Are Straight Pull Spokes Strong Enough For Trail Riding? | Ask GMBN Tech

Are Straight Pull Spokes Strong Enough For Trail Riding? | Ask GMBN Tech


– Welcome to another weekly
Ask GMBN Tech Q&A Clinic. Get your questions in to us at the email address on the screen or you can add them in the comments below. Alright, so first up this
week is from Freddy Dembrey. Freddie asked GMBM Tech,
“Can you run SRAM brakes “(levers and calipers) on
Shimano rotors? Thanks.” Yeah, is the answer to that. Bearing in mind that some disc
sizes are slightly different. For example, you get
the 200 versus the 203 with the SRAM Shimano thing there. And disc rotors, actually some of them are a little thinner than others although, your brakes
will compensate for that. In case you wanted to
know, Shimano rotors are 1.8 mil thick as standard and obviously they get thinner as they wear. If they start getting
beyond, I think it’s 1.5 then you want to sack them off because they start losing their
strength and their integrity. With SRAM ones I think it’s 1.85 so they’re very, very, fractionally bigger and I think Formulas are
fractionally smaller. But that doesn’t really
make too much difference, as I say, your pistons
will compensate for that. As long as you have the hardware correct where your brake is
mounted, so if it’s mounted on a direct mount, you might
need some of those cone washers to compensate for the 200 or the 203 rotor depending on which way
round your brakes are and, of course, if you’ve
got the correct adapter. Always make sure that your brake pads sit completely onto the actual
disc rotor braking surface and make sure the disc rotor can’t foul the inside of the caliper
as it passes through. And if that’s all good,
then you’re good to go. Okay, nice punchy one
from Daylight Sensor IMA. Asked GMBN Tech, “Is it
normal to blow through “160 millimeters of rear
travel on a two foot drop? “I have a 2013 Canyon Strive AL 8.0.” No, it’s not normal, but that does depend on a lot of things. It depends on how you
like your suspension, how you ride, the way you
even approach that drop. Let’s just talk about the actual drop from physical riding point of view. If you’re going off a drop really fast you can actually meet
with the ground a bit and you can actually lessen the impact. Whereas if you’re just
popping off something you get all that down force in one hit. Now, of course, if it’s a wheelie drop you can lower that back
wheel if you just pop it off you have more impact. So, it does affect you
slightly differently. And, of course, your ability as a rider to use your body to absorb that impact. But just the physicality on the bike, it sounds like to me
either your rear suspension is slightly too linear for
the way that you want to ride if you want to be doing drops like this or perhaps it’s set up
slightly under sprung. So, the first thing you want to do is check the spring on your bike whether it’s a coil
spring or an air spring is basically giving you
enough or not too much sag. So, you’re looking
between 20 and 30 percent of the available travel to
sag when you sit on a bike. If you’ve got an air
shock, you can measure this with the O ring on the actual shock shaft. If it’s not, if you’ve got a coil shock the best way to do that is to measure with you not sat on the bike the distance between
the saddle and the tire and then by subtracting the amount of suspension travel you have on the bike you can work out your 20 or 30 percent sag when you sit on it and that
gap will obviously close. So, get that set up
and if it’s not correct then, if it’s an air
shock then you can adjust the air volume in that shock. Sometimes you can do that
with air volume spacers. Sometimes, it has to be done
in different ways internally. But that’s basically
your solution to that. So, hopefully you can get that done. Alright, next up is from Herby. “Is there any disadvantage
of overspending grease “in a headset? “I normally put grease
between the spacers, “and between stem and steerer tube. “I just got a new Canyon Spectral AL 6.0” nice bike, dude, “and I took the forks off “just to have a look how it works “in there and I noticed that there is “much less grease inside
than I would put in, thanks.” Bearing in mind that when
bikes are put together in big production lines, they put in what’s an efficient amount of grease. So, cartridge bearings themselves they all have grease inside them the whole point of them is
they’re a contained unit you pop into the bicycle,
you pop into the headset and it works. The advantage of having
more grease in there, really is an extra barrier
against corrosion and water and getting water into that
bearing in the first place. Of course, any water getting into the actual cartridge
bearing, that is where the problems start arising so the more you can ward that
off, the better, in my eyes. I would always prefer to
have a bit more grease especially coming from the UK,
we have a lot of wet weather. So, I tend to put a bit
more grease in there when I put stuff together and afterwards you can just wipe it down on the outside. And then, periodically after, I don’t know two or three months or
however bad your weather may or may not be, have a little inspect make sure that it’s
basically still in there. If it’s gone this sort of
a brown-y sludgy color, it’s a good idea to wipe it all clean and check the bearings are
good and then replace that. But bearing in mind
the bearings themselves are only good if they’re
running nice and smooth and have grease in them
in the first place. The minute that they are
actually all gritty in there no amount of grease being applied to them is going to repair them. So, just take that into account. So yeah, just treat it
as a waterproof barrier. – Okay, Frank Town wants to
know, “What is the purpose “of the star fangled nut?” “You said that with the top cap it helps “align and tighten everything “but I don’t get how that works exactly.” Okay so, parts of the headset right, so if you look at the fork itself you have the steerer tube on there. Then on the steerer tube you
have the lower crown races on the crown of the fork you have bottom part of the races
sits into the bearing the bearing sits into the cup in the frame steerer tube passes through that the upper cup sits on the frame, steerer tube passes through that bearing sits into that, then you have the selection of washers
that sit into that like a compression ring, then you have the stem, you have the top cap. On the inside of that steerer tube you have the star fangled mount which is wedged in, it’s like a
bob so it can’t move. When you adjust or tighten
the bolt on the top it basically pulls the steerer
tube up through the stem. That’s why you have to leave
that gap at the top there. When I say, pull this, I’m
making quite a big movement you’re actually talking like
less than half a millimeter or so when it moves. And the idea is, you’re
pulling everything taut or you’re pre-loading the bearing. So, it’s not actually doing anything to the bearing itself,
it’s just making sure that all the components of the headset are all taut and they’re in place against each other so there’s no movement. As in, any sort of movement that’s not just a physical turning of
