Paddling tips, tricks, news and gear reviews from an Unsponsored point of view

Wahoo Kickr 18 Repair

Wahoo Kickr 18 Repair
Wahoo Kickr 18 Repair

I have had Wahoo turbo trainers for the last few years. The first being the Kickr Snap which worked well but its resistance would fluctuate quite a bit depending on tyre pressure and air temperature.

I decided in January 2019 to get a wheel off Kickr 18 as I really like riding on Zwift and the wheel off meant that I could almost fit and forget.

Within a couple of weeks the unit began to display the clunking and clicking that many units had suffered. The flywheel was also running with a bit of a wobble. A replacement arrived a few days after raising a support ticket and submitting a short video of the issue.

I have been using that replacement ever since and have covered almost 2000km on it for almost the last year and a half.

Last week it started to make a few slight noises that I didn’t like the sound of and a vibration could be detected through the pedals. The noise was a slight click and a rubbing/squeal from the belt drive. The squeal was noticeable when the flywheel was coming to a stop.

As it turns out is seems that the noises it had been making had been developing for some time but as it was gradual I didn’t really notice straight away until it was pretty bad. I didn’t realise this until it was fixed.

Given the current world wide lockdown situation all makes of turbo trainers are in high demand and I didn’t want to be in a situation of being without a trainer. Or even worse receive an equally broken replacement as a few users on social media have reported. Wahoo are also no longer sending out the DIY repair kit (K118).

Now to save you reading on I have diagnosed and fixed the issue with parts that are readily available and using tools that I had.

There are lots of great videos online that show the Kickr taken apart so I haven’t bothered to show that.

Kickr have acknowledged there is an issue with some units. It looks like my replacement unit also fell within the window of the dodgy batch.


Taking apart YOUR trainer is at YOUR risk. I take no responsibility for any damage or injury that may occur if you do what I did. Please presume that any DIY work may void your warranty.


To remove the cover and get access to the pulley you will need a 2.5mm hex key, and two differently sized Philips head screw drivers to remove three cover retaining screws.

Hex keys were needed to remove the original M6 and M5 two bolts. 10mm and 8mm sockets were needed to fasten in my new bolts. I also used a punch to help fit the new key.

A torque wrench was also used to ensure the new bolts were snug but not too tight.

THE Big Hammer


Once of you have access to the pulley wheel and belt tensioner. The pulley is held on with a M6 12mm bolt and the tensioner is held in place with a M5 12mm bolt. The tensioner is moved up and down with a long bolt. I used a marked to identify where the centre of the bolt was located. The tensioners M5 bolt was back off and the tensioning bolt was unwound with a 2.5mm hex key to remove the tension on the belt drive. The belt was then removed from the pulley.

Old bolts and deformed washers

Both the M6 and M5 bolt have washers that are deformed during fitting. In order to avoid this the replacement bolts were ordered, M6 x 12mm and M5 x 16mm with flanged heads and a larger M6 18mm diameter washer.

In the Wahoo repair kit K118 the bolt supplied for the pull wheel is a high tensile 10.9 flange steel hex which will take 16Nm. I originally used a black stainless bolt as pictured and torqued up to 10Nm but have since forced the 10.9 bolts and have replaced with a 16Nm torque setting.

New parts assembled

The Key:

When the pulley was removed the key simply fell out. I found it was undersized when I measured it so was never going to fit. 5 x 5 x 12mm replacement parallel keys were ordered from Amazon. You can get boxes that contain multiple sizes but you’ll only need the 5 x 5 x 12mm ones.

This is culprit if you have the banging or clicking sound.


The flywheel rotates on two doubled seal 6003 bearings from NSK. Both popped out easily enough when the flywheel and axel were removed. The flywheel side fit is much tighter. I have read some reports that this bearing needs a bit of coaxing to come out. It’s certainly a tighter fit than the other but I didn’t have to resort to hammering it out.

Both of the bearing looked OK and span freely but as they were out I decided to replace them as they did have signs of corrosion.

The two SKF 6003 replacements cost £5.66 each. I could have got them cheaper if I searched around a bit but I wanted them fast.

