Di2 groupset change, bike helmet cleanse and excess chain lube: GCN Tech Clinic

We’re dropping into the GCN Tech Clinic once again to diagnose your bike tech and maintenance issues and dish out the appropriate treatment. This week Ollie and Alex take a closer look at shifter and groupset upgrades, power output discrepancies and sealant solutions for punctures.

What could be impacting my power outputs and timing on like-for-like rides?

There are so many variables that could be impacting your performance on two rides that otherwise look the same. We'd suggest it’s not always useful to compare rides in this way. When you factor in things like weather conditions, the clothing you’re wearing, traffic volumes, tyre pressure and the accuracy of your power meter there could be one or several reasons for the difference in your data. Rather than focussing on average power it can be more useful to try and assess where you’re actually putting any increased power down during a particular ride. You can do this via Strava for instance by looking at some key segments and analysing your performance there.

Can older Ultegra shifters be repaired or do they have to be replaced?

While it is possible to repair shifters it can be a very complicated process as sourcing individual parts isn't straightforward. The only real way you can do this is by having two shifters from which you can make one 'good' shifter. However that in itself is not an easy task, so unless you’re a very competent mechanic you may be better off trying to source another used one that has less wear than your current shifters.

Is sealant in inner tubes an effective way to give double protection against punctures?

This can work although is not as effective as a dedicated tubeless tyre system. Rather than offering double protection it’s more working in a similar way to a tubeless set up although you will pay for the extra weight.

Is it worth changing from a Dura Ace 9100 mechanical groupset to Ultegra Di2?

This ultimately comes down to personal choice and the state of your current groupset. Assuming your Dura Ace set up is still in decent condition then there should really be no reason to change - it’s such a good groupset and offers great shifting, we’d suggest you’re better off saving your money. If on the other hand it’s showing signs of wear and needs replacing then yes, you should consider Ultegra Di2 rather than spending on new Dura Ace.

How should you treat a smelly bicycle helmet?

You do need to be careful not to put chemicals that might be detrimental to the foam materials of the helmet. You could rinse the helmet with a mild washing up liquid solution after each ride or even spray with a dedicated air freshener like Febreze. Alternatively some of the bigger helmet manufacturers often sell replacement pads for your helmet. You could buy a set and alternate them after washes to help keep it fresher for longer.

How much excess lube should I be wiping off my chain after application?

When you’re lubricating your chain you’re really trying to lubricate the inner parts of the chain, making sure that it permeates into the gaps within the chain itself. The lubing process means that there’s usually plenty on the external areas of the chain but you really don’t want it there as it’s likely to attract dirt and detritus. So once applied make sure you wipe it off all of the outside areas of the chain.

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.

For more maintenance-related advice check out our dedicated section on the GCN website.