|
Alright, here's what I have to report:
1) I found a local place that, unbelievably, sells M6 x 1.00 socket bolts up to 110mm in grade 12.9 steel. About $1 a piece, much better than the huge costs online with shipping. I bought 110mm and 70mm lengths. The 70mm fit my two rear mount points without bottoming out or leaving too short of bolt left to get a nut on.
2) Using an M6 die, I was able to add threads to a standard Lowes 8.8 partially threaded bolt with relative ease. Trying the same with a 12.9 grade bolt == fail. Not a chance in hell, at least not with my friend's Craftsmen made-in-the-USA somewhat decent quality tap and die set.
That leaves us three options:
a) Get a coupler nut, and use two bolts to bridge the distance. Main bolt would go up into the coupler nut, then short bolt goes through cross bar from top into same coupler below. Downsides is lack of continuous bolt holding the whole thing together, and unlikelihood of finding rated coupler nut.
b) Drill the undertail threads out. Lets us use one continuous high grade bolt without any breaks. Downside is that it modifies the bike in a non-fixable way.
c) Forget the crossbar entirely and hope for the best. (Keeping in mind that the whole mount breaking loose could very well result in death.)
I'm leaning towards option B. Even though it is a permanent mod to the bike (which I have never done, and don't normally do if I can help it) undoing it would simply mean a nut and a slightly longer socket bolt. Should be invisible / unnoticeable both functionally and aesthetically in terms of selling the bike in the future.
What do you think?
(By the way, let me know if you need any of the aforementioned bolts. I will be going back to that local place, and could buy and ship them at cost to you.)
|