Replacing Wheel Bearings & Preventing Seatposts From Seizing | GCN Tech Clinic
Replacing Wheel Bearings & Preventing Seatposts From Seizing | GCN Tech Clinic

(zapping) – Welcome back to another
episode of the GCN Tech Clinic, where I aim to help and solve
your bike-related problems. So if you’ve got something
that’s troubling you, let me know down there in
the comment section below and I will do my very
best to help answer it in a forthcoming episode. And, with no further adieu, let’s crack on with the
first question this week and it comes in from Thymen Vuik who says, “The rear wheel bearings
are getting worn out. Made an appointment at the bicycle shop. Only thing is, there is not
a single piece of information to be found on how big the bearings are. Is there a way to find out without taking the whole bike apart? And if not, how do I take the bike apart? Thanks in advance.” (blowing) Well, Thymen, without actually knowing what sort of hub you got on there it’s very hard to give
you a real diagnosis to take apart the hubs. You can investigate those bearings but it’s likely that the
actual seal was on them ’cause you say on there
you need some new bearings. So I reckon there probably
are some sealed ones in there. It’s very likely that
the bearing cap covers or the end axles of the actual hub, can actually pull off or
they screw on to an axle. Have a try at both of those. Obviously, if you’re not sure do take it in to the bike shop but if you can get
those axle end caps off, wipe away any dirt and grime, anything like that,
covering those bearings. Then look very, very closely and you should be able to
find some numbers or letters, a mixture of the two normally, on the side of the bearing. That identifies the actual bearing type. You can then go online basically
and type those numbers in and it will tell you the
exact bearing type you need. It’s not that easy to actually
identify them that way. Ideally, you want to be able
to measure the outer diameter, the inner diameter, and also the width. But if the bearing’s
already inside of the hub well, without some specialist tools it’s not always easy to
be able to remove them. Last bit of advice I’m
going to give you though, if you are going to be
buying your own bearings, and giving them to a bike shop to install, do not buy cheap ones! Don’t be tempted by ceramic
bearings for one pay 99 on eBay because they’re not going to last. Buy yourself some good bearings. They will stand the test of time. (whooshing) Next up is Oliver Lowe. Now Oliver asks, they’ve got themselves, “an old orange crush
frame, but can’t work out how to attach the cables as
there are only pop rivets along the frame where I thought
the cable run should be.” Any ideas?” Oliver, it sounds to me
like a mountain bike frame. What you probably are
talking about here is well, if it’s for brake cables let’s solve that one first of all. If it’s brake cables or brake hoses you can actually get self-adhesive patches which go onto the frame and then they can zip tie onto
a full-length outer cable. But if it’s gear cables
we’re talking about and you’ve only got pop rivets on there, sounds like something
could well have broken off. So you want to actually have split cables. You can run a outer cable,
separately from the other cable. You got two different
bits of lengths of cable. You know where I’m coming from, Oliver. Right, there’s a company
out there called Oring 8, that’s how you spell it, O-R-I-N-G eight. So you pronounce it originate. See where I’m coming from? They actually make a clamp-on cable guide that’s suitable for your needs if that’s exactly what it is. But like I said, if it’s for the brake cables or brake hoses, run a continuous length outer, and just use those self-adhesive guides. (whooshing) Next up is filimonchik who says, “Hi John! Can I use an alloy handlebar with carbon stem and carbon fork? Also, can I use a carbon
seatpost on an aluminum frame? Thanks a lot my cycling guru!” Yep, you sure can! Do exactly what you want to
do on both of those questions. What I would use is some carbon paste to help the surfaces just stick together a little bit better. What you’re going to be using that for is well, is actually to try and
prevent galvanic corrosion which believe me, it can happen
with aluminum and carbon, when the two things are put together. Once you’ve got electrolyte
present it starts to corrode. I remember one evening I had to saw out a carbon seatpost from my aluminum frame. Yeah, what a fun evening that was! Just use some of that carbon paste. (whooshing) George Sebastian is next, who says, “Can I also use electrical tape to prevent the seatpost from
seizing into the frame?” (blowing) George, you could. The problem is with this is
that generally a seat tube and a seatpost are really
close in their sizes. You know, in fact they should be the same because it’s really an interference fit. But mostly the seat tube itself is oversize very, very slightly to prevent scratching up the seatpost when you go to install it, and then you gradually raise it as you get taller, I guess. Particularly if you are a growing cyclist. But by using some
electrical tape on there, you’re going to be increasing
that diameter or circumference of the seatpost and when
it goes to being fitted inside of the frame,
well it may not even fit. And ultimately, when you put