When they arrived I placed one (still in its plastic bag) in the freezer for a couple of hours. This was to shrink it very slightly in size so I could refit into the flywheel side recess with ease. The flywheel side had a tighter fit.

The bearings in the pulley tensioner are 6001 ZZ bearings. They have a metal shield that can’t be removed in order to inspect/regrease. Mine seemed fine but I imagine that the two that sit in the tensioner would be both difficult to get out and back in without the correct tools.

Putting it back together:

Bearings replaced with the frozen one dropped straight into the flywheel sided without issue.

Flywheel axel greased and refitted. I used Phil’s Waterproof Grease.

Key hammered into the keyway with a little Loctite 243. I used a hammer and punch to send this home making sure it was tight and as far back as it would go.

Pulley was refitted and bolted in place. The M6 flanged bolt was given some Loctite 243 and the washer refitted before doing it up to 16Nm as recommended in the Wahoo DIY repair instructions.

The pulley tension bolt was replaced with the M6 flanged bolt. I decided to use another M6 washer to help spread the load further, although a wide M5 washer would have been better. Again this was given some Loctite 243 before bolting it up. This bolt just needs to be tight enough to prevent slippage.

New parts in place

The belt was then fitted and the tension returned to its original position ensuring the tension was good. Both trainers I have had apart have the tension set at about halfway as seen in the image above.

I then tried spinning the flywheel by hand to ensure nothing was binding. Unfortunately the rubbing/squealing was still present. Changing the tension didn’t make a difference. A little research led to a fan belt video on youtube. As the video suggested you could diagnose a belt issue with water. I filled a water bottle with some tap water, protected the electronic elements of the trainer and poured the water onto the inside of the belt as I rotated the flywheel. Once wet the noise disappeared indicating it was a belt issue.

The water also flushed out a load of fine black grains of rubber that must have been from the belt. A bit of Aerospace 303, that I use for dry top latex seals, was sprayed on the inner side of the belt and excess wiped off.

Aerospace 303

Did it work. Yes, no banging clunking, squealing. The only noise is from my bikes drive train. I have completed numerous rides on Zwift without issue including a jaunt up Alpe du Zwift today.

No issues at all.

For the parts required I spent under £30 but have enough bolts, washers and keys to do another nine units. Excluding the bearings it is around £2.00 per Kickr.

I have since repaired another Kickr 18 with the parts I have sourced.


30th November 2020. Six months on and the Kickr is working as it should. It remains quiet and bearings seem to be OK. I have had the cover off a few times over the last few months to check on the Woodruff key and it hasn’t budged at all.

3rd January 2021. The trainer has been used more and more over the last month as outdoor cycling due to Covid and the weather has ceased. I completed the Rapha Festive 500 cycling over 500km on the Kickr during between Christmas Eve and New Year’s Eve. The trainer remains quiet.

Repair Packs:

I do have enough spares to do the bolts and keys for a handful of trainers. If you are in the UK and are interested in getting hold of some please drop me a line in the comments section below.


  1. Bob Goodman

    Great write up. Just a couple of comments. The pulley bolt is M6, not M8 as stated part way through your writeip. As well, there is a very specific Loctite product made for keyway installs, and it is much better suited than regular blue thread loctite. It’s Loctite 660.

    • Unsponsored

      Hi, thanks for the M8 spot. Thats been changed. I used 243 as I want the key/keyway to come apart in the future if needed. As my new keys are sized correctly its more belt and braces than anything. 660 is a metal replace and is high strength which may prevent the parts coming releasing in the future.

  2. Darin Schaffer

    This was an awesome read. I had the high pitched squeal and rubbing noise. I opened mine up to find a bent tension bolt and a tension plate that was not locked into place(thus the bent bolt). I was able to fix that which seems to have eliminated the squealing. I still have a rhythmic rubbing sound which I will try the aerospace 303 on. Wahoo has been pathetic on their customer service. Literally my only option is to pay shipping both ways, parts($.50), labor and be out a trainer for a month. I’m hoping the 303 works because I like the kickr but I am done with Wahoo. Maybe if they learn what customer service means, I might give them a shot but I doubt that will happen based on my interaction with them. So thanks again!

  3. Michael Marks

    Hey. Great blog. Looks like I will be going down same route. So this is a valuable resource. Can you confirm the size of the bearings so that I can by the correct ones



    • Unsponsored

      6003 for pulley/fly wheel. One each side.

