Swapping Stems, Turbo Troubleshooting & Numb Feet! | GCN Tech Clinic

[@gcntech]

Let us know your tech questions using #askgcntech 🛠

[@RupertSutter]

#askgcntech I saw this in a previous comment, but I also had this problem. Do you know a solution to attach a rear rack to a carbon bike that doesn't have mount points?

[@tanadonsupanurat8674]

#askgcntech I come back to cycling and think about building a new bike. Is it a good idea to do a bike fitting first to know what to buy, or does it really matter? I have also been watching GCN since middle school, barely speaking English. Now in college, I speak almost fluent English. Thank you for the cycling lessons and the English lessons .

[@andrewmcalister3462]

Re the numb feet. Before spending on new shoes, try adjusting the cleat placement (it costs nothing to move your cleats). In particular, try moving them backwards on your shoe.

[@janeblogs324]

I've had numb foot "randomly" just this year. It was from lack of pre stretching and low hip angle (low bars).

[@gcntech]

Great point! playing around with cleat position may unlock some hidden potential in your current set-up 🙌

[@hawkeye2816]

Also moving the cleats as far toward the arch as you can. Wider stance can relieve so many hot spots.

[@resurrectorbikerepair454]

Sometimes replacing the insoles with ones that have better arch sort support than the ones that come in shoes can help.

[@docj511]

The main consideration when choosing stem length is the effect this has on bike handling. A shorter stem makes the bike feel a bit more “twitchy” while a longer stem makes a bike feel more stable. I would definitely go with the slightly smaller frame and longer stem. You will never notice the 1cm spacer but the improved handling you will feel.

[@gcntech]

Very true! It'll all come down the the riders style and preference

[@Porathen]

Quite sure the the person asking about stem ment cm and not mm, according to bike fit it perhaps was 95 mm and ha had to chose between 90 and 100 mm

[@derekmattice3077]

He did, the printed part of the question had the person saying his headset top cover was 0.8mm. Since most headset top covers are 8mm I'm sure it was a case of not understanding the metric system.

[@jeremyemilio9378]

THIS

[@TerjeRiisnaes]

When in doubt between different bikes with different fits, always choose the one with the best paint job 😊

[@BreakawayB]

🥴The title promised numb feet, but mine are still warm and cozy!

[@gcntech]

Think yourself lucky 😂

[@frederickvillarete1755]

New word, "flexibilitiness." Thanks Manon! 😂

[@petedannatt]

I reckon you guys are off the boil this week. Was there an early Xmas party? 🎄😅 Clearly the guy talking about 0.5mm stem increments meant 0.5cm. In other words, what would you do if your ideal stem length came out half way between 2 options? For the person who had sore feet after starting out with cleats, surely you should have also mentioned cleat position. Incorrect gait, fore-aft and cleat angle can all cause sore feet. A bike fitter once did magic for me by moving mine around and fitting some pedal spacers. Hope you haven't sent GCN viewers off buying new shoes when they should be trying out the free option first. And, I think a lot of us get better connectivity with ANT+ compared to Bluetooth, especially in environments where there are a lot of Bluetooth / wireless devices. An ANT+ dongle on an extension lead is usually very stable on Windows PCs / Laptops.

[@billkallas1762]

Two of my old race bikes were made in the 20th Century and were made for quill stems. Most quality quill stems were available in 5mm increments. One of mine has a 140mm, 73 stem, and the other has a 135mm, 73 degree stem.

[@rickcski8082]

I had the same issue as Millicente regarding numbness in my toes. I solved the problem with Specialized Blue footbeds. No more numbness in my toes or pain in my feet.

[@gcntech]

Awesome! Did you try that yourself or was the change the result of a bike fit?

[@rickcski8082]

@@gcntech No bike fit. I have relatively flat feet and found that some type of arch support was needed. The footbeds that came with my Sidi cycling shoes didn't offer the necessary support. The blue footbeds from Specialized worked perfectly. I use them in all my cycling shoes now.

