New to indoor training and Zwift

General Discussion
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Hi all I’m very new to cycling indoors and have been looking for an indoor trainer to help me over the winter keeping me fit.

I have a gravel bike with a 40T from chain ring off the front and 11 - 42T cassette on the rear. I have a 142mm rear through axel and I’m a heavier rider in the UK. I have been looking at the spec of the Zwift hub smart trainer for my first step into indoor training.

My question is around the front chain ring. If i order the trainer with the 11 cassette will i be at a disadvantage in the application with a 40T from ring only ?

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Depending on ability, 40T is small for front chainring and you’ll spinout at pace. Zwift have tools to help with that for downhill (Trainer Difficulty) but on the flats you may struggle. At my average cadence of 80rpm with 11t rear and a 40T, I’d be ~37km/h. The low-end Cat C pace bot Coco cruises around Tempus Fugit at ~40km/h.

You can use bikecalc.com to work out speed vs cadence/gearing to give you some insight.

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Dean is right, but because I typed this up before I saw his reply I’ll still post it, lol. Running 40-11 at 90 RPM will get you almost 27mph/43kph. That should be good on the flat for many people, although sprinting will be affected–and if you’re a stud you’ll spin out on the flats too :slight_smile: . Downhills will spinout though, yeah. But 40-11 won’t be bad for a lot of zwifting for a lot of people, at least.

If you can throw for example an XD hub on the trainer and get a 10-XX cassette, then 40-10 at 90rpm will get you around 30mph/47kph.

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Depending on the bike, you might also be able to throw on a larger chainring (will need a new chain too at that point). But that might be cheaper. What make/model/year of bike do you have?

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That is my sprint … :rofl:

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I have a Niner RLT 9 in aluminium with an SRAM Apex gear set.

Would an alternative trainer be better and match the rear cassette i have or still going to have issues ?

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So to clarify: It’s a matter of gear ratio. The smaller you can get your smallest cog in the back, the faster you’ll be able to go. It’s usually not a concern for most people on most bikes, because A) we’re not monsters like those elites and pros and B) something like a 40 ring up front and an 11 smallest cog in the rear is plenty fast for gravel riding. Using it for road, or simulated road, and for training, it would be ideal to get a faster ratio–either a bigger ring in front, or a smaller cog in back. (Road bikes will come with much larger front rings for that reason.)

That said, most cassettes will have an 11 as the smallest cog, like yours. That’s because 10t cogs are fairly new, and won’t fit on standard hubs. I think most trainers are going to come with the same standard (HG) hub. The smallest cog you can get on those will be an 11. You can get a cassette with a 10t cog (like a 10-42 for example), but those need different freehubs (the part that the cassette slides onto). I don’t know of any trainers that come stock with a hub that will take a 10t cog. You’d need to get either an ‘XD’ hub (SRAM) or a Shimano ‘microspline’ hub.

I know bikes more than I know trainers, so you’ll have to check to make sure that whatever trainer (Zwift Hub or other make/model) can take one of the other kinds of hubs. If it can, then you’d buy the trainer with the HG hub, you’d buy the new (XD) hub, buy a cassette with a 10t cog, buy a new chain most likely, and you’d be off and running. Other people here will know better which trainers can take an XD or microspline hub. And you’re running SRAM, so sticking with SRAM and the XD hub will be a bit more preferrable (although SRAM and Shimano can often be mix-and-matched).

What I’d maybe do is this: find a trainer that can take an XD hub. It’ll likely come with a more standard HG hub. Put your normal cassette on, with your current 40t chainring, and use it that way. If you find you need more speed on the flats or downhill, you could go to a new hub/cassette later on.

You could also get a bigger front chainring. But you’d have to contact Niner to see how big you could go. Their website lists ‘NA’ as the maximum chainring size, which is unhelpful :slight_smile: But increasing the size of the chainring in front will do the same as decreasing the rear cog size. There will be a max size you can go, so Niner will have to tell you that.

