# Tips for cutting carbon handlebars



## geofharries (Jun 2, 2006)

I have a Enve M9 carbon handlebar that's uncut at 800mm wide.

I've been riding these bars for a year and want to go a little shorter, to 780mm for the sake of my wrists and shoulders. I find 800mm too wide and 780mm seems ideal for me.

Can I just use my tube cutter on carbon bars? See below for what I mean, tool-wise.









I've also seen people wrap tape around the bar to prevent splintering. Is that recommended?

Thanks for your help!


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## J.B. Weld (Aug 13, 2012)

Yikes! Definitely don't use that!

Go easy with a standard 32t hacksaw blade and you'll be fine. Some sort of guide is highly recommend.


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## rusty904 (Apr 25, 2008)

J.B. Weld said:


> Yikes! Definitely don't use that!
> 
> Go easy with a standard 32t hacksaw blade and you'll be fine. Some sort of guide is highly recommend.


I also like to put a tight wrap of masking tape on the bar before cutting. The finer and sharper the hacksaw blade, the better. Smooth the cut edge with a sanding sponge.


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## Battery (May 7, 2016)

I believe there is a hacksaw blade just for carbon: 10 Best Hacksaw Blade For Carbon Fiber of 2022

Don't use a tube cutter! It could damage the bar from the pressure.


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## Cleared2land (Aug 31, 2012)

I have been successfully cutting carbon with a 32t for years. Seems to work just fine.


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## rocwandrer (Oct 19, 2008)

The way that tube cutter makes a cut in metal inherently will not work for carbon. 

I like to wrap in wide masking tape to give me a reference for cutting, cut with an abrasive cut off wheel, and then use the edge of the wheel to face down to very close to the tape. Then use 1000 grit emery cloth to clean up the end of the cut. Put the emery cloth on a hard flat surface and drag the end of the carbon tube across it flat, rotate and repeat a few times until flat and to desired length. then scuff the inside and outside edge of the tube with the emery paper to break the sharp edge.


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## 127.0.0.1 (Nov 19, 2013)

diamond abrasive cutter wheel is best
and a guide of some sort

simple dremel with cutter and careful hands will do


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## J.B. Weld (Aug 13, 2012)

127.0.0.1 said:


> diamond abrasive cutter wheel is best



I'm not sure about "best". Admittedly I've never used an abrasive cutting wheel before and I'd be scared to go at a carbon tube with one.

I think an abrasive hacksaw blade made for carbon used with a cutting guide would probably be technically best but having used both that and a regular fine tooth hacksaw blade I think both are fine.

The reason I'd pick a blade and a guide over a cutting wheel is that it seems like a lot more controlled process.


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## davec113 (May 31, 2006)

127.0.0.1 said:


> diamond abrasive cutter wheel is best
> and a guide of some sort
> 
> simple dremel with cutter and careful hands will do


Yeah, I have a mini mitre-box saw with a diamond blade specifically for cutting carbon tubing, it cuts the stuff (and handlebars) like butter.


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## dysfunction (Aug 15, 2009)

J.B. Weld said:


> I'm not sure about "best". Admittedly I've never used an abrasive cutting wheel before and I'd be scared to go at a carbon tube with one.
> 
> I think an abrasive hacksaw blade made for carbon used with a cutting guide would probably be technically best but having used both that and a regular fine tooth hacksaw blade I think both are fine.
> 
> The reason I'd pick a blade and a guide over a cutting wheel is that it seems like a lot more controlled process.


If you can see a line, you can cut a line... power tools just makes it faster to **** up


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## Cary (Dec 29, 2003)

I use the clamps from an old set of grips as a guide. Gets me a straight cut, which for me is impossible to do freehand.


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## Tommy E (Oct 30, 2019)

Definitely take the advice previously given and do not use a pipe cutter on carbon. A little tip that I learned on here is to put a coat of clear nail polish on after you’ve made your cut and got everything all smooth. It will add a seal to any unprotected fibers and leave a nice finished look.


