Wheel and arm bent

Hello again,

I posted here about a month ago, enquiring about how much I should spend on
a new bike. After reading the many helpful responses, I bought a new Trek
3500 with semi-slick tyres and was happily riding it to work and back every
day.

On Tuesday, I was almost home, cycled off the road onto the pavement near my
house, and before I knew it I'd gone over the front and hit the ground, the
bike flipped over once and then stopped. When I picked myself and the bike
up, I noticed I couldn't push the bike as the wheel was bent quite badly.
Since the bike didn't hit anything else after I fell off, I can only assume
that the wheel must've bent as I hit the kerb, and the bent wheel was what
caused me to crash (it's a perfectly straight bit of road pavement, not the
sort of place where you think anyone could have an accident). In the fall I
fractured my radius near the elbow, which is proving to be a considerable
nuisance!

I hit the kerb between pavement and road where the pavement ramps down to
the road, so the kerb was not more than 2 or 3 cm high. It was at quite an
oblique angle (i.e. I went up the kerb almost parallel to it , not straight
at it) and I was doing about 20mph or less. Should this cause a MTB wheel
to fail?

I took it back to the shop today, expecting sympathy, explanations, a
replacement wheel and perhaps apologies. I didn't get any of that. Looking
at the wheel, they agreed it must've been some sideways force that bent the
wheel, as there were no marks on the rim that would've indicated a big
impact from the front, they looked at it in more detail the workshop, then
said it was too bent to repair and suggested I buy a new one. I was pretty
incensed at this, and suggested that a 3 week old mountain bike wheel should
not be expected to fail going over a 3cm kerb at 20 mph, and that as such it
wasn't fit for its purpose. They looked at me with disbelief, shrugged and
said the only other thing they could do was send it back to Trek for
analysis and see what Trek had to say, so I agreed to that.

Am I going mad? Assuming you believe I'm telling the truth, and that I
really didn't ride it into a wall at 50mph or something similary stupid,
shouldn't a mountain bike wheel take a bit more stick than this? Doesn't the
fact that the wheel is badly bent indicate that it's failed? Shouldn't the
shop be a bit more sympathetic??

Roger

Roja Doja wrote:
...............
I hit the kerb between pavement and road where the pavement ramps
down to the road, so the kerb was not more than 2 or 3 cm high.

Can you go back and measure the exact height to check?

It was at quite an oblique angle (i.e. I went up the kerb almost
parallel to it , not straight at it) and I was doing about 20mph or
less. Should this cause a MTB wheel to fail?

First of all, regardless of wheel strength, it's really dangerous to go up
a kerb at an oblique angle, full stop. You can loose control all too
easily, as you've found. Always take any kerbs straight on and at low
speed, easing your weight off the wheels.

Wheels aren't always built very well (in terms of spoke tension) but it's
highly unlikely that the *rim* was not of "merchantable quality" or "fit
for the purpose" when you bought it. Even the cheapest rims tend to stand
up to all normal use ok in this respect.

If the rim is actually dented in (with a distinct dent in the sidewall
edge) then it's probably entirely your fault. That usually means the tyre
was soo soft or you had a severe impact. A minor bump couldn't do that.

If not dented but the wheel is buckled, again that could just be from the
impact, but poor building can contribute: by spokes being under, over or
unevenly tensioned. The supplier could possibly be to blame then, but I
think it's unlikely.

Another very real possibility (especially if no distinct dent in rim) is
that you lost control because of the oblique angle and the wheel buckled
*after* the initial impact. That would definitely be entirely your fault.

Anyway, hope the injury heals quickly (that's more important).

Note: Wheel can be rebuilt using existing hub and spokes. Don't need a
whole new wheel.

~PB

Roja Doja posted ...

Am I going mad? Assuming you believe I'm telling the truth, and that
I really didn't ride it into a wall at 50mph or something similary
stupid, shouldn't a mountain bike wheel take a bit more stick than
this?

Riding up a kerb is a big no-no .. especially on a cycle. If you kit a kerb
square, or nearly square on, then you can sometimes get away with it, but
more often than not you'll hit at an angle, as you describe, and the tyre
simply won't be able to grip enough to go over the kerb, so 'slips off'
sideways, probably buckling the wheel - this sounds exactly what you've
done. Whenever I go up a kerb I lean way back and lift the front wheel up,
then bunny-hop the rear over the lip, as though it's a jump lip .. I rarely
do this at a very (nearly parallel you said) oblique angle, unless I'm doing
a full bunny-hop, the tyres simply can't cope .. and neither can _any_ wheel
...

