GT550 vs GT750 4LS front drum

[Acebars]

Would anyone be able to tell me exactly what the difference between the GT550 and GT750 drums are?

I am told the 750 is wider.

Is it a case that the hub itself is wider? Or are the plates just wider near the axle? Are the internals the same etc.? Would be appreciated.

[Acebars]

I think I found the answers.. it's the plates.

[canaletto5]

Hi. The 750 hub is wider but it is also of a smaller diameter than the 550. They are not interchangeable in any way. The 550 hub is common also to the 380 and 250.Kev

[Acebars]

Thats odd, the part numbers in a parts catalog for both bikes were the same online.

Are there any visual tell tales of how to spot a 550 vs a 750 hub from sight? Fin numbers or something?

[canaletto5]

Um no, visually, they look very similar. The 750 brake plate is about 19cm in diameter whereas the 550/500/380/250 is about 20cm. Kev

[Acebars]

Could anyone let me know the width of a GT550 drum and it's plates at the axle hole? That would let me nail it for sure, I'm looking at buying one now.

[Alan H]

I know the early 550 drums were not as wide as the later ones. Not sure of the measurements.

[Acebars]

Well I'd appreciate any measurements that enables me to identify it, preferably 550 measurements.

The hub I'm looking at has no axle so a width measurement would be great without axle..

The plates are the same

The 750 brake plate is about 19cm in diameter whereas the 550/500/380/250 is about 20cm

This doesn't strike me as correct, both 550 and 750 are 200m brakes.

[heathcliffe]

ive always been of the opinion that 550 and 750 front ends are they same i havent owned a 550 J' so i cant state definitively on that but they ought to be manufacturers are all about saving money so it doesent seem logical for the japanese to make 2 different front drum units for the 550 and the 750 when the rest of the front end is the same?,380 J' drum braked bike yes i can see that because they were not the same front end as the other two,ive bought later model front and back wheels for 750 that came from 550 because they are they same .i am forunate in having a copy of the fitting guide leaflet from Suzuki for the optional disc front end that could be bought as a kit back in late 72/73 to fit to GT380/ 550 and 750 drum braked machines this one is for 380/550 the 750 had a different instruction leaflet purly because it had twin front discs to fit unlike the other two which just had one, in the instruction leaflet is a complete list of parts that was in "the box" for 380/550 disc conversion so have a look and see if it has any measurements on it, double-click to fully enlarge
regards
Glenn.

[canaletto5]

I've been talking about the back drum !