Post crash analysis observation
#1
Senior Member
Thread Starter
Post crash analysis observation
i crashed on the Mup yesterday at sun set. it happened at this place where Mup tramsition into sidewalk. there are obsticles ( bollards) on the ground to force cyclists to slow down. i felt like someone yanked the handlebar out of my hands...then felt the front wheel go sideways...then i was over the handlebar and on the ground...knee bleeding.
not sure what happened. i look back and only unusual thing i saw was there was 3 bumps on the ground where plastic bollards used to be. i guess i didnt see this bumps. but these bumps were not big enough to cuase my front wheel to go sideways. so something else is going on.
i had changed the handlebar twice, few weeks ago. the bike is a bolt-upright cruiser geometry with heavy swept back handlebars. i replaced the handlebar with one thats 10 degree sweep, 58mm wide...and used a 80mm stem instead of the original 30mm...so that i could lean forward a alot more.
right after this first modification, i noticed the bike felt very tweetchier. i forced myself to ride this for a week. after a week, i got used to it. but decided, it was too tweetchy for the Mup i had to ride on daily basis.
so....i replaced the h bar again...this time with a 45 deg sweep and 55mm wide. the result was much less tweetchy than the 10 deg bar...but theres still some. and i am back more upright.
i ride down these steep long ramps everyday. with 45 d bar and 80 stem, it still feels tweetchy enough that i dont dare take one hand off.
i recall with the original heaily swept bar and 35mm stem, i could ride down rhese ramps one hand easily.
one last observation about the 45 deg sweep. i felt the angle puts yur grip in a very weak position. there were instances before where my front wheel hit a small bump and i felt my hand almost was pulled off the grip. i dont think i would have crashed if i was using a 10 deg bar. so there was a tragic consequence. but i am lucky i did not hit my head or break any bones.
the bumps looks like these...but with the veritcal piece missing.
not sure what happened. i look back and only unusual thing i saw was there was 3 bumps on the ground where plastic bollards used to be. i guess i didnt see this bumps. but these bumps were not big enough to cuase my front wheel to go sideways. so something else is going on.
i had changed the handlebar twice, few weeks ago. the bike is a bolt-upright cruiser geometry with heavy swept back handlebars. i replaced the handlebar with one thats 10 degree sweep, 58mm wide...and used a 80mm stem instead of the original 30mm...so that i could lean forward a alot more.
right after this first modification, i noticed the bike felt very tweetchier. i forced myself to ride this for a week. after a week, i got used to it. but decided, it was too tweetchy for the Mup i had to ride on daily basis.
so....i replaced the h bar again...this time with a 45 deg sweep and 55mm wide. the result was much less tweetchy than the 10 deg bar...but theres still some. and i am back more upright.
i ride down these steep long ramps everyday. with 45 d bar and 80 stem, it still feels tweetchy enough that i dont dare take one hand off.
i recall with the original heaily swept bar and 35mm stem, i could ride down rhese ramps one hand easily.
one last observation about the 45 deg sweep. i felt the angle puts yur grip in a very weak position. there were instances before where my front wheel hit a small bump and i felt my hand almost was pulled off the grip. i dont think i would have crashed if i was using a 10 deg bar. so there was a tragic consequence. but i am lucky i did not hit my head or break any bones.
the bumps looks like these...but with the veritcal piece missing.
Last edited by mtb_addict; 06-01-20 at 10:39 PM.
#2
Senior Member
Join Date: May 2016
Location: Southeast US
Posts: 937
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 318 Post(s)
Liked 149 Times
in
104 Posts
Man I feel for you. Sounds like a harsh shock.
I went between some bollards a couple days ago, I had to push off of one to keep my line, even at slow speed.
How's the bike?
I went between some bollards a couple days ago, I had to push off of one to keep my line, even at slow speed.
How's the bike?
#3
Senior Member
Join Date: Jun 2013
Location: SW Fl.
