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CGAF about your made up non calibrated "range" TBH
LOL.
Has this forum got even more stupid recently?
No. But there seem to be more arses about.
"I was molesting my front end in the kitchen" snort snort
regarding the torque idea I have some RS SIDs and some Hope Pro3 which have been converted to 9mm thru axle.
When a QR wheel with Hope XC hub or the Pro 3 with Superstar 9mm axle is put in the fork the wheel is central.
With a DT Swiss RWS 9mm axle the wheel sits to the left of centre - probably showing up a flaw in the SIDs.
Which could imply that the torque applied with the Ratchet system on the DT Skewer is greater.
Nice photo of the Ice Cream Run 🙂
I personally would never go back to QR/9mm, having ridden 20mm for a years.
The flex has as much to do with axle size, as it does stanchion size. My 32mm boxxers are very flexy - despite being triple clamped, 20mm, and 'only' 170mm travel.
My Monster T's on the other hand.... zero flex! Stiff as a priest at Choir practise....
Stiff as a priest at Choir practise...
that must be stiff then...
much easier to imagine the following
5mm QR wheel in the dropout undone, or done up with fairy hands, i.e 0 tension. you can rock the hub in the drop outs from side to side.
do the QR up, as tight as poss, with a rubber hammer, and you may reach the limit of the M5 screw thread - around 8KN tensile load. (although i dont think a QR cam mechanism get near this), now when you rock the wheel you have an 8KN opposing force reacting the rocking
put an length of M9 threaded bar and two nuts and do it up to full torque you should be around 25KN tensile load, now when you try to rock the wheel you should have 25KN reacting.
agree the DT swiss RWS ratchet could get to higher torques, and hence improve stiffness. the superstar 9MM one however, with the standard QR cam lever cannot improve stiffness.
QR's and 9mm skewers are shear joints, rely on tension in the skewer.
15mm and 20mm through axles are pinned joint, rely on the bending stiffness of the axle.
Not read all the post above. But i currently ride with 2011 140mm QR Revs. They are pretty flexy, but i believe most of that flex is actually from the steerer (based on me standing with the front wheel sandwiched between my legs and me rotating my 800mm bars - plenty of leveage)
However with these 15/20mm through bolts, the actual size of the axel/bolt (either Q/R or say 20mm) isn't going to make a huge difference. It's the way the bolt through connects to the forks that makes all the difference. The fixing point on a Q/R is maybe 3/4mm thick, compared to the 20mm bolt though which is maybe 20-25mm thick. This is where all the extra stiffness is coming from.
This is why converting to 9mm bolt through doesn't make any difference.
You think you can twist your steerer now you have silly wide bars? 😆
Thru axle diameter actually makes quite a bit of a diference.
Do you also think that if fork steerers were half inch diameter instead of one and an eighth an ahead stem would clamp securely enough?
Update- Just installed a new front wheel and 9mm thru axle, the difference in stiffness in holding the front wheel and rotating the bars, sitting on bike and applying front brake, really is night and day.
My stiffness increase could be down to so many variables since it's a new wheel i've stuck in.
Hardly scientific, but i will need to get on some good pump track berms and see the difference in real life.
Jono - I agree with you in a ideal world situation where everything is manufactured 100% straight, dropout faces perfectly parallel, with loads perfectly perpendicular to the axle axis. The axles are exclusively in tension. In this scenario they are shear joints.
In real life, there are no ifs or buts about it (in my mind), the dropout faces are not going to be parallel, this is one instance where there is a moment being applied to the axle, a moment which can be counteracted with tension force, tension stiffness and bending stiffness.
Lean the bike slightly, the load force is no longer perpendicular to the axle axis, there is now a moment acting on the axle again, which again can be dealt with by tension force, tension stiffness and bending stiffness. The dropout faces will be forced further out of parallel by the acting moment which the skewer will be do its best to battle.
Do you see what i'm getting at? I'm not trying to get my e-nuts out and disprove anyone, i just hope we can have an adult debate about it. Am i completely wrong and imagining these loading scenarios? (if only i had time, i'd get onto some FEA and put it to bed (obviously doing my best to avoid rubbish in = rubbish out))
thanks deanfbm... looks like my gut feeling that it would help was right.
did you use the Superstar 9mm QR or a bolt on?
i have almost same fork and think i'll do the same. i'll be adapting a 5mm front wheel (Hope Pro2) so i'll be able to give a better comparison, maybe.
also yes the wheel itself may be bending less.
i have a 20mm maxle fork too that's spare, not using because it's much heavier and not as plush as my reba.. if i can be bothered i might try that too!
QR skewer stretching is one reason I won't use a titanium skewer.
Lack of a titanium skewer with a shimano internal cam mechanism is the other.
I've seen some replacement bolt up axles for some shimano hubs. Would be quite happy to replace front and rear axles with bolt up (using a nut) and carry a nice lightweight spanner/socket with me but not sure I can get front and rear for my LX hubs.
I keep meaning to try some bolt up skewers (normal style without the cam) to see what the stiffness is like but I kind of trust shimano cams more than an allen key skewer!
do agree, when you factor in the dropouts being a bit flexy, when you put a large side load on, you overcome the tension, and start a bending moment on the skewer..
i know this because my front skewer was bent when took it out once..
I'm interested in the subject because i tred to improve front wheel stiffness on my '08 superfly.
I concluded after a bunch of different tests that there are quite a few factors that go into determining front wheel stiffness / steering response.
tyres and their pressure
spoke tension / spoke thickness
number of spokes
rim stiffness and diameter
fork stiffness
steerer tube and crown stiffness
frame head tube stiffness
front hub / skewer tension
In my case adding the 9mm thru skewer did little or no noticable improvement, as i think the most flex in my system was coming from the f80 fork, and the 28 spoke 29" wheel
I also have a dirt jump bike with std QR marzocchi dj3 36 spoke, wheels and a heavy guage steel frame, and its a stiff as a post!
smiff - superstar qr, done up reet tight. But as jono suggestion, in all likeliness it's not any tighter than a standard qr.
jono - good post. It makes it glaringly obvious to anyone reading this that is is a sum of all parts.
28spoke 29er and fox forks, that's never going to be a stiff marriage.
I put my increase in stiffness down to the thru axle, stiffer rim, stiffer spokes and having a much larger interface between the hub and dropouts.
Obviously the stiffness increase due to a thru axle is all down to load direction. Backwards and forwards, a thru axle is going to do diddly squat. Leaning the bike or glancing blows, the thru axle should hopefully do some good.