where do you clamp?

[vqdriver]

i know the seatpost is the de facto spot for clamping a repair stand now, but what if it's a carbon post in a steel frame? do you go back to the seattube or tt?

[fourflys]

i know the seatpost is the de facto spot for clamping a repair stand now, but what if it's a carbon post in a steel frame? do you go back to the seattube or tt?

I clamp on my carbon post in my Ti frame... my thought is if the carbon post isn't strong enough to support the weight of the bike and a little wrenching, how is it going to support my fat arse?

[fjaws]

http://www.parktool.com/product/ISC-4

A clamp doesn't exert the same type of forces as you riding. At least if you crush something though it will be your RELATIVELY cheap carbon post. Better than crushing the frame I suppose.

[Steve in SLO]

I clamp the post...it's always round and lightly but firmly clamping it shouldn't do any damage. I sometimes prewrap the post with a length of old innertube slit lengthwise to ensure no pressure points from the clamp.

[Ralph]

Using my Park stand....I still clamp the seat tubes on my steel and Aluminum bikes.....very carefully. And not overly tight. With soft rag around tube. No problems yet. I know the exact diameters, and how loose to set up my clamp for my bikes.

But if you were to bring your bike over to my house for us to do some work on it....I would clamp the seat post. Or just put the seat nose over the arm of the stand...and not clamp it. Or for all CF bike turn the clamp horizontal to ground, and put the top tube in it without clamping. You hold the bike firm.

[David Kirk]

Always the post.

Dave

[Dave Wages]

http://www.youtube.com/watch?v=zZhrbE2rS1M&feature=related

Don't even look at it!


All kidding aside, I clamp the post.

[AngryScientist]

post.

none of my bikes run a carbon post, but even if they did, if something has to fail, i'd rather the post than the frame every time.

[torquer]

Another reason to hope ISPs soon go the way of the Dodo?

Or will Park come up with some work-around for that, too?

[maxdog]

For redundancies sake, let me say, the seat post.

[rice rocket]

How tight are y'all clamping down that this is cause for concern? The bike is clamped to the stand for repair, not for riding... :D

Another reason to hope ISPs soon go the way of the Dodo?

Or will Park come up with some work-around for that, too?

I have an aero ISP. Did you just poop your pants thinking about it?

[false_Aest]

*Edit*

If you're going to clamp your post with so much force as to damage a seatpost or frame then you need to re-consider your ability to work on your bike.

That said, if you're worried about damaging the finish (I'm sure a lot of the people here are) go out to your LBS and see if they have a destroyed alloy seatpost to give or sell for cheap (over $5 and its too expensive).

[130R]

i use a spare thomson seatpost

it helps that my gf's bikes and mine are all 27.2

[torquer]

I have an aero ISP. Did you just poop your pants thinking about it?
'Tis the season to get one's knickers in a twist, I guess...

Just asking the question, "Can one (safely) clamp an ISP frame?"
I see the pros use workstands that hold the fork and cradle the BB, so no issue with where or whether to clamp. Is this the only solution?

My other issue with ISPs (but also hardly worth soiling the Calvins over) is the difficulty of fitting them in travel cases. But that's for a different thread.

[vqdriver]

I don't know that anyone is crimping their frame but the bike does twist inside the clamp as you work on it which isn't a real concern with al posts with no clearcoat.

[StellaBlue]

http://www.parktool.com/product/ISC-4

A clamp doesn't exert the same type of forces as you riding. At least if you crush something though it will be your RELATIVELY cheap carbon post. Better than crushing the frame I suppose.

1+

[avalonracing]

i use a spare thomson seatpost



... and when I'm adjusting my saddle and post I slide them into a spare Colnago frame and clamp the top tube really tightly.

[fjaws]

... and when I'm adjusting my saddle and post I slide them into a spare Colnago frame and clamp the top tube really tightly.


That's some funny stuff! :hello:

[Nil Else]

Get a cheap alloy post.

[maxdog]

How tight are y'all clamping down that this is cause for concern? The bike is clamped to the stand for repair, not for riding... :D



I have an aero ISP. Did you just poop your pants thinking about it?

