Would someone pls let me know if they can help me troubleshoot/repair a Fitness SD 520R recumbent exercise bike issue?

Hello Friend,  we've picked up the above bike for my wife recently and seemed to be working properly until the other day.  Seems that the tension/resistance function is not functioning now.  Have scoped out the web and there is little to no intel on this bike nor the manufacturer. Made in China, go figure.  I'm thinking something is up with the belt but there is no sound of duress and there seems to be some tension but @ the lowest possible level.  I am not extremely handy but I am willing to give it a shot.

thanks for your time,
Roland

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open vessel (author) 2 years ago

Hi Folks, remember me? I'd actually gotten the pedals off a while ago but only just recently had an opportunity to pull off the housing. I have a feeling after doing some reading that this most probably is a resistor or sensor or capacitor issue. I've attached a couple pix for ur viewing pleasure....as usual, any next steps support would be appreciated from the community.

thank you

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Excellent pictures..

It appear that your loading device is a friction break, which is adjusted by by a cable that is tightened by a Gear motor of some kind.

The gear motor appears to have a potentiometer to measure the fractional turn rotation of the output shaft.

The photos show the mechanism to be in a zero friction setting.

.

First need to determine if your problem is electric or mechanical.

Does the gear motor appear to activate when you press the up down control buttons ?

Does the gear motor wheel turn at all ?

Does the cable release causing the spring to pull up break shoes ?

Is this bike a plugin the wall outlet ? or powered by pedaling ?

open vessel (author)  iceng2 years ago
cheers ice! good to hear from you.....theres no plugin only batteries inserted into the read out monitor so i assume that it is a pedal powered? the gear motor/wheel/cable release do not seem to be functioning under any circumstance, i own a multimeter but am not sure how to do the testing to confirm gear box failure....

Then I am guessing your wife could only change load while pedaling ?

That cable seems to continue beyond what I thought was an electric gear motor ( this could not be powered on a simple battery ) you need to trace where that cable continues onward to a mechanism.

My thinking is there may be a very small solenoid that engages that cable when the up/dn button is pressed.

What I believed was a gear motor must only be a pot control to sense the load level.

Possibilities are the pot is dislodged and prevents the controller from adding load or the real mechanical load device is broken ...

open vessel (author)  iceng2 years ago

could the solenoid which you speak of be the one outlined in the attached doc? if so how would i test it so?

Doc1.docx368 KB

Sorry cannot open docx

open vessel (author)  iceng2 years ago

sorry ice, i've attached another and what i am speaking of is the silver dime sized circular piece.....

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That is a pot = Potentiometer = rotary variable resistor like you adjust volume on your High-Fi or radio.

What I believed is be a pot control to sense the load level. Possibilities are the pot is dislodged and prevents the controller from
adding load or the real mechanical load device is broken..

The middle terminal swings from one side to the other pin.

Potentiometer.jpg
iceng2 years ago

You have a failed machine.

Before you throw it out. Cut the plastic to gain access in such a way that you may be able to reassemble it later.

I assume you have looked into having it repaired ?

open vessel (author)  iceng2 years ago
"failed machine"? may I assume that means that this product is manufactured in such a manner and is so disposable that it is beyond repair?? having it repaired is not an option as I'm pretty confident that the costs associated will be more than what we've paid as it was purchased second hand (gently used I may add).....if cutting it up is the last resort then so be it, I'll try and make a fw more attempts @ doing it the "right way" and then go from there.....tx for your insight Ice.

another quest. to my experienced and distinguished Instr. colleagues, if and when I can reasonably dissassemble this machine, seems I've read somewhere that the magnetic tension on these types of bikes has a built in battery and possibly a resistor or fuse that requires replacement, any ideas folks?

thanks all,
Roland

Depends on how your wife adjusts the peddle load.

If it is a push button or dial it could be an electro-magnetic brake but if a turn-screw it is basically a wear out friction brake pad.

Never had a battery except for electronic instrumentation displays.

open vessel (author)  iceng2 years ago

it is a push button.

That sounds repairable. HOLD OFF cutting it up.

Can you access the electronics & wiring ?

open vessel (author)  iceng2 years ago

I'll have some time next week to remove all the screws and I estimate I may possibly be able to wedge the 2 plastic sides a hands width apart or so.....will respond then....tx

Sure we will be here :)

open vessel (author)  iceng2 years ago

Hi Ice, hope alls well with you and yours.....not sure if im utilising the message board correctly but i sent out a new quest. yester re. this sitch.....take care for now.....

open vessel (author)  iceng2 years ago

tx folks!

iceng2 years ago

Remove the wheel enclosure and show us several well focused pictures, as a start !

open vessel (author)  iceng2 years ago

sorry about pix, camera batteries discharged......

What can you see from underneath ?

open vessel (author)  iceng2 years ago

nothing @ all really, seems that the pedal is only fitted onto the square seat as pictured previously.....

open vessel (author)  open vessel2 years ago

Hi Folks, remember me? I'd actually gotten the pedals off a while ago but only just recently had an opportunity to pull off the housing. I have a feeling after doing some reading that this most probably is a resistor or sensor or capacitor issue. I've attached a couple pix for ur viewing pleasure....as usual, any next steps support would be appreciated from the community.

thank you

open vessel (author)  open vessel2 years ago

sorry, missed the pix,they are here now.....and i see that the belt is intact and the fly wheel is rotating freely.....tx again.

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open vessel (author) 2 years ago

just an update....found the below UTube vid that I believe speaks to the issue @ hand, apparently a "crank puller" tool is prescribed, I'll try implementing this method and report back accordingly:

+1

open vessel (author) 2 years ago

would love to, big prob. tho.....been trying to remove the encl. for the last 2 hrs b/c am not able to figure out how to detach the pedals.....if u have some idea pls let me know, pix attached.....

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Undo the bolt in the middle of the pedal. this may be a hex allen key or may be a star type Torkex fitting. Use the correct tool. the pedal should then pull off.

open vessel (author)  rickharris2 years ago

Hi Rick, I know it is difficult to see and I apologize for that, but I've already removed the bolt from the middle of the pedal but then I could see no further fixture to loosen/remove and there is no Torkex type fitting....I tried wiggling/jimmying/prying off the pedal(s) to no avail. I've attached a couple more pix and a couple capture's. Capture 1 highlights the screw that the bolt was removed from. Capture 2 shows the square seat upon which the pedal is pushed onto so it seems that with some force the pedal should be able to slide off but it is very difficult to get any meaningful leverage since the plastic housing enclosure cannot take too much pressure otherwise it will break....thank you.

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It's like on normal bikes too...

Screw removed, use a puller or pull yourself on the pedal.

Give the centre a good tap with a hammer (helps to have the nut on loose so you won't damage the thread.
After 2 or 3 good gangs the pedal comes off.

open vessel (author)  Downunder35m2 years ago

I've dealt with normal bikes previously, no comparison to this beast of a predicament.....I'll try the bolt on method and give it some whacks as you've suggested, hope I don't mar the bolt/screw tho....