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Blog Date 18th June 2023

Well how odd.

First off we have another trip coming up in the not too distant future and we had noticed one of Sharon's tyres was getting just a tad thin in the tread department. She duly ordered and received a new rear tyre for the Z250SL. The only fly in that particular ointment is it's the front tyre that is worn. How the hell? I... well obviously I'd like to blame Sharon and call her a silly billy but there's this small, subtle, nagging doubt in my mind that I may have been complicit in this cock up. 

I mean we were both there looking at the same front tyre and front wheel but I can't help but think when she said "I'll order a new rear" I might have agreed with her. Look, I won't tell her if you won't OK? Anyhow that's now a spare and a front tyre has now also been delivered.

I brought the front wheel complete with the worn tyre, and the new tyre back home and fitted it here. The old one came off and the new one went on as easy as a pushbike tyre - I have a new technique see. I'm not yet ready to reveal my new technique until I've tried it on the much stiffer tyres on the 500 - but I am hopeful.

The new michelin pilot street on Sharon's 250
New rubber will keep her legal.

So that went OK. While the wheel was off Sharon with a tiny amount of guidance from me repainted the fork legs too. It's not a top-notch professional job but they look a lot better and will keep the corrosion worms at bay for a while. Sharon was freaking out thinking she'd made it worse and the whole bike was ruined. However once completed and fitted it'd take a close inspection to see the flaws. 

The front of Sharon's Kawasaki with the fork lower in satin black looking quite good
Looks fine to me.

I'm not one for precisely torqueing every nut and bolt and screw to specifications - but - when it comes to wheel spindles that hold wheels on and can potentially crush wheel bearings - I do use a torque wrench. Sharon has a torque wrench of her own plus she has the Kawasaki Owners Handbook which is surprisingly comprehensive. It has quite a few settings including the rear wheel spindle torque. But not the front. Gosh darn it.

Sharon's Draper Torque Wrench
Sharon's wrench is still quite shiny

A comprehensive internet search thence ensued. With the Z250SL not being a popular model (in spite of the excellent ride, perky performance and being all round good fun) we could not find a satisfactory, definitive and well-sourced answer. Sharon is the queen especial of Google, if it's online she can find it, and even she failed. 

I mean... it's a 10mm spindle therefore M10 thread. It's the same gauge and thread pitch as my CBF125's front wheel which is torqued to about 40 ft-lbs. We find quite a few similarly M10 threaded motorcycle front wheel spindles with similar specs so we settled on 40 ft-lbs. But... but, well, but. It's still not the true and definitive answer is it.

Out of desperation and curiosity I dropped an email to Kawasaki UK (customerservice@kawasaki.co.uk) with the specific model of Sharon's bike (Z250SL could be different across the globe, hers is a "BR250EF/FF") and a request for the front wheel spindle torque settings. We left it at that, not hoping for a reply.

And there it is! The next working day a reply from KMUK (presumably Kawasaki Motors UK). I quote...

Good morning, Ren.

Thank you for contacting Kawasaki Motors UK.

I can confirm that the front axle nut torque is 53 nm or 39 ft-lb.

I have added a list of some common torque value for your machine.

...end quote. 

Attached to this is a COMPREHENSIVE list of all the torque settings I can think of. It is a number of images which I presume is are scans from the official service manual. 

Now don't get me wrong - I'm not saying Kwak has come out and serviced the bike for free, given Sharon an official KMUK sponsorship deal and are now building a lowered Z400 specially for her. What I am saying is KMUK's response was prompt, to the point and the attached datasheets were above and beyond our expectations. Well done KMUK and thank you.

I did consider publishing the datasheets on here but I'm sure I would have fallen foul of some copyright laws. If you have a Z250SL BR250EF/FF - just ask me OK.

And yes, we were right. About 40 ft-lbs would have been fine, what's 1 ft-lb between friends. Still, it's better to be sure ain't it.

Sponsor a page - contact ren@bikesandtravels.com

Reader's Comments

Upt'North ¹ said :-
Well done to Kwakisaki indeed, it's exactly what you would hope for from a manufacturer but would rarely expect. This is the problem with the Internet of course, too many darn blogs and forums full of crap and no real decent info. Then if you do manage to find that elusive setting some muppet will immediately state if you use the figure you'll lose your job, your significant other, your best pair of Levi's and the sun will never come up again. Hell, you might even have to sell up and move to the EU!
Well done to the dynamic duo. She can paint my legs anytime she likes.
26/06/2023 09:34:33 UTC
Glyn said :-
There are many that are disrespectful of published torque figures and I've heard a lot of owners say that they "do it by feel" as they have a "knack for these things". Getting things tight is not really an issue but many bolts are "stretchy" and if you overtighten these it can be as bad as leaving bolts too lose. I always use the torque figures and am often more surprised at how low the tension feel is rather than how high. In those circumstances I would have certainly overtightened them had I done it by feel. Cover the bolts in copper grease and a lot of this goes out of the window because the threads are too slippery. I still use it myself though. Apparently there is a better aluminium based anti slip so I'm hoping one of our number can tell me what it is. Agree fully with Up't it's good to hear of help from an manufacturer, Kwak have won themselves a few points here.
26/06/2023 10:28:39 UTC
Ian Soady¹ said :-
Of course most of the nikes I ride have no published torque figures so feel is all I have. I do use a torque wrench on more modern machinery but have to say not all the time. You're quite right about lubicating threads making nonsense of published figures, and the same can be said to some extent about loctite etc.

