Is an aluminum frame fatigue prone?

**Jason Smolka** · #1 9 Dec 2002

Is an aluminum framed motorcycle fatigue prone, or is the XR650R a worthy bike for a pole to pole ride?

**t0by** · #2 9 Dec 2002

If you're asking about the KLR frame being fault prone, the answer is YES. Highly recommend upgrading the sub-frame bolts. There is a thread here that discusses it.

http://www.horizonsunlimited.com/ubb...ML/000033.html

Happy travels

**RichLees** · #3 9 Dec 2002

yes. aluminium is much more fatigue prone than steel. aluminium is good for strength to weight ratio, but has no endurance limit so, no matter how low the stress, there will always be a finite fatigue life. steel can often indefinitely endure cylic loadings of approx 1/3 of its max stress. steel is easier to design for and get repaired.

as for the XR650R - the frame looks good, but, IMHO, the subframe should be remade in steel. the suspension is great, but fuel consumption etc may drop it from the top 10 overlanders. also its got a 1,000 mile service interval and its a bitch to start when the decompressor gets stuck.

all being well, I'll be able to compare XR650L, XR650R and Tenere when we get back from Algeria at the end of Jan.

Rich