How to Ream a Bicycle Head Tube and Seat Tube
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- čas přidán 27. 08. 2019
- It's time to do some reaming, facing, and slotting on my mountain bike frame! First, you'll see me ream and face the head tube, then I ream the seat tube, and then I slot the seat tube.
Here's the podcast episode I mentioned with Drew Guldalian of Engin Cycles in the video: cobraframebuilding.com/podcas...
So, for the head tube reaming and facing, I'm using a Park Tool head tube reamer/facer. In case you're not familiar with it, I give some background on the Park Tool reamer/facer, then I show the process for how to get a nice full clean up and make sure the headset will fit snug inside.
For the seat tube reaming, I used an adjustable reamer with straight blades that I'm actually not a huge fan of-but it was affordable. I also talk in the video about why helical reamers are better for seat tube reaming if you can afford one.
For the seat tube slotting operation, I use a homemade seat tube slotting tool that I made based on one I saw Drew Guldalian from Engin Cycles using.
Here is the playlist of the whole Hardtail Mountain Bike Frame Build-I'll keep adding to it as we go: • Building a Hardtail MT...
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Great video Joe. I’m a huge fan of seeing for myself how bad (or good) a certain thing can be. No matter what I’m told, I just like to experience it for myself. And if shit hits the fan and it’s a disaster, I’ve always been able to take that real life experience and apply in other ways. Kudos for wanting to find out for yourself.
Thanks. It’ll be interesting. Press for bottom brackets are so contentious! I think seven cycles and some others actually use cnc mills to threadmill (interpolating the helix in three coordinated axes of cnc goodness) the bb threads after machining. Maybe I’ll try that next time for fun.
Love these vids... the quality of the information and the actual video quality is just bonkers
how much I thought the cycle frame was easy in my mind . u changed everything about bike frame . but the mind ,soul and heart u put I started liking you video . it usually very long .but I get ur deal now . best work .thanks
When I used to finesse the seat tube, we had a light abrasive brush that we put on a drill and gave it a few seconds. Worked like a charm.
I wanted to put a modern 30.9mm seat post in my old aluminum Specialized MTB which originally came with a 30.8mm seat post. I used the adjustable reamer and flex hone exactly as shown here, and got a perfect fit. Thanks a billion for the tutorial!
tenth of a milimeter difference. You have to wonder what clowns come up with these standards.
Very interesting....I have been concering having a custom frame built. Nice to see what go into building a frame. Thanks
I think I have binge-watched almost all your videos at this point. Keep up the great work! Just getting information at this point to build my first bike this winter.
Congrats! It’s a very fun and rewarding process.
Hey, great vid!
Unless it has already come up, you could make the center hole in the aluminium puck of the head tube reaming setup somewhat bigger to fit the cone of the reaming too itself so that you would get the benefit of the spring action of the nut.
And another thing could be to make the height of the minor diameter of the shoulder longer so that the spacer registers in the headtube interior wall from longer distance. That would negate some of the possibility if the face of the tube is out of square to the length of the tubes centerline before the reaming is done.
So much useful and well thought through info. thank you for sharing
I recommend tilting the seat tube so you are reaming "uphill" so that chips and extra oil tend to come down and out rather than into the frame. Not a big deal, but it helps a little bit when you are trying to clean out the seat tube.
Good tip.
This channel is amazing. Thank you
Love flex honing seat tubes on the lower end bikes at my shop. Makes me feel fancy lol.
Great video as always👍
Thanks!
Great video.
A seat post really doesn't have a strength issue at the clamp, it has a stress concentration issue.
Rather than radius the bottom of a 1/8" slit, you should drill a 1/4" hole and slit in to that.
That will greatly reduced the chance of crack propogation from the end of the slit.
Glad I found your vid Joe, good work. It's six months later; how did the press fit pan out?
Cobra Frame Building: Build first, Bike hard, No mercy.
Very good explain. 😊
Yes I like you work bro.👍
Hey Joe: Can you post some information about the handle you made? I'm especially interested in how it clamps to the square top of the reamer. Thanks!
thank you for the great explanation! Do you do anything to the seat tube before reaming to remove any small bumps that might be there from welding?
Very cool video ^_^
Question: can leaving that edge of material on the bottom of the bore cause it to interfere with a headset cup remover tool?
Subscribed!
put the material your measuring with the calipers as far back in the jaws as possible. then rock the callipers back a forth over the flats on the jaws. the smallest reading is your measurement. easy peasy.
Hey Joe, I'm curious if the Chris King reamer/facer tools are much different than the Park tool ones?
I haven’t used them and I don’t know, but now I’m curious.
Question: I just ordered a brand new Santa Cruz Jackal frame will I need to have the head tube reamed before I can install my crane creek 40 headset or is it ready from the factory?
Any new bike from the factory should be ready to have a headset pressed in.
