1100 Swingarm mod for underslung gsxr caliper

[niclpnut]

what's the procedure for mounting the caliper stay bar on the stock 1100 swingarm for underslung gsxr rear caliper?

Is there a stock gsxr torque arm long enough to reach the engine mounts?

If anyone has pics/measurements of the orientation I'd greatly appreciate it.

Nic

[GregT]

It is possible to keep the underslung caliper as a floater by anchoring the torque arm to the bottom rear engine mount bolt.
Ideally you'd weld an extra bracket to the frame and use a longer bolt passing through a bracket each side of the torque arm so the mount is in double shear.

[niclpnut]

Just a bump for more ideas/info.

Nic

[GregT]

Just done it on a customer bike.
GSXR 750 18 inch rear, bandit disc, GSXR 750 J caliper, hanger and torque arm. Onto a longer bottom rear engine bolt with an extra bracket welded to frame as previoiusly recommended. Spacers made to suit.

Fits like it was designed that way. This would work with a 17 inch rear too.
This one was on an original GS1000 arm but it would fit the 1100 alloy arm just as well.

The owner may post pics when it's done...

[Reaper0001]

if you mount the break caliper to the engiene mounts then when the swing arm moves ither the caliper or the caliper stay arm will break from the tension between them

[kingofvenus]

if you mount the break caliper to the engiene mounts then when the swing arm moves ither the caliper or the caliper stay arm will break from the tension between them

Not if they are using the floating style caliper bracket that a lot of gsxr's used.

[pontiacstogo]

Not if they are using the floating style caliper bracket that a lot of gsxr's used.

Even if the caliper floats, the length and angle of the swingarm and brake stay is important - the stay should be exactly parallel to, and the same length (axle to pivot) as the swingarm. The two should create a parallelogram. If not, the rear suspension will lock up when you apply the brake.

At least, that's always been my understanding.

[akckhim]

I would think it should be attached to the swingarm only. Unless the rear is rigid.

[niclpnut]

that was my understanding but alot of people seem to be mounting the stay bar to a frame/centerstand bolt hole location.

[akckhim]

I would think if its attached to the frame it would restrict suspension movement while braking

[GregT]

Oh dear, the misconceptions here....

The caliper hanger (GSXR) has a bush in it which lets it pivot on the axle as the suspension moves...The front end of the torque arm has a ball joint which again allows movement.
While a parallelogram linkage is ideal, a non parallel setup works just as well - and does not lock up the rear suspension while braking - or introduce strange torque reactions.
I'm aware of non parallel rear suspension geometry on race cars, used for pro or anti squat, IMO the loadings put into a non parallel brake linkage are pretty low and any angular variation caused by suspension movement while braking is unnoticeable....

Been there, running that on more than one bike....

[gotgixers]

ALL 1st gen gsxr's came factory with the brake torque arm mounted to the frame .....
and a floating caliper mount ...