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Discussion Starter #1
Kids!
Take one brand new YZ125 chuck it at a full sized concrete fence post (6 foot tall and angled at the top) and snap it off and this is what it does to the bike
38674

Just not good enough, also got a damaged rad cowel and scuffs on other plastics!

Seriously this does concern me, hate the fact the bike was damaged (should have snapped the bike in half) but much better than my son hitting the post, both my twins were saying they were for some reason twisting the throttle more than they intended to now and then but I rode with them for much of the day and they seemed in control just fine, not sure if the throttle is lighter than the 85's they just came off or the power comes in more agressive, told them just take it steady until you get used to it.
He says he went on a different line than he had used all day to pass his brother and hit a big hole, somehow twisted the throttle right back and it reared up, luckily be bailed out, he got a scuff on his back and looked pale but apart from that seems ok just hope it teaches him to show caution for a fence lined rough track.

We are supposed to be out again on wednesday but can not get parts, no moving parts in that top section of the forks, a marshall rode it back and a friend rode it down the parking area and it seemed ok, I might do a lap on it to check it is ok to use first.
 

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glad ya boys ok. its heart in the mouth shit when you see them fold.
first time I saw my boy have a big off my first thought was his mums going to kill me!

if the wheels pointing the right direction and no cracks or leaks it should be safe to use.
 

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Mmmm, is this a case of not riding for the covid year then going a bit banzai?
As I was rebuilding my linkage yesterday, I had a sudden wave of paranoia about riding again after nearly 18 months off😮
During which I've broken 2 more ribs on the MTB, now totalling 6 broken ribs, 1 broken toe, and a shattered thumb. Not a lot of chance of leaning from my mistakes??!!
 

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Discussion Starter #5
Don't think they went Banzai, seemed ok when I was riding with them, yes it has been 5 month's since they rode and they were starting to look big on the big wheel 85's and they have both shot up since so got them 125's. Yes we learn from out mistakes until that red mist comes down :LOL: I did a few laps on my much modified africa twin to get a feel for if I was going in the right direction and found myself pushing way harder than I intended racing with some MX bikes, had to pull over and stop myself.
glad ya boys ok. its heart in the mouth shit when you see them fold.
first time I saw my boy have a big off my first thought was his mums going to kill me!
Yes can be a fine line between letting them do motorsports and bad things happening, I just make sure I am not being the "schoolboy motocross dad" encourage them, try to teach them but know when enough is enough, some dads:rolleyes:
 

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Thankfully he's not injured, at least he'll have something tell his mates when he sees them. The scariest thing some of these kids do nowadays is get shot on a PS4 !
More importantly he needs to get back on the horse ASAP !✊✊
 

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Discussion Starter #8
Thanks, Yes thats the main thing.
Must say thanks to the WOR events team, marshall was quickly on the scene ( I had started washing my bike off ) once they knew he was ok congratulated him on taking out a big concrete fence post with a 125:) but said the farmer might well not be so impressed. Airing in the side of caution he put my lad on the back of his quad to take him to the medical center for a checkover whilst another marshall rode his bike back, the lady in the medical center delivered him back to me. Good to know your kids are in good hands(y)
 

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Glad all’s turned out well. Not nice explaining you’ve broken the kids to the mrs.

Will the dent in the fork tube affect free piston movement on the base valve?
 

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Discussion Starter #12
Glad all’s turned out well. Not nice explaining you’ve broken the kids to the mrs.

Will the dent in the fork tube affect free piston movement on the base valve?
Piston, Base valve, no you don't understand its the forks not the engine :LOL: Its many years since I messed with forks, all sorts of trickery goes on inside them these days, I do not have a spanner or socket to take the top off, looking at some videos there is a kind of tube that is part of the top nut that goes in to the section where the damage is so it does not look lke anything slides directly on the inside of the part of the forks where the damage is, just hope it has not distorted the tube that goes inside, damage at the worst point is 5mm of crushed area
Push up and down of the front end and it seems to do what forks are supposed to do, I have put some araldite over the damaged area just in case oil or air could leak out if there is a small hole. I will take it out for the first lap on wednesday then have a good look around it, if all is ok with my 19 stone on it then I will let my son use it but keep an eye on it, not a lot of stress in that area if it had been below the bottom clamp not a chance I would let any one ride it.