Posts: 5,604
Bikes: Day6 Semi Recumbent "FIREBALL", 1981 Custom Touring Paramount, 1983 Road Paramount, 2013 Giant Propel Advanced SL3, 2018 Specialized Red Roubaix Expert mech., 2002 Magna 7sp hybrid, 1976 Bassett Racing 45sp Cruiser
Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 1063 Post(s)
Liked 771 Times
in
499 Posts
DANG, that was some dissection, OOPS - post crash analysis observation. Good to read that you made it through relatively "unscathed."
Post crash analysis observation of my crash 5 weeks ago yesterday 4/27/2020 at 1:25AM >>>>
At 150lb MAMA Wild Hog ran up and side swiped me, I went off MUP, front tire dug in, got flipped off the bike, still smarting from cracked scapula + 2 cracked ribs + punctured lung + JUST FOUND OUT YESTERDAY that I also have shoulder damage.
Post crash analysis observation of my crash 5 weeks ago yesterday 4/27/2020 at 1:25AM >>>>
At 150lb MAMA Wild Hog ran up and side swiped me, I went off MUP, front tire dug in, got flipped off the bike, still smarting from cracked scapula + 2 cracked ribs + punctured lung + JUST FOUND OUT YESTERDAY that I also have shoulder damage.
#4
Senior Member
Thread Starter
the bike is a tank...no damage at all. just twisted the steering stem out of alignment.
i realized later my right shoulder got messed up. it hurts a little when i put pressure on it.
after two days, the knee hurts more than before. it is too painful to walk down stairs now.
i wonder if it is infected.
i realized later my right shoulder got messed up. it hurts a little when i put pressure on it.
after two days, the knee hurts more than before. it is too painful to walk down stairs now.
i wonder if it is infected.
#5
Senior Member
Join Date: Jun 2014
Location: Ontario, Canada
Posts: 4,655
Bikes: iele Latina, Miele Suprema, Miele Uno LS, Miele Miele Beta, MMTB, Bianchi Model Unknown, Fiori Venezia, Fiori Napoli, VeloSport Adamas AX
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1324 Post(s)
Liked 927 Times
in
640 Posts
Those sections that support the bollards could easily deflect a front wheel if hit on the wrong spot with the bollards removed. With the bollards removed I'd considerthem a bicycling hazard.
On a trail I rode sometimes they decided to put up a barrier gate but supposedly left enough room on the right side(as you are approaching it form the west side) but they also put in another steel post. Unfortunately that post wa hidden by brush/leaves and when I moved right to miss the barrier I hit that steel post. A few scrapes becuase I was knocked down and my front fork was pushed sideways a bit.
Some infrastructure seems to NOT be designed with bicyclists in mind and in low light it can be downright dangerous.
I'm glad you're okay.
You might want to mention your experience to your local council or whomever is responsible for those bollards. It might prevent it from happening to some other poor soul.
Cheers
On a trail I rode sometimes they decided to put up a barrier gate but supposedly left enough room on the right side(as you are approaching it form the west side) but they also put in another steel post. Unfortunately that post wa hidden by brush/leaves and when I moved right to miss the barrier I hit that steel post. A few scrapes becuase I was knocked down and my front fork was pushed sideways a bit.
Some infrastructure seems to NOT be designed with bicyclists in mind and in low light it can be downright dangerous.
I'm glad you're okay.
You might want to mention your experience to your local council or whomever is responsible for those bollards. It might prevent it from happening to some other poor soul.
Cheers
Likes For Miele Man:
#6
For The Fun of It
Join Date: May 2007
Location: Louisissippi Coast
Posts: 5,843
Bikes: Lynskey GR300, Lynskey Backroad, Litespeed T6, Lynskey MT29, Burley Duet
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 2131 Post(s)
Liked 1,639 Times
in
822 Posts
Front wheel washout has been what's taken me down the last 3 times I have been down on the road. Different reasons for the washout each time. If I understand what you are saying correctly, those bollard bases could definitely wash out a front wheel.
#7
Senior Member
Join Date: May 2005
Location: Queanbeyan, Australia.
Posts: 4,135
Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
Quoted: 3450 Post(s)
Liked 420 Times
in
289 Posts
Sorry about your crash.
I'm not 100% sure that I understand your handlebar changes, however, if nothing else changes other than moving your hand position forwards, this really should make the bike more stable. Moving the bars back with back sweep usually makes them twitchier.
The only thing I can think of is that you have changed the headset adjustment when you changed the bars.
How well adjusted is the headset and what type is it? A-head or quill?
I'm not 100% sure that I understand your handlebar changes, however, if nothing else changes other than moving your hand position forwards, this really should make the bike more stable. Moving the bars back with back sweep usually makes them twitchier.
The only thing I can think of is that you have changed the headset adjustment when you changed the bars.
How well adjusted is the headset and what type is it? A-head or quill?
#8
Senior Member
Join Date: Jun 2016
Posts: 147
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 55 Post(s)
Liked 67 Times
in
44 Posts
It's very clear that on this bike, with a long stem, flatter bars = twitchier handling and worse hand grip.
Conclusion: put the original stem and bars back on, they make the bike work MUCH BETTER.
(If you're feeling adventurous, try the 10 & 45 degree bars with the original stem.)
#9
Senior Member
Join Date: May 2005
Location: Queanbeyan, Australia.
Posts: 4,135
Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
Quoted: 3450 Post(s)
Liked 420 Times
in
289 Posts
While you are correct in theory--and there is probably a complex combination of specific factors at play that the OP describes as "swapped bars & stem, handling changed"--direct experience trumps theory.
It's very clear that on this bike, with a long stem, flatter bars = twitchier handling and worse hand grip.
Conclusion: put the original stem and bars back on, they make the bike work MUCH BETTER.
(If you're feeling adventurous, try the 10 & 45 degree bars with the original stem.)
It's very clear that on this bike, with a long stem, flatter bars = twitchier handling and worse hand grip.
Conclusion: put the original stem and bars back on, they make the bike work MUCH BETTER.
(If you're feeling adventurous, try the 10 & 45 degree bars with the original stem.)
#10
Senior Member
Join Date: Mar 2007
Location: SF Bay Area, East bay
Posts: 8,680
Bikes: Miyata 618 GT, Marinoni, Kestral 200 2002 Trek 5200, KHS Flite, Koga Miyata, Schwinn Spitfire 5, Mondia Special, Univega Alpina, Miyata team Ti, Santa Cruz Highball
Mentioned: 52 Post(s)
Tagged: 0 Thread(s)
Quoted: 1589 Post(s)
Liked 2,486 Times
in
1,188 Posts
i crashed on the Mup yesterday at sun set. it happened at this place where Mup tramsition into sidewalk. there are obsticles ( bollards) on the ground to force cyclists to slow down. i felt like someone yanked the handlebar out of my hands...then felt the front wheel go sideways...then i was over the handlebar and on the ground...knee bleeding.
not sure what happened. i look back and only unusual thing i saw was there was 3 bumps on the ground where plastic bollards used to be. i guess i didnt see this bumps. but these bumps were not big enough to cuase my front wheel to go sideways. so something else is going on.
i had changed the handlebar twice, few weeks ago. the bike is a bolt-upright cruiser geometry with heavy swept back handlebars. i replaced the handlebar with one thats 10 degree sweep, 58mm wide...and used a 80mm stem instead of the original 30mm...so that i could lean forward a alot more.
right after this first modification, i noticed the bike felt very tweetchier. i forced myself to ride this for a week. after a week, i got used to it. but decided, it was too tweetchy for the Mup i had to ride on daily basis.
so....i replaced the h bar again...this time with a 45 deg sweep and 55mm wide. the result was much less tweetchy than the 10 deg bar...but theres still some. and i am back more upright.
i ride down these steep long ramps everyday. with 45 d bar and 80 stem, it still feels tweetchy enough that i dont dare take one hand off.
i recall with the original heaily swept bar and 35mm stem, i could ride down rhese ramps one hand easily.
one last observation about the 45 deg sweep. i felt the angle puts yur grip in a very weak position. there were instances before where my front wheel hit a small bump and i felt my hand almost was pulled off the grip. i dont think i would have crashed if i was using a 10 deg bar. so there was a tragic consequence. but i am lucky i did not hit my head or break any bones.
the bumps looks like these...but with the veritcal piece missing.
not sure what happened. i look back and only unusual thing i saw was there was 3 bumps on the ground where plastic bollards used to be. i guess i didnt see this bumps. but these bumps were not big enough to cuase my front wheel to go sideways. so something else is going on.
i had changed the handlebar twice, few weeks ago. the bike is a bolt-upright cruiser geometry with heavy swept back handlebars. i replaced the handlebar with one thats 10 degree sweep, 58mm wide...and used a 80mm stem instead of the original 30mm...so that i could lean forward a alot more.
right after this first modification, i noticed the bike felt very tweetchier. i forced myself to ride this for a week. after a week, i got used to it. but decided, it was too tweetchy for the Mup i had to ride on daily basis.
so....i replaced the h bar again...this time with a 45 deg sweep and 55mm wide. the result was much less tweetchy than the 10 deg bar...but theres still some. and i am back more upright.
i ride down these steep long ramps everyday. with 45 d bar and 80 stem, it still feels tweetchy enough that i dont dare take one hand off.
i recall with the original heaily swept bar and 35mm stem, i could ride down rhese ramps one hand easily.
one last observation about the 45 deg sweep. i felt the angle puts yur grip in a very weak position. there were instances before where my front wheel hit a small bump and i felt my hand almost was pulled off the grip. i dont think i would have crashed if i was using a 10 deg bar. so there was a tragic consequence. but i am lucky i did not hit my head or break any bones.
the bumps looks like these...but with the veritcal piece missing.
#11
WALSTIB
Like changing the door hinges after you slammed your finger in the door
#12
Senior Member
Thread Starter
Spending a few days indoor to heal my wounded knee, gave me a lot of time to reflect and do research.
Regarding the hbar forward/aft positioning, using a longer (forw/aft) stem in my case, puts my hand closer to the axis of rotation (See foto below.). According to Sheldon article on English Roadsters, this change will majke steering less stable.
This is the old 40mm stem (more aft). My hand would be behind the rotation axis.
But the current 80mm stem (more forward), looks like this.
Last edited by mtb_addict; 06-08-20 at 03:56 AM.
#13
Senior Member
Thread Starter
Regarding the steering bearing tighteness...
my steer bearing is perfectly adjusted...no freeplay...no drag.
but, i guess i can try to tighten the bearing a tad more...maybe a bit of drag will help.
one more thing, is that with the more forward stem, putting my body weight on the bar will make it feel less stable. for example, if i coming down steep ramp and put my body weight on the bar, it will feel wobble. it was scary, the first time i felt it...it was a steep ramp down a 4 story garage.
my steer bearing is perfectly adjusted...no freeplay...no drag.
but, i guess i can try to tighten the bearing a tad more...maybe a bit of drag will help.
one more thing, is that with the more forward stem, putting my body weight on the bar will make it feel less stable. for example, if i coming down steep ramp and put my body weight on the bar, it will feel wobble. it was scary, the first time i felt it...it was a steep ramp down a 4 story garage.
Last edited by mtb_addict; 06-07-20 at 08:36 PM.
#14
Senior Member
Thread Starter
Another thing I recall is that few weeks ago, I had a close call. I didnt think much about it at the time.
I was riding at slow speed. There was nothing on the ground but smooth pavement. I was trying to make a tight turn, and all of sudden, it felt like the hbar wants to pull out of my hands. It was such a wierd feeling I never felt before. i had a light grip on the bar.
at the time, i attributed it to user error.
I was riding at slow speed. There was nothing on the ground but smooth pavement. I was trying to make a tight turn, and all of sudden, it felt like the hbar wants to pull out of my hands. It was such a wierd feeling I never felt before. i had a light grip on the bar.
at the time, i attributed it to user error.
Last edited by mtb_addict; 06-07-20 at 08:39 PM.
#15
Senior Member
Join Date: Oct 2013
Location: Mich
Posts: 7,291
Bikes: RSO E-tire dropper fixie brifter
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked 2,909 Times
in
1,884 Posts
It just dawned on me; maybe you should put the more predictable setup back on before you cause probable harm to someone else.....
js
js
__________________
-Oh Hey!
-Oh Hey!
#16
Senior Member
Join Date: May 2005
Location: Queanbeyan, Australia.
Posts: 4,135
Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
Quoted: 3450 Post(s)
Liked 420 Times
in
289 Posts
Regarding the steering bearing tighteness...
my steer bearing is perfectly adjusted...no freeplay...no drag.
but, i guess i can try to tighten the bearing a tad more...maybe a bit of drag will help.
one more thing, is that with the more forward stem, putting my body weight on the bar will make it feel less stable.
my steer bearing is perfectly adjusted...no freeplay...no drag.
but, i guess i can try to tighten the bearing a tad more...maybe a bit of drag will help.
one more thing, is that with the more forward stem, putting my body weight on the bar will make it feel less stable.
Steerng from behind the centre point can be even wonkier than at the centre point yet I don't really believe that this is your problem. Is the front wheel aligned in the forks?
EDIT: and maybe the headset bearings are worn out. If it was me I would be pulling it apart and checking it before cleaning it and rebuilding it with fresh grease.
#17
Senior Member
Thread Starter
yes. perfect alignment. The rear triangle also align good.
One thing though....is that there is alot low speed wheel flop...and it is dominant to left side.
Last edited by mtb_addict; 06-07-20 at 08:52 PM.
#18
Senior Member
Join Date: May 2005
Location: Queanbeyan, Australia.
Posts: 4,135
Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
Quoted: 3450 Post(s)
Liked 420 Times
in
289 Posts
no movement. i spent alot of time adjusting the steering bearing, to get it right, when i first got the bike in January. But i didnt regrease it, cuz it felt smooth enough.
yes. perfect alignment. The rear triangle also align good.
One thing though....is that there is alot low speed wheel flop...and it is dominant to left side.
yes. perfect alignment. The rear triangle also align good.
One thing though....is that there is alot low speed wheel flop...and it is dominant to left side.
Well I'm guessing that that's it. Redo the front wheel bearings.
#19
Senior Member
Thread Starter
Went back to scene of the crime. I hadden realized how big those bumps were. until i got closer to take these pics. ..Thats a 12 inch pump.
i landed near the first patch of grass.
it looks like the top poles were sawed off!
i landed near the first patch of grass.
it looks like the top poles were sawed off!
Last edited by mtb_addict; 06-08-20 at 04:11 AM.
#20
Senior Member
Thread Starter
On the way back to the scene of the crime, I noticed how hard and slippery the rubber grips are. When the path got unexpectedly bumpy, my right hand almost slipped off!
Last edited by mtb_addict; 06-08-20 at 06:07 AM.
#21
Senior Member
Join Date: Jun 2014
Location: Ontario, Canada
Posts: 4,655
Bikes: iele Latina, Miele Suprema, Miele Uno LS, Miele Miele Beta, MMTB, Bianchi Model Unknown, Fiori Venezia, Fiori Napoli, VeloSport Adamas AX
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1324 Post(s)
Liked 927 Times
in
640 Posts
Yes, those images in Post #19 seem to confirm my earlier idea that if your front wheel hit the side of one of those bollard bases that the front wheel could very easily get deflected. You could be down before you even realized it. Those remaining bases are accidents waiting toi happen especially if the bases are wet from dew or rain.
Cheers
Cheers
#22
Senior Member
Thread Starter
Yes, those images in Post #19 seem to confirm my earlier idea that if your front wheel hit the side of one of those bollard bases that the front wheel could very easily get deflected. You could be down before you even realized it. Those remaining bases are accidents waiting toi happen especially if the bases are wet from dew or rain.
Cheers
Cheers
It was a confluence of multiple events at the same time: getting dark, destracted by lots of pedestrian, complacency bec i was almost home, fatique, slippery rubber grips.
#23
Senior Member
Join Date: Jun 2014
Location: Ontario, Canada
Posts: 4,655
Bikes: iele Latina, Miele Suprema, Miele Uno LS, Miele Miele Beta, MMTB, Bianchi Model Unknown, Fiori Venezia, Fiori Napoli, VeloSport Adamas AX
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1324 Post(s)
Liked 927 Times
in
640 Posts
Cheers