tube benders

[zank]

Question for those bendings chainstays, seatstays or tubing for racks...

What's your weapon of choice? Are you simply using forms and dies and muscle or is anyone using an automated bender? For multiple bends, how are you keeping the bends in-plane? Pics?

[Tom Kellogg]

For our stainless racks, we used to use standard hand benders that you can get at any cheap tool place like Harbor Tool Freight. They actually work pretty well, but like any hand bender, they will NOT make perfectly symmetrical bends. Last year, Jeff and I made our own bender for the major bend at the front of our racks so that we could match the width of a Brevet crown with the radius of the bend. It turned out to be much more difficult to figure out the spool radius and groove depth than we thought. We got it after four tries. For our blades, we just use a split pulley sheave. We don't bend chain stays, so that is easy.

Keeping stuff in plane? practice and care. Jeff has gotten pretty good at it. You don't want me anywhere near a tube bender. I can bend fork blades pretty well and we keep them in line with the oval by eye. Works pretty well.

I have heard that Ron at King cage used to use the cheap benders like we do, but as his production went up he eventually made his own stuff.

Merlin does all of its stay bending with dies. Very expensive, but it seems that when it comes to tissue paper thin Ti tubing, it is the only way that can be reliably made to work. They do have CNC benders down there, but they can only use them when bending somewhat thicker stuff. I have seen them work, amazing. I saw a batch of triple bend heavy MTB chain stays bent. The bender accomplished all of the bends exactly to spec. and in plain in about six seconds each. Pretty cool.

[steve garro]

For our stainless racks, we used to use standard hand benders that you can get at any cheap tool place like Harbor Tool Freight. They actually work pretty well, but like any hand bender, they will NOT make perfectly symmetrical bends.

Keeping stuff in plane? practice and care. Jeff has gotten pretty good at it. You don't want me anywhere near a tube bender. I can bend fork blades pretty well and we keep them in line with the oval by eye. Works pretty well.

I have heard that Ron at King cage used to use the cheap benders like we do, but as his production went up he eventually made his own stuff.

i agree with all the above. for racks {i've only done 4 - they take more time then you would think} i bend 3/16th 4130 with a bender from aircraft spruce. for the bending on the sit-ski we made the bender, there's a pic of it in the flicker stream with my buddy doug. we started with cast pulleys, but had one explode so we have milled ones. for SS's i have an arbor press with a "shoe" and "rockers" i'm doing some S-bend SS's tomorrow, i'l post some pics. i reckon that for what i assume you are doing {light cross stays, maybe?} that you would want a simple wood radius bender {drew has some really cool ones} you need less bensd then you would think to get a good S-bend stay, esp. if the SS is 400mm+ in length........allot of bending is developing feel and still you end up chucking one {or two} into the recycle bin now & then.......Ron at king cage has a way cool dedicated widget to bend cages, i'll see if i can get the video. my buddy welds them, he says ron can bend a cage faster then he can weld them...he has a 6' tall cage in his yard!........steve.

[Curt Goodrich]

The only bending I do other than fork blades is for racks. Like Tom, I just use a cheap hand bender, pulley and a Wilton vise. I don't bend stays. The hand bender works great and since each rack is different I don't see that it makes sense to tool up more than that. Phase isn't that difficult and let's face it it's a rack! So if it's a little off a little gentle persuasion and all is fixed.

I think Garro has something a little more sophisticated given all of those droopy (I'm teasing) top tubes.

[steve garro]

I think Garro has something a little more sophisticated given all of those droopy (I'm teasing) top tubes.

those are their whole own animal, but i'll go into them if you really want......steve.

[suspectdevice]

I borrow an Ercolina numeric control rotary die bender...



It made all that stuff a lot easier...

[EnginCycles]

I am working on some new bender stuff this week during my "i will never have time for this" projects. Dedicated this week and next for shop improvements.

I use wood and aluminum dies. I have rollers that follow the tube in all the applications. I also pack all my stays with sand before bending.

more after the holiday.

Cheers and Happy New Year.
-Drew

[maunahaole]

those are their whole own animal, but i'll go into them if you really want......steve.

If there ever was a place to discuss such things, I think you are there. I'd like to hear about it...I may not totally understand it, but fire away.

[steve garro]

If there ever was a place to discuss such things, I think you are there. I'd like to hear about it...I may not totally understand it, but fire away.

sure - but i'll wait until Zank responds so maybe we can focus on his project. there's always more to learn when it comes to bending........steve.