that inside of the frame, it’s just going to compress a lot. But the question begs, why don’t you use a
specific product for that? If you’re worried about it
becoming seized in place then just remove the seatpost
every couple of months because it’s not going to seize
in place during that time. But if you’re like me and
really, really particular about your saddle height, something which I’m
convinced always changes from ride to ride. What you can get is something
from a company called BBB. They make actually, a
secondary clamp, if you like. It’s called the BSP 97, I think. Hopefully, it’s on-screen
right now, the product. What it is, it’s a clamp
which goes onto your seatpost before it goes into the frame. Now it’s not a seat clamp, perse. It’s kind of like a backup so if you’re original seat
clamp on the frame was to fail, this one kind of acts as, like
I say, a secondary measure. I don’t use mine for that. So I only use it so I know that my saddle is in
exactly the right place. So I torqued it up correctly
and it just doesn’t move. Alternatively, if you don’t want to go out and buy one of those, just get yourself an old reflector bracket and put that on there. But yeah, if you’re
worried about it seizing, just take it out every few months, just put some more grease
on there, or carbon paste, whatever it is you want to be using. And, yeah, everything’s going to be A-OK. (whooshing) Next up we’ve got audax333, who says, “Hi John! I have a 1992 Giant CADEX 980C.” Hoa! Lucky, aren’t you? “One of the carbon/alloy hybrids where the carbon tubes
are glued to the aluminum. A local bike shop owner
warned me of these bikes because they have a tendency to just fall apart after a while. Should I be scared when riding and just use it on a bike trainer?” Audax, that is such a
nice bike, my friend. It is true. Some of the older carbon
into alloy lux bikes, they did have a tendency to just kind of pull apart a little bit. However, a friend of mine, he’s got an original
look Bernard Hinault bike from, I don’t know, like mid-80s. And, he still uses that daily and it’s still working absolutely fine. In fact, another friend
of mine, he even sells, or he’s got, he does have a bike shop. He does have some of the glue to actually re-bond aluminum
frames and carbon frames back together. All that aside. I personally wouldn’t use
it in a turbo trainer. The reason being is that, like you say, is an older model and
that when you’re fixed inside of a turbo trainer, the bike doesn’t have it’s
own freedom of movement ’cause it’s clamped in place, it can’t find it’s
natural path, so to speak. So I’d probably avoid doing that and keep it as your best bike. You’ve also got another question here. “The bike is fitted with
Campagnolo Chorus 8-speed, how can I fit it onto a modern
direct drive bike trainer?” Well, I just told you to not do that but I’m going to try and
answer your question. “They all seem to require at
least a 9-speed group set.” Yeah, now sadly, an 8-speed cassette is very unlikely to fit
on a modern style free-hub and also the actual
over allotment distance, is different as well on the rear axle. There was a hack, many years ago, that you could put a cheaper
9-speed Campagnolo cassette onto an 8-speed body and it would work. But it’s probably unlikely
you’re going to be able to get all those components. This is something, I would love
to have the time and energy, and all this, to actually be
able to grind down some spaces and try and solve this problem for you but I’m afraid I can’t really
help with that one personally. Try and keep that one for your best bike. I’m jealous! (whooshing) Next up is trbeyond, who says, “After getting a chain waxed, how do I know when it needs re-waxing or some other maintenance? What about issues if I ride in the rain?” Right, well normally a chain
waxing lasts about 500 miles. You’ve got that to work around but of course that does
depend on your riding style, also how many watts you’re putting out, the condition you’re riding it. All of those things. It’s just like any other chain lubricant although this one is probably
a little bit harder-wearing. But people will out there,
at that store, will disagree. Like you say, will rain affect it? Yeah, it will. Just like a normal lubricant. I mean, I’ve been out before, start to rain and it washed out all of my dry-lube from a chain. And, you know when it’s time to re-lube or re-wax your chain because it will make quite a sound. (whooshing) Next up is 6ft8incyclist, that’s a pretty tall, tall rider there! “Hi Jon! I have an unusual question and problem. I’m a true Campagnolo fan. That’s not a problem. “But my bike that I have on my
smart trainer has 105 on it. I use Zwift a lot since I work nights. My problem is shifting. I keep wanting to shift with my thumbs like I’m riding Campagnolo, but my thumbs are lost
when I ride the 105 group. I need help. I am asking for my thumbs. Thanks.” 6ft8incyclist, nothing we can
do here I’m afraid, my friend. Unless, you upgrade your
bike to a full 302 group set and you add some sprint shifters on there. There’s some nifty little
handiwork, I’m afraid, because well, nothing
can get done about it. The only thing you could do, like you say, your thumbs feel redundant, and you know, I guess you want to use them still. But what you could do, is make the best out of both worlds and put that smart trainer into ERG mode, so it automatically adjusts
