This doesn't always work, I have done a number of upgrades and used straight tethers. On several of them I had to revisit them and put the 90 degree one back on. I had better luck when I stripped the rubber shield off the tether and used braided cable cover, it's much more flexible and allowed operation without the connector working out of the locomotive connector. I used Loctite 380 to secure it to the tether connector and make a semi-neat looking tether.
