Trek 4300 disk brake crash

The Rookie

The QR has a nut on the other end...........

Car engines just fall apart all the time as the bolts come loose don't they.......

Didn't really think about that statement I think!

Bolted is much more secure than QR, much better and more consistent bolt tension, it is bolt tension (creating a stretch) that is what makes a bolted joint secure.

Northwind

The Beginner wrote:

The QR has a nut on the other end...........

Car engines just fall apart all the time as the bolts come loose don't they.......

Didn't really think about that statement I think!

Er, relevance of car bolts is slim, since they're mostly larger, under more torque, and generally crtiical ones are threadlocked or otherwise secured- not to mention normally corroded in. But yes, they can vibrate loose.

Yes QRs have a nut on the end but think about the range of operation of a QR- the nut needs to slacken off (and not just from vibration- stretching or wear also) massively for it to become a problem. Whereas the Halo is secure but only needs to slacken slightly or be done up slightly wrong to become an issue.

So for that reason, I don't put blind faith in 'em, either can go wrong, regular bolt check required for either.

The Rookie

The same loosening of the QR nut will have the same result on tension as the loosening of a bolt through skewer, the same loss of tension and the same potential further loosening - what is on the other end of the skewer part is of no relevance, the nut sees a threaded shaft is all, even the thread size is the same, I think you are being very blinkered on this.

As for car engines, lots of critcal small bolts, most have no threadlock, most last the 120,000 miles most manufacturers use for the engine life without being touched (That's my day job, I do know a bit about it!).

We do agree about the need to check them, the fact I usually take my wheels off to put the bike in the car means they are done up before every ride anyway!

97th choice

I took 4 QR wheels off this morning to load up the family bikes, and one 15mm bolt through. The 15mm was the quickest to remove!

cooldad

97th choice wrote:

I took 4 QR wheels off this morning to load up the family bikes, and one 15mm bolt through. The 15mm was the quickest to remove!

Which one's on the unicycle?

merkin

Doesn't the nut on the other end of a QR have a knurled face against the drop out to prevent slippage? If a regular nut had that it would damage the drop out each time you turned it.

Northwind

The halo also has a knurled face on the nut end- the bolt turns within the other head, so there's no part rotating against the bike/fork.

97th choice

cooldad wrote:

97th choice wrote:

I took 4 QR wheels off this morning to load up the family bikes, and one 15mm bolt through. The 15mm was the quickest to remove!

Which one's on the unicycle?

Rear wheels stayed on genius.

sm1thson

I like the axle theory, quite possible.

Also what if the threads on the qr are worn / out of spec so under load they 'jump' causing the qr to be be loose and fail.

rockmonkeysc

QR skewers are just crap. I have found mine loose mid ride loads of times, that's why all my currant bikes have some sort of bolt through axle. The only axle I have used which absolutely never comes loose is the non quick release type 20mm maxle DH in my boxxers.
A wheel absolutely cannot come out of the forks unless the QR has come loose CWNT may be a horrible person but he is right. Axles come loose, acccept it and check regularly pre ride and mid ride or accept a bit of facial gravel rash.

cooldad

Never had a QR coming loose. If it happens to you loads you are seriously doing something wrong.

bennett_346

I've never had an issue with QR coming loose (at least not that hasn't been caused by my own stupid self).

On a second note by Maxle used to have the opposite problem. If it wasnt taken out once per ride it would seize itself in and nearly needed drilled out at one point.

YeehaaMcgee

cooldad wrote:

Never had a QR coming loose. If it happens to you loads you are seriously doing something wrong.

+potato.
I have however, seen a shit-ton of riders, from newbies to experienced cyclists, who really don't have the QR in tight enough.
Remember that the nut on the opposing end needs to be screwed in and out when putting a wheel in, or taking it out, respectively, so that there's actually a fair bit of tension on the QR lever.

In the past, with rim brakes, it was quite conceivable that a QR not quite tight enough would pose little hazard. However, with a disc brake generating considerable downward reaction force, the tightness is critical.

cooldad

Only if you have lawyers lips. My road bike doesn't and just needs the lever flipping.
So lawyers lips have actually made the whole process more hazardous.

YeehaaMcgee

Does your road bike have disc brakes? If not, it's highly unlikely that braking forces will pull the wheel out.
My Trek roadie certainly has lawyers lips though.

cooldad

YeehaaMcgee wrote:

Does your road bike have disc brakes? If not, it's highly unlikely that braking forces will pull the wheel out.
My Trek roadie certainly has lawyers lips though.

Roadie and disc brakes? That's like asking for a pic of me in my tight lycra. Wash your mouth out.

supersonic

Not all skewers are made the same of course. The enclosed cam of Shimano offerings gives significantly morec clamping force than open cams such as Hope etc. (for a given lever force). Also the way they are designed, ie towards the very end of the lever stroke the effort gets easier - this makes them harder to be knocked undone and come loose.

cooldad

Fair enough, I do have some terrible ones that have come with wheelsets or on bikes I've bought but they live in a drawer and my bikes all have Shimano.

YeehaaMcgee

cooldad wrote:

Roadie and disc brakes? That's like asking for a pic of me in my tight lycra. Wash your mouth out.

I was led to believe that one of the reasons lawyers lips came about was because of disc brakes, and the hammering that a mountain bike wheel takes. Both of those reasons mean that their advantage is negligible on a roadie.

(Everyone knows that real lawyers don't have lips, on account of them being evil lizard "people")

Northwind

My early-90s tange forks have lawyer tabs. To resist teh awesum powah of Altus cantis.

But yeah, the whole ejection force thing is totally different for brake discs, with rim brakes it's a case of the wheel falling out, not being fired out.

supersonic

And smaller rotors give more reaction force than larger ones.

The Rookie

2 1997 steel rigid frames, not a disc insight, both with lawyers lips.

Even the old Townsend had them, and the plastic bodied canti's on that were so aweful to call them brakes would contravene the trade descriptions act.

YeehaaMcgee

The Beginner wrote:

2 1997 steel rigid frames, not a disc insight, both with lawyers lips.

Even the old Townsend had them, and the plastic bodied canti's on that were so aweful to call them brakes would contravene the trade descriptions act.

Still doesn't mean they weren't put on bikes because of disc brakes.
They may not be, admittedly, but like I said, I was told it was one of the fundamental factors. I can't vouch for the authenticity of that little bit of trivia. Maybe Nicklouse would know for sure?

cooldad

YeehaaMcgee wrote:

The Beginner wrote:

2 1997 steel rigid frames, not a disc insight, both with lawyers lips.

Even the old Townsend had them, and the plastic bodied canti's on that were so aweful to call them brakes would contravene the trade descriptions act.

Still doesn't mean they weren't put on bikes because of disc brakes.
They may not be, admittedly, but like I said, I was told it was one of the fundamental factors. I can't vouch for the authenticity of that little bit of trivia. Maybe Nicklouse would know for sure?

No need to verify it - we're used to you posting random sh1t. Probably excused by the excessive intake of shrooms.

YeehaaMcgee

No need to be a twunt all your life, you know. There's not much left you old pillock, you should considering ditching the attitude for your short time remaining.

bennett_346

Fluffy bunnys...

cooldad

Just doing my bit for humanity trying my best to make Yeehaa's head explode.

bennett_346

Many have tried, and many have, regretfully, failed.

YeehaaMcgee

bennett_346 wrote:

Many have tried, and many have, regretfully, failed.

Many have failed, but not all.