Any reason not to cut Islabike seattube down?

My daughter could do with the saddle a tad lower then it’s current minimum on her new Islabike Cnoc 14. She can touch the floor with tip toes but not ball of foot.

Any good reason not to cut 20mm or so off the top of the seat tube?

(I realise in due course it will compromise maximum extension and maybe ultimate resale value – not bothered about that).

Seatpost – perfectly fine, seattube – not a great idea 🙂

Why not?

Why would you cut the frame when you can just cut the post?

Because cutting the post won’t achieve what I want, it’s already at maximum insertion. What I need is the seat clamp a bit lower.

Will you have room to then cut a vertical slot in the tube?

Ah, I see. Usually you can get the post a bit lower by lopping a bit off the bottom.
I have no experience chopping frames down. Am sure someone on here may be able to advise though.

I guess it could put more stresses nearer the other welds and cause an issue. Can you still get a seat clamp in? Personally I’d get her in some chunky shoes and make do with toes on ground for a couple of months. They grow so fast anyway she’ll be wanting seat put up in no time .seems a shame to take a risk on frame strength. Even if warranty and resale value aren’t an issue

Ive done it to bikes in the past- back in the 90s i even did it to the headtube on a hack bike so that i could replace the forks, very common on bmx scene to chop seat towers down.

Wouldnt bother me in the slightest, if theres enough room to put the relevent fittings and slots back in, and the tube is sized and reamed to tollerance for deep enoughto still provide a good quality interface with the seat post and its not a big tube shimmed down.

I wouldnt just be having at it with the grinder or hacksaw though.

Did it on a Cnoc 16,left just enough for the clamp.
Still going strong after 2 yrs of constant use!

Thx all, several fair points.

I wouldnt just be having at it with the grinder or hacksaw though.

OK, what tool?

Don’t know anything of aftermarket children’s saddles but one with ‘low profile’ rails would yeild a useful height reduction (on a Cnoc 16) without resorting to cutting the frame.

Having looked at a photo of cnoc , you dont have room to cut anything off of that and retain the function.

The saddle and seatpost are horrendously tall though , you could lose nearly an inch just by swapping the saddle and post !

Will she use it much over winter? She’ll be big enough soon and it’ll keep it’s SH value.

Christmas morning , Big smile on childs face 🙂
Can i ride my bike Daddy?
Bike too tall,can’t put feet on the ground 🙁
You can ride it next week when i get a new saddle for you 😉
Childs face 😥
Hacksaw and file!
Childs face 😀
A childs smile is worth more than any re sale price in my eyes.

Having looked at a photo of cnoc , you dont have room to cut anything off of that and retain the function.

yeah there is

The saddle and seatpost are horrendously tall though , you could lose nearly an inch just by swapping the saddle and post !

true too

If you cut that down how are you going to reinstate the slot that allows the clamping action to take place.

The stress relief hole at the bottom must be very close to being between the seat stays ?

How about a BMX pivotal seat and post?

looks good mamdirt thx

Will she use it much over winter? She’ll be big enough soon …

Think I’m swaying to this. Also the measure I took this morning was in her stockings, she’ll gain a cm in shoes.

No more trailing feet to stop, she’s going to have to learn to use those brakes!

My little girl had a isla and i found some slimmer tyres for it to drop the ride height a bit cant remember which one tho. But it worked for around 2 months the. She was big enough for normal tyres

Shes back on tiptoes again today as santa brought a new frog 62 😉

Looking at the Cnoc 14 we just gave the offspring, there’s not much space to extend the slot downwards – and if you did you’d still have the hole part-way up too. Could maybe cut it down by a cm or so.

Solution is obvious; thicker soled shoes.

I think this is one of those tasks that if you are having to ask if/how/what-tool, then you shouldn’t be doing it…

Buy a bike that actually fits?

Buy a bike that actually fits?

There’s always one.

Yes, and he’s spot on.

Yes, and he’s spot on

Errr no. Someones doing the usual and not reading the actual post 🙄

She can touch the floor with tip toes but not ball of foot

Also the measure I took this morning was in her stockings, she’ll gain a cm in shoes

Swap out the seat that came with the bike with yours (to remove the rise) for a few months until she grows that extra cm to be able to put her feet comfortably on the floor. After that you can swap everything back over.

It would be crazy to suggest to buy a new bike for christmas, to then buy another one in 3 months when shes grown again

I think this is one of those tasks that if you are having to ask if/how/what-tool, then you shouldn’t be doing it…

Most things I’ve ever done have started this way.

FTFY

Yes, and he’s spot on.

Care to propose one? 😉

Not that I’m sending the Cnoc back**, it’s a beautifully made and put together item.

Thanks to everyone who put in helpful suggestions. I’m going to hold off cutting and see if I can gain a cm with a saddle change.

** also she had it on the carpet this PM waving my hex keys at it and playing “fixing my bike like Daddy does”. Don’t think I’d get it back out of her hands.

Also, if you do chop it down Isla will hunt you down and scowl at you.

As suggested above, different post/saddle is the answer. With our older Cnoc 14, the seatpost wouldn’t go right the way down, so cutting that down would have helped, but not enough to get the saddle as low as I needed. My solution was to buy a new cheap seatpost for the Rothan saddle (it takes a cheap one which uses a separate clamp, but with a hole drilled through for the bolt). With that cut down so it would fit right in the seattube it was far lower than you could have got by cutting the seattube. The family we sold the Cnoc too had the same height issue, but also had a Rothan, so I gave them the seatpost.

Not necessarily that useful if you don’t have a Rothan, but you can buy such saddles cheaply – pivotal saddle and post is probably better if you’re buying both though.

thanks to everyone who put in helpful suggestions suggestions I agree with.

FTFY.

What size seat post? Onza mini saddle is what I have on my sons bike.

Similar trouble when our lad moved up to a bigger bike. He was only just able to get his feet down safely at first….Before I knew it we were raising the saddle because we’d fed him too much valuable nutrious food.

Did you sort it yet?