I just ordered one of these "MudStop" covers today. I've done 650km in wet Cairngorms conditions and all off road so decided to strip down the R/H side, remove the cranks, thoroughly clean everything up and see what wear there was. These are my findings:
1- the "green Bosch grease" I packed into the void behind the circlip on the crankshaft was dirty on the exterior but like new once I'd removed the circlip and carefully cleaned out the void with cotton buds- so this is working well and has been packed out with the same grease.
2- the thin O ring was in bad shape. Fitted new one on reassembling.
3- 16T sprocket is showing marked signs of wear on the drive edge of the teeth (chain is still not 0.5% stretched)
4- Removed the Bosch seal and all looks well- cleaned it all up, regreased and refitted a new dirt seal. Assembled it all back together.
I then looked up Performance Line Bearings to see if Pete was selling an alternative to the "green grease" as I'd used up a small tube on 2 assemblies- to find this product "MudStop"
This is my main area of concern- the dust seal from Bosch is better than nothing but the plastic spins against the alloy casing and surely over time must wear the outer edge? I'd already planned a 600km service as a regular thing and see it as a weak point (though much better than no seal at all!)
So I ordered one today and shall refrain from using the bike until it arrives as it will then just need swapped over not cleaned up. Seems a much better design god knows why Bosch never did it, and it's a pity nothing similar for the LH/ crankshaft/casing is available. I'm considering putting on a new 16T sprocket at this time while I'm at it....?
Excellent post Barrio, at Performance Line Bearings, we have been packing the crank bearings and main motor bearing for some time now and although the original Bosch silicone grease helped for a while, it picked up dirt and disappeared over time. The new Bosch "green" grease is definitely an improvement. We also smear the outside of these bearings before fitting them and this seals the small gap between the bearing and the motor casing.
I too had the same concerns about the MudStop wearing through the motor case, I deliberated a lot before deciding they were a good product. I spoke at length to the manufacturer and fitted one before going ahead. The fact that these are officially approved and recommended by Bosch helped. Basically, there is a fair gap between the MudStop and the motor case, and when you fit it the grease squeezes out, right to the outer edge and seals it well. If grit does get behind it, all it does is takes the paint off the case. The case at this point is very thick and even in the worst possible conditions, I can't ever see it wearing through the motor case. Plus the fact that we have literally hundreds of motor cases, so if a product I was selling caused damage, I would give someone a case for free.
Just for your information, I'm sure the green grease Bosch use is Motorex Bike Grease 2000. I have tried this grease against the Bosch grease and can find no difference between them?
As Itchy99 said, please give us an update in 600km .