All that aside–nice bike :smiley: My wife has a Niner RLT and absolutely loves it. It’s too small for me to really ride, but when I zip around on it after doing some maintenance to test ride, it’s fun.

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Enve has a nice page explaining the different hubs, btw.

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Thanks for the help and assistance, all new to me so glad i asked rather than diving in

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No problem. I’m a bigger rider too (200lbs), so I down downhill fast :slight_smile: I suspect that at least to start, the setup you have now should work for Zwift in most ways. You might not be able to pedal much on steep downhills–meaning you’ll be going faster than you can keep up with while pedaling. But you may find that doesn’t matter much to you either. If it does, and if you get a trainer than can take a hub swap and a 10t cassette, you’ll have that option.

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Good to know and thanks. I’m hoping that as i get better and fitter ill end up upgrading the 1 x set up to a 2 x setup as i seem to be doing more road than gravel or keep an eye for a good deal for a road bike. Might plump for the Zwift trainer when they are back in stock in the uk and see how i get on.

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For my preferences, I don’t know that I’d ever want a front derailleur again :smiley: I’m running a 1x on one of my gravel bikes (Salsa Cutthroat), and with the ability to go to a 12speed cassette with a 10t cog–that’s a wide range of gearing. Something like a 10-52 cassette with a 40t ring will be pretty comparable to many 2x road setups. With that range, a front derailleur is just one more thing to have to maintain, lol. And in your case, that RLT can pretend to be a road bike pretty effectively, maybe with a skinnier set of wheels.

But New Bike Day is always good too. As they say, the proper number of bikes to have is N+1, where N is your current number of bikes :slight_smile:

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FYI, it looks in this video like the Zwift Hub trainer can take an XD hub. Would be worth it confirming with customer service or specific documentation though. (It might be the ‘Jetblack XD-R Freehub’–the Zwift trainer is basically a rebranded JetBlack trainer.)

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Yeah I’m looking to change the wheels and was looking at the DT Swiss 1600 series with a 32 M tubeless setup but then needed to buy some new glasses so had to go on hold, the current wheels and tyre will do me for winter set up so i can save for summer, thanks again fo the advice and ill take a look and see as I don’t really want to go to 2 x at the front as you say less to maintain and I’m not doing to bad on rides keeping up with a slower group of riders but want to improve my fitness or not loose it over winter, only had the niner since April and love it but the n+1 might be a BMC Roadmachine or TREK domane AL5 ish if i can save the cash.

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AL5 is a good bike. Can’t compare it to the Roadmachine, just because I don’t know the Roadmachine very well (so nothing against it for sure). I don’t know what next year’s AL5 will come with, but this last model year came with Shimano 105, which is a perfectly good groupset, and some decent stock rims. Pricing for everything has been crazy lately, but the AL5 has been a good buy at least in past years.

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FYI Zwift turns all descents into 50% of what you see (10% is actually 5%). Throw in 50% TD and you can turn a 10% descent into 2.5%, 25% TD turns that 10% into 1.25% - even mtb gearing can get resistance!

EDIT: fullly support N+1 however to solve this problem

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For sure, definitely important, and will help the situation even more. :slight_smile:

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I run the exact setup…40t up front and 11-28 (or maybe 30-32…i forget) in the rear. This is fine unless you set the trainer difficulty to 100%…then gauranteed spinout going down even modest hills. Need to run ~60% or less TD.

Another option is to go XD-type freehub. Should be an option on your Direct Drive trainer of choice. My IRL rear wheel has the eThirteen 9-34 cassette. 40-9 is roughly equivalent to 53-11. I decided to forego the expense (Saris H3 hub + $$$ cassette) and just live with lower top end. I do not have real need to use the 12 cog…much less the 11. Downhills are for recovery after slogging up the hill. At 102 KG…I can keep up with most riders just with light power and coasting.

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Good to know Chris and thanks for taking the time to reply. As I’m terrible. At hills and a larger rider 200lbs or just over coasting down hill will be great idea for me to recover.

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Get a BMC and you will love it so much you won’t ride anything else :slight_smile: Definitely fantastic bike!