Can I mix rim and disc brakes?, big cassettes, and TPU inner tube reliability | GCN Tech Clinic

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I’ve been immersion waxing chains for mine and wife’s bikes for a decade. I always install nickle plated cassettes and chains to show off how clean our drive trains always are. I too have noticed little orange spots of rust sometimes. Not entirely surprising since the grime free drivetrain means the only cleaning our MTBs and expedition bikes need is a hosing. Usually, after hosing I just spin the wheels and bounce the bike to get big drops off. This low effort cleaning is a big motivation for chain waxing. Here’s what I’ve found with the little bit of orange I’ve encountered. If I lift and spin back wheel by fast hand pedaling for half a minute there is very little moisture remaining to initiate the rust. If the bike sits in rack without riding for many days humidity may initiate slight traces of orange. When we ride the bike again the orange quickly disappears. But again, I’m using nickle plated (shiny chromey looking) cassettes and chains. The standard black finishes are likely to have massive amounts of rust without a coating of petroleum based wear inducing grime.

This is the best GCN tech video ever! You answered a few questions that many people have and only one about waxing (which was also interesting). Thanks!

Mixing rim and disc brake: Of course you can ! It's easy and effective. On my road bike I have a cable actuated disc brake (TRP) at the front and a rim brake at the rear, both in combination with Ultegra 6800 brifters. By the way, my front wheel is dual purpose with a rim brake rim and a disc brake hub and vice versa on the rear.

For the 11 spd conversion, you do have to note that Shimano Road HG Freehubs are mostly split into 2 groups, 7/8/9/10 hubs and 9/10/11/12 so if he had the second group he could just slap on an 11 spd cassette

I rode from Copenhagen to Alpe d'huez this summer on TPU tubes - No Punctures. Just pump up the tyres each day.

I've had these bright pink RideNow TPU tubes for ~6 months now and they've been perfect, no flats or issues and there have been multiple benefits. Beyond losing ~200g, I have more space in my little storage case, the tires/tubes seemed to make less noise when pedaling hard after swapping from butyl tubes, and on carbon fiber rims they were so easy to install because of the color and low friction between the two materials that I didn't need a tool for installation.

I ran a mountain bike with hydraulic front brake and canti rear brake for a few years and that worked well. Also a cable operated disc brake as a front brake on a cyclocross bike, with a canti rear. Both were improvements on what i had before, improved safety and performance and were easy to adapt to.

RE: Fixing up an old bike - I am 66 and just got back into riding about 4 months ago. I first tuned up my 1980 Motobecane to see if I was really going to do this. The bike works fine, by my "geometry" had changed enough in the past 40 plus years to make it less comfortable than I remembered. I now have a new Trek Domane that I love, but still can't quite part with the old Motobecane. BTW - the GCN videos on YouTube have been an enormous help getting me back into this sport. I can't thank you enough! (Still miss Manon though....)

Alex, you may want to revisit your answer to the 1st question. The OP is running 105 di2, which means 12 speed. 105 is spec'ed up to 11-36, which is slightly easier than what they are currently running, but I am not aware of anyone offering a 2x12 cassette bigger than 36t. Also, the Roadlink derailleur extensions are 11s, not 12s.

Great content as always, thanks for sharing! A few unsolicited thoughts from an ancient cyclist follow… 105 Di2 lower gears: switch to 11-36 cassette and/or swap chainrings from 50/34 to 48/32. Disc/rim brake hybrid: cable operated disc and linear-pull (V-brakes) will allow use of same brake levers, but you’ll probably have to use MTB bar and controls. Older bikes are cool, sometimes a fork swap will allow use of larger tires. Tubeless is great for racing, but I prefer flat resistant touring tires and tubes for commuting. Preferred gear selection for long term storage: the chain and derailleurs aren’t affected by which gear you select during storage, but shifting to the smallest cogs leaves the shift cables slack, which will prevent damage to the linings of the cable housings. Long term storage with tension on the shift cables can imboss the housings with the spiral pattern of the cables, and increase shift effort/decrease shift precision. Ditto brake cables, relieve tension on them for long term storage. Addendum: if you’re paying attention to details like these, you’re digging deep into diminishing returns, but you’re exactly the sort of owner I like to buy used bikes from!😁❤️

For the question on sealant drying up over the winter, you can also rotate the tires daily. Spin the wheels and then have it stored/stopped a quarter turn from where it was last, that way the sealant won't just settle on one side. It's a bit of a faf, but if you don't, you'll have a lump and should just reset from scratch before the start of the next riding season.

Informative, as usual. Regarding a disc brake on the front, and rim brake on the rear: a simple solution would be to fit a cable-actuated disc brake on the front, so there'd be no need to replace the brifter for the rear (assuming you already have a pair of such brifters, that is).

Hi Guys. If you want to leave your tubeless tyres over winter, take a tip from the wine cellar guys and turn your wheels a bit every week. Simples.

Before I knew anything about cycling, I rebuilt an old hybrid bike. I put a disc brake on the front, with a new front fork, and kept the old "V-brake" on the back. No one said I couldn't but I didn't ask (no GCN Tech back then). It works perfectly. There are no issues with differential modulation - you have to do that instinctively front and rear anyway, and nor is there any issue with the brake levers being different, which they are. The rims on both wheels are aluminium and have a brake track and can take a bolt mounted disc - so, they are a compromise w.r.t. weight. I rebuilt the bike to keep it going rather than waste it. I doubt I would do the same to a road bike, but do not see why not, if you wanted to improve the braking of an old rim brake bike - esp if running carbon rims which are daunting with rim brakes?

Shimano 11 speed cassettes of 34t and above will fit 10 speed free hubs. The larger top sprocket allows them to overhang the fee hub body slightly.

Been living off a Cannondale M900 hardtail. I use the original rear rim brakes and hydraulic disc on the front. It works awesome. I love it.

Re adding a larger cassette ie 11-40: before buying that extra link, try backing all the way off on the B screw to give the derailleur extra space. It worked for me on my GRX derailleur which was only rated for 36. Shimano derailleurs typically have more capacity than they are rated for in the manual.

There are some budget mtb's with a disc brake on the front but a cantilever rim brake on the rear

In the '70s, I had a bike with a disc brake in the back and rim brake in front - my first 10 speed. I thought it was great. I'm also not convinced the front brake is more important.