      I got two doubled seal 6003 from SKF.

      • Matthew McGarry

        How do you remove the 6003z’s from the flywheel once it’s removed? Yours sound like they just fell out, while mine definitely seem to need some force but I don’t want to hammer away. Thanks

        • Unsponsored

          On another recent repair one was loose, the flywheel side. I gently tapped the other one out. It wasn’t tight at all. They certainly are not a tolerance fit.

          • Chrisd

            I got to this point having changed the bolt and key as you described. I chickened out on the hammering. My kickr was bought on eBay and also was out of warranty. So two months ago I took a video showing the bolt wobbling on the axis of the flywheel. They sent a courier to collect and two days later I got a new kickr 2018. Dropped dead with surprise.

          • Matthew McGarry

            Awesome thanks, I ordered some so when they come in I’ll get them to pop out. Seems like a cheap easy way to eliminate that from the list of things that make noise.

      • Matthew McGarry

        Any tips for getting the 6003z’s out of the flywheel? Did you have to hammer them out?

        • Unsponsored

          Hi. The bearing sits in the stand rather in the flywheel. Both just slipped out when I removed the flywheel.

  4. Eduardo Gómez

    Excellent article,
    I have the exact issue and I also had discovered that cleaning the belt mitigates the noise temporary.
    After removing the pulley, how did you manage to remove the axle and the flywheel? Mine is stuck and doesn’t appear to move outward.
    Finally, I want to add that I will experiment with a new belt since I am tired to clean it every 2 weeks.
    I found one compatible here:
    I will post once the belt arrive here.
    Best Regards

    • Unsponsored

      Good to see a belt can be had for not very much cash. For the axle once the key dropped out the flywheel and axle cam e out without issue. It wasn’t a tight fit at all. The flywheel is pretty heavy and needs to be pulled out dead straight. You may need to give it a bit or it may need to be persuaded.

    • Ks teo

      I would to check, have you had the belt replaced? Glad if you can share the result.

    • Terry Muldoon

      Hi Eduardo, great resource. My kicked had been rumbling despite the wahoo key fix. I’m going to order a new belt drive but interested to know how many ribs on the belt drive that you ordered? I notice the link gives different options. I’ve just taken my kickr 18 apart and put it back together so I don’t lose any bits and would probably count the ribs wrong anyway!

  5. Chris

    Can you confirm belt tensioner. Seemed mention 2mm and m2.5.

    • Unsponsored

      It’s a 2.5mm hex bolt, fits a 2.55 Hex key.

  6. Unsponsored

    Several hundred miles now completed on the repaired Kickr. No issues at all. Everything is working as it should, with the only noise coming from the 105 drive train.

  7. Chrisd

    Thanks. Did all as described except for bearings no problem following your excellent I nfo. New woodruff key much snugger. Better but not cured. When I look at the bolt without the pulley and then with the pulley and belt under tension in both situations the bolt is not turning true but wobbling along its axis. I cannot see that that could happen unless the nearest bearing was worn by the eccentric load on the pulley.

    • Unsponsored

      Thanks, glad it was useful.

      It could well be that you have a damaged bearing. Worth changing it f you can.

  8. Chrisd

    Thanks. When the pulley was off did the axle knock out to the other side through the bearings easily

    • Unsponsored

      Yes super easy on one once the key and pulley was off it drop straight through. A little tricky on the other kickr I repaired. A little persuading with a drift did the job.

  9. Paul W

    Not finding the 5x5x12 woodruff key… Anyone have a link where I can buy one? Thanks in advance.

    • Unsponsored

      Amazon have them.

      • Chrisd

        I bought from judd racing. No more expensive. Likely to be high quality. Came 48 hrs. Was nice snug fit. Easier to fit as rounded ends self aligns.

  10. Unsponsored

    It’s been 5 months since I carried out the repair. I decided to pull the Kickr apart to see how things are holding up and everything is A1.

  11. raffy o

    would replacing the belt for a new one and before putting it in apply the aerospace spray work well ? my belt is old .

    • Unsponsored

      The spray should only be needed if the new built is noisy.