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## 127.0.0.1 (Nov 19, 2013)

J.B. Weld said:


> I'm not sure about "best". Admittedly I've never used an abrasive cutting wheel before and I'd be scared to go at a carbon tube with one.
> 
> I think an abrasive hacksaw blade made for carbon used with a cutting guide would probably be technically best but having used both that and a regular fine tooth hacksaw blade I think both are fine.
> 
> The reason I'd pick a blade and a guide over a cutting wheel is that it seems like a lot more controlled process.


from the dozens of carbon frames and accessories I've seen *cleanly* cut in half with a diamond wheel and a dremel, I'm sticking with best. you do need to operate and guide it correctly, but high speed diamond grit gives very clean composite cutting action w/o a lot of setup...and it's a pretty common tool


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## goldsbar (Dec 2, 2004)

I've always opted for a hacksaw. I'd be concerned about the dust thrown off from a cutting wheel. Tape and a guide makes it real easy. You really don't have to be that accurate for handlebars, but it's worth the extra two minutes to do it correctly.


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## plummet (Jul 8, 2005)

Just to throw you guys into a flat spin. I have cut carbon bars down with a tube cutter before..... It worked. Not ideal though. And a hack saw and a diamond blade on a dremel and an angle grinder wirh a thin disc. 

Good thing about the tube cutter is that is a perfect square cut. You can also to a couple laps on the tube cutter then finish off woth any of the above tools. They them follow the tube cutter square edge......


Ps I died a little inside when my wife insisted i cut her enve bars down to less than 700......


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## dysfunction (Aug 15, 2009)

127.0.0.1 said:


> from the dozens of carbon frames and accessories I've seen *cleanly* cut in half with a diamond wheel and a dremel, I'm sticking with best. you do need to operate and guide it correctly, but high speed diamond grit gives very clean composite cutting action w/o a lot of setup...and it's a pretty common tool


Correct, but so too is a hacksaw and if you don't have one, the price of admission is far lower. As is the relative skill required to use.


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## davec113 (May 31, 2006)

plummet said:


> Just to throw you guys into a flat spin. I have cut carbon bars down with a tube cutter before..... It worked. Not ideal though. And a hack saw and a diamond blade on a dremel and an angle grinder wirh a thin disc.
> 
> Good thing about the tube cutter is that is a perfect square cut. You can also to a couple laps on the tube cutter then finish off woth any of the above tools. They them follow the tube cutter square edge......
> 
> ...



I don't think it's safe as the pressure required could crack the cf and it may not even be noticeable.


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## JKA (Jul 26, 2006)

I have always used a carbon specific blade like this one with a saw guide. I'm sure a 32 TPI regular blade with using a grip clamp for a guide would work too, but I'm way too OCD for that and I like buying tools anyway.









Amazon.com : Park Tool Carbon Cutting Saw Blade : Bike Repair Tools : Sports & Outdoors


Amazon.com : Park Tool Carbon Cutting Saw Blade : Bike Repair Tools : Sports & Outdoors



www.amazon.com


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## BadgerOne (Jul 17, 2015)

I use a standard steerer tube saw guide (tightened lightly of course) and a hacksaw with a very fine tooth and it works perfectly. Avoid the dust, chit will kill you.


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## gdb85 (Mar 4, 2017)

As others have stated, 32t hacksaw. Freehand if your not real particular like myself, lock on grips hide any slight flaw (uneven cut) or if you are particular a cheap plastic mitre box from HD or LOWES will do the trick. They have little plastic pieces that lock the bar in place, straight cut and done. Never seen the need or had an issue without tape but if you want to go with the extra effort, it certainly won't hurt matters.


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## Tall BMX'r (Jan 11, 2021)

Not sure why this is in the Clydes & Tall forum, but do think that we are a different animal. Definitely apply too much force into everything we do I can remember telling my 6'6' 260 lbs dad, "that's tight enough dad!" just before he broke the gooseneck bolt on my stingray..


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## J.B. Weld (Aug 13, 2012)

plummet said:


> Just to throw you guys into a flat spin. I have cut carbon bars down with a tube cutter before..... It worked. Not ideal though. And a hack saw and a diamond blade on a dremel and an angle grinder wirh a thin disc.
> 
> Good thing about the tube cutter is that is a perfect square cut. You can also to a couple laps on the tube cutter then finish off woth any of the above tools. They them follow the tube cutter square edge......
> 
> ...




Man that's cringe worthy, it seems you got away with it and I'm glad you did but no way is that safe or right.


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## mlloyd007 (Dec 7, 2009)

A tube cutter is designed to be used on ductile material (metal), not composite. Using a tube cutter on a carbon composite structure will crush the epoxy and tear the carbon fiber, resulting in the end of the bar being weakened.

I use a dremel tool with a cutoff wheel, a respirator, and position the vacuum cleaner very close to the cut to get all the carbon dust. Carbon dust is extremely small and sharp, and if inhaled, can result in permanent lung scarring. Really, really bad stuff, so be super careful to vacuum as you cut.