I have an aerosol of the aluminium anti seize you mention which is used among other things for stopping alloy car wheels from seizing to their hubs. I prefer it to copaslip as that seems to get everywhere and is a pain to clean off. See link for one type.
26/06/2023 13:14:47 UTC
Ren - The Ed¹ said :-
Torque settings it seems are like the oil debate to be found on many a forum (and here). Opinions, opinions, as far as the eye can see and some of these opinions even have merit to them! Dry or lubricated in my opinion would make a difference and this is backed up by some manuals stating whether or not the torque values are "dry" or "wet". In which case if dry or wet is not stated then your guess is as good as the next person's. We can then argue what is even meant by dry and/or lubricated. Dry and clean? Dry with a light film of corrosion? Lubricated with engine oil or moly grease or coppaslip or even allyslip?

There is no such thing as a straight answer, life is complicated and your experience will not be the same as someone else's.
27/06/2023 07:37:48 UTC
ROD¹ said :-
Ren, Does your new tyre fitting technique involve heavy duty cable ties?
I am going to try them for the first time this week, so any tips before your full post would be appreciated.
27/06/2023 08:06:13 UTC
Ian Soady¹ said :-
Having read your tale I confess I can't quite see how you can "crush wheel bearings" as there is always (well nearly always as someone might have said) a substantial spacer between the bearings so as you tighten the nut you're merely squeezing the inner races against that spacer. You'd have to be stronger than I am to crush those.....
27/06/2023 12:09:18 UTC
Ren - The Ed¹ said :-
Rod - I'm not using cable ties specifically - having used them in the past with "varying" results - not all good results. The key, the absolute key is to ensure BOTH beads are in the well of the rim.

Ian - that substantial spacer is there quite true. I can also understand that'd take a SUBSTANCIAL amount of force to crush that. However not knowing what that force is I'm not wanting to find out. Yes, yes OK you're far more likely to strip the thread long before you crush the spacer. My recommendation still remains - If your manufacturer recommends XX foot pounds / newton metres / kilogram yards / BSTNs (British Standard Nipple Twists) then I reckon they know more than I do.
27/06/2023 13:04:21 UTC
Upt'North ¹ said :-
Oh Ian you poor naive soul, you've never come across truck mechanics. They can break anything.
How do I know that?
27/06/2023 13:27:04 UTC
ROD¹ said :-
Ren, I tried the cable ties today, but it did not work too well. The BMW rear wheel (my nemesis) does not have a very deep well, so as a result the tyres are a very tight fit.
Posted Image
27/06/2023 20:31:02 UTC
Ren - The Ed¹ said :-
Not very deep?!?! Like a cave that!

I do wish wheel manufacturers would make the well just a little deeper. Or... is there a reason? It has crossed my mind it may be a safety thing - ie if the wheel had a truly deep well which made removal a doddle is there a risk during a deflation incident (puncture to you and me) that the tyre could just fall off the rim and tangle in the swingarm? I don't know, what I do know is it's blimmin 'ard wuk.
27/06/2023 21:07:03 UTC
Glyn said :-
Pray do tell, what is the heavy duty cable tie method? Is this for removal and / or fitting of the tyres, tubeless,tubed or both? I've missed something here.
28/06/2023 08:07:06 UTC
Upt'North ¹ said :-
Glyn, just Google zip tie motorcycle tyres on YouTube.
You basically use zip ties to squash the shoulders of the tyres. It can make getting the tyres on and off more of a DIY experience. An even better tyre fitting experience can be ascertained at Little Richies in Hartlepool. No zip tyres required and flowing tea.
28/06/2023 09:30:07 UTC
Ian Soady¹ said :-
The little ribs just outboard of the well are intended to stop the tyre rolling off the rim but also make mounting / dismounting harder.
28/06/2023 10:17:26 UTC
nab301 said :-
Quote Ren " I have a new technique see. I'm not yet ready to reveal my new technique until I've tried it on the much stiffer tyres on the 500 - but I am hopeful."

I'm looking forward to the reveal Ren, I've been putting my recent tyre fitting difficulties down to advancing years , I used to be able to fit new tyres even the 180 rear on my BMW with my size 12's but now I'm thinking that tyre construction has changed . A recent puncture on my 125 (tubeless) required the use of my bead breaker, It wouldn't budge and it wasn't on the wheel that long either.
28/06/2023 15:52:44 UTC
Ren - The Ed¹ said :-
I have a home made bead breaker nab301 and I wouldn't even attempt to start a tyre change without something similar. Them beads are really on there, and they need to be. I also have not found a way or getting the tyre back on the bead without an airline - so I now have an air compressor. No... I'm not trying the spray gas and match technique, I have visions of hospital and doctors removing shards of rubber from my face and nether regions.

While I am dedicated to this blog I'm also dedicated to my fiscal needs. I'm afraid I'm not going to fit a new tyre to the 500 until one is due. Aaaaaand that won't be TOO far off, the front looks like it's got around 2k miles left in it. I shall try to record the event both here in writing and images, and possibly on video too. Don't get too excited though, it's not like I'm some kind of special genius who's worked out the answer to life, the universe, everything and tyre fitting. I'm just a regular idiot.

So Ian - the small step (as circled below) is designed to keep the tyre in the "right" position even in the event of a deflation? Yes, I can see that. In a perfect world the wheels would be spit rims with bead lockers - easy to change and secure even in the event of a puncture. But of course this would make the wheels heavier and more expensive, and no-one wants that. Apparently.
Posted Image
28/06/2023 17:16:51 UTC
nab301 said :-
Strangely Ren,although I do currently have a proper air compressor but for years when I didn't managed to seat tyres (even 180's) onto rims with a cycle track pump .

29/06/2023 20:58:19 UTC

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