FrankenTrek - old MTB converted to 'modern' gravel bike

 
old chromoly bikes are great. There not that plentiful anymore and you can't buy a new one. Much more rigid than aluminum, and for a recreational bike the weight difference isn't enough to matter.
 
old chromoly bikes are great. There not that plentiful anymore and you can't buy a new one. Much more rigid than aluminum, and for a recreational bike the weight difference isn't enough to matter.

I remember riding my first aluminum hard tail xc bike and it was a much stiffer than my flexy flier chromoly frame. I think chromoly is kind of unique that it can be flexible but still very tough, strong and long lasting. Aluminum will fatigue cycle out if its too flexible and most carbon fiber frames built light enough to not ride like concrete seem susceptible to crash damage. Although I think almost no generalizations can be made on frame ride quality or strength based on material, other than steel rusts... The frame design can make the bike ride like the manufacturer wants with almost all materials.
My former xc race AL frame gravel bike, is a noodle compared to my freeride AL frame. Light weight butted tubing and curved seat stays makes a big difference.
 
A while back I did this project, really just as something to do with a bike that wasn't getting used, an interesting idea that may or may not have turned out OK. As it happens it turned out great!

Take one 1997 Trek 830 Mountain Track rigid XC chromoly steel mountain bike...
View attachment 127355

Then scavenge, scrounge and acquire parts as cheaply as possible in order to:
  • convert from 3x7 to 1x10 gears
  • convert from flat bars to drop bars
  • convert from cantilever to disc brakes
  • convert from 26" to 700c wheels
  • convert from threaded to threadless fork
View attachment 127356

A few details:
  • Shimano Tiagra 4600 levers/shifters (one shifter is obviously redundant)
  • Shimano 11-42T 10-speed cassette
  • Shimano Deore XT 9-speed derailleur on a drop-link to clear the largest cogs
  • TRP Spyre cable disc calipers
  • Unknown steel fork - donated by a friend from his junk stash
  • A2Z Universal Disc Mount adaptor for rear caliper
  • Maddux RD 2.0 700c disc wheels
  • Rock'n'Road 43mm tyres
  • Sunrace square taper cranks with 36T narrow-wide chainring and frame-mounted chain-guide
  • FSA Orbit II 1 1/8" threadless headset
  • 12° flared drop bars on a 100mm 6° stem
  • Charge Spoon saddle
  • Original bottom bracket
  • Original aluminium seat post.
I really enjoyed this project - the first such project I have undertaken. It took me around a year between first deciding to do it and starting the build - in that time I was doing research into parts, compatibility etc and also slowly amassing the parts needed through donations, eBay and other online purchases to keep cost as low as possible. I was concerned that it might not turn out well - that maybe the geometry would be all wrong, that the parts wouldn't work together, or that it would not be nice to ride. It turns out to be one of my favourite bikes (I have quite a few, including carbon fibre full-sus and hardtail MTBs, a carbon fibre road bike and a titanium hardtail MTB).

I've ridden it over 1,500 miles now including all kinds of terrain, from smooth road and hard-pack gravel to deep mud and quite technical singletrack - it takes it all on. It also gets a lot of love when out and about, people often taking time to look it over and ask about it.
Respect brotha. You did a heck of a job on that. I enjoy bike builds. It’s a skill for sure.
 
... Although I think almost no generalizations can be made on frame ride quality or strength based on material, other than steel rusts... The frame design can make the bike ride like the manufacturer wants with almost all materials. ...
True. My flexiest frame was a Vitus 979 (Aluminum) I raced back in the 1980s. My stiffest frame was a Trek Aluminum, so rigid you almost needed a mouthpiece to ride it. The best frame I've owned is my Fezzari Empire (carbon) - stiff and efficient yet also comfortable and light.

As for frame durability and fatigue, here's a test you all may enjoy reading:
 
True. My flexiest frame was a Vitus 979 (Aluminum) I raced back in the 1980s. My stiffest frame was a Trek Aluminum, so rigid you almost needed a mouthpiece to ride it. The best frame I've owned is my Fezzari Empire (carbon) - stiff and efficient yet also comfortable and light.

As for frame durability and fatigue, here's a test you all may enjoy reading:
It is interesting the that the chromoly frames failed earliest. I guess it may be pushed to the engineering limits the most in order to come close to the same weights as AL and carbon?
I broke my chromoly frame after some chain suck scarred the chain stay and then it eventually cracked through there before I noticed it. When AL parts have broken they have been sudden and complete with no noticeable bending which hasn't been nice either.
 
I have bikes with chromoly, aluminium, carbon fibre and titanium frames. To be honest I can't really tell the difference between frame materials except for the Ti bike. All these bikes are for different things and so don't really compare side-by-side EXCEPT for the Ti MTB, which is a hardtail and is a direct replacement for an older carbon fibre hardtail - both have 29" wheels, both have 100mm forks. I notice that there is some 'bounce' in the Ti frame vs the stiff CF one, and that the Ti frame is a more sluggish climber. It's a tank in the winter though - go anywhere, do anything, shrugs off the conditions.
 
Regarding frames & materials, here are words of wisdom and physics cutting through BS and marketing:
 
Except when you love your TitanFlex frames like I do. All components have been replaced a few times and the cassettes dozens of times. Although I did have to replace one of the frames, which finally cracked after about 100,000 miles. My opinion is the TitanFlex is one of the greatest road frames ever built.
LOL, I feel like you and that frame deserve mention in the Bike Snob's book
 
Agreed. I'm a bike snob, I admit it.
I'd like to be, but am too poor to 😂

Seeing your bike made me think of the The Bike Snob's book - in it he had a picture of a trick track bike that had been converted into a townie, complete with a little dog riding in a basket.

The caption for the pic read
"I'm all for re-purposing old bikes, but turning an exotic and outdated time trials bike into a townie bike is like eating your lunch with a comb. Meanwhile the dog reflects ruefully on his life and contemplates on the series of missteps and bad decisions that brought him to this place"
 
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