R

Randy Erwin

Active Member
Is there a recommended tension for the tail wheel cables? I bought a flying RV-8 2 years ago and have put about 160 hours on it so far. I recently replaced the stock Vans tail wheel with an Aviation Products dual fork model. The question of cable tension came up. How much slack, if any, should there be? Originally there was quite a bit, requiring a couple of inches of pedal travel before applying any force on the tail wheel steering horns. Now I have taken a couple of links out such there there is a small amount of tension on the springs on both sides. Taxiing seems to be a bit more precise and I am really happy with the change but I am wondering if I am doing any long term harm to the rudder horns or the tail wheel?
 
Hi Randy...

I doubt any tension / slack would cause "harm". it is really down to personal preference - some prefer slack, some want them taut.

I was passed a tip, and now pass that on, say when test flying someone's RV, that a good starting point is with the tailwheel straight, you can move the rudder approx half the rudder horns width each way. I find that about right for me... am sure others will disagree :eek:
 
Check to make sure the rudder deflection is not hampered by the limitations of a tight chain. On my RV-4 my chains/spring is loose enough to allow for maximum slip and a 180 on the ground when taxiing.
 
Thanks for the replies fellas. I'm pretty sure that there is no restriction on the rudder movement by the chains while in flight, however the tail wheel will be moving with the rudder. On the ground it feels like I have much more positive control of the direction I am going - or want to go. I can definitely feel the spring tension in the pedals now and the slightest pressure results in a change in direction. I guess the real test will come when I am faced with that unexpected cross wind landing at an unfamiliar airport. I'll let y'all know how it turns out. :eek:
 
caution on taught cables

Remember that when the tail is on the ground, the tailwheel spring is deflected some, and tends to add some slack to the cables/chains. In flight, the cables or chains will be tighter.

It is best to jack up the tail so the tailwheel is off the ground, and make sure that there is not any significant tension in the chains, or it will put a lot of load on the lower rudder hinge pivot and wear it out.

Set it up with the tailwheel off the ground, and just a very slight amount of slack. Then, with the tailwheel on the ground, there will be some slack. Some pilots like more slack than this, but you should not have less.

A single steering link avoids this problem of course. (But instead, the tail wheel is probably turned slightly in flight, with a very slight drag increase - doubt that is measurable)
 
Timely post.

I been running mine tight and I'm thinking about loosening them a little.

Based on this post, I'll try some of the suggestions listed.

Thanks guys for reading my mind again!
 
panhandler1956 said:
Timely post.

I been running mine tight and I'm thinking about loosening them a little.

Based on this post, I'll try some of the suggestions listed.

Thanks guys for reading my mind again!
Click to expand...

After less than 100 hrs on the hobbs, but lots of landings, my chains went from tight to loose. I guess that chain can stretch pretty easy. I had a larger back seater in yesterday and landed 3pt, tailwheel slightly first and it shimmy'd a little and then didn't steer great on rollout - had to get into the brakes to hold it straight with a 10kt direct crosswind. Also, the stupid chain clip got turned around on one side as it's prone to do so that might have been the issue.
 
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