ST1100 Cracked Tail Frame

paulcb

paulcb

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Jun 4, 2013
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Location
Celina, TX
Bike
'97/'01 ST1100 ABSII
Came back last weekend from an 8 day trip with my brother to UT and CO and found my top box was a little ‘wobbly’. Pulled the rear tupperware and found this...

IMG_2139.jpg IMG_2140.jpg

I’ve read about this failure, but didn’t expect it. During our trip, we did ride quite a few miles on some pretty heavy washboard. I was usually able to ride fast enough to kind of float over it, but sometimes it was really, really rough. My top box had my clothes bag in it, weighing 15-20 lbs. Pretty sure it wasn’t fully broken when we left, but maybe it was already cracked?

Fortunately, I still have my ‘spare’ ST11 from my low side a few years ago, so just pulled the good tail frame off that one and got it installed. My son’s a welder, so going to get this one welded with a plate. Then I’ll still have a spare.

Note that I could see and feel the crack with just the seat removed, so check yours!

6/10/2020 Edit: uploaded better pics
 
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Yeah, I don't understand why Honda decided those plates needed holes through them, as that is where they always fail. I think the max weight allowable on that tail is 10 pounds.
 
Bush said:
Yeah, I don't understand why Honda decided those plates needed holes through them, as that is where they always fail. I think the max weight allowable on that tail is 10 pounds.
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maybe the same engineer decided those supports needed holes, and the saddlebag mounts needed more wobble.

Now that you mention the 10lb weight limit, I've toured around on mine for years with a fully loaded playmate cooler strapped up top on a homemade shelf. Might go take a look and see how mine look.
 
I looked in the ST11 owners manual and there was no mention of the top box load, likely because the bike didn’t come with one. Perhaps the load limit is in the paperwork that comes (came) with the Honda top box? The manual did say the saddle bag limit was 20 lbs each and the fairing pockets were 5 lbs each.

Don’t see how the tail limit would only be 10 lbs when the box itself likely weighs at least 5 lbs. Is the limit stamped inside the Honda top box? Can someone that has one check?
 
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dwalby said:
maybe the same engineer decided those supports needed holes, and the saddlebag mounts needed more wobble.

Now that you mention the 10lb weight limit, I've toured around on mine for years with a fully loaded playmate cooler strapped up top on a homemade shelf. Might go take a look and see how mine look.
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I think the Yamaha FJR 1300's had a rash of the same type failures. But it only happened with the Yamaha factory rear top box. I Remember some forum members trying to get their rear frame fixed on Yamaha's dime. Yamaha blamed it on the customer overloading the trunk so tuff luck.
 
The Honda Service Manual calls it a “center plate.” Anyone with a top case should check theirs... the 4 bolts for security (25 ft lbs) and the plate for cracks. Bill Rankin lost a bolt(s?) on one of our WeSTOC trips. I noticed his big GIVI was wobbling and drooping on one side. No damage, procured a replacement locally and carried on.

edit: capacity listed on the Hondaline topcases: the 21ltr (14.3 lbs), and the 35ltr (5.6 lbs)

John
 
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Have welded up two support brackets so far. Both cracked at the same point and was noted when the rear box moved more than normal.
 
John OoSTerhuis said:
capacity listed on the Hondaline topcases: the 21ltr (14.3 lbs), and the 35ltr (5.6 lbs)
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Will have to check the labels on inside of lid for that (got both cases at home)
Instructions of the Carrier Stay Kit indicate 10kg (22lbs) max load and 130kph (80mph) limit with accessories installed.

I never had a cracked center plate, but considering the impact on handling/safety, would I never carry much weight that high and that far aft to begin with...
(TC's are for lightweight stuff only, thermal liners, spare gloves, a few roadmaps, neck-warmer/Balaclava... heavy stuff goes into the tank-bag and the lower/forward sections of the panniers...)
I also suspect lounging passengers as cause for mentioned structural damage on this sub-frame... just imagine the mechanical forces with 80kg (180lps) mass added there...
 
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ST1100Y said:
but considering the impact on handling/safety, would I never carry much weight that high and that far aft to begin with...
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The only bike I had with a top case was my GL1000 and a Vetter trunk. A sporting goods store had a sale in iron plates for barbells and dumbbells. I put maybe 50-60lbs of weight in the trunk and headed home. WOW was that an interesting ride. I've carried a pillion or two (not at the same time) over the years, but that was a lot of weight in the Way Back and it let me know it. Never carried anywhere near that much weight again.
 
I have seen the cracks in the tail tupperware section of my 97. I didn't see a crack in the centre plate. Unless you have the proper rubber stops installed on the Givi rack the top case is prone to vibration. I know some people have actually bolted the case to the rack. Last year I started rethinking what to actually load in the top box keeping it as light as possible. I will admit that is no easy task! My rain gear alone weighs pretty close to that limit :( I have installed a charging station in my top box to charge camera batteries, and my second intercom or ipad. On a long trip it's nice to have the top box to carry a few extra things but mostly a place to lock up a helmet when you've stopped for a meal.
I now will only install the box for longer trips.
 
Timely post. Yesterday I put the ST on its centerstand and noticed play in the left grab handle. In the past I've disassembled that area to gain access on 2 separate occasions and the last time I used lock washers and Loctite on everything. Not a complicated process, but time consuming. So in prep for that I took a quick peek and see that the bracket is cracked this time, not just loose.

I'll look at pulling it off and getting it welded or something. Anyone in Canada have a spare one kicking around? If so, please PM me with your price and postal code.

PLATE, CENTER GRAB RAIL 77313-MT3-000
 
ReSTored said:
Timely post. Yesterday I put the ST on its centerstand and noticed play in the left grab handle. In the past I've disassembled that area to gain access on 2 separate occasions and the last time I used lock washers and Loctite on everything. Not a complicated process, but time consuming. So in prep for that I took a quick peek and see that the bracket is cracked this time, not just loose.

I'll look at pulling it off and getting it welded or something. Anyone in Canada have a spare one kicking around? If so, please PM me with your price and postal code.

PLATE, CENTER GRAB RAIL 77313-MT3-000
Click to expand...

For $86.00 US and still available, I'd be buying a new one, instead of a used one, where you may not know the stresses that it has already been under.

And . . . before installing it, I would have a couple of small plates welded over the hole areas. Of course, you could do that on a used one too.
 
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As nice as some of those 1100s are - if it were me I'd want somebody to cut and shape some 1/4" stock that would fit inside each bracket matching the contour. Weld or bolt them together. Finish it if desired - Krylon or powder coat or even machine turning. You'd have brackets that last as long as the engine or more.
 
Inscriptions (decal inside lid) state 6.5kg/14.3lbs for both, the 21 and the 35ltr case...
I'd also rather expect a [22lbs max load - case weight = max payload] calculation

I've seen bikes with the notoriou Givi Maxias, where the rear wheel just wouldn't stay off the ground when placed on the main-stand... and then owners are totally astonished, not only about stripped threads, broken bolts and cracked subframes, by also why head-bearings and fork-bushings are shot...

well...
 
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