Is steel tube available 7mm to 9mm dia for this small job (pics)

[mart]

I want to make this saddle clamp from steel so that it is stronger than the original aluminium one.

At the narrowest point it is approx 4.5 x 4.5 mm, and quite weak, especially considering there is constant motion of 11 stone swaying about on the saddle. It is all that holds the saddle to the carbon seat post.

The original has already snapped. Whoever fitted it to the saddle probably over tightened it, or did not screw the little allen screws up evenly etc.

Fitting the replacement aluminium one (in the pics) is probably a waste of time.

So, simple question: Is small dia steel tube available and where from?

My intention will be to saw the tube in half length ways & weld to a bit of steel plate. Holes drilled and it should be sorted. Thanks.

 

[cumbriasteve]

If you have a decent pillar drill you could drill down the centre of a bolt with the dia that suits you, in effect being left with a tube.

 

[Wightsparks]

Lots on ebay. for example
https://www.ebay.co.uk/itm/STEEL-TU...hash=item4b2ee7bd7a:m:mDyKU2xI7KJQfEeTiKyy5SA

 

[mart]

If you have a decent pillar drill you could drill down the centre of a bolt with the dia that suits you, in effect being left with a tube.

Very ceative thinking Steve.

I have a pillar drill. I am trying to imagine if I could clamp the small dia bolt vertically straight enough in the pillar drill vice to allow me to do this.

 

[mart]

Lots on ebay. for example
https://www.ebay.co.uk/itm/STEEL-TU...hash=item4b2ee7bd7a:m:mDyKU2xI7KJQfEeTiKyy5SA

I will have look on there.

 

[Richard.]

Very ceative thinking Steve.

I have a pillar drill. I am trying to imagine if I could clamp the small dia bolt vertically straight enough in the pillar drill vice to allow me to do this.

I’ll put a hole through a small lump of bar on the lathe if you want
Pm me a little sketch to work too and I’ll do a 10 minute job for ya.

 

[mart]

When fastened properly the original ally part is plenty strong enough.

It breaking suggests misfitment or maltreatment, and if that's the case then making it stronger will just move the point of failure - probably to the carbon post (which I'd put money on having an overtightened frame clamp) or the frame itself.

What do you mean? (my bold)

 

[Fazerruss]

Just cut two piece of flat steel or aluminium of about 10mm thick and clamp together. Then sit them on their side and drill down the centre line where the the two faces meet with the appropriate sized drill.
Then separate and you will have a semi circle hole blank of the correct size, and a spare!

This will be much stronger as it's made from one piece of material.

 

[Fazerruss]

Like this but obviously smaller.

 

[sardine]

As far as I can see you want to hand make the old fashioned type of saddle clamp, which you can get off any scrap bike or off eBay for 2 quid ?

 

[Kent]

Why not just get a better made seat? There's a plethora of after market bike stuff.

I mean how far you want to go, forged from tool steel?

 

[Welderpaul]

Fun to make stuff, but if you have a carbon seat post its not a micky mouse bike? Just buy the correct fitting?
Or a nice new saddle

 

[mart]

As far as I can see you want to hand make the old fashioned type of saddle clamp, which you can get off any scrap bike or off eBay for 2 quid ?

As far as I can see you want to hand make the old fashioned type of saddle clamp, which you can get off any scrap bike or off eBay for 2 quid ?

No. I want to make a saddle clamp that is almost the same as the original alumininium one in my photo, but in STEEL.

I would make a stronger one in aluminium if I felt I had the ability, or buy a stronger one in aluminium if it was possible.

BTW The clamp in your picture is not the type of clamp that is compatible with the carbon seat seat post.

 

[mart]

Why not just get a better made seat? There's a plethora of after market bike stuff.

I mean how far you want to go, forged from tool steel?

No disrespect intended, but you have not understood the issue.

There is nothing wrong with the seat. The clamp is intrinsically designed for the carbon seat post, while at the same time has been designed to also accommodate a saddle with rails.

In actual fact, the current saddle is an after market one. (The original saddle was also of the type that had mounting rails). It is however much kinder on my boney ass.

 

[mart]

Fun to make stuff, but if you have a carbon seat post its not a micky mouse bike? Just buy the correct fitting?
Or a nice new saddle

Correct Paul-not a Micky mouse bike.

Not a saddle problem. It is a fitting problem (current clamp not fit for purpose).

I agree with you that it can be fun to make stuff. At the moment with this jobby my preference would be to buy a decent clamp, but that is easier said than done.

 

[mart]

PDG, Thank you for your comprehensive reply. I fully undertand the points that you make, and I feel they are all valid ones.

People do over-tightened things. The misconception that tighter is better. The reality is untold damage.

The 3rd paragraph of my OP is testamont to the fact that I am very much on your waive length.

I also concur that "professionals" are at times incompetent. My bike was purchased new from abroad, and delivered with the broken clamp. Most probably due to what I describe in that 3rd paragraph.

I already have a spare duplicate aluminium clamp in stock. £18 with shipping-ouch!

Based on your comments, particularly regarding the designed flex, I will now fit this spare clamp. However, you will understand that I do not have 100% comfididence in this part at the moment. Time will tell.

I will forge ahead with my plans. The spare fabbed one made of steel will be light enough to carry in the bike bag. I would not want to be somewhat stranded 30 miles from home if the aluminium one failed again.

 

[Kent]

It won't d

No disrespect intended, but you have not understood the issue.

There is nothing wrong with the seat. The clamp is intrinsically designed for the carbon seat post, while at the same time has been designed to also accommodate a saddle with rails.

In actual fact, the current saddle is an after market one. (The original saddle was also of the type that had mounting rails). It is however much kinder on my boney ass.

It won't do that ass no good if the stem comes into harsh contact mind.

 

[wookie]

Is it off a racing bike or a mountain bike ? racing stuff can end up being too lightweight to do the job properly because they are obsessed with weight. Can you not find a suitable clamp off a mountain bike seat for example ? I've the same setup on my fully rigid mountain bike and that's more than happy supporting my 15 stone.