the resistance accordingly and you don’t have to
worry about changing gear. (whooshing) Next up is Paul Sweet, who says, “I have an old bike that I
have been limping along on, and have been learning
the basics of bike repair to keep it going. That said, I do not
believe this bike is worth the investment of a major new
tool or component purchase. My major concern on the bike is it’s wobbly bottom bracket. At what point has a bottom
bracket become damaged to the point where it is no longer prudent to continue using the bike?” Right, Paul. It seems to me like you
want an excuse really just to get a new bike. I mean, you don’t have to get a new bike just because the bottom
bracket’s worn out. You said, at what point
should you not ride it? Basically, when it’s wobbling because once it starts wobbling, you’re asking the axle to work in a different way to normal
and ultimately that could fail. I know it sounds a bit drastic but it can. I’ve seen it happen. And, also you’re going to be
getting a lot of power there, too. Now, for the relative in
expense of, or lack of expense, of buying a new bottom bracket and a tool, I’m pretty sure that is a lot cheaper than buying a new bike. I’d probably just opt for that unless there’s something really,
really wrong with the bike. That’s the best advice I
could give you, I’m afraid. (whooshing) Next up is Prashanth Ruthala, who says, “I’m having some indexing
issues over the past few weeks. I tend to index the gears
on a stationary trainer in the apartment, however,
after riding outside for a couple of hours, the gearshifts become less than optimal and I have to tighten
my rear derailleur cable by a quarter to half a
turn to get things right.” Now Prashanth, they, “live in Texas and it has been
getting quite warm lately, is it possible that the
temperature difference between the inside of the apartment and the outside is causing
the derailluer cable to contract and expand, causing the gear changes to be sloppy?” Right, I reckon this one
is to do with the tightness of the skewer or the
over lock nut distance. So the reason I say that, I lived in a place where
it was pretty warm outside and then pretty cold inside. Similar sort of temperatures
what you mentioned to in that and I never had any problems with this. So if you’re setting up the indexing on your stationary trainer,
the over lock nut distance, so that is the measurements of the axle of that stationary trainer, is I reckon, slightly different to what
it is on your rear wheel, that you’re riding with. Or, that the actual tightness in which you fasten it into the wheel, as well as the stationary
trainer, is different. So you’re putting different
amount of tension on, when you’re doing it up, the rear derailleur is
slightly moving inwards on the derailleur hanger. It’s quite a common thing. The best way to actually try this is to try and index the gears on the bike, then put the bike back
on the turbo trainer and see if it works. Probably won’t. Did it work? I don’t reckon it did. So have a look at actually trying to get the tension exactly the same. Alternatively, measure
the over lock nut distance of that rear axle and also of the axle on the turbo trainer. If it is different, you
can probably get them to match almost perfectly
with some very thin washers. Just make sure you do it symmetrically so that the wheel is not
lopsided, one side or the other. (whooshing) And, the final one this week comes in from mario bonatti, who says, “Hi Jon, I live in a pretty flat place. My bike has a 52/39 crankset on it and I usually ride time trials. Should I look for a 55 tooth chainring, and if so, where can I find one?” Right, Mario. It depends, really. If you find yourself spinning out in that 52 with an 11
sprocket on the rear, if so, then yeah, why not go for it? Alternatively, if you
do find yourself riding in that gear quite often, it’s not the optimal chainline. You’ve got a little bit
of a diagonal shape to it, so, with a 55 tooth chainring, you could well get a straight chainline, because you’ll be riding
further up the cassette. Probably in the 15, say, so you’re going to have
that nice smooth line. You’ll see these days,
loads of time trialists on the UK scene, in
particular, doing that. As for the question, where
can you find a 55 from? Well, you’re going to
have to search around and actually make sure
the manufacturer makes one and also that the distributor in your country brings them in. If it don’t, have a look around, somewhere like eBay because there are some
aftermarket alternatives, too. Right? I hope that I’ve been able to help answer and solve
your problem this week. If not, well, leave me
that question down there, below, and I’ll do my very
best in a future episode. Remember as well, like
and share this video with your friends. Give that big ole thumbs up! Remember as well,
subscribe to the channel. Click that little bell notification. You get that little ding-a-ling-a-ling each and every time we put a video live. Remember, the GCN Shop at, for two more absolutely great videos. How about clicking, just down
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59 thoughts on “Replacing Wheel Bearings & Preventing Seatposts From Seizing | GCN Tech Clinic”

