1x road bike

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Discussion

3rtt

Original Poster:

943 posts

251 months

Wednesday 28th October 2020
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With 12 and 13 speed drive trains available now, do you think road bikes could go to 1x ?

Bathroom_Security

3,323 posts

116 months

Wednesday 28th October 2020
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There's a sram groupset with a 1x. It's on a spesh tarmac, cant remember which one

Would love to try it, but can't see a large 50+ front cog being any use up a really steep hill no matter the size of the rear cog. But what do I know, I'm sure the marketing will tell me I'll be 2.35% better due to some efficiency and stuff I dont understand.

yellowjack

17,065 posts

165 months

Wednesday 28th October 2020
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Meh. I'm still running a 105 9-speed triple chainset on one bike. They'll be screwing down the lid of my box before I buy a 1x road bike...

Ilovejapcrap

3,274 posts

111 months

Wednesday 28th October 2020
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3t do a road bike designed just for 1x basically get a 2x for road, unless you only do a set route in a not to hilly area, or your a professional cyclist.

defblade

7,392 posts

212 months

Wednesday 28th October 2020
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I'm wondering about this for if/when I do get a new bike.
I'm in South Wales, and roads are mostly either up or down, there's not so much flat... and even that is not as flat as Oxfordshire, where I used to ride about!

I've got an old audax bike with a triple on the front with 8 speed on the back (up from the OE 7 speed), and, while I do use all 3 rings at times, there's not quite so much time spent on the middle any more. I don't race, I'm not in a hurry, I ride for fitness and joy, so I like to push myself a bit at times, but also just revel in smooth gliding progress while keeping within myself... it's all exercise wink

In practice I need, in gear inches, around 100" at the fast end - I'm not the fastest descender, not helped by the gravelly/twisty/narrow/lumpy nature of the back roads around here - if I'm spinning that out, it's around 50kph/30mph at 110rpm, I'll probably just tuck and freewheel.
And at the slow end, something one-to-one or slightly better, about 25", to allow me to ride up longer steep stuff at 5mph without having to stop for a lay down at the top (or even half way up loser ho hum).

A quick look at https://www.bikecalc.com/gear_inches suggests that with a 40 on the front, and an 11-42 on the back, I'd be near enough those figures. I've not researched if those exact ratios are available, but certainly the 12 speed cassettes can have a greater range than that, according to a quick google. I'm certain something in the ball park could be found.




Then it's a question of would I be happy with the gaps between?

I haven't really looked into this, but I think with some careful selection of the ratios it would work ok.

They don't need to be exactly evenly spaced - there's already pretty big jumps when I'm on the top ring - I'm in 7th or 8th because I've got straight clear downhill; if I'm using anything lower at the back, it's overlapping the middle ring ratios, so that's 6 almost completely unnecessary cogs... and downhill, exact cadence doesn't matter too much, so long as it's not spinning out! And I don't use big/8th much as my bike just doesn't seem happy in it and 7th is still over 50kph. So that's 7 of my 24 gears not needed!

Then I've got 8 gears on the middle ring. They overlap from above big/6 down to small/3ish. There are some 3 tooth gaps on my current cassette. I would have cursed them in Oxfordshire, I don't even notice in Wales (although, tbf, my cadence range has increased). But I mainly use 3/4/5/6 on the middle for rolling hills - and I'm up and down from one end of that to the other in Wales, rather than hunting for the perfect cadence one click up or down for the next few miles of near-flat.

Finally, the small ring gives 3 gears shorter than the middle. My 25" suggestion is in between 1 and 2 on my current cassette - I can get up most stuff around here on 2, but there are a few 10%+ bits that would defeat me without rest stops (until I get fitter - I will get fitter!) if I didn't have my lowest. But those are the bail-out options, and I'd like some choice between middle/3 and lowest, so say the equivalent of 4 cogs on the small. Basically, I want finer effort/cadence control going uphill compared to going down.

So, in the real world, I need to use (I will actually use more options than this, but I don't need to, it's just convenience of not shifting front chain rings... which is why we're considering a 1x in the first place!):
1 cog on the big ring
4 cogs on the middle
4 cogs on the small.
And that's just 9 speeds; there is space then for smaller jumps with 1, 2 or 3 extra cogs at 10,11 or 12 speed... which suggests to me that the whole thing is very do-able smile

Not sure I want to spend a lot of money finding out, though... let me know how it goes wink

Like I said, I have been wondering about this!




ETA: Here's an example, with exactly my gear range: https://alpkit.com/collections/sonder-road-bikes/p...
None of the reviews mention the gears, so I guess they work wink


Edited by defblade on Wednesday 28th October 23:32

andySC

1,187 posts

157 months

Wednesday 28th October 2020
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https://www.merlincycles.com/3t-strada-pro-aero-ro...

If I had the need for another bike I could be tempted to give one of these a go. The massively discounted price is probably telling, maybe we’re not quite ready for 1x on the road & these bikes did get a bashing from some of the Aqua Blue boys who raced a similar model for a season. The type of riding I do & where I go I’m sure this thing would work fine. I quite like how it looks too.

Paul Drawmer

4,864 posts

266 months

Thursday 29th October 2020
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Last year, I built myself a new winter bike.

It's based on an old alloy Trek that had a Shimano sora 3X 9.