[@jessegaudet22]

Best way to clean a commuter bike. What winter riding has taught me is that as soon as I finish my ride I use my air compressor to knock off all the ice, salt, mud, as much water as possible with an emphasis on the chain... It only takes a minute. Then I wheel it into my shed where I'll tend to it properly after I shower and warm up.

[@aronanlife9039]

the shoe question, had the same issues with a top brand 'wide' fit, it caused numbness in my feet. LAKE shoes we were recommended as an alterative for people with v wide feet, there are better than anything I've ever had, pity they don't do causal shoes!

[@KeithCollyer]

Came here to say Lake tend to be wider fitting than most other brands

[@throughthespokes21]

I run an Ant+ dongle connected to my laptop for Zwift and it has fixed all of my connection issues. I run bluetooth headphones and our house is littered with bluetooth and wifi interference which caused me tons of issues. I also run max Zwift difficulty, not that it is actually harder...watts are watts. But it makes you shift more and "feel" the elevation more, which causes you to shift, just like when outside. Think of Zwift difficulty as "how much do I want to shift?". My first trainer bike had an old cable operated thumb shifting triple ring, and as such, I ran difficulty on the easiest. Now that I have my 1by gravel bike on there with eTap...not an issue.

[@B_COOPER]

Manon is right about turning off any lingering connections with Bluetooth and wifi. My old roommates phone would just have its hotspot turned on and it would sometimes cause issues with my phone Wi-Fi list not showing my own home Wi-Fi if his hotspot was on.

[@DavidvanderWant]

Numbness and hotfoot often caused by pressure on nerves between metatarsal bones in foot. Inserts that spread metatarsals usually relieve this pressure and solve the problem. Several manufacturers available. I use g8 metdomes.

[@gcntech]

Lots of people have good results using insoles, Bike fitters will be able to advise on this if you are not too confident

[@yogatriathlete]

The most common reason for feet numbness is cleat position. Moving the cleats back towards the heels will usually fix it

[@nsjohnston]

The guy with the trainer issue, I have this now and again. What it turned out to be was the elite trainer. There's several connections to the trainer when attaching to zwift, they all work when in ERG mode, but when free riding only the FE-C version, otherwise if feels like hills have no gradient

[@JosephRank1]

This is exactly the issue I have every once in a while. I un-pair and re-pair and it is good

[@StephenCrimmins]

I've had a similar problem on my Direto XR. For some reason Zwift has decided to try connecting to a different channel for the controller from what it connects to for power and cadence. I have to disconnect it and reconnect to the right controller channel now about half the time.

[@nsjohnston]

@@StephenCrimmins Yeah, that's the trainer I have. I 'upgraded' from a taxc flux...much better trainer but can't do as steep a gradient. The first couple of times was during zwift league races, I'd do an erg warmup and everything was good, then the race would start and I'm in top gear spinning at 110 rpm uphill struggling to hit 300W. It would happen every now and again for no real reason. After the 3rd time I'd figured out the issue. I try and double check that it connects to the correct one every time, occasionally it still happens. I don't get why elite included a 'this doesn't work' channel, my tacx never did that.

[@sgbryant1962]

Re Stacked or slammed, adjust it for your comfort, not for how someone thinks it should look. It will also help with numbness 😊

[@gcntech]

Yes! Function over form 🙌 Always get the fit that you like the most, not the one that gets the most likes

[@carlosdeno]

The riders wanting to look like the pros 😂 you’ll need that extra 5mm as time rolls on and your flexibility decreases. (I’m 60) Comfort is the key to enjoying your bike and avoiding possible injury. 👍🏼🚴🏼🚴🏼

[@tomasztomaszewski9275]

Cleats should be well aligned. They can't go too far forward or too far back. Usually they need to be moved back a little. But not too far cos it will be bad too! Another issue is the height of the saddle. If it is too low, constant pressure will cause numb feet. Another issue is poor blood circulation in the feet. You may also have crooked feet and you need shims. Changing the insoles may also help. A well-chosen insole will spread the foot pressure more widely and will not cause pressure in one place. There are many possibilities and you don't necessarily have to buy new shoes.

[@tomasztomaszewski9275]

Stretching may help a bit. But don't expect a spectacular effect. First of all, a good position on the bike and than correct cleats.

