Swing Arm Swap pre to post?

[scarface]

Will the post swingarm fit on the pre?with out any modification?

[Kreylyn]

Will the post swingarm fit on the pre?with out any modification?

No, it's 5mm wider at the pivot.

The brake arm is also mounted on the bottom of the post vs top on the pre.

Swap the whole rear is simple to do, but you need the post swingarm to be cut down by 2.5mm either side of the pivot, brake system from the post or change the location of the brake arm mount on the swingarm, and post dogbones/linkage. Shocks are interchangable.

Krey

[Breeze]

What Krey says is correct. If your wanting to upgrade to the wider post rim and tire size, you don't need the swinger to do it. I'm running a pre with the post rim and brake assembly. The change over is very easy and pain less...

[scarface]

What Krey says is correct. If your wanting to upgrade to the wider post rim and tire size, you don't need the swinger to do it. I'm running a pre with the post rim and brake assembly. The change over is very easy and pain less...

With new tire and brake assembly what did u do for the brake support?

[HemiKat]

The wheel is only wider at the tire mounting point. The hub is the same width so they are basically a simple swap, you can use all your Pre parts, incluing the brake caliper.

[scarface]

The wheel is only wider at the tire mounting point. The hub is the same width so they are basically a simple swap, you can use all your Pre parts, incluing the brake caliper.

So I could put a chrome post rim on with no problem. By how much would it increase the tire size?

[HemiKat]

So I could put a chrome post rim on with no problem. By how much would it increase the tire size?

I personally havent done the swap but everyone Ive talked to says its a direct swap. You will be able to safetly go up to a 160 tire on the rear.

[cintidude04]

you can, with no modification, run up to a 160. but there are a few brands that make a 170 to fit the 4.5 inch rim. for that you will need to modify the existing brake arm, or switch to post brake system which is what i am thinking of doing (not for the wider tire really but for easily using a rear hugger without having to cut it). but remember if you switch to post wheels the pre rotor has a different bolt pattern. this is only important due to the post rotor being slightly smaller width wise, which ive been meaning to ask krey if he knows any other bike rotors that have the same bolt pattern but are closer in width. and if i read your previous question correctly you were asking about using the post brakes on the pre an how to mount the arm to the pre swingarm. I have not done this yet but have been thinkin upon the subject. my simplest solution; measure and measure then weld your own bracket onto the swingarm. (notice measure was typed twice, not a misprint, save yourself a little hassle lol.)
hope this helps

Cintidude04

[Kreylyn]

The differnce between the pre 250mm OD rotor and the post 240 OD rotor is minimal. Your looking at 5mm offset or differance, and isn't a concern. There is like only 1 or 2 other bikes that use a 250mm OD rotor, and they are all exactly the same as the Kat. It's the same rotor.

If your talking thickness... ( I think the post rotors are also a little thinner?) then the older 240mm OD rotors from like a early 90s GSXR will match up in thickness... but again, it's not really enough of a difference to cause any major issues.

Mounting a post caliper on a pre swingarm would require cutting and re-welding the arm mount point on the swingarm. If you don't want to weld at all, then get a post swingarm.

Krey

[cintidude04]

me personally, i feel more comfortable welding than trying to shave 2.5mm off each side of the post pivot point so that will be the way i will perform this if i do it. i havent measure the thickness but by eyeballing it the post rotor is quite a bit thinner than the pre, enough so i figured i may as well mention it.

[Kreylyn]

me personally, i feel more comfortable welding than trying to shave 2.5mm off each side of the post pivot point so that will be the way i will perform this if i do it. i havent measure the thickness but by eyeballing it the post rotor is quite a bit thinner than the pre, enough so i figured i may as well mention it.

Remove the pivot bushings, take a socket just smaller than the pivot tube that will sit against the bearings... lightly tap them further in. Check often the distance it's moved in until it's just 2.5mm from the edge. Do the othe side.... now use a grinder and make the tube flush with the bearings without removing any of the bearing edges. Final tuning could be done with a hand file or sanding disk. Debur/round the outside edge slightly off the tube. Remove the bearings. Paint, replace old bearings with new, and use the Pre center tube bushing (it's the right size).... and your all set.

This gives you the right amount of material to remove, makes sure the edges are straight and "square" as the bearings can't shift inside.... their edge will be as straight as you need.

This is not to imply that cutting off the mount and just welding it on another spot is any harder/simpler than shortening the pivot tube... Just saying it really isn't that difficult to do at all, and do it right.

Less parts needed though to mod the pre arm for changing up the location of the brakes to that of the post. All you would need parts wise is the post caliper.

Krey