GCN Tech Clinic: Swapping stems, turbo troubleshooting and numb feet

In this week's clinic Alex and Manon take a look at questions on bike fit, in-built power meters and cleaning your bike at work

Clock18:00, Wednesday 29th November 2023

Back in the tech studio this week are Alex Paton and Manon Lloyd. The Tech Clinic is the place to get any cycling or tech-related questions answered by those in the know.

This week, we take a look at getting the perfect bike fit, and why we aren’t all riding around with power meter shoes just yet.

Is it better to get a bike with a slammed stem or one that requires spacers underneath the stem?

This comes down to aesthetic preference as much as anything else. If your bike fit is correct and comfortable for you then either option will work. If you are new to cycling or want to try and retain a slightly higher resale value for the bike, then opting for the bike that needs spacers is the better option.

This will give you more space to move your position around in the future as well as ensure your bike will fit more prospective buyers when it comes to selling it.

Trainer difficulty on Zwift intermittently drops out. What can I do?

If you find that the trainer's resistance whilst using Zwift appears to drop out whilst riding, this sounds like it is most likely a connection issue or a bug in the software. The best place to start would be to make sure that you are running the latest version of Zwift and the latest version of your indoor trainer's software. If you aren’t the best bet would be to give them an update and see how you get on.

It is also worth trying to limit the amount of interfering devices that could be affecting the connection between the device running Zwift and the trainer. Things such as Bluetooth headphones or connections to smart devices can limit the wireless transmission available which could lead to the dropout.

Why aren’t power meter shoes or insoles a thing?

Although in principle this does sound like a good idea and would make riding with power on multiple bikes a doddle, in reality, it isn’t that straightforward. Measuring power is a precise science that needs to have consistent and reliable inputs for it to work. A shoe-based power meter would introduce a lot of variables that could not be compensated from rider to rider or shoe to shoe.

The rigidity of a shoe will have a difference, as can the fit and the interface with the pedal. It also would make a lot of work for any brand to produce as there are many different shoe sizes and fits to accommodate whereas with cranks or pedals, there are only a handful of variations that need to be manufactured.

How many watts does a ticking disc brake cost?

If the issue is purely audible and when you spin the wheel to inspect the issue it seems to spin freely, it is unlikely to cost you a measurable amount of watts.

If the brake is catching and if it is causing some drag, the first thing to double-check is that your brake rotor is not warped. If it is you can straighten them out with a disc brake tool. Equally, it is worth checking that the calliper is properly aligned with the rotor as this can cause some rubbing too.

I'm new to cycling-specific shoes and pedals and I am experiencing numbness in my feet. What can I do?

If you are experiencing numbness in your feet after making the switch to cycling shoes it is most likely to be caused by the shoes themselves. Much like saddles, shoes are a very personal item of kit. What fits one rider might be an incredibly uncomfortable option for someone else.

The best way to overcome this issue is to head to a physical bike shop where you can try on different shoes from different brands and see which ones fit best. A lot of bike shops will even have a static bike that you can try pedalling on to get a feel for how they work for you.

Heading to a good bike shop is the best way to get all the necessary advice and support to find the right shoes for you. They will also be able to help you find the correct cleat placement, as well as mouldable shoes or insoles, if necessary.

What is the best way to clean my bike after a morning commute so that it is good to ride home?

Commuting by bike in the winter isn’t just tough on you, it is also tough for your bike. If you have a particularly long ride to work or a particularly dirty route it can leave your bike in a bit of a state.

If you want to do everything you can to look after your bike even when there are limited or no facilities, the best thing you can do is to bring a rag or cloth that you can use to wipe the worst of the grime off of your chain.

If you want to really step it up, bringing a very small bottle of degreaser that you can wipe your chain over with will bring it back to life as well as adding a fresh coating of lube.

It isn't an ideal situation but it is one a lot of us find ourselves in through the winter months. Giving your drivetrain a wipeover is the best you can do with limited space and resources and we are sure your bike will thank you for any love you give it!

If you have any tech-related questions that you need answering, head over to this week’s Tech Clinic video on the GCN Tech YouTube channel and add your question to the comments along with #ASKGCNTECH. Or leave your question in the comments below.

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