Her you should do custom frame building it seems hard and machine are extremly high cost but many ppl will look for custom frames
Hi, I'm planning to ream the seat tube of a vintage chromoly lugged steel road bike frame to accept a larger diameter seat post, specifically 26.8mm to 27.2mm, so ill be removing approx 0.4mm of material? correct? I'm planning to buy an adjustable hand reamer with a 26-29.5mm reaming range, the seat tube is already slotted so I'm planning on going as slow as I possibly can , the outer diameter of the lug measures approx 30.8mm, and the seat tube approx 29mm. Is this advisable? will there be enough material in the tube for it to be safe? in my head it works haha but id like an expert opinion before I go through with it, I'm doing this so ill have more options for seat posts. Thanks
I wish all builders (look at you big box guys) would do this before shipping unbuilt framesets.
for the seat tube, would a "Flex-Hone Tool" on a cordless drill work?
we used to use them on tubes in a factory I used to work at.
oh ha you got to it later i see :)
Question. So I’m trying to build my own bike out of an old mountain bike frame, but the headset tubes are 32mm and I have a pair 34mm headset cups. I can fix that by using a reamer? Just wondering if it’s worth a try
Reaming is a finishing operation. The tubing should be pre-engineered slightly undersize so that reaming brings it into final size and roundness. This process isn't intended to change the spec of the tubing. You wouldln't have much luck with that and the tubing would be too thin after reaming even if you could do it.
I'm looking for a video that shows how to machine a headtube from scratch for semi integrated.
Is there a low-cost way of doing that seat tube slot? Assuming you're yet to buy a milling machine or a lathe.
Absolutely. The most common methods probably are to use a die grinder with a cut off disc, or a dremel with a cut off disc, or a hacksaw method. For the cut off discs, you need a lot of experience and control with the tool because you can ruin your finished frame really fast. Lots of people do it this way with good success. You can also put 2-3 hacksaw blades on the same hacksaw frame and cut the slot that way. The triple blades gives you the slot width. Use small hand files to clean up the slot and round the bottom. You can pre-drill a hole where you want the slot to end and slot up to that hole so the end will be nice and round.
@@cobraframebuilding Thank you so much! This is truly encouraging, I never would've thought about using multiple hacksaws. Seems like a steady and controllable method.
Thanks again!
question, is it safe to ream a bicyclye head tube top part so it could be of the same level with the top tube and achieved a slammed headset?
If I understand your question correctly - I think you're confusing reaming and facing. Reaming opens up a bore and facing takes material off of the end of the tube. Facing isn't really intended or useful for removing more than a fraction of a millimeter. You could cut the tube shorter and then face it. You'd have to perform this work carefully and effectively. Whether or not it would be advisable from a structural perspective is a whole other question and would depend on the specifics of your frame and how it would be used.
@@cobraframebuilding thank you so much for your reply, I wanted to achieve something like how a current trek marlin frame design looked where the head tube is shaved and slammed, but I agree with you that it may not be advisable...
Try using a three leg brake cylinder hone?
cat's meow ...? bees knees ... ? pajamas sounds good though. enjoying the videos, thanks.
Good luck with the BB. This is Cannondale's original spec for BB30: www.bb30standard.com/bb30-technology/. You have to agree to all that stuff and then you get to download a pdf. The tolerances look very fine but most interesting is how they say the left and right sides need to be machined with one cut to ensure concentricity. It also says all dimensions are post weld and heat treatment so you can't just lathe it before you build the frame.
I work as a professional bike mechanic at canyon and not once (out of about of maybe 1500 bikes) had a issue with pressfit. If it's made properly it's easier lighter and less problematic than threatet once. At home I don't even use a speciality tool other than a rubber hammer. To me it's a mystery how pf got such a bad reputation.
It's just like he said in the video. There is nothing wrong with the pressfit concept, but it's less tolerant of geometric faults than threaded. Also the pressfit arose to reduce the expense of putting threaded shells into carbon fiber frames. It's a cost saving measure, not an improvement. In a perfect world, press fitting and threaded would have equal longevity and ease of maintenance. In the real, bicycle industry world I'll take threaded every day of the week.
Ha, yeah it is pretty unanimously hated but then you have your occasional proponent and it makes you wonder how people can be so upset about PF while other people are having good experiences. My English thread BBS have creaked, too.
@@tobyvision I understood that. But if you ain't buying crap it's better.
@@cobraframebuilding I was curious, if you did go T47, what bottom bracket would you have used? I see very few options that are "approved" for MTB use. I have avoided T47 for the very same reason--expensive, fragile taps.
@@cobraframebuilding I think a few dramatic instances like those bikes that had press fits directly into carbon fiber that disintegrated when exposed to sand put it over the top.
It is possible to make oval headtube to normal???????
Drill a hole wider than the slot then cut the slot. Standard practice.
hot damn
Since you have a milling machine in the background, couldn't you set up the frame carefully and then use a single-point cutting tool in a boring bar to do all these jobs, without needing all those expensive hand tools? (I guess it would be a pain getting the frame carefully aligned with the boring bar though.) The funniest thing I ever saw was a machinist in a big factory whose seatpost rusted into the seat tube and couldn't be removed, so the guy clamped his bike frame into a giant lathe with a 6 ft. diameter 4-jaw chuck, and bored out the seatpost!
He mentions that possibility at 38:00
hello .IM IN VIETNAMES I WANT ORDER THIS TOOL PLS SHOW IT TOMY
*I gather that the average consumer would never need to do these procedures, no? We may press headset cups and press-fit bottom brackets, but I assume that manufacturers do this for us, right?*
You should also watch how thick the metal is in the frame as you could split the metal. I also feel these video's are no longer DIY anymore.
You guys kill me, learn what stress reliving is.
Nice work but u talk to much 🙈
Why are you going Metric pains what's wrong with sticking with the Decimal system scads of Decimal tooling scerw the metric system be 100% American .🔔🔔🔔
He is using it because the entire bike industry uses the metric system, and if he were to translate those measurements to non metric, it would be way easier for him to screw it up.