Are there special heavy-duty front derailleurs for recumbent trikes or recumbent bicycles?

Question

I have a "normal" short wheelbase highracer recumbent bicycle (Radius Hornet I) for about 20 years now, so I'm generally used to recumbent-specific things. But since recently I also own an older, pre-owned (adult) KMX recumbent trike from the estate of a deceased friend. (Seems to be an KMX X-Class from 2003 to 2007.)

On the first tour with the trike, I noticed that, if I forgot to shift down on the front derailleur (labeled "Shimano Altus") in time before going uphill, I can't shift down anymore when already going uphill, because if I push into the pedals quite strong due to going uphill with a high gear, the chain just pulls the derailleur back into the position behind the biggest front gear, making shifting the front gears impossible until the hill is less steep again. (And I don't think that I'm too heavy for that trike with my about 82kg. :-)

Questions (and potential answers, but I don't know which of them might be the right one):

• Is this normal because maybe standard derailleurs just aren't made (or weren't made back then) for the heavy tensile load which can easily appear on the chains of recumbent bicycles and especially recumbent trikes? (If that's a nowadays solved issue, I wouldn't mind recommendations.)
• Or is this just a cheap derailleur which can't cope with that tensile load on the chain at all? At least Shimano says that the current Altus M2000 series is for first timers, i.e. probably rather cheap and not heavy-duty. (In that case, I'd be happy about recommendations for alternatives, too.)
• Or could it be a cheap and too stretchy bowden wire?
• Or is this something I can fix by adjusting some spring tension in the derailleur or so?

Additional information added after the first answer as there were some questions in there:

• The trike had a "service" at some local bicycle shop just before that tour. So I assume the derailleur is neither too dirty no missing lube nor defect in general. It also worked under other conditions, despite not always perfect.

• I usually ride the recumbent bike not in hilly areas as steep ascents are generally difficult due to keeping the balance is more difficult. So I never noticed such an issue with the recumbent bike even though while riding I see the front derailleur there, too. With the trike there's no need to keep balance, so hills feel like no more being an issue as long as my legs keep pushing into the pedals.

Answer 1

This is normal for front derailleurs - they can't shift under heavy load because you're putting pressure on the chain, and the front mech has to push the chain sideways with enough force to overcome your leg muscles.
The only way to get a good shift is to back off the chain/leg pressure, and that's not easy if it has already become steep.

I'm taking it that your existing bike doesn't show the same reticence to change gears at the front on a climb? Next time you're riding, have a think about when you change gear - I wonder if the added stability of the trike is letting you get further into the grade before you shift down, whereas the recumbent bike needs the lower gearing sooner to help maintain balance.

Adjusting spring tension anywhere won't help, although a good clean and degrease then relube may help. It is also possible that the existing front derailleur is damaged somehow.

Also check the "gear inches" value for both bikes - it may be that the trike has different gearing and combined with the smaller wheel rims it simply needs to be shifted earlier on the climb. Something like https://www.sheldonbrown.com/gear-calc.html can be very helpful here.