I’ve been keep my eye out for an old mountain bike I can put around on simply because they remind me of being a kid. I found this diamondback in pretty good shop and my size, but the frame is early aluminum. I’ve heard stories about old aluminum frames and this makes me second guess. Of course I would check the bike out thoroughly before, but don’t want to buy something that’s fragile. Id appreciate what you all think of this. Thank you!
by Imnothere1980
4 Comments
I would hesitate, but I would like to hear from a true expert in material science.
I believe I can feel an increase in frame flex on my 2018 alu frame ridden almost daily. If it continues linearly it will be unridable in another 5-6 years. I’m not an expert so I can’t say if that’s actually possible or just my imagination, and it’s impossible for me to measure.
I wouldn’t worry about the fragile aspect of it unless it’s been ridden to death. Aluminum has a fatigue life but it’s unlikely this bike has hit it, considering the good condition.
The problem with early aluminum is that it was overbuilt due to material and manufacturing limitations. If it was not overbuilt it would be fragile. This caused aluminum to get the reputation of being stiff, because it was. More recent advances in materials science, design, and manufacturing have allowed bike frames to become thinner without sacrificing strength.
For just riding around for fun this is a perfectly fine bike most likely. Put some modern tires and MTB pedals on it at a minimum.
No. I’d look for 4130 at the minimum.
More likely to buy 80s aluminium than 20s carbon second hand for sure, especially one that hasnt been mullered by a muppet, id say over 90% of mountain bikes ever sold at most have been off a few kerbs or ridden across a grassy field as their off road life. Id give the welds a once over and drop it a few inches a couple of times to listen for any weird rattles or cracks.