Rear wheel spacer size? 10mm or 16mm?

[plox]

I'm working on my rear wheel after I found that the axle nut was tightened down far enough that the cotter pin wouldn't be doing anything. I thought I was completely missing the rear wheel spacer, but I found out that it's actually in the wheel on top of the bearing on the sprocket side. It's about 10mm, which seems like the stock size. However, when tightening the whole assembly down, I have too much slack in the system it seems. I tightened to around 40 ft-lbs and couldn't use the cotter pin since the bolt was too far down the threads.

Anyways... I ordered some used stuff on ebay and the spacer was a little larger than the one in the bike currently. 6mm larger to be exact. This gives me a little better clearance from the sprocket. to the swing arm. With the original 10mm spacer, I have almost no clearance, but there is no contact. I'd like to try to fit the larger spacer in and run with that just to be safe, but I may need to spread the swing arm just a tiny bit.

Basically, I am asking if anything has thoughts on this or has done this in the past? I need more washers or spacers on the axle to get the proper spread to tighten the bolt all the way.

[92xjunker]

I have beefed up my spacer as well. I bought all new axle parts and still the same issue. I think the replacement bearings are a little thinner than OEM.

[plox]

So, I ended up struggling really hard trying to get the wheel in with the larger spacer. I will need to spread the swing arm slightly or have a few more hands to have a chance at it. I went back to the smaller spacer and used an extra washer (same one that goes under the castle nut). I drilled out the center a little to be able to fit over the axle and put it between the spacer and the swing arm on the inside. It gave me a bit more clearance and I was able to get it in after a good while of struggling trying to line it up. Torqued the axle nut to spec (around 70 ft-lb) this time, so hopefully nothing will loosen up. Everything looks to be in proper working order now, might finally get to put some more miles on this year!