A Little Help, Vets
So I got really lucky and was actually able to ride tonight, granted all the rain mid-mo's been getting today. I had plans on riding at Four Winds down at the lake, but unfortunatly didn't have the time, so I was "forced" to ride Binder.
The ride was good, slow for the most part, and I did get to ride with another guy for the main part of the ride. But heres the problem I need your guys help with. Lately I've notice a little to much flexing going on with the Jamis Dakota. I notice it most when coming into corners at speed, going over rocks, roots, and the tech sections. What happens is my back end either comes shooting out from under me leaving me to hope I can straighten it back out, or my front and back wheels skipp really bad. It almost feels like the hubs or loose or something, but when I go to do the push and pull test they seem to be tight. The air pressure in my fork may be a little off, I still need to check it. But my tire pressure is about the same, 32-35 psi.
It wouldnt bother me so much if it had started from the begining but it has seem to be getting worse. Until I bent my seatpost Monday, I had some really bad creaking noises coming out of the top tube area, where it joins with the toptube to seatpost connector. See the bike at jamisbikes.com to see what I mean. I don't know if this is a problem that is coming from a tiny hairline crack, or if the wheels just really do need tightend. Have you all ever had this happen to one of your bikes? Any suggestions would be great. Unit, next week I'll have to let you ride it and see if you notice anything.
Other than that I had a great ride. Even got to get in a narly crash that came just an inch from breaking my collar bone. Got a nice strawberry on the shoulder though. Crashes, ahhh, how they really bring you back to reality. I really am human, and yes, it really does hurt when you wipe out.
I'm going to start doing some looking at where would be a good weekend getaway adventure for our upcoming ride. I think a saturday-sunday thing would be cool, especially if we go down to Arkansas. I think that'd be a good time. Any suggestions?
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Breaking another Jamis frame?
You think you're breaking yet another Jamis frame? What is that, something like three now? GW, you're in a whole different league.
Unit will know where to look and what to recommend, I bet.
Dude you are hell on bikes.
Dude you are hell on bikes. Think maybe it is time to try something that isn't Jamis?
I think you should check the
I think you should check the ht-tt joint. If there is a crack in the frame that is where it will most likely be found.
Get out the spy glass!
I would clean the bike really really well, and then go over it with a close eye. Use a magnifying glass when necessary.
A frame should not change in its performance, or creak like you are describing. I would bet that the creak is coming from a component, but a frame crack is also possible.
It could also be that you are not quite accustomed to riding Binder when it is so dusty. Simply changing tires may be the answer, but I would clean and check everything first.
If you want to stop by some time, or take it to the LBS and strip the frame down so you can clean it well. (not completely perhaps, just wheels, seat post, cages, bars and stem) Sometimes these components will creak when their junctions get dirty...also with them out of the way, you can spot cracks easier.
I would spend a bit of extra time checking all HAZ (heat affected zones from the welding processes). I would be surprised if this is a crack/frame failure....Jamis is not a bad company and I would like to believe that they have worked successfully to correct the problems they had with their first 29er design.
Thanks
Yes, I would be very suprised if this was a frame issue. But then again shit does happen. As you stated Unit, this could be caused by multiple things. And yes, it has been very dusty lately. But with that being said I still think there is too much flex for this aluminum frame.
This thing was stout as a rock at the start. That's why I liked it so much, you could really bomb the downhills. I've ridden it on several different trails lately and I just don't feel the same confidence on it. I don't think there is anyway I'm going to break an aluminum frame but you never know. And unit, this bike came out when my Exile came out so they could have problems, who knows.
I'll play around with it and see if I can find the culprit.
Huh?
You said, "I don't think there is anyway I'm going to break an aluminum frame".
What on earth makes you think this?
Don't sell yourself short, you can break anything if you set your mind to it.
As far as materials go, a rider should never feel more confident (in terms of breaking) on one material vs. any other (or to say it another way...any material should inspire maximum confidence as long as it is built/intended for the type of riding you are doing). All materials can and do fail, but the mode of failure can be different.
Steel often gives warning by cracking or bending first (been there, done that, had it repaired),
Aluminum by contrast usually fails more catastrophically (suddenly and without much of an obvious warning) (seen it, very ugly does not usually "bend", but "crumples" and shatters),
Ti (I am told) is similar to aluminum in that it fails suddenly (tiny cracks may pre-warn the user, but they are very hard to spot until they propagate rapidly) (saw this on a couple bikes...never seen a tiny crack, I always observed a major breakage type failure...oddly enough I have seen several break in the same place as in this photo but different brands/makers), and
Carbon does all sorts of things depending on how the fibers are placed and bonded (seen failures of nearly every description...abrasion/fraying, cracking, brittle failure).
As a rule of thumb: If someone tells you that a frame is "unbreakable", what they often mean is, it is "so tough that very few riders have broken them" (but they can be broken...especially if flaws are present). If the component is said to be "lightweight", you should probably count on replacing it regularly (perhaps annually). If the part/component has a stated rider weight limit that is less than twice YOUR body weight, YOU should probably avoid it (works for me).
There is an entire field of science for materials...but the take away is that nothing lasts forever, and nothing is superior (some riders will benefit from one set of properties, while another prefers something else). If you want more facts/opinions check here (I can give you more links if you like).
Come see me this weekend, we can strip and prep your ride for some serious riding...it is probably overdue for such maintenance anyway.
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