Alternate 1973 Side Cover -- why?

At first glance, these two 1973 TX650 right side covers appear to be identical -- but they are not...


The top cover stands "farther off" from the frame than the lower cover, due to extended tabs (top), and an extended arm (bottom)...


The rubber "carb damper" is also longer...


And, there is an added crescent of sheet metal to hide the gap that all of the extended stand-offs create.


Finally, the mounting bolt is longer on the extended version.
I believe that the extended side cover was a mid-year change. I am not sure, but I believe that only the right-side cover was extended. My speculation is that one of the components that gets attached to the right-side of the battery box must have grown in size, necessitating more room under the cover.


This is a 1972 battery box. You can see that 1972 already has the safety relay and regulator, and they never got bigger. So, maybe the mid-year 1973 right side cover was extended for some other reason? Thoughts?

I heard there was a difference between some of the early, 70-73, side covers. Never had the chance to see if it was true.

Both of those covers look to be 73 original........maybe that may not have been the case and one was painted

That’s really interesting. If you ever figure this out, I hope you’ll post the results. Could it have been to add air flow to cool electrical components? Perhaps they were experiencing some warranty related component failures?
We may never know for sure.

never seen one extended like that, 3-4 sets of 73 covers. IIRC the 70 use a smaller diameter bolt.

Off a police bike maybe? Would follow along with the extra electrics thought...

Dogbunny showed me those covers during my visit last month, and I gotta say it's a real head-scratcher. Tip-toeing thru the 73-74 TX stuff, the obscure 306-366-446-447 transitions, is terrifying. My original guess involved some sorta changes to the battery box, but the parts lists show no battery box changes for 72-73.

Just another coupla wild speculations.

The seat changed for '73. Maybe they wanted a better appearance/fit of the seat's overhang with the top of the side cover.

The '74 model would've been in development, nearing release. And, just like the inclusion of some XS2 stuff into the later version XS1B, maybe some upcoming 447 stuff was planned to make it's way into the '73, maybe using the obscure 446 number. One possibility would've been the new airbox, requiring more sidecover clearance, but then not actually making it into the '73 models.

Oh, well. At least this bumped the thread...

Thanks for all of the replies. I like all of the possible explanations. I'm glad that Gary and Skull weighed in, I thought that if anyone would know it would be them. I guess we'll never get to the bottom of this one.

A little more info: I noticed my extended cover a couple of months ago, and at that time, I examined every 70 to 73 side cover on eBay. Of course, the 70 and 71 covers are very rare, so there were very few on eBay. Not much of a sample set, but none were extended.
There was a pretty fair sampling of 1972 covers. None were extended.
When it came to 1973, there were about 3 or 4 extended covers for sale on eBay. All for the right side. That represented about one third to one half of the right-side 1973 covers listed. The sample set for 1973 LEFT-side covers was much smaller. I have always observed that there are far fewer left-side 1970-1973 covers listed on eBay than right-side covers. Who knows why? Anyways, none of the left-side 1973 covers were extended, but the sample set was small.
Finally, adding to the mystery, if you go on eBay right now, you will find that 3 NOS right-side 1973 covers are listed. And none are extended. Of course, those covers could have been shipped to dealers before the speculated mid-year extended cover change was made.

forgot i sold an old XS1B years ago and found some pics for the sale............

The 3 Tins on the right show the extensions around the carb area and the top center fixing bolt bracket can be seen to be sticking out a bit further on one of the tins........2 Rights and 1 left.

The bottom pic is from a 73 i downloaded from FleaBay...........left tin as well

Excellent pics Skull. So, both left and right "extended" covers were made...

650Skull said:

The 3 Tins on the left show the extensions around the carb area and the top center fixing bolt bracket can be seen to be sticking out a bit further on one of the tins........2 Rights and 1 left.

Click to expand...

I think you meant to say the 3 Tins on the RIGHT...
Yes, your pic seems to show a pair of red 1972 extended tins... which confuses things even more... who knows, maybe there are even 70 and 71 extended tins out there...
Sure would be nice to know why both regular and extended covers were made...

Yea right not left, Edited so i made the left right..............Those 2 right redish tins are primer paint.......

I would go with 2M's thought the tins were extended to match the straighter and wider 73TX seat



On the left or right now DB.......lol

Okay, cool, so only 1973 had the extended covers... Yes, I agree with you and 2M... 1973 had the wider seat... Until new or contradictory info comes to light, I think we have figured this one out.
I think the bottom line is that either the regular or the extended cover will fit up, but the extended covers will match the 1973 seat better and look better.