[@Millicente]

Thank you for the advice!

[@andrewmcalister3462]

Re shoe based power meters. Brim Brothers a few years ago had a promising shoe based prototype, but ran out of money before they could make it to market. I don't think anyone else has tried since. Developing a PM is really hard - vibrations, sprints, temperature compensation, etc trip up a whole lot of new entrants. The angle of the foot and pedal "float" would be additional factors for a shoe PM to overcome.

[@TransAm2k4]

A possible answer for training difficulty, I have seen were either ant+ or bluetooth my Saris Hammer 2 was adding difficulty. Once I switched to the other protocol it worked. I can't remember which on is the one that worked. I tried updating Zwift and firmware and non fixed it so now i just make sure to use the correct connection style.

[@JanneRasanen2]

@millicent Lake 237 and 238 and Bont Vapour 23 have wide front of the shoes reportedly so they might help with numbness. No personal experience though. Reportedly the Bont has a stiffer sole so the Chace of the cleat pushing nerves in the bottom of the foot causing issues like numbness should be lower. The other parts of shoes are reportedly softer in the Lakes. Lakes for leisure Bont (light and stiff) for racing. This advice is from bike fitter Neil Stansbury (hope I remember correctly) on KZbin channel Road Cycling Academy just recently so the video should be easy to find.

[@BUY_YOUTUBE_VIEWS_d035]

you give me motivation every day

[@jhoff80]

It sounds like maybe you should do a video on Zwift trainer difficulty because it sounds like that asker (and potentially even the presenters, couldn't tell) don't actually know what it does.

[@TimR123]

Y'all missed it on the bike fit question. I don't know if the sender mis-wrote or you mis-read, but clearly it wasn't really a question of 0.5mm difference in stem. To your point that most stems are offered in 10 mm increments, I think the intent of the question was 5 mm aka 0.5 cm. IOW if theoretical fit requires a 75mm stem, get a 70 or 80mm? Ironically, I think the answer of 'it doesn't matter' comes to play anyway. Make the best guess if a bit more or a bit less would be more comfortable and don't worry about it.

[@lbx5359]

Concerning the zwift/trainer issue, also consider if you have a wheel-on trainer to check whether the roller thing is correctly installed and secured. Bad installation could explain why you need maximum training level, and could also explain slippage during effort which could feel like loss of resistance.

[@The_Cotswold_Cyclist]

Power is the measure of strain not pressure so it would be very difficult to measure the shoe sole movement. Particularly as you don't want shoe flex. Power cranks have stain gauges to measure the flex and Power pedals do the and but with the axle flex.

[@oplkfdhgk]

5:25 yeah and if it's not centered then you can most likely loosen the caliber bolts little bit and then hold down brake lever and while doing that you can just tighten the bolts.

[@katerineshapiama272]

Excelente video

[@yosmanbalza5691]

Gran trabajo 👌

[@JanneRasanen2]

If you wipe the chain of a wet commuter and apply lube the lube will transport dirt particles into the chain and that grinds the chain and rings and cogs faster than a properly washed chain does. If possible I would not lube the chains until a proper chain cleaner was used.

[@bele13]

3:36 I think shoe geometry is way too complex to allow power measurements. In pedals, cranks, spiders etc., the stiffness can be calculated fairly easily, which allows the conversion of the strain measurement to a force reading and, consequently, the torque.

[@festerofest4374]

And unless it can be made so thin, like a replacement insole you could swap in, nothing could work with normal shoe design.... it would essentially mean building it in to the sole of the shoe. Expensive, and what an inventory nightmare carrying all the different sizes and styles.

[@mikecornwell2014]

Mike C from Oklahoma. Just purchased new pair of Fizik shoes & read about SoleStar performance insoles. What's your thoughts on these? The top of the line insoles are pricey but do they really work as advertised?

[@simonsepic]

The shoes person i had the same issue and after 3 pairs of shoes and 3 different styles of pedal the thing that fixed it was buying shoes 2 sizes bigger than my foot.

