cncwhiz

I have an older road bike frame that I want to build up. I have been messing around with older mountain bikes to ride on the road for a few years with slick tires etc. I want to build up a road bike to improve my speed and distance. I am thinking about finding a newer road bike and stripping the parts to use on my road bike. I think I might have to cold stretch for the rear wheel but what do I do when going from a 27" wheel to a 700mm wheel as far as brakes fitting?? Please help me out on this issue. Is it dumb to buy a small frame road bike as they are less money and build up my bike? Money is an issue in that I see group sets for 500 to 600 dollars and wheel prices can climb to the sky in prices.

Gresp15C

I'm puzzled why you wouldn't buy a road bike and just ride it. There's almost assuredly something from the new bike that won't fit the old, forcing you to buy additional new parts. Murphy's Law.

Still, a project is a project, and I won't discourage you if it will get you to a bike that you enjoy riding.

As for 27" to 700c, I've done that conversion. The radius of the 700c rim is roughly 4 mm less than the 27", so you can look at your existing brakes and see if there's enough adjustment room for 4 mm more reach.

Edit: I guess I mean the new brakes have to have sufficient reach. So you're going from new brakes on the new frame, to the new brakes on the old frame. This is where I think you have to measure the reach of the new brakes versus the dimensions of the old frame. Unless someone smarter than me can think of a shortcut.

dabac

While buying a donor bike may well be cheaper than purchasing the parts separately, what is it about that old frame that makes it worth keeping?


It's hard enough to achieve a full transplant when staying in same-generation bikes due to the number of competing standards available. Doing it on a cross-generation build would take either supplementary purchases or crazy luck.


For a steel frame, usually not a problem. Protect the brake bridge and align the dropouts while you're at it.


With the double whammy of smaller wheels, and most likely shorter reach brakes, the pads are unlikely to line up with the brake track.


Easiest fix is to mount wheels in frame/fork and measure what reach you require. Then buy your way out of the problem. Tektro makes brakes with a wide range of different reaches.


Or there are drop brake pads, and various DIY options for lowering the brakes.


Note that your old frame/fork is probably made for nutted brake mounts. The threaded section of the bolt protruding through the fork crown/brake bridge.
New brakes are generally made for recessed mounts. Meaning it's a long, cylindrical nut that's countersunk into the crown/brake bridge.
You'll either have to drill your fork/frame, or replace the mounting bolt.
If you want to run fenders, the latter is an easier option.



Really?


IME size isn't hugely important in pricing compared to component level, condition, age, brand...


'Course, if you have someone needing to sell NOW, you might be able to force the price lower for a bike with a smaller number of potential buyers.


A less stressed seller might decide to wait.
Anyone needing a smaller-than-average frame might be willing to pay more, since they are rarer.



Using a donor bike as such is an established method of cost control.
But usually only applied when there's something special about the frame about to be built up.
It's definitely faster and easier to look for a bike that's instantly rideable instead.
And I don't think the cost will be much different.
Unless you like trading and bartering with used stuff, you'll have to pay full prices for the complementary purchases(BB, headset, front derailer, stem, brakes, seat post... to mention the most likely culprits) and will only get secondhand prices back when you sell the incompatible stuff off.
It won't take many full-price purchases to offset the possible saving of starting with a cheaper donor bike.



In that case, prioritize where the biggest improvement is.
Frankenbikes can be built a lot cheaper than matched bikes.


What actually is it that you want from your "new" road bike?


Unless you get into the aero/tubeless/disc brake stuff, front wheels haven't changed much in decades.
Rear wheels offer a few more gears.
Dual pivot brakes can be a bit better.
Brifters - shifting built into the brake levers is nice.
Modern drop bars together with modern brifters offers a more comfortable position on the hoods.


Decide what you want most. Consider starting from there.

cb400bill

Thread moved form General Cycling to Classic & Vintage.

Bianchigirll 

I agree this may turn into a quagmire. No one has even mentioned the seat post size or the BB threading issue. Just what is the older frame? I would think as long as your going to buy a newer bike and swap the parts you may as well buy a new bike and see if it fits you.

cdmurphy

cncwhiz, rather than get into the specifics of kitting out your old frame, I just wanted to address the basic premise that a road bike will be faster than your mtb fitted out with slicks. I'm not sure that's true. I don't have it any more, but for a few years I had a Trek rigid mtb that I fitted with drop bars and cushy Schwalbe Kojak 2.0"x26" tires. Since then, I've acquired some really nice race bikes from the 70's - 80's. It hasn't been until recently that my fitness has improved to where I've consistently beaten the times I managed with that old Trek. At the time, it was at least as fast, if not faster than any of my road bikes on a 6-7 mile loop I do most mornings for exercise.

It was 4-5 lbs heavier than a good road bike, but the ride quality, and speed of those slicks pretty much made up for it. I'm not saying don't build up your frame, just don't get your expectations too high as to any speed increases. You may be disappointed if that is your only reason.

cncwhiz

From most of the input I have received the awnser to my question is its a lot more of a problem to build a newer bike on an old frame than to buy a complete bike. Now what to look for???

palincss

You get longer reach brakes.