Doesn't the fact that the wheel is badly bent indicate that
it's failed?

Depends how badly bent badly bent is. If the rim has _any_ kinks or steps,
or dents in it then I'd never use it again. If it's bent further than, say,
30 degrees from straight then again I'd never use it again except in an
emergency, though a lot depends on exactly how it's bent, and is hard to
describe adequately without a picture ..

In the situation you have described the wheel isn't being used in any
'normal' manner of riding, including competition riding, and is almost
definitely unlikely to be covered by any potential warranty.

Shouldn't the shop be a bit more sympathetic??

Why ? If you ran up a kerb without un-weighting the front-end then you
possibly deserve all you get .. and have been very lucky to get away so
lightly.

PS Get well soon ..


--
Paul

(8(|) Homer rocks ..

"Pete Biggs" wrote in message
...
Roja Doja wrote:
..............
I hit the kerb between pavement and road where the pavement ramps
down to the road, so the kerb was not more than 2 or 3 cm high.

Can you go back and measure the exact height to check?

As it's just outside, yes! It varies between about 1.5 to 2.5 cm (which
seems almost nothing kerb-wise)

It was at quite an oblique angle (i.e. I went up the kerb almost
parallel to it , not straight at it) and I was doing about 20mph or
less. Should this cause a MTB wheel to fail?

First of all, regardless of wheel strength, it's really dangerous to go up
a kerb at an oblique angle, full stop. You can loose control all too
easily, as you've found. Always take any kerbs straight on and at low
speed, easing your weight off the wheels.

Easy if you're crossing a road, but I guess if you're coming off a busy
road, you can't really pull out into the middle of the road so you can turn
towards the kerb straight-on can you? At least I've never seen anyone
attempt that! Perhaps I should've pulled over and got off, then lifted the
bike onto the pavement, maybe if I had a race bike with super skinny wheels
I'd have been more inclined to do that, but I assumed it wouldn't be a
problem riding a mountain bike with bit fat tyres, it's never been a problem
before. My arm tells me I was wrong though!

Perhaps the rock-hard tyre pressures and aluminium frame make the new bike
more of a precision-machine, and maybe it's more unforgiving than the crap
old bikes with half-inflated tyres I was used to riding.

Wheels aren't always built very well (in terms of spoke tension) but it's
highly unlikely that the *rim* was not of "merchantable quality" or "fit
for the purpose" when you bought it. Even the cheapest rims tend to stand
up to all normal use ok in this respect.

If the rim is actually dented in (with a distinct dent in the sidewall
edge) then it's probably entirely your fault. That usually means the tyre
was soo soft or you had a severe impact. A minor bump couldn't do that.

No dents, and the tires (and ride) are rock hard, as supplied by the shop.

If not dented but the wheel is buckled, again that could just be from the
impact, but poor building can contribute: by spokes being under, over or
unevenly tensioned. The supplier could possibly be to blame then, but I
think it's unlikely.

Buckled is probably the word, looking along the line of wheel, it's
bent/warped into a kind of s shape, but looks otherwise ok, no dents, tyres
still pumped up and OK.

Another very real possibility (especially if no distinct dent in rim) is
that you lost control because of the oblique angle and the wheel buckled
*after* the initial impact. That would definitely be entirely your fault.

I'd concede this is a possibility, I'm just not sure how my losing control
and then falling off could cause the wheel to buckle? The bike didn't hit
anything, I had my hands on the handlebars, it just kind of wobbled,
stopped, I went over, the bike tipped over and then hit the ground. Without
my weight on it, I'd have thought that was even less likely to be the cause
of wheel buckling?

Anyway, hope the injury heals quickly (that's more important).

Thanks.

Note: Wheel can be rebuilt using existing hub and spokes. Don't need a
whole new wheel.

Yes, I guess that was what they meant when they talked about a buying a new
one (new rim?). To be honest at that point I was a bit miffed and not
listening attentively. Because of my injury I can't ride it for a few weeks
anyway, so it'll do no harm sending the wheel back to Trek. If they say
there was nothing wrong with it, and I have to buy a new rim and have it
rebuilt, it won't be the end of the world, I guess I'll just learn to
appreciate that wheels can be fragile, and approach kerbs with more caution
in future.