[@timhands6681]

@gcntech should you rotate your tyres? That is when the rear tyre starts to get that straight edge due to more weight at the rear. Should you change it to the front?

[@bikingmoments]

#askgcnteck why it feels safer to lose rear tire traction compared to front ? I have experienced this in a muddy downhill (bike only has 35mm hybrid tires) last weekend and wonder why.

[@mitch_smith]

Lake seems to be the only company that legitimately make wide cycling shoes. Several others claim a wide size, but i've never found any that are actually wide. They even have extra wide on some models. Naturally they are expensive. Wide feet are seriously under represented in cycling.

[@mommamooney]

I have very narrow feet and also suffer from numb toes

[@JanneRasanen2]

There are shoe sole power meters for running but presumably they would give way off figures if at all. The movements thus algorithms are different. If data from running shoes would come up and be repeatable it still might not scale up correctly between different power levels. The sensor technology is there and the algorithms could be close to bike based power meters but there are r&d costs. Shoe power meters should be doable now because everything needed exists already and some forms of everything needed are on the shelves. Neat idea hope it takes off. Insoles and shoes wear faster than bike parts so retaining accuracy throughout the life time of a sole or a shoe is challenging.

[@john_7986]

Regarding numb feet and shoe fit, what about molded orthotics? They're quite common for ski boots for improving fit and power transfer

[@festerofest4374]

Most orthotics have more thickness than a typical insole.... particular cycling shoe insoles where it's often very thin because not much walking is expected.... I think fit would be a big challenge adding orthotics to an existing shoe.

[@truvc]

What about power meter *cleats*? Not shoes. That would solve most of the problems you mentioned.

[@mommamooney]

I have one foot that goes numb on longer rides. I have very narrow feet and even loosening the shoe doesn’t help. We did move the cleats back and it takes longer to go numb, but didn’t fix the problem. Like Manon, I just have to unclip and get feeling back.

[@mohyla91]

Sounds like a disbalance towards one side. I would advise getting a proper bike fit, there are zillion options what could be the core reason. A professional bikefitter should be able to pinpoint it and offer solution.

[@alkfema]

hi! I have a chain thats linked with a rivet. I bought the correct tool for it to remove it, so i can reconnect it with a reusable quicklink. My question is, does the quick link make the chain longer, do i have to remove an existing chain link before? I hope you understand my question, english isnt my native language Thanks!

[@badannyrey4296]

Imprescindibles

[@marivelalarconveliz2172]

Excelente

[@davidlind9905]

#askgcntech can you please do a deeper dive into foot numbness as it affects allot of riders. I use mtb cleat and 3 pairs of shoes and I still get numb toes after 50k

[@mommamooney]

Yes please!

[@Cous1nJack]

50k what 2h riding with your feet locked to pedals and strapped in shoes? My feet would do numb driving or sitting I. The sofa if I didn’t move them

[@paopixel]

#askgcntech I have an aluminium road bike, the Swift Enduravox Comp with a 2x10 Tiagra groupset with mechanical discs. What would be better value at the same final investment, buying Carbon Wheels ou selling the bike and buying a carbon bike with aluminium wheels and 105 11s?

[@jamesking144]

Hi, I recently bought a new pair of cycling shoes that have mounting holes for both mtb and road cleats, but when i put on road cleats the mount for the mtb cleat moves and rattles around inside the shoe. Is there anything I can do about this? thanks.

[@___Bebo___]

If you have numb feet try some composite mountain bike flat pedals paired with leather oxford shoes with work safety sole. It's pretty much impossible to get sore feet with this combo. You can get a pair of barely used work Timberland Oxfords at the used shoe store for about 10 dollars. It takes awhile to break these shoes in so I recommend used. If I am doing any sort of bike touring the Oxfords get dusted off for sure. They have cycling specific version of these shoes but they are marketed towards Dentist riders so you will be paying over 200, not worth it.

[@oplkfdhgk]

7:32 i just use very rust resistant chain and chain wax. no issues.

