I need a stronger solution for my convertible hubs D771SB/D772SB which have weak axle. My bike can take standard QR only. Is there any possibility?
Yes, you can go for 9mm through axle (TA) front and 10mm through axle rear. The dropouts on your fork and frame can take them so you can replace standard QR clamping for through axle system.
Pictures below shows what I mean:
In the image above you can a see steel version of TA and cassette body which assures maximum strength, but of course it is the heaviest solution.
You can go for lighter option though, by using alloy through axle and alloy cassette body:
The weight difference for rear hub is as follows (alloy option):
By doing some easy math is clear that adding only 26grams extra weight to the rear hub you get a strong solution for your wheel. It is very similar weight for the front hub, about 20 additional grams.
So, if you don’t mind some extra weight on your bike (around 50 grams for alloy execution), you can go for this suggested solution. It is definitely stronger than standard skewers.