As I was stripping the engine for cerakoting, all the bearings had to come out. It will be a clean rebuild with every bearing and every seal changed. May as well!!... though I am finding out that there is a lot of bearing ££££ in a Ducati engine! The bike is a 888 SP4, so 32 years old. Most bearings are quite standard and the same references can be had from bearing suppliers, though I could do with some confirmation from people in the know. The big end bearings are angular with reference RHP 7207X2 TB and 7307X2 TB I am going to get them from Ducati dealers, but I only seem to be finding the references 7207X2ETN and 7307X2ETN. Same sizes, same specs it seems. Do people know if there is a difference? I have also noticed that the gearbox bearings are the reference NU203ECP/C3 (which can be had), but it seems like Ducati has moved to BC1-0538 (same dimensions), which are quite a bit dearer. Do people know the difference and if it is worth going for the BC1 bearing? Thank you p
Yeah - all that was in there was SKF and I am putting SKF in. No cheapo, it is a false economy. Interestingly though, most seals are CORTECO and most references have been discontinued. I am thinking about getting all of those from Ducati and record all the equivalence. Alternatively, 123Bearings have a good range of seals for all those sizes in NBR and FPM.
Quite possible that some of the reference details have changed for some reason over the last 30 plus years? If you're sourcing from established and experienced Ducati dealer like Moto Rapido or Snells then I think you can be confident that any differences in the description are because of updated parts.
Not sure why ducati changed the numbers but you can get "equivalent" mains from a bearing supplier BUT they have a different contact angle on them so be careful.
Just to be clear - I am replacing SKF with SKF and same references. Interestingly, it seems like the Gearbox bearing was changed. The one I showed in picture states 2nu03EC but the inner sleeve on the shaft says NU203ECP/C3 and you can get those. But Ducati seems to sell BC1-0538 now which seems identical and such reference is available in the public too. So, I am curious if there is a difference between them and a reason for the change. On the mains, I am not finding information on the difference between the TB suffix and ETN topic. I will order from Ducati and see what I get dealt. I was just curious if somebody was in the known
Sometimes the difference can be in the cage material, different spec of plastic or metal, depending on previous service history feedback.
Yeah - I will report back when I get those. One thing that I am amazed about however, it looks like most of the bottom end architecture of a Ducati, from a 1992 888 to a 2007 1098 and including even some Desmodue does not look so fundamentally different.
From memory, the references on the mains are contact angles but more importantly, rated speed. Back in the day folk were rebuilding 916 etc. with cheaper bearings that were “almost” the same. The difference was a lower rpm of about 4000rpm. They didn’t last long, especially after the running in period. At the time, my bearing supplier wanted over twice the cost of what Ducati were selling them at for the correct bearings. I would only use oem. I won’t fit anything anything other than oem if customer supplies either. Been there done that and when it goes bang, it’s always been my fault LOL
Desmophil, I presume these bearings are the same as in the 900ss casings. Please confirm, but if so see below the old ones I took out of my 92 900ss. The bearings come with a centre cylindrical piece which you just take out. Hope this helps and does not confuse. Cheers Gaz
I got my main bearings from Anglia Bearings. They knew exactly what I was after and had the exact bearings in stock. Well they actually had all the bearings and seals in stock and most of them were cheaper than Simply bearings or Bearing Boys. The roller bearings were a tad more but I bought them all from them. The 2 main bearings were just over half than Ducati's price. Here is their website. https://www.anglia-bearing.co.uk/
Thanks - The NU203 ECP/c3 is for the gearbox. Actually the insert is useful because it sits at the end of the shafts. I think that the RNU202ECP is used on the layshaft and on the the cambelt caps
All the bearings in my 916 w That's right, 2 off them need the inner race and C3 is the clearance, the timing shaft and camshafts run directly in the bearing.
I have just been through some of this bearing info hunting. I found this old RHP doc with suffix details. Shows both X2ETN and the X2TB
I've always shopped around for the best prices for my bearings, apart from the Mains for Ducati's I always use genuine items for those. Standard mains on 99% of Ducati motors are ball races, the roller mains are usually for Corse/race motors that are stripped regularly and aren't a good idea for road based motors IME and I have tried them, so I'm using personal knowledge here and not just something I've read somewhere. The standard ball race mains were good enough to handle 169rwbhp on Troy Bayliss's British title winning bike. One of the mains used in the 748,851,888,916 and 996 etc is exactly the same as both of the mains in a Bevel Twin motor. Steve R
WOW - awesome - this answers my curiosity definitely and I am going to save it. It is about the material and location of the cage. For the main bearings I will order from Ducati anyhow and I am curious if they supply the TB still.
