Swingarm cracked...

[900Rebuilder]

Originally Posted by Kato

WOW Lucky you caught that !!!

That is an 851/888 swing arm and they were notorious for cracking, given the distance that the pivot has moved I would also have a good look at the engine casing just to make sure there is no damage ??

That arm is toast the effort/cost to repair if indeed it could be reliably repaired will make it unviable you will need to remove a lot of metal to get weld penetration while trying to keep it from worping and then linebore the spindal holes.

As for the bracing on a road bike it is purely cosmetic and you will not feel any difference on the street, however If you do trackdays and you run high spring rates, slick tyres and you are capable of running with the fast guys it will indeed have the desired effect.

The later arms toward the end of 888 production and susequently fitted to the Monster used a better grade alloy and no bracing, but no reason why you could not move the brace over to your spare arm if you really have to have it on the bike

Good to hear about the 888 arms as that's what I'll be running if I can locate the correct hugger

[Kato]

Originally Posted by 900Rebuilder

Good to hear about the 888 arms as that's what I'll be running if I can locate the correct hugger

As long as you keep an eye on it should be OK, the problem part is the cast bit welded into the end of the tube, Ducati changed the grade of alloy, the casting process and amended the design somewhere around 1990/1 and the later arms don't crack, the production non - braced arms also cracked but it was always claimed that the pinch bolts were over torqued and not that there was a problem in manufacture

For what amounted to quite a short production cycle, there are actually quite a lot of those braced arms about, reason being they were changed almost every race because of the cracking so teams went through 100's of them

Also had a similar problem with the SS swingarm but they useually cracked on the shock mount