Boring out bars for bar-end shifters
#1
Senior Member
Thread Starter
Boring out bars for bar-end shifters
Just suppose you are dead set on a certain handlebar that is only made with an ID too small for bar-end shifters.
I have seen Sheldon Brown's photos of a jig for drilling them out, but I don't have a drill press. Has anyone done this and still have the jig or know of a shop that can do it?
I have seen Sheldon Brown's photos of a jig for drilling them out, but I don't have a drill press. Has anyone done this and still have the jig or know of a shop that can do it?
#2
Senior Member
I would use an expandable reamer. They're available at auto parts stores. Put it in your tap handle, and adjust to where it just fits in the end, then tighten it just a bit, ream, and repeat. No jig required.
#3
Senior Member
Thread Starter
#4
Senior Member
Don't thank me yet--they're notoriously difficult to use properly (get an evenly reamed hole), especially with cheap ones. If you have a mechanic friend, you might try to borrow one of theirs.
Before you start, it's a good idea to take it apart all the way, clean the knives, slots in the body, and adjusting nuts, then reassemble everything with a healthy coat of cutting oil.
Before you start, it's a good idea to take it apart all the way, clean the knives, slots in the body, and adjusting nuts, then reassemble everything with a healthy coat of cutting oil.
#5
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Expanding the tube with a flaring tool rather than reaming might be safer. But if it's heat treated aluminum it may not work well.
If possible practice first on some identical tubing, including if it's heat treated. Maybe a wrecked handlebar identical to the one you have in mind.
If possible practice first on some identical tubing, including if it's heat treated. Maybe a wrecked handlebar identical to the one you have in mind.
#6
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Going in the other direction, can you reduce the outside diameter of the barcon pieces? It would be pretty easy to file down the bolt head part and the three wedges might be pulled in enough by the circlip for everything to fit. Just thinking out loud.
#7
Senior Member
If I understand which tool you mean by "expandable reamer", I would suggest you not do that. They are carborundum grinders. They are meant for honing steel cylinder walls.
The bars are aluminum. Aluminum is soft and usually "smears" very easily rather than being ground down like steel. This smearing could destroy those carborundum stones in no time flat.
How thick are the walls of the bars?
What is the inner diameter of the bars?
What is the outer diameter of the bar end shifter?
How deep do the shifters have to go into the bar?
Anything can be made to work but...
P.S. - Are you sure it's not just a burr on the bar end that is constricting the opening?
The bars are aluminum. Aluminum is soft and usually "smears" very easily rather than being ground down like steel. This smearing could destroy those carborundum stones in no time flat.
How thick are the walls of the bars?
What is the inner diameter of the bars?
What is the outer diameter of the bar end shifter?
How deep do the shifters have to go into the bar?
Anything can be made to work but...
P.S. - Are you sure it's not just a burr on the bar end that is constricting the opening?
Last edited by Bad Lag; 02-23-19 at 05:33 PM.
#8
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This doesn't sound like an exciting project. It appears to be just the opposite.
#9
Senior Member
If I understand which tool you mean by "expandable reamer", I would suggest you not do that. They are carborundum grinders. They are meant for honing steel cylinder walls.
The bars are aluminum. Aluminum is soft and usually "smears" very easily rather than being ground down like steel. This smearing could destroy those carborundum stones in no time flat.
How thick are the walls of the bars?
What is the inner diameter of the bars?
What is the outer diameter of the bar end shifter?
How deep do the shifters have to go into the bar?
Anything can be made to work but...
P.S. - Are you sure it's not just a burr on the bar end that is constricting the opening?
The bars are aluminum. Aluminum is soft and usually "smears" very easily rather than being ground down like steel. This smearing could destroy those carborundum stones in no time flat.
How thick are the walls of the bars?
What is the inner diameter of the bars?
What is the outer diameter of the bar end shifter?
How deep do the shifters have to go into the bar?
Anything can be made to work but...
P.S. - Are you sure it's not just a burr on the bar end that is constricting the opening?