  1. GCN Tech says:

    We love to help here at GCN Tech, so if you've got a question that you'd like us to answer leave it in the comments below using #AskGCNTech

  2. Bondy says:

    GCN Tech…..YES👍🇦🇺

  3. It is I who Nuts to That says:

    Just when I found a bearing broken in half in my front wheel, glad I had a spare one…

  4. Stuart Dryer says:

    I get about 250 miles on a single paraffin wax application. 500 miles seems pretty over-optimistic.

  5. Hugo Carlos says:

    #askgGCNTech my bike is making some "metal" noises, I can't locate the source (one of the wheels hub? Pedals?). Have any tips on what I have to investigate in order to found the noise source?

  6. The Adventure Biker says:

    Well if you'd just run Shimano Dura Ace, Ultegra or Deore XT / XTR then you'd never have to worry about this then would ya? Making this video pointless…

  7. Matt Harris says:

    Ref: 105 shifting on the Zwift bike. You could buy Microshift shifters which are similar to Campy style but also run the same spacing as Shimano. 11sp and 10sp options available.

  8. Gabby Jabberson says:

    What colour might one call the logo on that sweatshirt?

  9. Tomi Saaranen says:

    2:14 Has this guy heard of GMBN (Tech)??

  10. Jabin Lim says:

    #AskGCNTech I currently have a Giant Propel SLR 2 (2016) and the problem is my down tube bottle cage screw cannot be unscrewed as the rivet is loose

  11. Sebastian van Burgh says:

    #AskGCNTech When should you replace brake/gear cables? Is there a rule of thumb for how many kilometers you should expect to get out of them? And when the are replaced, should you always replace both outer and inner cables or is it okay to just replace the inners in certain situations?

  12. Josse McKenney says:

    Hi John (or whomever is presenting), I have a Castelli gilet, jersey and bib shorts who celebrated their one month birthday by having holes ripped in them when a deer popped out in front of me in Richmond Park. Is there any way to repair ripped cycling clothing or are they a lost cause? The holes vary from a 5 pence piece to a playing card. I thought of perhaps going to a local tailor or a patch from online. It's over £200 worth of kit that I REALLY don't want to replace. Thanks. #askgcntech

  13. Gemilang Bayu Ragil Saputra says:

    As I said many videos ago, just gimme that baby blue bike! #entitledhumanmode lelz

  14. JayB29 says:

    52 to 55 chainring = 3/4 of a tooth on cassette. so to have a great line with the chain, every tooth you go up the cassette you need to add 4 teeth on the chainring. so to equal a 52×11 with a 55 you need 12 behind. not 15 john! to be on the 15 behind, you need 16 teeth more than 52 to have similar development. which is 68!! nobody runs 68 at the front john.

    with a 60 chainring, to equal a 52×11, you need 13 behind.