the headset bearing itself. Because any movement you get,
any sort of rattling in there that, with the amount of
leverage that you have at the wheel end and the handlebar end is going to start slowly
destroying those bearings which, of course, can
lead to other problems. So, it’s essentially just a
way of pre-loading the system making sure everything is nice and tight and doing its job correctly. If you ride a bike with a loose headset or if you try and basically
put the system together without having that top cap on there you will never get it
tight and the headset will always be slightly loose. That’s all it is. Alright, so Sumner Bob is next. “Doddy, I’ve got a
specialized FSR downhill from the nineties” oh dude, trick bike got a friend who’s got one of
them, at Shrewsbury actually and he’s got a Palmer replica. “And the suspension linkage
bolts keep loosening “after every ride, even though “it’s been torqued up properly. “It uses bushings instead of bearings, “will Loctite fix this?” In theory, yes, so
Threadlock does a great job of stopping bolts coming undone, however, if the reason
they’re coming undone is because of movement coming elsewhere, and the bolts are starting to unwind rather than rattle loose then they won’t help, they will
always unwind basically however much you put on. And if that’s happening,
that would suggest that the bushes are worn. So, my advice would be to,
with all the bolts tight, check to see if there’s
any play or any movement in the back end of that bike, you should still be able to track down the relevant bushing kits for it. Get a fresh bushing kit in
there if that is the problem then, when you put it back together, use the relevant greases,
assembly compounds and Threadlock of course and
use your torque wrench on there then hopefully, you’ll have no problems. Basically, it sounds like
movement is happening from somewhere, but
Threadlock on the bolts is your first point of
call if everything works because it’s designed
there to lock those threads and stop it rattling loose. Okay, next up from Kenny Minigun. “Are straight pull spokes
stroke hubs suitable “for abusive riding like
downhill and enduro? “Are they any better than traditional “J-bend spokes and hubs?” Yeah, they’re absolutely
fine, to be honest. It’s more down to how they’re built and laced up and tensioned as is the case with any sort of wheel. If you look on screen now,
we’re just going to look at the J-bend pros and cons
and we’ll do the same for the straight pull afterwards. So first up, J-bend pros,
they’re easily available to suit any hub, basically any
sort of standard hub that is with a flange and drill
holes, they’ve always been made this way and been made so long that companies make
excellent spokes like this. They can be laced in any
cross-pattern like this as well. You’re not sort of
confined to have to build hubs in a two cross or whatever pattern you can build them two
cross, you can build them radial with three cross, four cross even or if you’re daft you can build them in a snowflake patter
if you really wanted to. There’s no limits to what you can do with a regular J-bend spoke. Arguably though, they
are slower to lace up. So, whether that’s a good thing or not that is just one of the facts because they take a little bit
more time to intricately put them into the hub itself. One other cons is they
can break at the elbow and although DT do say that
their spokes pretty much versus each other are about
as strong as each other it’s basically down to how they’re built and the quality of the
hub that they’re put into that affects this with the J-bend spoke. So, for example, if the holes in the hub where you put the spoke into
are slightly bigger than the actual size of the
spoke going through that that can create a sort
of amount of movement and of course, that could
stress the elbow itself and it could crack at the elbow and break. Now also, if the wheels
are under-tensioned it enables too much flex and
the flex has to go somewhere in the spoke and it’s going to basically fatigue that elbow which
eventually will break. And, of course, there’s
slightly more material. We’re talking a marginal
amount here, so you could argue that you’ve got a slightly heavier wheel with J-bend spokes as well. But if you look at straight pulls, right, so the straight pull chart
is on the screen now. The pros are, they’re
slightly shorter spokes so you can build a slightly lighter wheel. We’re talking like a minute amount here but in some cases, that’s a
really, really important thing. Arguably, they’re easier to lace as well because you just drop
them straight into the hub so that’s a great thing too. And they can arguably be stronger as well because they don’t have a bend. So, this isn’t really a
physical problem of the spoke it’s more the fact that
you can drop the spoke into a hub and it’s going
to be as strong as it can be because it can only do a
certain job in a certain way it’s not subject to the
quality control of a hub or the way it’s built to
sacrifice the strength of that. The cons are, you have
different straight pull spokes for different hubs,
they’re not all the same. There are some standardized version, but Mavic have their own
slightly thinner ones at the head they also have some slightly thicker ones and different brands do that as well. So, it’s just not a standardized
item like a J-bend spoke which you can get
literally in any bike shop. The advantage again of a
J-bends is you could buy one for a 29 inch wheel and
you can have it cut down and re-threaded and it will fit a 27 1/2 or 26 or anything. Really convenient if you’re
doing any sort of traveling or globe-trotting, to
have J-bends for that sort of reason. Another con is that they can only be laced in the orientation that the hub allows. So, if you’ve got a straight pull hub and it’s set up for two
cross you can only ever lace your hub wheels up two cross. You’re not going to be
able to take advantage of having a three cross
design for example. It simply will not allow that. And also, if not tensioned correctly, this is very rare and this used
to happen on older designs, the head of the spokes can
actually become unhooked which is I think is probably
one of your concerns. But let’s not forget that a wheel works on even tension, it’s not
pushing, it’s a pulling thing that basically enables
a wheel to be strong and tensioned, so really, they’ll
be absolutely fine for you and hopefully you’ve just
seen a little bit of detail, pros and cons for both styles. For the record, I think
think straight pulls look way cooler on a bike, they look so futuristic and purposeful. But, I think I prefer traditional J-bends for all of the obvious reason. So, there we go, there’s another weekly GMBN Tech Clinic in the bag. If you’ve got any questions, let us know in those comments or you can just email them direct to us. For a couple more cool
videos if you want to learn how to fix a chain when you’re
out on the trail in the rain check this video out
that’s just down here. That’s fixing a chain three
ways there, that’s really cool. And if you want to win
some insane Syncros wheels, super, super ridiculously light ones, click down here. All good stuff there. As always, give us a
like, give us a share. Subscribe to the channel.