[@mikewallis5937]

#askgcntech quick question regarding cross compatibility with Shimano components, do GRX brakes and shifters work with Tiagra derailleurs? TIA

[@AbelAlencar-dg6jr]

Bien

[@kurre_kallkvist]

#askgcntech Hi! What is the main reason winter riding is so slow? I seem to lose about 5km/h average speed for the same power output over my regular commute as the temperature drops from nice summer/autumn temperatures to freezing winter. Is it just the bulkier clothes or do the tyres actually roll slower in the cold as well?

[@JudithSaNo-pm7fu]

Genial 👌🏻

[@serisingh]

#askgcntech when I was coasting down a hill on my gravel bike in the hardest gear, my chain spontaneously jumped off of my cassette. Could my chain be too long? Could this be prevented if I remove one link, or would that cause other issues?

[@ryanwilliams2518]

I’ve had this on my road bike a few times and it’s scratched my crank pretty bad. Would love to know a fix!

[@clbs0303]

#askgcntech, hi guys, this is a question for Manon, when i ride on the velodrome my hands are really sore. So much i can only ride 30 minutes at once, they are not numb but my handpalm is red. I spoke with 3 different bike fitters, but unfortunately they all say that they dont know how to set the position on a track bike, on my road bike and my gravel bike im sitting perfect and have no issues, any tips for setting up my position.

[@runplatypus]

Glitches in zwift can also be fixed by doing simple power cycling on your wifi and devices.

[@ime06]

#askgcntech Dear Ollie, Alex and Manon, You have successfully convinced me to take the plunge into waxing my chain. How long could I store a waxed chain without it losing its favourable properties? Given the effort it takes to initially treat, clean and wax the chain, I thought it would save time to wax multiple chains at the same time, and then when my chain is worn, I can effortlessly switch to a chain that has been pre waxed. Also I planned on waxing multiple quick links for the same reason. Thank you for your great work, love the channel.

[@festerofest4374]

I would just store them in a bag of some type so they don't collect dirt/dust.

[@kaupo80]

A confused asker (not understanding what a cm or a mm is) confused the expert panel - Manon and Manivald totally messed up the 0,5 mm reach question. Obviously, the asker meant 0.5 cm (not mm). The real question was: if one has ideal reach with a stem of 95 mm (9.5 cm), should this one person choose 90mm or 100 mm (9 or 10 cm).

[@sirmarch]

#askgcntech I had a bike fit before buying a new bicycle and I am debating between two models. With one of them I would have the stem with no spacers but the stem should be 90mm instead of the 100mm it came with. With the other one I would need to have 1cm of spacers (plus the headset cover of 0.8mm), but keeping the 100mm stem that would come with the bike. So should I choose the bike with 1cm of spacers or the bike with a stem that is 1cm shorter? What is better in terms of handling, etc.?

[@ScottWaltonDev]

2:54 I think a reason might be they’re on a training session, assuming it’s not happening while riding.

[@randomname8442]

Do you think they meant cm instead of mm....?

[@djmanahan9466]

Hi GCN, #askgcntech I have a sidi shoes that needs a cleat nut bolt replaced. The problem, i cant find a replacement online. Is there an alternative nut i can use to replace it. Thanks and more power. - dan

[@simonsepic]

Oh and I did pay a bike shop to measure my feet and fit my cleats incase that was the problem but no that didn't fix it.

[@ajackson999]

#askgcntech Dear Gurus, I have a chain maintenance question. Living in Australia I pretty much only ride outdoors in dry conditions and aim to do around 200km per week. After every 30-50km ride, I wipe down my chain with a rag and then lubricate it with Muc Off dry lube. I still tend to notice greasy deposits after wiping down the chain between the inner and outer plates. If I’m using a wax based dry lube, should I still be completely degreasing my drive chain (inc cassette, jockey wheels etc) every week, or just wiping down and reapplying the dry lube?

[@mohyla91]

Unpopular opinion - Mucoff basic dry/wet lubes are crap and always leave a residue which is pretty difficult to remove. Either use their top line (pretty expensive) or find a different one. I'm not sure what's best available in AUS but your LBS should be able to advise. Enjoy!

[@brandonallen7748]

WiFi and Bluetooth inteferences is extremely unlikely. ANT+ on the other hand it is possible.