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## plummet (Jul 8, 2005)

DIRTJUNKIE said:


> I get a certain psychopathic enjoyment riding up on another dude and asking to pass while disguising my voice to sound like a female. After a mile or so of them not letting me by I force a pass I say thank you in my deep normal, man voice.





mlloyd007 said:


> A tube cutter is designed to be used on ductile material (metal), not composite. Using a tube cutter on a carbon composite structure will crush the epoxy and tear the carbon fiber, resulting in the end of the bar being weakened.
> 
> I use a dremel tool with a cutoff wheel, a respirator, and position the vacuum cleaner very close to the cut to get all the carbon dust. Carbon dust is extremely small and sharp, and if inhaled, can result in permanent lung scarring. Really, really bad stuff, so be super careful to vacuum as you cut.


Hehe, Flat spin engaged. 

For the record i have a load of carbon experience and did it to see what would happen. A small amount of delamination right at the cut. A bit of sanding cleaned it back up to non-delaminated carbon.

Job done. 

And yes i have a resparator and go full ppe when i dive into carbon sanding and cutting.


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## 127.0.0.1 (Nov 19, 2013)

plummet said:


> Just to throw you guys into a flat spin. I have cut carbon bars down with a tube cutter before..... It worked. Not ideal though. And a hack saw and a diamond blade on a dremel and an angle grinder wirh a thin disc.
> 
> Good thing about the tube cutter is that is a perfect square cut. You can also to a couple laps on the tube cutter then finish off woth any of the above tools. They them follow the tube cutter square edge......
> 
> ...


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## Cleared2land (Aug 31, 2012)

A wrap of just about any tape makes a good line.


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## BoomShakkaLagga (Apr 18, 2008)

As others said - use a hacksaw with a carbon blade. And wear a respirator mask - seriously. 😷


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## mtnbkrmike (Mar 26, 2015)

Pro tip: leave those 800mm beauties unemasculated.


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## RS VR6 (Mar 29, 2007)

I used a *FRESH* 32 tpi hacksaw blade, painter's tape wrapped around the area to be cut, and a mitre box. Perfect cut each time. Measure twice...cut once.


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## ice29 (Nov 11, 2011)

I have used pipe cutter for carbon since years, though mainly for fork steerer cutting (on road bikes’ carbon forks), these are of thicker carbon than handlebars. If you use a bit of common sense when tightening it and the cutter is sharp (not used before) it works fine (also used it to cut carbon bars once, worked fine, again tightened it very very lightly and spinned it many times rather then tightening it to force the cut)

But a hacksaw is definitely a safer solution  If you don’t have a guide you can use old grips or just clamps from old grips (metal or plastic) as guide (the same is valid for steerer cutting, just take some old stems and position them as a guide, leaving a tiny gap for the saw blade)


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## geofharries (Jun 2, 2006)

Thanks everyone for the great advice!


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## J.B. Weld (Aug 13, 2012)

I guarantee using a pipe cutter would void any and all warranties involved with the product.


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## feral (Feb 10, 2007)

Chop saw with a carbide finishing blade works beautifully.


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## Tall BMX'r (Jan 11, 2021)

Just to put things in perspective, most of the force you apply to your handlebars is at the base of your thumb where it meets your wrist. The ends of the handlebars only get force from the outer edge of your palm and pinky finger. I've epoxied 15mm extensions on to the ends of various bars without an issue. Super strong.


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## Shark (Feb 4, 2006)

Dremel or hacksaw.

Wear a mask!!! 

Sent from my SM-G991U using Tapatalk


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## Cleared2land (Aug 31, 2012)

Respiratory protection can not be overstated


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## Tommy E (Oct 30, 2019)

Just buy the Park Tool carbon cutting specific blade for like $9 and be done with it.


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## brawlo (Mar 13, 2012)

Hacksaw or dremel, both will be creating carbon dust, so take the appropriate precautions for your own health. The dremel option heats up the resin enough so as to seal the cut end and is the best option, but a hacksaw will suffice


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## goldsbar (Dec 2, 2004)

I'm changing my answer to hammer and chisel.


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## dysfunction (Aug 15, 2009)

goldsbar said:


> I'm changing my answer to hammer and chisel.


Well, all cutting tools are effectively chisels. I think you're into something.


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## plummet (Jul 8, 2005)

goldsbar said:


> I'm changing my answer to hammer and chisel.