  12. johnny

    SUPERB! Really appreciate the effort taken to document your experience. Will be a great service to all of us Kickr users out there. It was something that struck me, there’s very little information by way of service providers in Ireland who provide servicing of these units. Given that they cost nearly €1k new, Wahoo should have a distribution model set up for after sales servicing.

  13. mloewen

    Hey Unsponsored. Really appreciate this article.

    I’m trying to get the flywheel off, but it appears very stuck. After removing the bolt and washer that secures it, I tried to pull the flywheel out (dead straight), but to no avail. I even tried using a slotted screw driver to attempt to drive a wedge into the tiny edge gap between the main body and the flywheel. It simply wont budge at all.

    The only thing I can think of is to try to heat it so that it expands enough to move it, but it don’t want to risk warping it. Is there a trick to getting this thing off that I’m missing? Also, do you know where I could purchase a replacement flywheel if worst comes to worst?

    • Unsponsored

      The key needs to be removed from the shaft. This will stop the flywheel being removed.

  14. Nuno

    Hi. Between the internal face of the wheel and the bearing that is inside, there is a piece, kind of a “washer”, very thin. Mine is deformed and is the origin of the noises my kickr is making. Anyone knows where I get a new one? I tried but I didn’t found any until now, to be honest I don’t know how to search for it.
    Thank you 🙂

    • Unsponsored

      The washer is a wavy washer. It’s not flat. It is designed to take up any slop in the side to side motion of the axle.

  15. Brian

    Excellent post, thanks. I just replaced my bearings after reading this and it’s a huge difference. Everything seems perfect, virtually silent and no vibrations. One note of caution- I over tightened the pully bolt and the head sheared off. I was lucky in the recovery – I extracted the broken one quite easily with a reverse drill bit.

  16. Mark Maidment

    Loved your documentation. A grade.

    With regards to the pulley tensioner 6001 ZZ bearings, did you need a qty of 1 or 2? i think its 2 as the 6001 ZZ bearings are 8mm each and the belt is around 15/16mm

    • Unsponsored

      There are a couple in there. I didn’t remove mine. Seemed ok. Would need a bearing puller to remove.

  17. Max L

    Does anyone know the exact type/dimensions of the long tensioning bolt? I stripped mine over many attempts to find the perfect tension, now stuck with a loose belt and no way of addressing. Thank you.

    • Unsponsored

      The bolt is a m2.5 x 45mm in length. A bit longer or shorter would also work without issue.

  18. Max L

    Is there a thread spec?

  19. stuart


    great article, could you confirm if this is the same repair and bearings for the kicker core?


    • Unsponsored


      I believe the process is very similar as both units use the same parts/setup.

      • stuart

        Appreciate the quick response, my Kickr core started to make some unusual noises today, a squeally type noise, and a clicking…thinking it could be the bearing, did send a support request to Wahoo as well see if they have any idea

        thanks again

        • Unsponsored

          May just be the key. It’s worth have a look.

  20. DonaldL

    Is there a substitute for the Aerospace 303? Is Aero 303 the sane as Armor All? I just want to make sure I dont use the wrong substance and create a slipping issue by accident… thank you for the great writeup

    • Unsponsored

      From what I have read Armor All is a similar product. Both are water based and don’t leave a greasy film. Aerospace 303 works well though. I haven’t used Armor all in this kind of application.

  21. Tony

    Really useful- many thanks. Going to try this 2018 Kickr recently started clicking and all Wahoo will offer is replacement reconditioned unit which could be ‘pig in a poke’ from what I’ve read. Looking at your illustrations, realised you had a map of coquetdale under the bolts- if that’s your home turf, wonder if you might be open (post l;ockdown!) to a visit from a man from Prudhoe carrying a half dismantled kickr if I mess it up!

    • Unsponsored

      Actually based on Teesside. Had the map from taking photos of the Naughty Northumbrian MTB Enduro in 2019. I do get to Ryton fairly often with work.

      • Tony Newton

        Would certainly appreciate a more expert eye than mine on what’s causing the clicking rather than me just assuming it’s a loose woodruff key and making the wrong diagnosis! Would be happy to get the cover off and bring it down to Ryton (post lockdown) if you had a few minutes to look it over.

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