29 August, 2013

Reaming, Facing, Tapping, and Threading

by Igor

So we delve into the world of frame preparation, mostly to answer questions we've had after Bruce Gordon's recent post about how some well known frames are delivered to the customer with no prep at all.

Back in the days of classic frames when you took delivery of your new frame it often had to go under the knife to fix alignment issues and other imperfections. It's almost impossible to build a steel frame that doesn't require some prep, though some are much better than others. The new owner would be expected to take the brand-new frame to a mechanics to ream and face the head tube to remove excess metal/paint so that the headset cups seated parallel to each other. The bottom bracket required the same process, in addition to cleaning up the threads of burrs and significant excess paint. The seat tube needed to have burrs removed in order to smoothly insert the seat post. Finally, dropouts required alignment to make sure the hub/rim/tires fit properly. This trend continued well into the 80s, especially with your super Italian racing bikes. Many frame builders assumed these preparations would be completed at the shop.


Our frames are made in what is possibly the best factory in Taiwan. A factory that truly puts quality construction first. The whole process of facing, reaming, tapping, and aligning are all done before the frame leaves the factory. Alignment is done on huge heavy duty machines and work tables that are very resistant to warping or going out of true. Even the best custom builders don't have access to tools like these.

On VO frames headsets can be pressed in, bottom brackets threaded, and seat posts installed without worry of burrs or cracked cups or improper alignment. What does this mean? It means that you, the customer, don't have to spend additional money on your frame, upwards of $75, purely for prep. To the shop, it means less time to build up the bike, and therefore less money spent on labor.

Frame tools at the VO shop.

Of course you can still have the frame prepped if you want. It's possible the frame has been damages in shipping or dropped, but in practice we almost never see that. And I'll bet the shop's tools are not as accurate as the factory's. It's up to you in the end whether you will sleep better at night if you have your frame prepped. So do you go through these steps when you take delivery of a new frame?

14 comments:

Anonymous said...

Decades ago when I worked at a shop I used to cringe when guys would bring in a frame for any of these prep tasks. The tools are expensive and must be kept very sharp to be effective, any slip can result in a damaged tool, a ruined frame or at the very least a paint chip in someone's pride and joy. Luckily I was not the mechanic, I only had to write up the tickets and pray that nothing would go wrong.

Thank goodness for prepped out of the box frames.

Anonymous said...

Bruce Gordon is right. It's "Unbelievable". Some of the comments on his post are worth reading too.

Anonymous said...

There's an option on your frame pages:"We can also prepare the headtube and press the headset cups in for a reasonable labor charge (option below)"

So... prep needed or not needed... which is it?

VeloOrange said...

When we press in headsets we check the head tube and remove the paint on the top and bottom edge. This isn't strictly necessary, but once in a while the paint can chip on the edge when you press in the headset cups. So if you're a perfectionist scrape off the paint. Note that Bruce Gordon, who probably has been building and prepping frames for longer than most of us have been alive, does not remove the paint.

Anonymous said...

I'm in the "you get what you pay for" camp. It would be unbelievable on a $1500 frame, but expected on a $400 frame.

VeloOrange said...

Sorry Anonymous, but I don't buy that. In this day and age there should be no frames sold unprepped. Our frames cost $500, use quality DB tubing, have some of the nicest welding and paint you'll find on a mid-priced frame, yet we can afford to prep the frame while still making a small profit.

JP said...

As someone who has considered buying some of those less expensive but still quality frames (as far as I can tell), Soma/Surly/Pake, etc., this is quite interesting to me. I had no idea that this was required. I assumed that you buy a frame and drop on your components and you're all set? I had no idea that this kind of work is required on a typical mail order frame. My guess is that there are an awful lot of people who don't know that, and don't do it. The question is, what are the consequences, realistically, of installing parts on a frame that has not had this prep done?

Anonymous said...

I have to agree with VO on this. My production Rando was exactly aligned and needed no threads chased or surfaces faced right out of the box. I'm sure there are exceptions, but my experience was great.

Anonymous said...

I'm shocked to see all those Park tools. I figured you would use classic VAR exclusively. The Francophile police will be pounding on your shop door any minute now!

Anonymous said...

Ha. Good read. Last year I bought a mountain bike frame for less than $200 from a British company that rhymes with John Dunn. (I think its Taiwanese make, but not sure) I wasn't sure whether it would need the usual prepping, but the headtube looked good enough to my Mark I eyeball. So I scraped off the excess paint with sandpaper, said a Hail Mary, and rammed on the headset with my homemade press. You know what - six months of hard riding later and its good as gold. The BB and seatpost went on with no issues either. So, yeah, if a I can get a $200 frame delivered ready to build (good enough anyway), there's NO reason more expensive frames shouldn't be.

John B.

Miguel Schor said...

It's a drag buying a frame that needs prep work. I like my local LBS. It is a fine shop. But they don't have much experience prepping frames. I think the real problem is that this sort of expertise is being lost.

VeloOrange said...

@JP,

Installing a headset on a headtube that hasn't been prepped can cause a cup to go in crooked protentially ovalizing the tube or cracking the cup. Bottom brackets can potentially be cross threaded if excess paint does allow for a good thread interface. Poor frame alignment has many repercussions, wheels/brakes not lining up, derailleur hanger crooked, weird tracking. Your shiny new seatpost getting gouged as soon as installed.

@Anon 8:19pm,

I assure you there is no shortage of VAR tools!

semi serious cyclist said...

Chasing and facing....i always enjoyed doing it on my own frames..... getting rid of the overspray and ensuring bottom brackets thread smoothly..... Also like to chase the frame eyelets.....that being said, less and less necessary on frames out of Taiwan.

it's still a good idea to scrape the paint away from the headset and BB and have a shop check the hanger alignment after you get the bike on the road.

James said...

Paint is not a load-bearing structure, nor is is laid perfectly flat -especially in areas of the frame that are highly subject to overspray such as the faces of the head tube and the BB shell.

Any builder who builds up over paint is suspect in my book. There is a heirarchy of better builders going down into the kids who assemble bikes for wallmart. Those who build up frames without removing paint and facing load-bearing surfaces, and at least checking alighnment are on one side of that spectrum and it isn't the upper end...

As for mail-order parts. Remember they were delivered via the mails. All sorts of stuff can happen from the time it leaves the warehouse until it reaches your front door. Yes, check alignment, and remove the nicks on the head tube and BB shell that will inevitably be caused by Mr UPS/FedEx man in a hurry to "drop" off your frame. And if it was delivered by USPS package delivery check the frame for spent shell casings...