15mm off set discs are needed (a must) which suggests the fork leg feet, showa to Ohlins must be different or the mounting for the calipers. It's not as if my calipers, or forks have been milled on either sets of forks. As I said I never measured it because when I bought the bits from Ducati Parts, they said they would all bolt straight in.. Still not quite sure, as it uses the same top yoke - therefore these forks are the same center to center as the previous, why the front wheel would be off center, obviously there is some slight difference (which I can get around as you say). Oh well, this is what I am working with and they are not too far out now.
Not really Old R. They are not center so will likely touch if they move.. Id say if they move 1.5mm with the wheel to right. I will have a good 2mm clearance all round and it's how they Should be. Also pistons pads and wheel will be equal. Everyones a winner. Sent from my SM-G935F using Tapatalk
Maybe but on mine the Brembo HPK discs are thicker than the originals and only around 1.5-2mm narrower than the caliper cut-out (test fitted without pads) and I felt it was too close for comfort as the discs were almost touching on one side of the caliper, of course the pads would centralise them but I preferred it to start central meaning the discs could float rather than being side-loaded. Moving the wheel over to the left by machining the spacers made it sit central but the 1198 spindle (needed in 1198 forks) uses spacers both sides to centralise the wheel and it locks up to the same position regardless rather than with the stepped spindle of the 916 series that is effectively the RH spacer and only goes in as far as the wheel allows it meaning that on a 916 spindle you should only need to alter the speedo side spacer/drive.
Are you sure the wheel is off centre to the forks and not the calipers. On a different bike I've had to shim the calipers to centralise them on the discs