Looking on the parts fiche it seems to say £756 for the complete fork or £755 just for the tube, can't be right! Not paying that just for the tube Ill make some calls tomorrow, buy another new bike for spares if need be. Any one know of any shops who have a new 21 yz 125 in? I tried the place I bought these from but got none until the end of the month.
 

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Discussion Starter #13
So at around 2.12 that gold coloured tube about 200mm long which appears to be part of the top nut, if that is not squashed/deformed it will be ok?
If I ride it and get the forks close to bottoming out and that tube is damaged I could do more damage or even have the forks stay stuck down?
 

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If he hit a concrete post and was pushing on there could be hairline cracks or other issues you can’t see with a naked eye. It may be fine for a month/6 months or a year and then just let go. For the sake of a few hundred quid I’d replace the triple clamps and upper fork leg. Bit salty price-wise but peace of mind knowing it’s safe.
 

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Discussion Starter #15
If he hit a concrete post and was pushing on there could be hairline cracks or other issues you can’t see with a naked eye. It may be fine for a month/6 months or a year and then just let go. For the sake of a few hundred quid I’d replace the triple clamps and upper fork leg. Bit salty price-wise but peace of mind knowing it’s safe.
I have no doubt I will but with shops shut today and we are entered for an event on wednesday there is no chance of getting parts in time, Parts fiche says out of stock as well.
 

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That gold coloured inner tube section is where the free piston moves up and down which is all part of your base valve. In simple terms, as the rod gets pushed into the cartridge it pushes the base (even though in the top) valve against the ICS spring (not main spring) and then as ICS compresses the free piston moves. If the inner gold tube is damaged then it won’t work right. I’d replace the outer tube. You’ll be able to find a second hand one as KYB are plentiful.

Tubes here.
 

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Discussion Starter #17
All good
38729

Not sure if those fork tubes are the same the part number for the 2021 125 is 1SS-23136-00
those from a yz450f 2008 are 2S2-23136-00
What are the first 3 digits?
 

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That’s good news.

I’m not sure what the digits mean. Could be model year and bike? Most suspension shops should be able to tell you what works. They might even have a tube. Those forks are very popular in MX so someone is bound to have done a similar thing and there’s a spare tube out there.
 

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Discussion Starter #19
The penny dropped :rolleyes: about an hour before we were going out to another practice day yesterday morning, the fork inner slides up between the small gap between the outer fork tube and that "gold coloured tube" so if the forks were getting close to bottoming the top of the inner would contact the damaged section of the outer.
I put cable ties on the forks to tell how much fork travel was being used and sent my other twin out on his bike with the un damaged forks, came back in after a lap and I measured it up to work out we should be ok.
Kept checking all was ok but not suprisingly the twin who's bike had hit the concrete post on saturday was very steady, clearly knocked his confidence.
Tried to encourage him but not pushing him, I think telling him when I was following him we seemed to be hitting every bump, with a bit more speed you tend to glide over the top of them but also said do not push it unless you are comfortable.
Then I noticed it was taking me longer to catch him, when i did I could see he was looking much more confdent, standing up more, moving his body weight about in a confident way, elbows up, and what rearlly told me he had made a positive step was the little blips of the throttle in just the right places, can not tell you how great it was to see that, just proves what I have always said, gentle encouragement is the way not shouting and screaming at kids or chasing that "perfect" suspension set up.

My other twin is coming on great as well, did wonder if I had moved them up on to the full sized bikes a bit early but they are ok, he says the bigger bike is so much better over the rough stuff, it's great to see them both making progress and being able to ride with them on these RED days.

The new yz 125's are going great no issues with them (except crash damage!) the kids find them easy'r to start than the 85's as well.

My older son rode with us as well, he suprised me at the pace he was going, he was a good trials rider as a kid and still a decent one from what people tell me but this was the first time he had been on an enduro bike for 3 or 4 years. I have kept telling him he should do some extreme enduro, maybe he will now.
He was enjoying my old 300 xc until we swapped and he had a go on my wr450f I think he preferred that, much smoother over the bumps.
Not sure if it is just me getting old or it is this "long covid" thing but I seem ok then suddenly drop off the edge of a cliff energy wise, not sure how I will go on in a competitive event like 2 day enduro or rally.
 
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