  15. DRBTempleRocker says:

    Good stuff! Love your tech knowledge!

  16. Joseph Leo says:

    #AskGCNTech Hey Jon, I was wondering if you have any storage tips for a road bike in a college dorm? We can't put any holes in the walls and all my searches for adhesive wall hangers are coming up zero. Do you have any tips or options?

    Thanks for the help,

  17. Chris Ko says:

    8speed groupset on a modern direct drive turbo trainer: simply put a spacer on the freehub. A friend of mine had that problem, i told him what to do and it works just fine.

  18. Aaron Horsting says:

    #AskGCNTech Hey Jon, great show! I have recently purchased an N=1 bike. I have been using it for road riding as well as some gravel. It has a 50/34 crankset and an 11-34 cassette. While one to one is pretty good for my road needs I could use some smaller gears when gravel riding. I'd like to run a 46/30 crank some but not all of the time. The chain length will be different for the two cranks. Is it better to a) break the chain and shorten/lengthen it every time I switch cranks, b) add a second quick link for an easy switch over, or c) use two chains of different lengths and swap them with the corresponding cranks? Sorry, long question. Cheers!

  19. Milton Smith says:

    @ Hi Jon, I have a pair Shimano 9000 Dura Ace wheels that have around 3500 miles on them. Question – At what point should I be concerned about servicing the hubs. Would it based on milage and if so how many, or on performance or noise? Thanks.

  20. MRGRUMPY53 says:

    Jon…..Campy 8 speed freehubs and cassettes have equal splines all around. 9 and 10 speed cassettes won't fit on the hub. 8,9,10,&`11 speed hubs are all 130mm over locknut.

  21. MRGRUMPY53 says:

    Good answer on why to use a 55 ring on a TT bike……..The only thing I might add, is to ask if the rider can spin a 52×15 at 90 rpm? If he can't, it would be silly to change rings.

  22. paul howell says:

    jon how do people get through that door behind you with a bike hanging off it ??

  23. Ben Baker says:

    #AskGCNTech – Hi John! The Seatpost on my new bike is slipping down inside of the seat tube whilst I ride. The frame and seat post are both carbon so I have used carbon paste and tightened it to 8NM which is stated on the frame. Any suggestions? Thanks for all the great content!

  24. Jack Swift says:

    Hi Jon, I have an old Cannondale RS300si (I absolutely love it) but been thinking about upgrading the bottom bracket/crankset. It's a Shimano BB-7700 octalink and it's been giving me problems with chewing through the crank arm 'interface' with the BB axle. Do you have any suggestions on how to upgrade to a hollowtech bottom bracket and 105 crankset? #AskGCNTech

  25. blueline says:

    based on the thumbnail for this video, I thought part of this video was going to be showing how to replace wheel bearings, not just talking about it.

  26. Glenn cortis says:

    Disappointing to see your bike build still has silver headset spacers.😩

  27. Simon Guard says:

    Nice glasses

  28. matyourin says:

    When waxing the chain, what do you do with the cassette, the derailleur cogs and the front cogs? Do you just degrease them? Wax them too? Grease them?

  29. Michael McDermott says:

    JC is The Man.

  30. Ozzy says:

    What are some good ceramic bearings for a Fulcrum carbon wheelset ?

  31. Ben Norley says:

    Hey Jon, I've got a 2016 Giant TCR Advanced. It has an internal wedge clamp for the seat post. But despite using the correct torque settings it's stuck. I can't get the post out. It's at the correct height so not too much of a problem. But I'd like to take it on holiday and it won't fit in the bag with the post in place. Any help would be great. #AskGCNTech

  32. Christopher Jenkins says:

    Forget about any future bike giveaways. What about that rocket coffee machine. My dream coffee machine 😍

  33. earthstick says:

    Waxed chains last a while before rewaxing is necessary. But the import thin is how clean it is before waxing. The other thing is if you use liquid lube it might seem like it is lasting longer but it will collect dirt and grime and turn into grinding paste. Wax falls off when it is done and you will know to rewax the chain.

  34. Jonathan Zappala says:

    Piece together an old sora 3400 group set for cheap. It has the thumb shifters

  35. Richard Perriss says:

    What is the bike ‘rack’ on the door please?

