Author Topic: I Found and Purchased My New Bike  (Read 1643 times)

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Offline Augie Dog

I Found and Purchased My New Bike
« on: February 22, 2014, 04:14:53 pm »
Well my search is over. After much thought and research I have nixed the Cannondale I was looking at and found a Trek 970 in my size I am going to build into a trekking bike. I want to be able to ride rail trails and do road touring. I have one of the first Trek VRX full suspension bikes that I am going to attempt a parts swap on to the 970. Fist thing is to purchase some trekking bars and get my Brooks B-17 and Thudbuster seat post onto the bike.The bike was owned by a former bike shop owner and he has gone through everything and tuned it up. The frame has a few chips and scratches. I am thinking about stripping it and doing a powder coat paint job. If anyone has one of these bikes they did an upgrade or knows of someone that has done an upgrade please let me know I would like to pick their brain for some ideas. And the transition begins!!

Offline paddleboy17

Re: I Found and Purchased My New Bike
« Reply #1 on: February 24, 2014, 10:23:12 pm »
I sent a frame out for power coating and was pleased with the results.  I think it cost me $90, and the painter admitted to having a soft sport for bikes and charging less for them.  The only detail you should be aware of is the temp you can bake your frame without altering its metalurgical properties.  I chose British Racing Green due to its low melting temperature.

As for swapping parts around and upgrading your bike, many of us do it.  Once you become a competent mechanic, you will do all sorts of swaps that you could never afford to have a bike store do.
Danno

Offline DaveB

Re: I Found and Purchased My New Bike
« Reply #2 on: February 25, 2014, 07:57:55 am »
.  The only detail you should be aware of is the temp you can bake your frame without altering its metalurgical properties. 

 As for swapping parts around and upgrading your bike, many of us do it.  Once you become a competent mechanic, you will do all sorts of swaps that you could never afford to have a bike store do.
The 970 was a welded steel frame so no reasonable baking temperature is going to harm it.   

Note that building a bike up from a bare frame is the most expensive way possible to get a custom bike unless you have a big supply of parts already on your shelves and can do all of the work yourself.  Buying your components at retail and having a shop do the work will be far more expensive than starting with a suitable used, or even new, bike.  That said, if the cost isn't a big issue, it can be a very rewarding way to get just what you want.  Even more rewarding if you can do the work yourself.

Offline paddleboy17

Re: I Found and Purchased My New Bike
« Reply #3 on: February 26, 2014, 12:07:50 am »
Dave I wished I remembered more of my steel processing lectures from college.  They made us Electrical Engineering majors sit through that stuff, and we knew we were never going to use it.

I think I remember some of the details from a project of making new J hooks for my panniers that involved heating the bent hooks up to 400F, followed by an oil quench, and then annealing them at 250F for 20 minutes.  I think British Racing Green baked at 275F, and I think there were colors that baked at over 450F.  So baking a frame at 500F could anneal stuff that was meant to be tempered.  Unfortunately I just don't remember very much about heat treating steel, and that is why I left it as an exercise for the reader.  I  just don't know the effect on a steel bicycle frame.

I do remember that I contacted Reynolds, and they OKed the melting point of the paint I chose on my Reynolds 853 frame.  Some paints need a much higher temp and that is why I avoided them.  I don't remember being told limits.  I will also concede that Reynolds 853 is more problematic than whatever steel is in the 970 frame.

Bottom line is that I still feel that it may be more complicated than what you have stated, but I am not able to defend my position.  There used to be a guy on this forum that seemed to know a lot about chromoly steel, but I have seen a post from him in at least a year.

I still vote for leaving this as an exercise for the reader. ;D
Danno

Offline DaveB

Re: I Found and Purchased My New Bike
« Reply #4 on: February 26, 2014, 01:19:51 pm »
Danno, well, they made us Chemical Engineers sit through a EE service course so I'm sympathetic.  I never did understand why you guys needed i.

Anyway, I looked up the heat treating of some typical Cr-Mo alloys and found this:

"4130 (and most of the other low alloy steels) may be annealed at 1550 F for a time long enough to allow thorough heating of the section size."

So I expect baking at even 400°F to fuse a powder coat won't do any harm. In fact, many factory and most custom steel frames are powder coated these days. 

