Fixing a Pro-Form Tour De France exercise bike with broken lift motor

Something like £1000 when new. Ouch!

Fixing a Pro-Form Tour De France exercise bike with broken lift motor

Another random how-to in hope it will help someone save an expensive piece of kit. This all relates to Ver1 of the Tour De France, model PFEVEX71316.0 but looks like many of them use the same lift motor which was the problem.

About the bike – “ProForm TDF Indoor Cycle Trainers replicate outdoor riding experiences like no other exercise bikes can. To imitate the feel of road bikes, the new ProForm Tour de France 1.0 for 2016 has configurable gears, a freewheel clutch and a three-piece crank. It supports uphill and downhill training with an automated 15% incline and 15% decline, and its workout programs help make rides especially true to life. Built-in coaching programs facilitate interval training and use incline/decline settings from French tour segments. Additionally riders using the iFit app can get full-color interactive street views for Google Maps routes.” Or in simple terms it goes up and down and has gears to better simulate a real bike.

As purchased. Constantly up and down & angry!

Issue – This was being sold cheap as the lift mechanism had broken. When the incline is adjusted it started a cycle of going up a bit and down a bit on a constant loop and generally being a bit annoying. My plan when I picked it was to bin the mechanism, replace with a solid shaft and just use as a normal bike. BUT when I started to fiddle, I realised that unlike normal spin bikes that have a resistance dial/buttons to adjust the effort level needed, this used the incline buttons to adjust both the bike lift motor and the electromagnetic resistance motor that adjust resistance. As such I had to use the incline buttons and associated annoying up and down or end up with a really easy effort level forever. Not ideal.

Plans – Came up with a couple of options:

• Replace the lift mechanism – Part number 381160 Model LMA60305-A – looked around on internet and struggled to find a price. Pro-forma have a parts website but no prices or anything useful, just a number to call. I could find similar parts for anything from £200 to £450! The motors I found all had power cable and a feedback cable so indicated some form of position measurement or counting of rotations to know where it was on it’s linear stroke.
• Replace with a solid shaft (or simply disconnect the cables if the motor itself was solid) and see if it would still simply adjust the resistance and the software would just ignore the lack of motor or feedback without throwing up errors or refusing to work. I measured the full stroke of the motor and it was approx. 26cm at shortest and 35cm at longest. So a 30cm length of bar or box section with some hole either end would work.
• Try and fix the lift mechanism.

Strip the side panels off – This video https://www.youtube.com/watch?v=wKQaDYKE-aE shows the process well

Lift motor inspection –

• Once covers off, it became clear the motor function (or linear actuator really) was fine but the plastic casing had exploded for want of a better word. The bearing was loose, and a small circuit board was hanging on a wire.
• The small circuit board was some sort of measurement device that counted rotations of the shaft based on a small metal insert in the plastic collar. Presume some form of inductance or similar.
• I tested the unit by holding the circuit board close to the plastic collar and operating the bike incline buttons. It all seemed to work as expected, with the bike rising slightly, then stopping. No annoying beeps, no bouncing up and down. So if I could find a way to repair the plastic housing and hold the circuit board in correct place it might be repairable.
• Now to remove the lift motor and have a look.

Lift motor removal –

• Disconnect cabling first. Take photos. In my case there was a + and – connection direct to motor. Also a white cable from unit with a connection close to the unit to pull apart. The loose circuit board that counted the rotations was on a multiway ribbon cable. I traced this back and it plugged directly into the main controller board between the pedals. This required cutting a cable tie on the seat post stem that held all other main cabling.
• Disconnect other cable ties – there is one that holds the flexible gasket section to the motor and another on the cabling to keep it away from the mechanism.
• Bottom of motor actuator is bolted into the base plate, hidden under the plastic cover just below the flexible gasket sections. The plastic cover pulls up. Need two 14mm spanners for the nut and bolt.
• Top is held by a metal pin that is bolted into the frame by an Allen key bolt either end. Remove the bolts and then drive the pin out with a hammer and drift.
• Motor is now loose. Either fit a new one, or try and fix it.

Lift motor repair–

• The seller had kindly given the sections of casing that had exploded, or all that he could fine.
• I could piece it back together with a slot available for the counting circuit board.
• Why had it failed? Fiddling showed that whilst the unit is normally under compression so very strong, if the unit is placed in tension the bearing is only held in place by the plastic casing. If you were to lift the entire bike up from the saddle, as you might well do to tip it onto it’s front wheels, the weight of the frame is hanging off the plastic casing. This seems a poor design and I suspect the lift motor is a generic part used for many applications where it would never be in tension like this so would normally be OK. Not in this instance. Likely this also means any replacement lift motor would be of the same design and inherent weakness.

• To fix I glued the sections I had back together with two-part resin for strength, making sure the small circuit board was inserted.
• The metal tube on the rear of the plastic housing is bolted by four long bolts. I decided to use a metal plate to reinforce the glued side, and extend the bolt holes through the unit to sandwich the plastic casing between two metal plates. This way if you lift the bike weight is now transferred from the rotating shaft, through these bolts and directly to the metal casing of the actuator and bike frame, not all hanging off a plastic casing (hopefully photos show this better!)
• After some tinkering I went with a very thick machine washer that fitted over the strut, drilled two holes that lined up with the now extended bolt holes and then installed two long bolts to sandwich it all together. I used locktight and double nuts to ensure it didn’t work loose.