  36. Scott Bayvel says:

    #askgcn adjusting wahoo kickr from normal rim brake skewer for disc brake thru axle. please and thank you

  37. trbeyond says:

    Thanks Jon! #answeredmyquestion #nowimfamous. Lol 👊

  38. Dan Di Vincenzo says:

    #AskGCNTech Hi Jon. Love the show. I have an older SRAM red 10 speed. Low miles on it. Occasionally when I’m trying to shift my front derailleur from the large to small ring it just won’t move. After multiple tries it eventually moves down. And then the rest of the ride is fine. I keep the bike spotless and lube all pivot points. Any ideas? Thanks

  39. David decider says:

    i have been given dillinger hub motor kit with its powerd wheel bieng on the front. can i fit it on to my cube analog stock 2016 wheels, will cutting an re treading stronger spokes take the strain? will i beable to fit a new 9 speed set on to it?.. should i even start ti do this ?

  40. Chris D says:

    Ok, so I have a 2014 LaPierre sensium 500 with Shimano ultegra DI2…only been riding this bike for about a month and I feel the bike is very noisy whilst pedaling…BUT…only in the big chain ring and while in the middle to upper portion of my rear cog, so going about 18-25 mph. I’ve cleaned it all thoroughly, made sure it was plenty oiled, even tried a different type of chain lube, ensured proper indexing on front and rear derailleur, nada! Nothing seems to improve the noise I’m hearing. And the noise sounds like it’s the chain rubbing on something but it clearly isn’t. Is the the ultegra front chain ring just loud? I’m at a loss and about to take it to get looked at but figured I’d ask some of the pros! Please help if you can!

    Also, maybe a good way to check for a cracked carbon frame? I have a small slit on the inside of my chain stay and not sure if it’s a crack or paint? HELP! 🙂



  41. Sheila stallard says:

    Don't touch the new stuff leave it to the lbs

  42. Daan Hoogland says:

    nice superbike in the background!

  43. Martyn Reidie says:

    Hi Jon, love the show. I have a Scott Speedster S30 with Shimano Tiagra 10 speed groupset which is about to become my winter and indoor training bike. It has new wheels so I have kept the rear and have put a turbo tyre on it. However I have put a 34 toothbrush cassette on the new wheel with a hanger extender to make the hills easier. Is it going to be problematic swapping between the different wheels with 28tooth and 34tooth cassettes? Saves me buying a new cassette for that too. #AskGCNTech

  44. audax333 says:

    About the thumb shifters for 105: microSHIFT has thumb shifters and are unofficially compatible with Shimano. The model for the current 105 11-speed would be SB-R512C.

  45. Rodrigo Landeros says:

    #AskGCNTech Helo John! I have a Shimano Ultegra Di2 r8070, and can't connected to my Wahoo Element Bolt or the E-tube App. The junction box jumps to adjustment mode (2 sec) directly without the 1 sec hold for the connection mode. Help!

  46. Ross C says:

    Just a thought for the guy with the loose bb. I have a ceramic bbinfinite and the directions show having to shave a bit out of the frame to get it to fit. Might be an idea. I had a shop install mine so no idea if they did that on mine.

  47. Rich A W says:

    More top stuff JC..👍

  48. Mav Erick says:

    #AskGCNTech great vid as always! Thinking about wheel bearings i can't help wondering (since we now have hollowtech for cranks & the stuff we use in headsets) why we haven't got anything like that for wheel bearings – come on shimano etc… pull your fingers out?!

  49. David Ide says:

    Hi Jon,
    Your tech shows are great I watch every one !
    My question is. I have some very high end wheels with very light titanium skewers. The skewers have to be very tight ( over tight ?), to stop a clicking sound when climbing hard. I have lubed the skewer shaft and nuts , but they still need to be extremely tight to prevent this. It seems like they stretch ? Is this ok or should I just buy some high quality but heavier skewers ?
    Thanks, Dave in the USA

  50. Bungle2010 says:

    You should have mentioned that it is not recommended to use carbon paste on the steerer/stem interface.