Cheers,
Roger

"Paul - xxx" wrote in message
...
[snip]
In the situation you have described the wheel isn't being used in any
'normal' manner of riding, including competition riding, and is almost
definitely unlikely to be covered by any potential warranty.

If I was taking about mounting a full kerb, then maybe I'd agree, but I'm
talking about the bit where the pavement ramps down to the road, I mean,
it's almost dead level with the road. I've never before felt I shouldn't
ride up or down these on a bike, (well perhaps other than normally one
wouldn't be on the pavement anyway, but I was outside my own house...) so if
this is really not 'normal' riding, then perhaps they should give some sort
of warning to new riders?

PS Get well soon ..

Thanks!

Roger

Roja Doja wrote:

"Paul - xxx" wrote in message
...
[snip]

In the situation you have described the wheel isn't being used in any
'normal' manner of riding, including competition riding, and is almost
definitely unlikely to be covered by any potential warranty.


If I was taking about mounting a full kerb, then maybe I'd agree, but I'm
talking about the bit where the pavement ramps down to the road, I mean,
it's almost dead level with the road. I've never before felt I shouldn't
ride up or down these on a bike, (well perhaps other than normally one
wouldn't be on the pavement anyway, but I was outside my own house...) so if
this is really not 'normal' riding, then perhaps they should give some sort
of warning to new riders?

Dropped kerbs can be badly aligned. You described it being up to an
inch high, which I reckon's too much for mounting at an oblique
angle. If meant for cycling up (i.e. you were joining a cycle path
on the pavement) then I'd consider a complaint to the council.

I wouldn't ever attempt to ride up such a high kerb at 20mph.

Simon

"Simon Proven" wrote:
[snip]
Dropped kerbs can be badly aligned. You described it being up to an
inch high, which I reckon's too much for mounting at an oblique
angle. If meant for cycling up (i.e. you were joining a cycle path
on the pavement) then I'd consider a complaint to the council.

I wouldn't ever attempt to ride up such a high kerb at 20mph.

Fair enough, given opinion so far, I forsee I won't be attempting to ride up
dropped kerbs again.

I don't think I'd like to actually put the bike to its supposed use then,
and ride it down a mountain, if a 1.5cm-2.5cm lip is enough to cause
problems?

Roger

On Fri, 28 May 2004 18:26:09 +0000 (UTC), "Roja Doja"
wrote:


If I was taking about mounting a full kerb, then maybe I'd agree, but I'm
talking about the bit where the pavement ramps down to the road, I mean,
it's almost dead level with the road. I've never before felt I shouldn't
ride up or down these on a bike, (well perhaps other than normally one
wouldn't be on the pavement anyway, but I was outside my own house...) so if
this is really not 'normal' riding, then perhaps they should give some sort
of warning to new riders?

I'm with you Roja, riding up the dropped part of the kerb that you
described (1.5 - 2.5cm) really isn't dangerous at all IMHO. It
certainly shouldn't be enough of a hazard to threaten the integrity of
your front wheel. I'm a pretty hefty bloke myself and I often clatter
up and down kerbs. This is full kerbs too, not just dropped sections,
and I have no trouble. Granted I don't do this when out on my "best"
bike, delicate wheels and all that, but on either of the hacks I don't
give it a second thought.

The point that has been made about being careful when tackling the
kerb at a shallow angle is valid, but as long as you are aware of the
danger this shouldn't cause a problem. Unweight each wheel as it
passes over the kerb and be positive in your steering. You can improve
the angle of "attack" without needing to sweep out and ride full on at
90 degrees - just a small lean and swerve at the appropriate (last!)
moment will help a lot.

You said you went over the handlebars which means the bike must have
stopped pretty darned sharpish. This isn't what would happen if you'd
just buggered up mounting the kerb at a narrow angle. If it had been
that then your front wheel would have slipped sideways along the edge
of the kerb and your balance would have been thrown off line. You'd
have gone down more sideways onto the kerb than over the bars.

Given how you described the incident I'm at a loss to understand how
the wheel was buckled so badly.

