I think you only have a breakage risk if you are causing large flex repeatedly. If you have a Tech standard (about 19cm exposed quill) attached to an extender (about 7 more cm), that is more rise-above-headset than nearly anyone has in his/her experience. I'm much smaller, so I'm not an example. With the largest Raleighs of the day (Grand Prix came to our shops at 25 inches seat tube), you have very long steel head and steer tubes, so there's additional opportunity for elastic flex. Elastic flex is not a precursor to breakage, it's the natural flexibility of metal parts. Your head tube plus quills are around 3 times longer than mine, so there's a lot more natural flex even at the same muscular strength level. It also sounds like you have a somewhat upright riding position, hence not too much weight on the bars.
At 6'5" and 240 you're big but not huge, so I'd not be too alarmed regarding the stem. But how is your seatpost? If you've had to set the saddle back, you could have a lot of seat rail flex and possibly flexing past the elastic point. On Mon, Aug 8, 2011 at 11:42 PM, Tom <twhar...@gmail.com> wrote: > Hi all, > > Haven't posted here before but I've been reading for a while. > > I'm 6'5", and I currently have a way-too-small bike (about to order a 68 cm > Bombadil, so I'm a future Riv owner!). > > On my current 60 cm frame I have a stem riser and a Technomic Standard stem > both at the max height. The guys at my LBS think that setup is incredibly > unsafe for someone my size (~240 lb). > > I realise that it's not an ideal solution long-term, and I can feel the > flex in the front end, but has anyone heard anything about the stem risers > failing? I use the bike as a commuter, entirely on paved roads, so no real > rough stuff to speak of—the issue would be the lever force my weight exerts > on the point where the riser enters the steerer. > > Any thoughts? Should I remove it ASAP? > > I'd appreciate any advice! > > Cheers, > > Tom > > -- > You received this message because you are subscribed to the Google Groups > "RBW Owners Bunch" group. > To view this discussion on the web visit > https://groups.google.com/d/msg/rbw-owners-bunch/-/_YjWJs9jQn4J. > To post to this group, send email to rbw-owners-bunch@googlegroups.com. > To unsubscribe from this group, send email to > rbw-owners-bunch+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/rbw-owners-bunch?hl=en. > -- Ken Freeman Ann Arbor, MI USA -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