  51. Emil Fitzner says:

    Hi Jon. No matter how much degreaser and soap I use and no matter how much elbowsgrease and gizmos, I still can't get my chain perfectly clean. Is seems like the grime appears out of thin air. Is there a way to get a perfectly clean chain, without using fancy equipment, such as an ultrasonic cleaner?


  52. Nicholas Byrne-Chinn says:

    John you are a wealth of knowledge and entertaining to watch! Keep up the good work!

  53. AJ Albin says:


    Hey Jon. Wet gravel speed wobble or headset issue? I’m utterly perplexed. I’m an experienced categorized racer (mostly road and some single track mountain bike), but had yet to try this gravel phenomenon until yesterday! I raced a 52 mile HILLY gravel grinder on my 2016 Specialized CruX Elite X1. Had the bike about 9 months – I’d built it up myself (probably my 20th build or so). Bike has been ridden 300 miles prior to yesterday with no issues. Well, yesterday during the race, it started to rain. That was fine until maybe 10 minutes of good rain when the bike started to handle erratically. The road surface didn’t change much with the moisture, as it was a pretty hard packed gravel. I couldn’t hold the steering straight! I’d been flying at 20+ mph but was stuck going half that fighting what felt like speed wobble!? Climbing up (very steep) hills was easiest to control but flying back down was impossible…had to ride the brakes hard to control the twitching. I “gave up”, almost forfeited, but was so far from any support I just kept slowing chugging along. The headtube creaked (never done that before) after the rain stopped. As the creak went away, the bike got back to handling back to normal…COMPLETELY UNEXPECTED. What could have been the issue?

    The front wheel is tubeless. It felt like the wheel was floating on the hub or that the wheel was way out of balance, but no missing spokes and wheel seems balanced enough. The tires hadn’t picked up much or any mud that would caused it to be out of balance. Thought maybe water could have gotten in the wheel (not the tubes, as that’s obviously sealed) to cause imbalance. Headset seems to be tight..

    I’ve read on speed wobble and watched your GCN video on speed wobble. Bike has almost a slammed stem (so shouldn’t have any extra flex in the headset). Bike frame fits me but may be a bit larger fit than my other frames (still have 8” of seat tube exposed). And I’m a pretty light rider (5’10” @ 135 lbs). I’d bought the bike from a guy who had raced the bike…I’m left wondering if there isn’t some alignment issue within the headset or wheels? Any ideas are appreciated!

  54. petembb says:

    #AskGCNTech Hi, Are all breake leavers and disc calipers created equal, or are there some parts that just dont match. I'm building a bike with Mechanical Etap and Trp spyre slc disc break calipers. When i pull the leavers there is 1cm of pull before the breakes start to engage. I't seems like they breakes come all the way in, but there is just no stopping power in them and the pull feels really soft. I read some where that Sram requires a different leverage bar length on the caliper then shimano to work propperly…..What to do, just want to be able to stop before the road does, cheers 😀

  55. airblade97 says:

    Hi, I am fairly new to cycling and bought a gravel bike last year to do a chrity challange from London to German. I found that I struggle to gain speed on the road and am considering buying a new bike, what would you recommend, I quite like the cannondale systemsix #AskGCNTech

  56. 麥Max says:

    Just switched to road tubeless. Is it normal to have the tires go flat at home within a day or two of not riding? Seems like a downer if I decide to tour on this puppy.. am I doing something wrong? too much gravity where I live or something? Cheers..

  57. Pierre Constantineau says:

    BSP-97: That seat post clamp is exactly what I have been looking for! My wife and I use the same Zwift bike in winter by simply swapping the saddle/seatpost. We both have a bit of tape on each of our seatposts but with time, inserting/re-inserting and eventual slippage, it never stays put and eventually needs to be re-measured and re-applied. Now that's a simple and more permanent solution! Thanks!

  58. stubbietubbie says:

    I ride a Cannondale Synapse Carbon but I want to screw riding up grades and buy some upgrades. Will 50mm carbon wheels be worth the upgrade on an entry-level bike (with entry-level standard steel rims), or should I save my pennies more and get a proper aero-bike with equal-to-or-better wheels? (I don't live in a particularly hilly area so weight's not a problem)

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