isuckatbiking

Wanted to get your opinion on something. I have a usual mechanic I go to. Probably went three or four times. Charges fairly, does pretty good work. He hired a helper recently and put his helper in charge of prepping the bike by putting it on the work stand. As I went to go look at some shoes, I noticed that the helper put the clamp on my seat tube. My bike is carbon and is matte black. I haven't gotten around to checking it out but my main concern is of course abrasions from the clamp which might result in marring up the finish. Is this something to talk to my mechanic about or should I trust that he knows that his mechanic is doing the right things. Again, im worried about damages to the matte paint job or even worse, a dent from the pressure from the clamp. Worried to check the bike in case there is damage.

GlennR

I would put the clamp on the seat mast/post and not the seat tube. That way if the clamp damages it, it can be replaced. But if the seat tube is damaged it's a frame issue.

Obviously it bothers you enough to post here, say something.

rpenmanparker 

You can't dent CF bike tubes. They either crack or they don't. Of course you can damage the paint. Seatpost is the safest plan, but I have clamped many a seat tube with no issues. You need a well cushioned clamp and sensible clamping force. By all means mention it to your head mechanic. I'm sure he will be glad to address your concerns.

Mike F

I clamp the seat post since it would cheaper to replace than the frame. If its anything more than a quick derailleur adjustment, I put in an old seat post for peace of mind.

Nachoman

seat post with shop cloth around the post.

isuckatbiking

Thanks for the replies guys. Gonna give the bike a once over when I get home. Do you guys think the mechanic will be offended if I request that the seat post be clamped next time?

And thats exactly why I want the seat post. Its ALOT cheaper to replace a damaged seat post while there is almost nothing that can be done if the frame is damage.

Fiery

What's worse - offending the mechanic, or having your frame damaged structurally? Sure, nine times out of ten, clamping the seat tube won't hurt anything. Nevertheless, clamping the seatpost is much safer still, and it really takes no extra effort to do it.

willhenry

Mechanic helper might be a newbie. I always clamp to the seat post unless it's not possible. Definitely request that in the future, they won't be offended.

bbattle

My mechanic replaces my seatpost with an old one and uses that on the stand.

datlas 

By all means mention it. Diplomatically, of course.

GlennR

I rather deal with the possibility, although rare chance that the seat post/mast is damaged than R&R it everytime you use a stand. I clean my bike every week and the mechanic I use is very knowledgeable in healing with high end carbon bikes... if he didn't i wouldn't use him.

The thought of swapping seat posts means loosening and tightening the clamp twice at every time. And while you can mark your seat post, i'm very comfortable with my fit and rather not mess with it.

If he's good enough to "build" the bike, he's OK to help maintain it.


LBS shop


The LBS I deal with has 4 locations. One is their main location with a large showroom. The second is their original store and deals mostly with lower and middle range bikes along with clearance items. The 3rd is very small and deals with middle and higher end bikes. The last is being built and will also do lower and middle end bikes. Each has a mechanic with the skills for their specific location. If a high end bikes comes in they'll transport it to the 3rd shop where a mechanic that deals with high end bikes is located. I just skip the middle man and bring it there myself.

My point is if the mechanic is trained to to work on high end carbon bikes then you need to trust him. If he's not than find another. When he sees that a "helper" mounted the bike by the seat tube, he should notice it and correct the helper. If he didn't then you should questions his qualifications.

It's that simple.

My work area.

BenPS

I always clamp the seatpost if possible, but sometimes if the bike has too many lights/seatbags/reflectors/short post on it, it's just more practical to clamp the seat tube or top tube. Metal bikes are no problem, carbon bikes we know to clamp lightly, and if it's a nice bike, will wrap a rag around it before it gets clamped. Also, make sure not to clamp on stickers, as they can rub off. Any shop that swaps out seatposts to an old one to clamp a bike in a stand either doesn't have enough work, or is realllllllly worried about it.

where the clamp can leave little marks on seatpost or frame, it rubs off with some cleaner. And if you are that worried about the matte finish of your bike, you're probably spending too much time on the internet, and not riding it enough.


[fwiw, the above bike definitely gets a rag, and clamped on the seatmast]

loimpact

I think the more important question is.......WHAT'S UNDER THE CAR COVER**********

As for clamping.....I've got a buddy w/ an S-Works full-tilt, blah blah $8,500 bike who has clamped his by the top tube for the last 5 years. He also has a similarly expensive 29er. He works with carbon fiber blowers for NHRA all day and tells me that there is absolutely no reason to not clamp by the top tube if you're not wrenching down on it. I don't do it (he ribs me for it) because I'm a sucker for "what if" but, again, he knows the stuff far better than I do and still maintains the top tube is just fine.