62 thoughts on “Are Straight Pull Spokes Strong Enough For Trail Riding? | Ask GMBN Tech

  1. #askgmbntech hi there , what are the pros and cons of larger disc rotors and smaller disc rotors? And i want to get a fast rolling tyre for my rear wheel and i was thinking of getting a high roller 2 or minion ss or do you have any other recommendations ? thanks alot!!

  2. One other advantage of straightpull is you can replace a broken spoke without having to remove the disc or the cassette

  3. #askgmbntech
    Hi guys, what would be the perfect travel for being as efficient as possible climbing and going downhill??

  4. #askgmbntech How to check rear shock bushing? How to know it is wear & when to replace it? Any maintenance tips for the bushing?

  5. As a guy who builds all the wheels he rides, straight pull eliminates the tedium from lacing, which makes it worth it to me. Shimano's new Scylence hubs offer both 32 and 28 hold sp options.

  6. #askgmbntech Hi Doddy, I have the Voodoo bizango 29 2018 and what love to upgrade the a tyres on it, what is the maximum tyre size I can fit on a 23mm internal width rim, thanks

  7. #askgmbntech Hi, love the show.
    I also have a question, I'm asking for a friend. He's got a kona with a santour 120mm fork, can he upgrade to a 120 mm rockshx fork?

  8. Hey Doddy, enjoying the show. What do you think of upgrading the travel of my fork from 150mm to 160mm at my Canyon Spectral 2016? #askgmbntech

  9. Mavic Deemax wheels – the go-to standard in world cup downhill for many many years – uses straight pull spokes. Yeah, they're strong enough.

