Top Case Weight Requirements

[tesla]

Yamaha's top case weight limit is 11 lbs and I assume this does not include the weight of the top case. How much does the factory top case weigh? Did the search and its not listed on Yammy's website. I have a Shad SH-50 that weighs in at a portly 12.2 lbs with a 17.5 lbs contents weight limit. Wife and I took a 850 mile trip over the weekend and had a total of 30 lbs in the top case which includes the weight of the top case. I know that this is right at the weight limit for Shads limit but what about Yamaha's limits for aftermarket cases? Do they have limits for aftermarkets?

 

[Bounce]

Yes there is a total limit. Load it until the sub frame breaks, then back off 15 pounds.

 

[wfooshee]

Keep in mind that the entire case is hanging out there behind anything structural on the bike. Have a look:

If you're using something attached to the stock rack (plastic,) it's notwhere near as strong as the Givi rack (steel.)

As for weight limits, Yamaha lists 7 pounds, Givi lists 13. Officially. We've all done more, usually way more. On the stock rack, though, I wouldn't load mine the way I do.

 

[FastSpy]

Are you saying that the three bolts that go through the stock rack do not bolt into anything other than plastic?

From the photo it appears they go into the rear of the subframe assembly right where you have the solid vertical line drawn.

 

[Bounce]

Are you saying that the three bolts that go through the stock rack do not bolt into anything other than plastic?

From the photo it appears they go into the rear of the subframe assembly right where you have the solid vertical line drawn.

i think he's saying that using an adapter with the OEM (plastic) rack lowers the max load even more than using a steel (after market) rack + adapter which then bolt into a light-weight aluminum rear subframe that can stress out when overloaded.

unloading the front wheel is a real possibility too, since all that weight is at the end of a lever where the rear axle is the fulcrum and the other end of the lever is wedged into the lower rear part of the engine.

push down hard enough on one end and unload the front wheel. push down even harder (bumps in the road, etc.) and eventually break the lever.

 

[robinh]

Most of the lads here in Blighty put Give luggage on. 2x 41 litre side boxes with 52 litre top box and then the put a tent and the wife on top of that.

 

[wfooshee]

*not quoting the picture yet again . . . *

Are you saying that the three bolts that go through the stock rack do not bolt into anything other than plastic?

From the photo it appears they go into the rear of the subframe assembly right where you have the solid vertical line drawn.

No, I'm saying the entire load is behind the structural parts. The bolts do indeed go into the rear of the subframe, but those bolts carry more than the weight of the load, because the load is entirely behind them, hanging out there in space.

There are reports of the stock rack breaking at the grab rails, which are loaded in tension by a top case. Once the grab rails fail, the subframe bulkhead is on its own.

Imagine holding a revolver straight out. Now hang a 10-pound weight from the end of the barrel. That strain on your wrist is what the subframe's rear bulkhead goes through with a heavy top case.

The grab rails are part of the structure, and brace the load by carrying the weight forward in tension. That's why I like the Givi rack better: it's steel, not plastic like the stock rack.

 

[Bounce]

Most of the lads here in Blighty put Give luggage on. 2x 41 litre side boxes with 52 litre top box and then the put a tent and the wife on top of that.

yeah but your whole island (from John O'Groats to Penzance) is about 828 miles.

el paso, tx to waskom, tx is the same distance and you've only crossed 1 state (at a posted 70 to 80 mph limit most of the way).

https://maps.google.com/maps?f=d&source=s_d&saddr=El+Paso,+TX&daddr=31.85402,-99.426075+to:Waskom,+TX&hl=en&geocode=FYCZ5AEdbSOn-SlpO_7Fiz_nhjEiAp2r44SR4w%3BFcQN5gEd5eAS-imhp_fg7iRXhjGlOVwxQ8_jpw%3BFSyW7wEdksNk-imx10VRqcI2hjHmSu28O2Jktg&mra=ls&sll=32.430977,-94.051208&sspn=1.174159,1.333466&ie=UTF8&ll=31.815665,-100.27344&spn=18.857878,21.335449&z=6&via=1

you can wear out a bike a lot quicker in the states it would seem. the sustained operation (without "resting the bike") might take a toll on the bike parts when not having to stop and wait for fairy rides and such.

 

[wfooshee]

To complete the hijack from "how heavy" to "how far" here's the pic I post to show them furriners what we deal with in distances here. The Europe outline is the same scale as the North America seen here.

 

[joebiodiesel]

I have a stock Yamaha top bag, and it has a backrest on it. If I can only load 11 pounds in it, I can't imagine that it would hold up to being used as a backrest. Hard accelerations and bumps alone would put WAY more weight than that on it, no?

Joe

 

[Fred W]

To make matters worse, Yamaha says that when you put their accessory top box on you must always remove the side bags.

Yeah right... :glare:

 

[stealth1]

I have a stock Yamaha top bag, and it has a backrest on it. If I can only load 11 pounds in it, I can't imagine that it would hold up to being used as a backrest. Hard accelerations and bumps alone would put WAY more weight than that on it, no?

Joe

No problem.

Just tie the box to your passenger and they will act as an extra structural support. :bigeyedsmiley:

 

[Zorlac]

"might take a toll on the bike parts when not having to stop and wait for fairy rides and such. "

I refuse to wait for fairies, period. :dribble: