Seat bolt snap - Advice

meso100

Hi

I left a thread here last year about me falling off the back of my bike because the seat bolt snapped which released the clamps and thus the seat from the post. I then landed on the post and scraped my chest! Not very pleasant!

Anyway, I got a stronger bolt and have been fine for 9 months until today that is! The bolt snapped again and released the clamps and the seat fell off although this time I landed on the seat post with my right testicle!! Sore isn't the word!

Ok so, everyone who I have spoken to have not experienced this before and told me to ring a Giant specialist. I did and they haven't heard of it either.

Is it my fault the seat bolt is snapping? The seat bolt is tight but I sit down a lot on long rides and weigh 15 1/2 stone. Is it because I am too heavy?

My real question is should I get a different seat post maybe one with a double bolt as opposed to my singular one (standard Giant post/clamp)? Any suggestions?

Many thanks
Mr Sore Bollox

cooldad

Ouch. Never seen that happen before. Maybe you are tightening the bolt too much.
Probably worth trying a better quality seatpost. Nukeproof are tough and cheap.

meso100

That would be good as I have a Nuke Proof stem.

I'll have a look now to see if they have any double bolt ones.

Is there a benefit of going double bolt? Possibly that the stress is put through two points instead of one?

s_blanche@hotmial.co.uk

this happened to me a couple years back... tho from the sound of it no where near as painful as your experiences :shock:

i slightly adjusted my bars so i could move my saddle further inwards on the rails and still have a comfortable riding position... longer bolt, some "locktight" and job done, still sweet as 8)

cooldad

As far as I know the Nukeproof have two bolts - microadjust

cooldad

s_blanche@hotmial.co.uk wrote:

i slightly adjusted my bars so i could move my saddle further inwards on the rails and still have a comfortable riding position... longer bolt, some "locktight" and job done, still sweet as 8)

That could be a point, if your saddle is at an extreme putting too much strain on the mounting.

meso100

Not a bad review from bikeradar http://www.bikeradar.com/gear/category/ ... ead-35737/

Can bag one for less than £30 too! Shall I get one ordered then?

Is locktight advisable for a bolt? I might try it but wonder if this affects the way the bolt deals with the stress...

meso100

See the below pics taken only the other day. This was the angle of the seat.

Thoughts please

http://db.tt/Gy2O2TP
http://db.tt/Xl3oICn

s_blanche@hotmial.co.uk

of course, for a seat clamp bolt anyway... it only locks the the threads to stop it rattling/coming loose over long periods of time. i highly doubt it well affect the way the bolt handles the stress, i only used it as an extra peace of mind thing, a slighlty loose (half a thread) bolt will snap/bend as there is no clamping force to keep it in place....

just one of those things you could change/try before spending some money

s_blanche@hotmial.co.uk

IMO... if it doesnt effect your riding position too much, move it forward a tad, from the pictures it does look at quite a steep angle and a fair amount of pressure on the rear... if not then

As far as I know the Nukeproof have two bolts

...go for it

bennett_346

How heavy are you?

cooldad

Looks like your saddle is right at the front of the rails, so could be allowing too much leverage on the bolt. There should be some markings on the saddle rails - the clamp shouldn't be outside the marks. Difficult to tell from the pics.
The Nukeproof post is tough, and having two bolts might spread the load a bit, but if you are at the extreme of your saddle rails a post with some layback in it might be a solution.

meso100

sblanche- yeah I see what you mean. Will try and get it forward a tad I think. The problem is I have no confidence in the bike now! I was lucky the first time the seat post didn't go into my throat with the way I landed on it and this time im lucky I didn't lose my man bits!!

bennett_346- I'm 15 1/2 stone (all muscle like!)

thel33ter

Does look quite nose up, and far back, but it still shouldn't be happening. Me as well as another guy I ride with are running these Nukeproof posts, and they are very good, slightly less ovalised internally than Thompson, but just as light if not lighter. Worth a shot if you need a 31.6mm post.

http://www.chainreactioncycles.com/Mode ... elID=27605

desweller

If you can measure the size of the screw, you might be able to get a high-tensile one from your local machine supplies shop.

meso100

thel33ter- yeah it is a tad isn't it! Good to hear the Nuke Proof are decent anyway!

DesWeller- very good idea. I might try and find one tomorrow for them to have a look at the snapped bolt.

ps snapped bolt below if you're interested.

http://db.tt/0qUYEjA
http://db.tt/XLD40qA

thel33ter

Deffo looks like it sheared cause there was too much weight pushing back on it, either a 2 bolt post, or as above, a high tensile bolt should fix it.

bennett_346

yeah 15 and a half stone is nowhere near what they rate them to lol, i was just checking in case you were like 22 stone or something :P

paulbox

This happened to me twice on my GT, caused by the seat being clamped too far forward on its rails...

Did your bolt go with a bang? I nearly crapped myself it was so loud... :oops:

gtd.

I've snapped a few before, the single bolted "micro adjust" kind with the M7 bolt yeah the most unpopular hard to get hold of off the shelf from a fastner shop metric thread size :evil: why they arent M8 which is much more common I dont know :?

meso100

PaulBox - a bang??? Damn right! It went with a bang and I heard the clamp drop off followed by the shooting pain of the seat post meeting my perineum! The one last year was worse as I fell off going down hill (when the bolt snapped) landing on the rear wheel with my nuts and the seat post dug into my chest!

Might try changing the seat angle but would feel better with a different post with double bolts.

GTD - so you've snapped some too? what do you put it down to?

gtd.

poop bolts and my weight :oops:

meso100

thel33ter wrote:

Does look quite nose up, and far back, but it still shouldn't be happening. Me as well as another guy I ride with are running these Nukeproof posts, and they are very good, slightly less ovalised internally than Thompson, but just as light if not lighter. Worth a shot if you need a 31.6mm post.

http://www.chainreactioncycles.com/Mode ... elID=27605

I've had a look at the Nuke Proofs and there seems to be 3 options:

1) Warhead
2) Warhead Layback
3) Warhead Inline

I don't know why but I'm thinking Inline is best but don't know what it is. Maybe the opposite of Layback? I need a 30.9mm so it's looking about £45 ish for an Inline.

What do you think?

Matt 24k

The layback option will allow you to keep your saddle in a similar position to as it is now.
The inline will in effect move your saddle position about an inch forward assuming that you do not move the saddle out of its adjustment range. After all the pain you have suffered I would hope that you have learned to keep within the adjustment marks ;-)

nwmlarge

change to thomson elite
carry on

The Rookie

PaulBox wrote:

This happened to me twice on my GT, caused by the seat being clamped too far forward on its rails...

Did your bolt go with a bang? I nearly crapped myself it was so loud... :oops:

The Daughters BF did it on his GT Ruckus as well......

Simon

Dohboy78

Hi there fella, firstly I feel your pain, something similar happened half way around whites level, the bolt snapped and I nearly became literally "as one" with my bike. Luckily there were some forest workers nearby with a toolbox, we managed to bodge the post back together with some bit and bobs. I too am a bit of a salad dodger weighing in at 15 stone, I have big bones and a nice personality!

Since then I have bent 2 seatposts and thrown away 2 due to them being cr@p. I have been running a Thompson elite seatpost for well over a year and had no worries at all. Nice solid build inspires confidence. I have heard good things about the nukeproof seatposts too.

So my advice would be to stump up some cash and get either of the 2 mentioned above. Ask yourself the question... Would you trust the same seatpost with a new bolt?? I didn't.

Hope that helps.

Tom

02gf74

what grade bolt did you fit? you cna get latlen bolts up to 14.9 T strengh.

.... ut since you have had the smae problem happen twice, maybe get a different post.

gtd.

Happened again...

Riding to work heard creaking, got to work, seat was a little loose
Forgot about it went to go home seat a little loose so got my multi tool out and tightened it... bolt spinning. alloy piece bolt screws into had rounded out must have overtightened it yesterday when I changed saddles.

Had to ride home on the pedals

sofaboy73

i'd forget messing around with different bolts and the like, just go and get a different post. worth spending the money for piece of mind that you won't be skewering your balls in a shish keabab fashion any time soon.

if it's happened to you twice, definitely ditch the old post. I can heartily recommend the thompson layback ones. may be a bit pricier but I always take the view that I'd happily pay the extra £30 or so to not have a spike shoved up me 'arris (metaphorically speaking)