    Straight pull spokes falling out when under-tensioned is a fault of the hub design. With hubs like those from Hope, it's impossible.
    https://www.hopetech.com/product/pro-4-straight-pull-6-bolt-front-hub/

  10. #askgmbntech Hi, I have a problem. When I move my wheel from right to left and holding the frame I can hear sort of knocking. I think that it could be some stuff from the rear hub. Could you help me how to fix it? Thanks a lot.

  11. I9 right down the road from me, and they look bitchin. However, it just comes down to what my checkbook can afford at the time 🙁

  12. #askgmbntech hi doddy, Im currently studying for my university exam and currently running a cube aim sl with a crappy sr suntour fork. Right now Im saving money for a better bike to buy after the exam so a new fork is out of consideration. Fork has a problem of being flexy under braking. It vibrates violently that I lose control. Any solution for this fork ? Thanks.

  13. Andrew, correct me if I'm wrong, but aren't straight-pull spokes harder to tighten once they're assembled to wheel with tire installed? Doesn't some of them spin when tightening? I haven't seen straight pull hubs with grooves or small notches to prevent this. It'd be even better if they were on the spokes as well. It'll catch/bite, on both parts, to prevent spinning. Cheers!

  14. #askgmbntech where did you get the 10mm reach stem from in the cut scene for gmbn? I've searched everywhere, mondraker don't even do them anymore

  15. Hi gmbn tech, I just got a Scott genius 720 plus 2017. I really want to buy some hope pro 4’s or halo vortex wheels however. The bike came with center lock disks, am I going to need to buy new disks as well?

  16. #askgmbntech can you fit a larger travel shock to your bike and can you explain the size and travel of a shock thanks

  17. #askgmbtech hi doddy I've got a cerrera vendetta and everytime I have puncture I can't get tyre on or off am even using moto x tyre levers which are no help it's a plus bike also I can't have any air in the inner tube otherwise tyre won't go on please can you help as I don't want to get stranded out on the trails

  18. #askgmbntech Would a one-by chain guide work with an E Thirteen TRS+ Double crankset set up as a one-by? Will the chain line be okay on a pre 2005 Santa Cruz Bullit? I currently have Shimano fc-m572 cranks.

  19. 0:18 – Can you run SRAM brakes (levers and calipers) on Shimano rotors?
    1:39 – Is it normal to blow through 160 mills of rear travel on a 2 foot drop?
    3:30 – Is there any disadvantage of overspending grease in a headset?
    5:08 – What's the purpose of the star fangled nut?
    6:58 – My suspension linkage bolts keep loosening after ever ride even after proper tightening.
    8:12 – Are straight pull spokes/hubs suitable for abusive riding? Are they better than J-bend spokes/hubs?

  20. Here is the real answer to running shimano rotors on sram calipers. You can, but it’s not advised. It’s not necessarily the thickness, it’s the rotor brake track that is different. Shimano is narrower than sram. So over time the rider will notice in even wear. And you will find yourself replacing the pads more frequently. There are tons of forums that discuss this, and they all say what I just commented. Short term you can do it, but longer term effects aren’t worth it. If you want ice tech rotors just get shimano brakes or buy SRAMs version.

  21. #askgmbntech Howzit Doddy. Why do my cranks keep coming loose? Its gotten to the point now that I need to tighten the bolt (quite a bit) every time before I ride. I'm tempted to use blue Locktite but I suspect that there may be a different problem than just the bolt coming loose. Any advice?

  22. #askgmbntech I am wondering what the pros and cons are between alloy and steel chianrings? does it effect chain wear? -cheers

  23. #askgmbntech
    Hi Doddy. Do you reduce air pressure in your shocks and tubeless tyres when travlling by aeroplane? Im off to Rotorua at Xmas and have heard mixed views on this for flying. Cheers and hope to see you guys in OZ and NZ some day soon!

  24. #askgmbntech My hub used to make a loud buzzing sound but after my last ride and bike wash, it became silent (in a pin drop room, you may hear some buzzing). I don't have any problem while pedalling forward but when I try to pedal back the crank rotates as if there is no chain on it. What could be the issue here? do I need to change my hub??

  25. hello doddy, my trek fuel ex 8 2017 29er has 130 mm suspension front and rear, can i use this bike for drops and trail jumps? can this bike take a beating?

  26. #AskGMBNTech Hi guys I have an SR-Suntour Epixon 120mm air fork on my hardtail. If I hit some jumps on normal air pressure (80 PSI) the fork gets compressed all the way. When I go on hard air pressure (120 PSI) it's too hard and not comfortable but the fork doesn't compress all the way and there is still 1 cm of travel left. My question is if my fork gets damaged when it compresses all the way and how I can setup my fork so that it's comfortable and doesn't get compressed all the way. Greetings from Germany 🙂

  27. #askgmbntech Hi Doddy, can you tell me if having a spare tube in my backpack for my tubeless have any sense? I often heard we have to have one in case of very big tear or if we smash the valve. But my tire is full of bramble thorns, my tube will die instantaneously when inflating. Thanks for any advise.

