33,485 reputation
13295
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location Minnesota, USA
age
visits member for 3 years, 8 months
seen 1 hour ago

Old, tired, crazy.


1h
comment Would a person standing on the top tube damage a carbon fibre road bike?
The videos show that if the tube is not straight it loses considerable integrity in compression. This is no surprise to an engineer. The "bending" that occurs is due to the "poor" design of the frame (from the standpoint of structural engineering principles), and it occurs when the top member is in reasonably pure compression, with no significant bending moment applied.
6h
comment Would a person standing on the top tube damage a carbon fibre road bike?
You will notice that they're not testing diamond frames. And, in real life, I've seen seen several bikes damaged by twist -- the fact that they didn't test for it is irrelevant (or perhaps deceptive).
7h
comment How can I avoid mud from splashing onto my back without a rear wheel fender?
Don't ride in the mud.
22h
comment Would a person standing on the top tube damage a carbon fibre road bike?
A lot depends on the style of bike. Blam's bike is a heavily-built off-road bike, others have lightweight racing bikes. You can't compare them.
23h
comment Would a person standing on the top tube damage a carbon fibre road bike?
@Blam - A "simple 2 foot drop" does not put any significant bending force on the tube. It's all compression/twisting. A pipe (any pipe) is very strong in compression, tension, or torsion, but very much weaker when force is applied laterally to the middle.
23h
comment Would a person standing on the top tube damage a carbon fibre road bike?
@Blam - It's true that in an crash an substantial amount of force might be applied laterally to the top tube. And it's not terribly unusual for bike frames (especially lightweight bikes) to be damaged in crashes. In ordinary operation, though, there is nothing present that would apply such lateral force.
1d
comment Would a person standing on the top tube damage a carbon fibre road bike?
Yes, a BSO from Wally World will probably support more weight on its top tube than any sort of fancy bike. In your traditional diamond frame there is very little "bending moment" on the tubes -- it's all tension/compression -- and the tubes do not need to be made to greatly resist bending. In the name of lightness the tubes of better quality bikes are made as thin as practical, and, eg, steel bikes generally have "double butted" tubes that have thinner walls in the middle than on the ends.
2d
comment Would a person standing on the top tube damage a carbon fibre road bike?
I would say that there's a danger on any lightweight bike. The center of the tube is its weakest point.
Jan
28
comment Is it safe to ride a steel bike with a dented/buckled frame?
(I once saw a bike with the down tube rusted completely in two, and still being ridden. Not that I recommend that.)
Jan
28
comment Is it safe to ride a steel bike with a dented/buckled frame?
While the dent there is not good, it doesn't look terribly bad. Where your dent is is probably about the lowest-stress location on the frame -- if you were going to dent it, that's the place to do it.
Jan
28
comment What size is the tiny ball bearing used in SRAM brake caliper quick release detents?
I've seen some pretty small balls inside a freewheel.
Jan
26
comment Hamstring pain while cycling
It sounds likely that your seat is too low. Your knee should be almost straight at the bottom of the stroke, while seated.
Jan
26
comment Brake pads and removing the wheels
(It's not "normal", but it happens, and is likely more common on "fat tire" bikes. It is unusual on road bikes, however.)
Jan
26
comment Brake pads and removing the wheels
There are several different brake designs, so perhaps you should describe yours better, or,better still, include a picture.
Jan
26
comment What size is the tiny ball bearing used in SRAM brake caliper quick release detents?
Likely any bearing of about the right size will work -- doesn't have to be exact. And any bike shop should have an assortment of balls, if you can't find something in your junk drawer.
Jan
26
comment How do I remove old hockey tape from drop bars
I generally start with regular bar tape and then apply the hockey tape when the bar tape begins to slide (which only takes a few weeks). A new layer is then applied over the old every year or two, after peeling off any bits that have come loose.
Jan
26
comment Wear and tear and warranty
When you figure chain length, don't measure the length of the old chain, count the number of links.
Jan
26
comment Schwalbe Marathon Plus recurring puncture - options?
FWIW, I favor Tyvek-belted tires over the ones, like Schwalbe, which simply use a plastic belt. The Tyvek is much more puncture resistant, and I feel that it's lower rolling resistance as well.
Jan
26
comment Schwalbe Marathon Plus recurring puncture - options?
Yeah, it sounds like there's still something embedded in the tire. Either that or the hole is large enough that the tube is simply ballooning through. (The hole does look pretty large in the pictures.) If it's just the hole enlarged you can boot it with either a commercial boot or a piece cut from the sidewall of an old tire. If there's something still embedded at this point then you'll probably destroy the tire trying to get it out, so just get a new tire.
Jan
26
comment How do I remove old hockey tape from drop bars
(And hockey tape really is the best thing for handlebars. Though it seems like the last stuff I bought was poorer quality than previous -- like everything else, I guess.)