(shrug)

loimpact

This is me, too. I pretty much leave my saddle bag (though tiny, it still interferes) and my Hot Shot tail light (ditto here) on the bike at all times. So that becomes a 5 minute (probably 3 minutes actually) PITA when I have to undo the straps on the bag and then unbolt the Hot Shot light mount (the light dangles on the bag so I went back to the seat post mount) which takes a little more time, but then allows me to clamp the seat post.

The alternative would be to extend the seat post & retract it each time (Not so much a PITA as I don't want to mess with my height setting, not abuse the post clamp more than necessary) or simply clamp somewhere else. I have let the bike sit "cradled" in the clamp via the top tube once when I was taking some pictures of the drivetrain but too chicken to "clamp" onto it.

(shrug)

GlennR

roccobike

I have two Wrench Force stands. I put CF bikes on the stands by the seatpost, seat tube, top tube, whatever. If you know how to adjust the pressure at the clamp, the rubber in the clamp is so thick, no damage can come to the frame, none. Depending on the bike and rider, a seatpost may need to be extended in order to put it into a clamp. IMHO, resetting the seatpost is more of a risk on a CF bike than placing a seat tube or top tube in a properly adjusted clamp. It's important to be sure that whatever is placed in the clamp is clean, dirt does more cosmetic damage than any rubber clamp. Of course, it's important to note where cables are exposed and not clamp onto the path of a cable, that will cause cosmetic damage. I NEVER use a rag to protect a frame. If a cloth is used it must be a clean, unused cloth.
As for cosmetic damage to a bike, car racks like a Saris Bones cause way more damage than a properly adjusted clamp that has adequate rubber in the clamp.

loimpact

Ahhhh.....I think I should have remembered. You were the one that posted the VW dual-48-IDA motor in the "what motor are you" thread from a couple months back. (As a VW connoisseur, I should've ID'd it thru the car cover already, but the Super Beetle front bumpers take that front profile a little lower & longer subtly diverting my otherwise keen sense of savvy.)

I'm dating myself, but this was mine....(snivvle, snivvle).....

GlennR

While the large bumpers show it to be a 74 or newer, the flat windshield tells you it's a "Standard" Beetle and not a Super.

You had it confused with a 1302 Super that had a flat windshield, but they were only made 71-72. In 73 the 1303 Super came out with a curved windshield.


BTW... I spent the day with my son who worked 7 years at a bike shop while in high school and college, and he said you would really have to want to do damage to damage the seat post. While not optimal, carbon is pretty tough and you would have to really crank down the clam to damage it.

pdedes

bikes with isp, i clamp the seat tube. there's clean rubber on the clamp, i'm not worried.

loimpact

Indeed! I was drawn to the rear-quarter intake vents & I always think *super* when I see those & while it *could* be a 1302, I think your bonnet on a standard is shaped a little differently too, no?

To further hijack this poor thread......a year after that magazine cover, I put a much larger motor (Tom Schuh) and a 5 speed trans (Dave Folts) in that puppy which put it into "stupid money" territory and got into a 30 minute argument w/ Gene Berg on the phone as to why he wouldn't sell me a Berg 5 speed shifter. (Folts' trans, not his, so he wouldn't hear of it) I ended up having to work around him to get one and drove it as a 4-speed for 2 months before I ever got to actually shift into 5th).

Again....apologies to OP......to put this back on topic.....Oldnslow....careful swinging that bike around on the stand no matter where you clamp it.....don't wanna hit the Bug!!!

GlennR

Some 10 years ago I came home after a night out and backed into the garage only to hear something hit the car. My son (15) left his bike in the middle of the garage thinking he would put it away before I came home. It put a small dent and 4 " scratch in the left rear fender. Two seconds after he came running out of the house because he heard the garage door open but it was too late. He "manned up" and apologized immediately offered to pay to have it fixed. I gave him a hug and said I was proud that he too responsibility (he's a Eagle Scout). Three years later, now 18, when he bought his Cervelo P2 I reminded him and told him carbon fiber doesn't dent, it cracks.

The car still has the dent and I touched up the scratch.... hey I drive it. It has 473,000 miles and 50,000 since it was restored.

kbarch

Hmm. What do I know? I just got a stand, and I've been clamping onto the top tube where it balances. Perhaps it's a better idea to clamp at the end of a tube, but really it's just holding it up and keeping it from flopping around if I brush up against it. I'll clean the chain, do a bit of spray and wipe on the frame; not torquing anything.