Reinstall –

• Reverse of removal, found it easier to attached the top first, then bottom, then connect cables.

Test –

• Plug the mains power in, turn it on and hope.
• The unit powered up and lift motor spun to lower the bike to lowest position then stopped ready.
• Fiddling with buttons and it all worked exactly as it should. Each 0.5% include increase have a small rise, no annoying bleeds, nothing else.

All works!

Fixing a broken treadmill – Nero Sport HU143NG Foldable Treadmill

Yeah I like tinkering in the garage and hoping this may well help someone in future.

Picked up a faulty treadmill (again) from someone local and figured I could have a tinker after the success of fixing my first one.

It’s a Nero Sport model HU143NG but as with a lot of treadmills they seem to a generic model and available under various brands.

Fault – dead. As disco. That was all I was knew.

Step 1 – Basic Check

Plugged it in and turned it on. The power switch lit up so it wasn’t something simple like the plug top fuse. It was getting power  to switch at least.

The control panel was dead, no obvious physical issue like a smashed screen but nothing on it, no display, no response to buttons etc.

Step 2 – Check Control Panel

Common faults can be the cable between control board and the main circuit board. Especially on folding units these can wear over time.

On this unit the display was wobbly and appeared to be missing the bolts to stop it rotating on the metal frame so could just rotate around and around until cable or screen breaks.

I took the rear panel off the control panel -lots of little screws.

First issue was pretty clear. The black cable with the white plug that connects to the circuit board was not connected.

Looks like the control panel has twisted around the frame enough times to pull out the cable.

Step 3 – Reconnect Control Panel and Test

Released the circuit board and adjusted the slightly pulled cable coupler socket and reconnected

Turned back on and screen powered up. Success!

It beeped constantly and displayed an Error. Bum.

This is where lack of attention wasted me time on the next few steps. Skip straight to step 7 if you want to save time!

Step 4 – Check Main Power Board

Couldn’t find anything on internet on the error codes. Some treadmills give useful codes identifying motor issue, speed sensor issue etc. This just said Error. So next thing to check was the main power board.

Took the cover off the motor housing. Standard arrangement of a big DC (direct current) motor and a main power board. This converts the AC mains power to DC for the motor among other things.

Main power board looked all OK, no signs of overheating, blown components etc. Most boards will have some large capacitors on that can hold charge even with power off. Don’t poke around like an idiot.

It did have a fair bit of hot glue applied to components on the board. It was unclear if this was done at factory or by previous owner in a repair. Given it was on other components on the treadmill I think it’s original.

It did have a separate fuse mounted on the board. I pulled this off and checked for continuity (is there a circuit through the fuse?) it was OK and hadn’t blown so pushed back in.

Not much else to check on board without a lot more effort or test gear.

Step 5 – Test Motor

The motor is direct current (DC) not alternating current (AC) like the mains so you can’t just connect 240V from the plug to it as you’ll fry it, start a fire and get told off for being an idiot and messing with electricity.

Instead I disconnected the motor from the power board by unplugging the positive (+) and negative (-) leads. Make a note of which is plugged into where if not clear. In this case the terminals were marker + and -.

You can use a small battery or a low voltage DC power supply to test the motor.

I used a 12V car battery charger, connected the crocodile clips to the terminals (all while off), red to red, black to black. If you get this the wrong way around it will just run backwards at this stage, no issue as you’re not running on the treadmill.

Turned on battery charger and the motor spun well, no noises, no burning smells etc. At very least I had a working motor to sell for spares.

Step 6 – Test Cable to Control Panel

Bum. The cable that connects to the screen from the power board is glued into it’s socket on the power board so couldn’t easily disconnect and check the continuity in the cable to determine if breaks in cable. Given the control panel was powered up and beeping it was fairly likely it was OK but would have been good to check. It’s a three core cable so without knowing detail of the wiring I presume it positive and negative power (+/-) and a signal cable of some sort so a break of just the signal could have a functioning board and errors potentially.

Step 7 – Stop Being Stupid – Safety Switch

When I first gave the unit a look over I noted it didn’t appear to have a safety key function. It didn’t come with a magnetic safety key and there wasn’t a separate board containing a reed switch (a switch that is closed in presence of magnet) as I was expecting. So I presumed it didn’t have a safety kill switch being a cheaper unit.

Then I looked closer at the control board and saw a tiny reed switch on the unit itself. Idiot.

Using a fridge magnet to close the switch I turned the treadmill on again. It worked. Error message gone, now just OFF, awaiting a start.

Step 8 – Put It All Back Together

Reassembled everything, put covers back on, all fine.

Step 9 – Kick Yourself

So the only things wrong with the unit were a twisted control panel section had pulled the cable out, and the magnetic safety switch was missing. I could have done skipped steps 4-6 if I’d bothered to realise all treadmills need a safety switch.

Step 10 -Tidy Up

Few bolts were loose or missing, so sorted them.

Installed some bolts and washers to keep the display in place for future and prevent a repeat of the issue.

Tensioned the belt. Looks like someone has fitted a slightly narrower belt at some point. Works fine but could do with being an inch wider.

For now using a fridge magnet but really needs a proper magnetic key, these are on eBay and Amazon for a few quid.