As Pete said, hope the elbow heals fast and you can get back to riding
soon.

Chin up
--

"Bob"

'The people have spoken, the *******s'

Email address is spam trapped.
To reply directly remove the beverage.

in message , Roja Doja
') wrote:

Hello again,

I posted here about a month ago, enquiring about how much I should
spend on
a new bike. After reading the many helpful responses, I bought a new
Trek 3500 with semi-slick tyres and was happily riding it to work and
back every day.

On Tuesday, I was almost home, cycled off the road onto the pavement
near my house, and before I knew it I'd gone over the front and hit
the ground, the
bike flipped over once and then stopped. When I picked myself and the
bike up, I noticed I couldn't push the bike as the wheel was bent
quite badly. Since the bike didn't hit anything else after I fell off,
I can only assume that the wheel must've bent as I hit the kerb, and
the bent wheel was what caused me to crash (it's a perfectly straight
bit of road pavement, not the
sort of place where you think anyone could have an accident). In the
fall I fractured my radius near the elbow, which is proving to be a
considerable nuisance!

I hit the kerb between pavement and road where the pavement ramps down
to
the road, so the kerb was not more than 2 or 3 cm high. It was at
quite an oblique angle (i.e. I went up the kerb almost parallel to it
, not straight
at it) and I was doing about 20mph or less. Should this cause a MTB
wheel to fail?

It most certainly should not do. I assume it was the front wheel which
bent? Was your tyre reasonably hard? Had you had any problems with
broken spokes before? Did you break any spokes in this incident? Do you
have any memory of the handlebars twisting round violently in the
incident (wheels are much less strong laterally than they are to forces
perpendicular to their axis)?

The oblique angle may have something to do with it (not generally a good
idea if you can avoid it) but given the very small size of the bump I'm
surprised.

I was
pretty incensed at this, and suggested that a 3 week old mountain bike
wheel should not be expected to fail going over a 3cm kerb at 20 mph,
and that as such it
wasn't fit for its purpose.

I'd agree with that.

Am I going mad? Assuming you believe I'm telling the truth, and that
I really didn't ride it into a wall at 50mph or something similary
stupid, shouldn't a mountain bike wheel take a bit more stick than
this?

Yes. It _must_ do, otherwise it isn't safe. Even quite ordinary off-road
cycling involves hitting things a lot bigger than 3cm at 20mph and
more. One of my regular runs involves coming down a stone chute with
rocks the size of turnips[1] and I must hit them at at least twenty.

Doesn't the
fact that the wheel is badly bent indicate that it's failed?
Shouldn't the shop be a bit more sympathetic??

Yes. But I have some sympathy for them, too. People do do ridiculously
silly things on bikes. Still, in this incident, with a near new bike I
would have thought a free replacement or rebuild would be the least
they could do.

[1] Not your namby pamby little white English turnips.

--
(Simon Brooke) http://www.jasmine.org.uk/~simon/
;; Skill without imagination is craftsmanship and gives us
;; many useful objects such as wickerwork picnic baskets.
;; Imagination without skill gives us modern art.
;; Tom Stoppard, Artist Descending A Staircase

Roja Doja posted ...

"Simon Proven" wrote:
[snip]
Dropped kerbs can be badly aligned. You described it being up to an
inch high, which I reckon's too much for mounting at an oblique
angle. If meant for cycling up (i.e. you were joining a cycle path
on the pavement) then I'd consider a complaint to the council.

I wouldn't ever attempt to ride up such a high kerb at 20mph.

Fair enough, given opinion so far, I forsee I won't be attempting to
ride up dropped kerbs again.

I don't think I'd like to actually put the bike to its supposed use
then, and ride it down a mountain, if a 1.5cm-2.5cm lip is enough to
cause problems?

It's not just the height of the kerb, it's your manner of approach that's
part of the problem too. In normal circumstances you can hit rocks etc that
are far bigger, but they'll not be quite as solid as a solid thing and will
give somewhat. A kerb doesn't give ...

I'd say, based upon your descriptions, that it's a combination of
circumstances that led to the wheel buckling and isn't at all indicative of
a particular problem with the wheel.

Dropped kerbs are mostly fine to ride up, I do it all the time without
thinking, but not when almost parallel, as you first described ..


--
Paul

(8(|) Homer rocks ..