KTM 690 Subframe (tank)reinforcement kit was well thought out product from the beginning. But there was one thing I always wanted to make better. 2014 and 2015 bikes use lower tank bolt as mounting point for exhaust bracket. In OEM setup, countersunk bolt and countersunk washer are used to hold exhaust bracket. This OEM bolt screws into OEM threaded sleeve. Using countersunk bolt and washer KTM's engineers prevented bolt cap to stick out too much, possibly interfering with chain.
In order to prevent free play in lower tank joint, we need to swap flimsy OEM rubber bushings with plastic bushings, than to swap OEM threaded sleeve with one without thread and finally to swap two OEM bolts with one long bolt.
This long bolt is really long - between 150 and 160 mm, depending on washer we use. Finding M8 bolt that long, in proper strength class (10.9) is not an easy task. On the market, two models of bolts in those size could be found - allen head and hex head. Both could be used, but with flat washer over OEM countersunk washer. Allen head bolt would stick out too much, possibly rubbing the chain. So, I used hex head bolt. Hex head is shorter then allen head, so it is less likely to rub the chain. And that worked well. But, there was room for improvement.
Finally, some time ago I was able to source M8x160 countersunk washer in 10.9 class.
This was perfect as this bolt fits with OEM countersunk washer perfectly.
M8x160 countersunk bolt is a bit too long, as it protrudes on the other side few mm's more than it would be perfect. So, I cut 7 mm's off, and that does the trick.
Now lower assembly for 2014-2015 bikes is as good as it gets. Looking from exhaust side, there is no visible difference between OEM setup and Perun moto setup.
Downside is that this bolt is made only in plain, non-zinc coated version, so I had to apply zinc coating, after adjusting the length. Also, price of this bolt is ridiculous (for a bolt) - 10 times the price of hex head bolt of that length and quality. But this won't affect customers, because I won't raise the price.