[@shanepepler8251]

#askgcntech, hi guys, I have a ultregra groupset and using the r8020 levers, every year I have to buy a new 11 speed shifter as the internals break. It skips down loads of gears, gets stuck and doesn't shift up. It's costing me 300 every year, do I change to 105 and hope for the best. What's your advice. Cheers guys

[@TnFruit]

I think the british person meant 0,5cm.. the metrik system is very complicated 😅

[@MrBastiBast]

#askgcntech Hi Manon and Alex, I'm planning on assembling a new bike with an aluminum frame and I'm not sure what type of grease or assembly paste to use to install my T47 bottom bracket, and also around the headset area (carbon fork). I have Muc-Off Bio Grease on hand that I already use on all my screws, pedals, thru-axle,... is it convenient for the bottom bracket shell and headset as well ? Thank you very much for your feedback. Cheers, Bastien.

[@janeblogs324]

Grease has zero anti corrosion ingredients, it just lubes and waterproofs. Some materials like 7075 aluminium will corrode/oxidise from within no matter what grease you seal it with. You want nickel anti seize, something sacrificial for the anode/cathode corrosion

[@Choedron]

Gotten too old for a slammed stem 😂👍

[@Choedron]

Previous attempts of making a shoe powermeter, have not turned out well.

[@K_I_M_A_N]

Расширитель костей в стельки. Решает проблемы онимения ступней.

[@AndryNieves]

❤❤❤❤

[@liacamposflores-ll2ti]

👍

[@cmarnold78]

The price of power meters will (should) eventually come down rendering portability of power meters a non issue.

[@niklasschmid9123]

If I want to change my drivetrain from shimano to sram, I have to change the freehub body and the bottom bracket. Are there any third party parts, who fit both systems? #askgcntech

[@gcntech]

Great question! Don't forget to use #askgcntech

[@SmartLittleFishy]

#AskGCNTech So I live where there is year round sunny weather (Hawaii). Here's my question. On rides under 4 hours I don't get a tan on my legs; I no longer even bother with sunscreen on my legs for shorter rides. Anything exposed above my waist would have have burn right away with out sunscreen. Why don't my legs tan? Do my legs not get sun light? Are they spinning so fast the photons are unable to hit them, or do I cast that much of a shadow over myself? Surely this has happens to other people? (side note: I'm a normal guy that doesn't shave my legs, or anything else.)

[@ryanwilliams2518]

I’ve noticed the same thing here in Australia. I wonder if it’s because your legs are underneath you while riding so don’t get much sunlight whereas arms are usually bent so forearms facing up to the sun.

[@StoccTube]

I suspect the first question was 0.5cm (5mm) just my guess

[@_J.F_]

0.5mm too long or 0.5mm too short reach sounds a bit as if someone is taking the mickey to be honest. Either that or the person has no idea what a mm is.

[@percyvelasandi8894]

Buena

[@openwheelracing88]

I would get the bike with best paint job. Just me.

[@RuthmeryCondoriquispe-ct3lo]

Como

[@savagepro9060]

5:13 That does NOT sound scientific, Alex. For the first time, I miss Ollie!

[@thekeytoairpower]

Pretty sure he meant .5 cm or 5 mm...

[@space.youtube]

To the person complaining that riding zwift on max hardness is too easy, maybe don't use your ebike. 🤣

[@KarenCcolque-hz4bp]

como

[@MTBScotland]

buy the bike with the better stack

[@hotsky83]

About leaving the bike outside during your commute. Spray WD40 on your chair and cassette to drive the moisture out.

[@gcntech]

You have to careful using WD40 around the cassette, you risk stripping the lube off the drive 👀

[@dryburn]

Can you guys get rid of Alex? I would watch many more videos if Alex wasn’t in them.

[@craigfoulkes]

I'm happy with Alex in the videos.

[@alexpatonGCN]

Ye totally, he is awful.

[@KarenPerezcachique-tl5oj]

Excelente

[@christianjimenez9967]

Como

[@AnthonyVilca-qp8wz]

Como

[@AlonsofernandoCahuanasur-jk8lv]

Como