Crush it in the vice then wiggle it back and forth until the bar breaks away........


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## williamson36 (Mar 24, 2006)

I used my dewalt compound mitre saw - worked like a champ!


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## mike_kelly (Jul 18, 2016)

What ever you use protect yourself. Carbon fiber dust is very very bad for your lungs. I cut carbon under a stream of water in my utility sink. Wear a mask. You might have one around?


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## badsneakers (Dec 12, 2015)

I cut my carbon bars down today using a guide and the park.tools carbon hacksaw blade and one of the ends frayed some. Is this brand new bar unsafe? Ugh. I should take a picture


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## Tall BMX'r (Jan 11, 2021)

badsneakers said:


> I cut my carbon bars down today using a guide and the park.tools carbon hacksaw blade and one of the ends frayed some. Is this brand new bar unsafe? Ugh. I should take a picture


Probably no problem. Take a picture anyways.


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## Tommy E (Oct 30, 2019)

badsneakers said:


> I cut my carbon bars down today using a guide and the park.tools carbon hacksaw blade and one of the ends frayed some. Is this brand new bar unsafe? Ugh. I should take a picture


I add some tape before cutting to prevent this. Just add some clear nail polish to it and it should be fine.


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## Tall BMX'r (Jan 11, 2021)

You can sand or file the CF smooth. No big deal.


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## badsneakers (Dec 12, 2015)

This is what happened. Pissed.


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## Tall BMX'r (Jan 11, 2021)

Not anything to worry about. If there are loose fibers that seem like they are not bonded anymore you could mix a tiny bit of 2 part clear 20min epoxy and brush it over the damaged area. (Sand the area first) Wrap a piece of wax paper tight around the bar and then wrap over the wax paper with tight tape. I repaired and spliced lots of CF tubes this way. Sometimes I actually wrap CF or fiberglass fabric around it as well. You don't need any fabric for your bar end, it more cosmetic than structural. Give the epoxy at least 12 hours to cure before sanding. Sand it down smooth with 220 sand paper. Then spray the area with a little clear acrylic. Or use nail polish
If they were my bars, I'd throw a grip on there and ride. No one can see it under the grip. There is very little force being applied to the very end of your handlebars. If that cut was near wear your levers mount or closer to the stem, then I'd be concerned. A 'Park Tool' carbon bar or tube cutter is kind of funny. I use a grinder with an abrasive blade or my chopsaw with a carbide tip blade or any ordinary hacksaw. It's a hacksaw painted blue🙃


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## badsneakers (Dec 12, 2015)

Tall BMX'r said:


> Not anything to worry about. If there are loose fibers that seem like they are not bonded anymore you could mix a tiny bit of 2 part clear 20min epoxy and brush it over the damaged area. Wrap a piece of wax paper tight around the bar and then wrap over the wax paper with tight tape. I repaired and spliced lots of CF tubes this way. Sometimes I actually wrap CF or fiberglass fabric around it as well. You don't need any fabric for your bar end, it more cosmetic than structural. Give the epoxy at least 12 hours to cure before sanding. Sand it down smooth with 220 sand paper. Then spray the area with a little clear acrylic. Or use nail polish
> If they were my bars, I'd throw a grip on there and ride. No one can see it under the grip. There is very little force being applied to the very end of your handlebars. If that cut was near wear your levers mount or closer to the stem, then I'd be concerned. A 'Park Tool' carbon bar or tube cutter is kind of funny. I use a grinder with an abrasive blade or my chopsaw with a carbide tip blade or any ordinary hacksaw. It's a hacksaw painted blue🙃


I'm a painter in a body shop so I have access to some nice 2 part epoxies and urethanes that could fill and repair that. My grips are single clamp too so only by the controls and not the end. 

I bought their specific blade to do this from being a problem in the first place.


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## rocwandrer (Oct 19, 2008)

I've cut a lot of carbon using metal cutting cut off wheels to cut and face square with no problems.

Hard to tell from the photo, but that looks like a nice clean cut right up until the end when the cut off end wasn't supported well enough at the end of the cut and tore out.


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## badsneakers (Dec 12, 2015)

rocwandrer said:


> I've cut a lot of carbon using metal cutting cut off wheels to cut and face square with no problems.
> 
> Hard to tell from the photo, but that looks like a nice clean cut right up until the end when the cut off end wasn't supported well enough at the end of the cut and tore out.


Yeah I'd say that's what happened. I wrote the manufacturer and sent pictures. They believe it is still fine and safe to use.


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