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#10
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I believe that the right tool for the job here is a hammer. Be sure to use the right kind.
Or use downtube shifters like a civilised human....
Or use downtube shifters like a civilised human....
#11
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FWIW: my friends at Terracycle offer recumbent handlebars reamed out for bar-end shifters. I think they built a piloted reamer for the purpose. If you're finicky, you could ask them to do it for you.
https://t-cycle.com/collections/hand...cts/handlebars
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Comcast nuked my web page. It will return soon..
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Comcast nuked my web page. It will return soon..
#12
Senior Member
Thread Starter
Yes, I did this. I thinned the wedges by filing their inside surface. I also turned down the outer diameter of the bolt by chucking it in a drill and using a file. I didn't bother turning down the shifter body- I let it stick out. Once the bolt and the wedges fit in the handlebar I assembled it mostly normally. (The shifter body stuck out- but the grip covered that part so it wasn't noticeable.) It worked just fine.
FWIW: my friends at Terracycle offer recumbent handlebars reamed out for bar-end shifters. I think they built a piloted reamer for the purpose. If you're finicky, you could ask them to do it for you.
https://t-cycle.com/collections/hand...cts/handlebars
FWIW: my friends at Terracycle offer recumbent handlebars reamed out for bar-end shifters. I think they built a piloted reamer for the purpose. If you're finicky, you could ask them to do it for you.
https://t-cycle.com/collections/hand...cts/handlebars
#13
Senior Member
I know what a reamer is, I own several. No, really, I do.
I'd never heard of an adjustable reamer and thought you were referring to an automotive adjustable hone. I went and looked up adjustable reamers. I had no idea such a thing existed.
I'd never heard of an adjustable reamer and thought you were referring to an automotive adjustable hone. I went and looked up adjustable reamers. I had no idea such a thing existed.
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Dremel and patience.
Die grinder and care.
Last edited by merziac; 02-25-19 at 03:29 PM.
#15
Banned
Maybe not yours , but...
is a Drill press available, to have it done for you?..@ a Machine Shop?..
measured a Sun Tour one ....@ 18.5 mm 0.728" or 47/64 inch
so go for 3/4. ,... 0.75" about 19mm
...
measured a Sun Tour one ....@ 18.5 mm 0.728" or 47/64 inch
so go for 3/4. ,... 0.75" about 19mm
...
Last edited by fietsbob; 02-25-19 at 03:56 PM.
#16
Banned
Jeff may know of Ryan Recumbents , he bored out bar ends for his under seat steered LWB bikes..
#17
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I'm heart broken, truly heart broken, that nobody commented on my zinger up thread. Tough crowd!
#18
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Just out of curiosity, @Roll-Monroe-Co, what are the bars that you're set on using?
#19
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#20
Senior Member
WAAAAAY too subtle for me! I did like the Campagnolo sledge hammer though!
if i am any indication of the overall "speed" of the group ( and i suspect not) things could spiral out of control at any moment in time around here!
#21
Full Member
My buddy at work bored 2 sets of bars out for me. Worked like a charm.
#22
Senior Member
Thread Starter
Just out of curiosity, @Roll-Monroe-Co, what are the bars that you're set on using?
I did ask if Terra Cycle would do it as suggested by Jeff Wills, and they said no, but I forgot to drop Jeff's name.
A bar that will work (and natively takes bar-ends) is the Velo-Orange Montmarte. The key is the nearly parallel grips.
#24
Senior Member
Not sure how much material you need to remove but I’ve used 100 grit or slightly less abrasive sandpaper wrapped around a near I D sized wooden dowel and checked bars frequently for fit. Slow and tedious but you can sneak up on a near perfect fit. Somebody mentioned a hone. I considered it. Might work. Ask for a brake cylinder hone. Not crazy expensive in most auto parts stores.
#25
Senior Member
Adjustable reamers are available in any size you need. They cost approximately $60. I was looking at Grainger, IIRC, so you might be able to do better than that price. Then again, Grainger is a great company and they have what you want.