Concerned about my $1000 Joe Bell paint job, not the tubes.

[oldpotatoe]

i know the seatpost is the de facto spot for clamping a repair stand now, but what if it's a carbon post in a steel frame? do you go back to the seattube or tt?

Use this......I do.

http://www.parktool.com/product/ISC-4

Never ever clamp a seat tube or top tube.

Ahhhh..RTFP, again.

[rice rocket]

Use this......I do.

http://www.parktool.com/product/ISC-4

Never ever clamp a seat tube or top tube.

Ahhhh..RTFP, again.

I understand that the seatpost is the preferred location to clamp to...but have you actually seen tube failures from over tightening in a stand from reasonable bike mechanics (i.e. not morons at home who are particularly ham fisted)? How do thousands of amateur racers move bikes on car carriers that clamp to top tubes? I'd reason to believe that the shock loading from something like hitting a bump, would produce more force than you could reasonably generate in the stand.

[rugbysecondrow]

I understand that the seatpost is the preferred location to clamp to...but have you actually seen tube failures from over tightening in a stand from reasonable bike mechanics (i.e. not morons at home who are particularly ham fisted)? How do thousands of amateur racers move bikes on car carriers that clamp to top tubes? I'd reason to believe that the shock loading from something like hitting a bump, would produce more force than you could reasonably generate in the stand.

This is what I would think as well. If I just need to get the bike in the air to swap wheels or something, I will gently clamp the TT, but if I am doing work which will involving any force, then I will use the seat post.

Thanks

[oldpotatoe]

I understand that the seatpost is the preferred location to clamp to...but have you actually seen tube failures from over tightening in a stand from reasonable bike mechanics (i.e. not morons at home who are particularly ham fisted)? How do thousands of amateur racers move bikes on car carriers that clamp to top tubes? I'd reason to believe that the shock loading from something like hitting a bump, would produce more force than you could reasonably generate in the stand.

Lots of morons in bike shops these days and yes, I have seen seat tubes crushed by 'wrenches' in bike shops. The car carrier clamp is nothing of the force that a shop level work stand can muster.

[martinrjensen]

I use both depending on the bike. I clamp the carbon top tube on my carbon bike but I just screw down the lever clamp to hold it firm (minimum clamping) when i do that. If the seatpost is available I will clamp there but the carbon bike is carbon in both places and the seatpost is not available. So far just screwing the lever down, it has worked fine. I find I don't really need much clamping for my work. If I did I would figure out something else but really, how much real forcing of something do you do on a bike anyways?

[fourflys]

I understand that the seatpost is the preferred location to clamp to...but have you actually seen tube failures from over tightening in a stand from reasonable bike mechanics (i.e. not morons at home who are particularly ham fisted)? How do thousands of amateur racers move bikes on car carriers that clamp to top tubes? I'd reason to believe that the shock loading from something like hitting a bump, would produce more force than you could reasonably generate in the stand.

I'm always afraid I'll get the cable caught between the tt and the clamp and scratch the paint...

[Dekonick]

I'm always afraid I'll get the cable caught between the tt and the clamp and scratch the paint...

I put a microfiber cloth around the tube with the cable outside the cloth and gently hand tighten the screw adjustment 'til tight, open the clamp, 1/4 turn more, then close the clamp. Minimal force - just enough to hold the frame. Often I just work with the frame in the clamp with the clamp open. I have an older park clamp that is too wide to work on a seat post without moving my post out. I figure if after 20+ years I have never harmed any of my bikes it must be safe. I also nearly killed a LBS mechanic who just tossed my Hors Cat in a Pedro's work stand and clamped the middle of the top tube - no cloth, nothing. Yes - it left a scratch. I have given thought to getting the seat post park tool - but, again, it means removing the sea post and I usually am just removing a chain, minor cable adjustments, or just cleaning the bike. For minor wrenching like that the bike doesn't need to be 'tight' and a loose grip shouldn't harm the bike. So usually it is the seat tube or top tube, with care.

So shoot me! :beer: