Charles Wahl

I was sidewalk-wrangling our two bikes, and let my spouse's fall against a sidewalk shed column, putting a bigger dent in the top tube than the small one that already existed, on the other side. I'd like to roll the tube with some blocks, to see if I can remedy this somewhat. I can buy one of these, but it's not like I have a weekly use for these things:


The top tube is French, so only 25 mm diameter, not 1", but I can use some tape. If anyone has a set that they'd sell me, or let me borrow (willing to pay shipping both ways), then please let me know.
EDIT: NOT 25 mm diameter^^^^^^, but 26 mm diameter; therefore any and all considerations/discussion below regarding use of a 1" frame block are pointless!

francophile 

I don't have quite the same blocks as you've posted. However, I ordered from Paragon, which it looks like you screencapped from.

I was working out a dent on a Trek 520 downtube. I got the FT4010 (1-1/8" Bore x 1-3/4" SQ x 2" Long). I'm open to sharing, but round trip will put you 1/2 - 2/3 of the way to the purchase price of your own - single pair of blocks cost $14 + $11 ship at Paragon. You'll be lucky to get them there and back USPS under $15. Almost worth the extra $10 to get the exact part and keep or donate to the Co-op after.

xiaoman1 

Charles,
Rolling blocks make cause more work for you because they will damage the paint...might want to consider leaving well enough.
The blocks will not get the dents out completely and you will need to fill the small dent left with some putty or Bondo and then paint....might be better to leave well enough alone unless you really feel the need.
JM2C's, Ben

Charles Wahl

Thanks for the offer, but I'll buy the FT4009 if I need to to get a 1" tube tool.

I know that messing up the paint is often the case, but I was thinking of wrapping the tube with polyester (3M "Magic") or vinyl tape (I have the latter 2" wide) -- anyone done that?

xiaoman1 

I would like to see the before and after to see how the tape works.
good luck.
Ben

francophile 

I'm not saying you can't do it and/or shouldn't try using the tape, but due to the pressure required while using frame blocks, I suspect you're going to really gum up your blocks due to its adhesive and may spend extra time clearing glue off your tubes and blocks. I'll be interested to hear the results.

I've tried a few different kinds of automotive lubricants when rolling out tubes. I personally find NGLI #2 worked better than most for me when rolling out dents. Need to clean the bare metal fully after though. It will absolutely eat off the paint.

cudak888 

You might have to make your own frame blocks with clearance. Make no mistake, these things fit TIGHT - tight enough that just clamping them to a tube will scrape part of the paint to bare metal. This is how the blocks are able to press down high spots.

-Kurt

nlerner

Charles, I have a set I'm glad to send though they don't bolt together as in the pic example. You use a vise. Let me know.

oneclick 

I suspect those might be alignment holes; that's how I'd make them.

It's certainly how I'd use them, I'd want a vice screw taking the load not those, wouldn't count on them not stripping/galling the threads.

Charles Wahl

Who knows if the Paragon blocks are meant to be used without a vise (just rotated with a big 'ol wrench) or should be used with a vise anyway? I live in an apartment building, and while there's a big vise in the handyman's shop in the basement, it may not have sufficient clearance around it to swing a bike frame. Paging Doug Fattic who posted this photo

along with some advice about them in this thread.

Offhand, my guess is that one wants a vise with all of them, but it's a question. Seems to me that if you designed blocks to be used free, you'd put in at least a pair of screws on each side, maybe even 3, like Fattic's wood blocks.

francophile 

It's my opinion it's easier to get a better result faster using a bench vice. That said, if space is a premium, and the blocks are like the Paragon blocks with bolts to pull them tight to each other, and you've got some muscle, you can do what I do without a vice, maybe some vice grips or a hand-made tool:

Grease the hell out of the tube in 1" either side of the tube Tighten down the blocks lightly snug. Clamp onto the block with your tool. Spin as close to 180º in each direction as possible a few times. Tighten the bolts another half or full turn. Spin again. Rinse/repeat until it's fairly difficult to tighten or you bottom out, then pull the blocks and assess your work.

If it's your first time, or the blocks are ill-sized, you may want to manage this differently. I haven't found any pros or cons to heating or cooling tubes before or during this process. The big thing is, use plenty of lube, expect to destroy the paint, and only use this method with steel tubing, never carbon, aluminum, etc That may sound like a total "duh" statement or stupid remark, but who knows what person may stumble on this later.

Lascauxcaveman 

Yeah, if you move the dent at all, you'll screw up the paint, no matter how much lube you use, and the dent will just be less, not completely gone. Putty and repaint will be needed to completely hide it.

Using a block with a small length, a hefty C-clamp will work as well as a vise, in the right hands.

Charles Wahl

I have an embarrassing confession: my entreaties and discussion above are predicated on my false belief that a French/metric top tube is 25 mm OD; well it's not! As oneclick has pointed out to me privately, it's 26 mm, slightly larger than an English 1" (25.4 mm) top tube. So nothing that Paragon sells would do the job anyway. I've edited my first post above.

xiaoman1 

if you must roll them...you can either make them from a block of oak or go to a machine shop and have the use a block 0f 7075...you will still have a dent left as stated above that will need to be filed and painted. Still not worth it IMO because unless the repair is"perfect" you will still be reminded that the dent is still there, that's what stickers are for...post a pic of the dent please.
Ben

easyupbug 

I don't understand the tape concept after having seeing this done, but having had our local framebuilder do a couple frames with a total refurbishment (paint, etc.) the results are excellent, both 25.4.

Cynikal 

Have you reached out to a local framebuilder? Coast or Porter have the correct tools for this and can walk you through the pros and cons.

oneclick 

I have offered to lend Mr. Wahl a 26.0 block, he has kindly offered to pay (some of*) postage.

It occurs to me there might be others who would could use this size. If it's ok with everyone he could send them on to whoever is next in need, and the blocks will eventually get back to me. If I have an urgent need I'll make some more.

* I was good with each pay one way, especially as I'm not in the USofA so postage is about the same as the price shown for the english size above.

EDIT: Charles got cold feet, dent too small and frame too nice to bother. Offer to all still stands, 28mm on the TBD list.

Charles Wahl

Photo of oneclick's machine shop fabricated blocks:

In my own defense, I did expect to pay shipping both ways, and told oneclick so.

Iowegian

Looks like a very well made piece of equipment. I'll keep that in mind since I have a Vitus Peugeot frame that has a dent. I know from experience that the paint will be ruined and the dent will not be completely gone but on the other hand it may still be worth it. Thanks for the offer.

xiaoman1 

Oneclick,
This is what the forum is all about...good Karma coming to you.....
Best, Ben