Offline paddleboy17

Re: I Found and Purchased My New Bike
« Reply #5 on: February 26, 2014, 01:51:52 pm »
Dave,

You have argued your case well and I am satisfied.  Glad to know that we can powder coat almost anything in the bike world safely.

I did OK in inorganic chemistry until we got into galvanics.  Scarred me enough to NOT take organic chemistry. We lost site of the Chemical Engineers after our freshman year. I generally enjoyed the mechanical engineering classes they made us take sit through except for thermodynamics.
Danno

Offline CanvasAndSteel

Re: I Found and Purchased My New Bike
« Reply #6 on: February 27, 2014, 10:02:46 pm »
Congrats, Augie!

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Offline driftlessregion

Re: I Found and Purchased My New Bike
« Reply #7 on: March 01, 2014, 01:56:57 pm »
I don't know much about powder coating. I take it that it is more expensive, not done on stock bicycles, but is less prone to being damaged and therefore may last longer before repainting is necessary. Correct?

Offline Augie Dog

Re: I Found and Purchased My New Bike
« Reply #8 on: March 01, 2014, 07:17:56 pm »
Interesting conversation on powder coating! Something I never thought about the temps they use for the process. I will inquire about that. As far as the durability of the powder coating process I am not sure about that but just look at it as a quick and simple way to refresh a frame. I have purchased some 26 x 1.50 tires and will be ordering my trekking bars. From some images I have seen it looks like I may be able to use the shifters I already have. One question I do have is can you convert from quill style fork to a thread less fork. I have an air suspension front fork I would like to use if possible. No big deal if it doesn't work. Also would like to increase 7 spd. hub to maybe 8 or 9. Just thinking out loud here and throwing ideas out. I will be adding my Brooks B17 and an early thud buster seat post to see how it rides but this is trial and error time to see what will work. Getting kinda excited about all of this and can't wait to do an overnight or three night trip as a shake down for me and equipment. Stay tuned!!

Offline DaveB

Re: I Found and Purchased My New Bike
« Reply #9 on: March 02, 2014, 09:32:56 am »
Tthreaded forks cannot be converted to threadless.  Even if there is enough extra length to accept the stem clamp, the threaded section is too weak to take the forces.  To go threadless you need a new fork, headset and stem. 

A work-around is to use a quill adapter in your current threaded fork.  These are a straight quill that goes into the steerer like a quill stem but then accepts a threadless stem. These allow you to use either a 1" or 1-1/8" stem and the newer 31.8 mm diameter handlebars. 

Here is one: http://www.nashbar.com/bikes/Product_10053_10052_175545_-1___202442

Converting a 7-speed to an 8/9/10-speed requires a new freehub body (8/9/10-speed is wider), removing some spacers from the non-drive side, recentering the axle and redishing the rim to center it properly.  I believe your 970 has either 130 mm or 135 mm dropout spacing and your current hub matches it so you won't have to spread the stays.  Of course along with the new freehub body, you will need matching shifters, cassette and chain so this can be a relatively expensive conversion.

Offline Augie Dog

Re: I Found and Purchased My New Bike
« Reply #10 on: March 02, 2014, 03:57:50 pm »
Thanks DaveB! I understand you can not convert an existing quill fork to thread less. I have a thread less suspension fork on another bike I was thinking of using. When I installed it I did not cut it down so I have plenty of material to work with. My question was I guess is can you replace the existing pressed in bearings with a thread less bearing set into the headset.

Offline DaveB

Re: I Found and Purchased My New Bike
« Reply #11 on: March 03, 2014, 10:04:55 am »
Thanks DaveB! I understand you can not convert an existing quill fork to thread less. I have a thread less suspension fork on another bike I was thinking of using. When I installed it I did not cut it down so I have plenty of material to work with. My question was I guess is can you replace the existing pressed in bearings with a thread less bearing set into the headset.
Assuming the new fork's steerer is the same diameter as the old one, yes you can certainly replace a threaded headset with a threadless one and then use the threadless fork.  It's an easy conversion and done frequently.  You will need a suitable new stem and spacers but otherwise it's very doable.

One caveat; the new fork may not play well with the bike's geometry is it's axle-to-crown length is significantly different from the old fork.