  28. 2 Questions. .. would going from 19 to 21mm internal width on my 27.5 wheels make a noticeable difference? 2nd… what kind of difference would it make ride, width and weight wise going 19 to 29mm internal running a 2.3 DHF front & 2.4 Ardent rear

  29. If a rim was bent but trued, how long before you need to replace that rim with a new one? Or can you ride the same way on that once bent rim or not that rough and recommend getting new?

  30. #askgmbntech The kashima coating on fox shocks a functional piece or just marketing. If functional, do you notice a difference between a shock with it and a shock without it.

  31. I put a new chain and derailleur on my bike it shifts perfect but when I put the power down the chain starts cracking/slipping does this mean I need a new cassette

  32. Thanks for answering the spoke question! I've been looking around for DT 240 hubs, my local shops sell only the 28H option of the StraightPull and the 32H version of the Traditional. That got me wondering whether StraightPull is so much stronger, that the number of spokes can be reduced? However, later I found that DT (on their site) also list a 32H version for StraightPull and that is, I think, what I am going for!

  33. I think of myself as a knowledgeable MTB rider and tickerer. I ride a 2018 Santa Cruz Nomad and race a variety of enduros and DH in the Pro class here in the east coast of USA. I currently run a tire combo of a maxxis exo up front, and a DH casing in the rear. My question comes from the rise of the tire inserts. Would a exo tire and a cush core out back be as reliable as the dh casing I'm used to. I LOVE the feel of Exo tires but get so tired of buying tire plugs and Co2 for rear flats.

  34. #askgmbntech I’m wanting to go tubeless but my rims aren’t tubeless ready. I don’t know what size rims I have so how do I measure the size of the rim for the rim tape? Thanks

  35. Hi Doddy,
    just wondering if you could explain how halo's 6drive and supadrive work. I have a vapour 35 supadrive (rear) and cannot fault it but just wondering how they differ to other hub manufacturers like dt and mavic

  36. also some straght pull spoke wheels are a pain in the butt to aline because when you turn the niples somtimes the spoke itself is moving with it, so to tight or losen the sopke, you have to clamp it some way and this may damage the spokes and will take a signifacantly more time than some traditional spokes

    i have some mavic cross-link wheels and i hardly aline them for these reasons

  37. #askgmbntech why do my rear gears select ok yet i get slip when i put force on the highest gear only. getting stuck I've checked the chain, indexing and sprocket wear but can't fix the issue. any ideas?

  38. #askgmbntech my sons got a carrera detonate 20 and forks are poo, can you point me in right direction of some light air forks with disk mount please? Thanks

  39. #askgmbntech I've got a Manitou Mattoc Pro 2 fork and have recently installed their Infinite rate Tune negative spring. The negative spring has to be set at least 10 psi higher than the positive spring. Will the negative spring have any effect on setting up the sag on the fork?

  40. Hi Doddy! Love the show! I am on the market for new hub. New XTR 9100 appeals to me most with its silence technology. My question is can I replace micro spline to be compatible with HG standard? Any adapters?

  41. #askgmbntech Hi guys. I have to do a lower leg service on a 2018 rock shox Pike and I can´t find the RS 0w-30 oil where Ilive. What other oil can I use?

  42. #askgmbntech One thing currently stopping me progressing is knowing what my bike can handle. I’ve got a Nomad 4 C XL, the fastest lines on tracks near me have huge drops to essentially flat. I’m 90kg, how far can I drop to flat before I ruin the bike

  43. I run shimano ice tec 203 rotas for years with Guide brakes and now the new codes, yes a spacer is used below cone washers. I do this as I found sram disc would warp as I only run sram sintered pads and they also hold heat longer and would burn my shin if wasn't careful but the ice discs stay cool.

  44. Oh my gosh, I think I was happier being daft. My mindset as a child, "get a bicycle, and ride it". Now it's all, "jibba jabba, jibba jabba; is there enough grease in my hubs? Is every spoke the same tension? How long are my cranks?"………..I think I've fallen into the knowledge pit of doom. I like the saying, "don't sweat the small stuff".

  45. Re the question re loosening bolt on the Spesh, why would you want to keep riding a 25 year old DH bike? If it's a 25 yr old 10 speed or fixie, with new tires, then OK. But DH?

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