. . . the making of XC FS racing machine - STEREO . . .
WEAKEST LINK
Published Tuesday, July 10, 2007 by indrek.
NEWS
Published by indrek.
It's been a while since the last addition to this blog, but I'm trying to fix this now! I've been busy with different things (writing my bachelor thesis and graduating school) so things have been slow around the STEREO. I hope to speed thing up a bit from now on... Good thing is that after almost two months of waiting my tubes finally arrived yesterday morning.
It turned out that Nova Cycles was the best place after all as the European suppliers were mostly missing some crucial pieces. Now before I can start machining the tubes and parts, the pivot that sits near the bottom bracket has to bee moved slightly up-and forward as it turned out that there is currently too much "bob" in the frame. When this is done the actual work can start.
It turned out that Nova Cycles was the best place after all as the European suppliers were mostly missing some crucial pieces. Now before I can start machining the tubes and parts, the pivot that sits near the bottom bracket has to bee moved slightly up-and forward as it turned out that there is currently too much "bob" in the frame. When this is done the actual work can start.
WEIGHT prt. 2.
Published by indrek.
Well I have to admit, I really like the new numbers:)
(new rocker arm, connecting parts, smaller bearings, shorter bolts and so on...)
@1780g it is more than 200g lighter than the previous version. Impressive!
(new rocker arm, connecting parts, smaller bearings, shorter bolts and so on...)
@1780g it is more than 200g lighter than the previous version. Impressive!
PROBLEMS
Published by indrek.
Last week, when I started to make the assembly drawings, it appeared that I did not have 100mm of rear wheel travel but only 83mm. I am not sure where did this mistake came in, but... Anyway when I started to fix the problem it appeared that it was almost impossible as the seat stays or rocker arm kept hitting the frame. As this wasn't enough it seemed that the shock wouldn't fit in the rocker arm...
Solution: I totally redesigned the rocker arm and changed the length of the seat stays. And the result was 100mm as promised. Also as I was re-making lot of things, I also changed the bearings to a smaller dimensions to save material and weight.
I know the new rocker arm is not even half as beautiful as the previous one, but it is almost 2 times lighter and 4 times as easy to manufacture (not to mention a lot cheaper)!
Solution: I totally redesigned the rocker arm and changed the length of the seat stays. And the result was 100mm as promised. Also as I was re-making lot of things, I also changed the bearings to a smaller dimensions to save material and weight.
I know the new rocker arm is not even half as beautiful as the previous one, but it is almost 2 times lighter and 4 times as easy to manufacture (not to mention a lot cheaper)!WEIGHT
Published Sunday, April 08, 2007 by indrek.
2062g (w.o. shock) is the first result (including all screws, seat clamp, bushings, bearings and cable stops). I'm defenitely makig it more light to get it under 2kg. Some details that I currently have from steel can be made from Al and some material shaved from some parts... Not bad:)
FINISHED
Published by indrek.
This is how it should look like. Some details may change after mechanical calculations, but the overall picture should stay the same.
MORE DETAILS
Published Thursday, April 05, 2007 by indrek.
This is BB pivot with two ceramic bearings (red):
This is left rear dropout with ceramic (red) bearing (it may still change when I've managed to do the load and stress test on ansys). Notice the extra screw for thightening the bearing:
This shows that STEREO has enough tyre clearence (this tyre is 2,1" wide):
This is left rear dropout with ceramic (red) bearing (it may still change when I've managed to do the load and stress test on ansys). Notice the extra screw for thightening the bearing:This shows that STEREO has enough tyre clearence (this tyre is 2,1" wide):
2nd PREVIEW
Published Monday, April 02, 2007 by indrek.
Changed the dropouts and seatstay to rocker piece. Also added the bridge for seat stays.
1st PREVIEW
Published by indrek.
All bearings, bolts, and nuts are yet to come as well as rear dropout solution...ALMOST DONE
Published Sunday, April 01, 2007 by indrek.
Here are the graphs from the frame. From top left: axle path, chain, forces, geometry, leverage ratio, pedal kickback, shockcurve. The result is bretty good. Although I will try to make it even better! (thats why the small pictures;)