I've replaced the rear with a a 11 speed 11 -42 and put a single narrow/wide 42 on the front. (had an old Alivio triple and the middle ring is in the correct 50mm spacing now with the single chinese front ring)

I am fitter now and don't need the 42-42 lowest gear, so will get a new 44 or 46 for the front, as I do spin out quite a lot.

I used a new GRX rear mech.

It's great. The change is better than the Ultegra on the main bike, and the front narrow/wide ring is much quieter than the plain ones. Seriously thinking about converting the other bike as well because the drive train is so good.

I've reversed the stem since the pic was taken. I hate the double sided SPDs OK for ordinary shoes, but a fiddle to clip into with proper shoes.
The mudguards are very close, definitely a road bike!


Castrol for a knave

4,639 posts

90 months

Thursday 29th October 2020
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Aqua Blue ran the 3T 1x road bike for 2 seasons.

The general view of the riders was that it had woeful ratio spacing and was generally not up to the job. Adam Blythe, in particular, hated his - gave it a real slating on the Cycling Podcast.

I'd stick to the traditional 2x - much better range in the gearing.

Probably fine for general use, but for a longer or lumpier ride, not so sure.

Mastodon2

13,818 posts

164 months

Thursday 29th October 2020
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I've ridden a few road bikes with 1x at the front, I can't remember how many teeth with on the front chainring, somewhere in the region of 42-44 I think. I found it quite pleasant to ride these setups; certainly the gearing is less than optimum for very high speeds or for very steep climbs and there is less "granularity", to use some really cheesy business-speak, for picking the perfect gear for a given bit of road as the jumps between one gear and the next become slightly bigger.

In practice, I never felt like the bikes were holding me back, though admittedly I never rode them on any really steep climbs or really fast descents. I'd probably always go with 2x on my bikes, as ultimately I think the penalties to weight, mechanical complexity and aerodynamics are not that much of an issue to me.

As an additional point, the chainline on 2x seems to be better for the gears you'd like be using, IE, it's straighter when using the little ring and the big cogs at the back or the big ring and the small cogs at the back. That could be worth perhaps 2, maybe even 3 watts in friction savings. I'm sure that we men and women of PH wouldn't want to lose such easy wattage savings.

lufbramatt

5,318 posts

133 months

Thursday 29th October 2020
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42-11 at 110rpm is about 30mph, doubt there's too many people that can realistically say they can spin that out on the flat ;-)

okgo

37,858 posts

197 months

Thursday 29th October 2020
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lufbramatt said:
42-11 at 110rpm is about 30mph, doubt there's too many people that can realistically say they can spin that out on the flat ;-)
Useless for that slight downhill where you want to push on though, 110 is a high cadence that doesn't suit everyone.

S100HP

12,645 posts

166 months

Thursday 29th October 2020
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I'm still rocking a 53-39 iirc. I remember when compact was the in thing laugh

lufbramatt

5,318 posts

133 months

Thursday 29th October 2020
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Actually it’s 33mph at 110, 30mph at 100rpm. Yea downhill it’s not ideal but for most people it will work fine.

okgo

37,858 posts

197 months

Thursday 29th October 2020
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lufbramatt said:
Actually it’s 33mph at 110, 30mph at 100rpm. Yea downhill it’s not ideal but for most people it will work fine.
Ah fair. Yes. Someone I ride with has the 3t bike, its fine for most rides, I don't think 15% stuff is great, but you can easily avoid that.

Watchman

6,391 posts

244 months

Thursday 29th October 2020
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I've been incrementally changing the gearing on my wife's bike (she's the roadie in our family) to suit her capabilities, and I've been considering moving her to a 1x system for a while. She loses her chain roughly once per ride, and I know from experience with our other bikes that a narrow/wide chainring would help to mitigate this. Also, simply not having the front derailleur would help.

Although she is very fit (she's up to 3400 miles this year so far) she isn't as strong as the men in the club rides, and originally complained to me that she cannot power some of the very high gears on the flat. She originally had a 50T large sprocket on the front which I changed for a 48. Then I changed the rear cassette to give her a better climbing gear - from a 25T large sprocket to a 28T.

So now, her current gearing is 48/34 front and 11/28 rear. To get the extremes (lowest and highest) from a 1x gearset, we'd need to either move to one of those newer freehubs which allows for a 10T smallest sprocket, or a fairly large "1st" gear in the cassette.

Equivalent gearing would be:

Fast on the flat
Current front/rear sprocket (11T freehub) Equivalent front/rear sprocket (10T freehub)
48/11 43/10


Climbing
Current front/rear sprocket Equivalent front/rear sprocket for 1x with 11T freehub Equivalent front/rear sprocket for 1x with 10T freehub
34/28 48/40 43/35


I favour smaller sprockets all round - they're lighter, and require less chain (also lighter), so moving to a 10T freehub seems the right decision.

As said above, I built our "towpath" bikes with 1x gearing and I'm hugely impressed with the narrow/wide chainrings which have completely eliminated chains falling off. Simply moving from a 1x with a conventional chainring to one with a narrow/wide was an instant success.

okgo

37,858 posts

197 months

Thursday 29th October 2020
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Without wishing to be rude, most people do not have chains falling off, ever, let alone every ride!


Hard-Drive

4,076 posts

228 months

Thursday 29th October 2020
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Don't get the whole 1x thing apart from on a proper trail/DH MTB.

When I specced my gravel bike I put GRX on it, 46-30 up front and an 11-34 at the back. This gives a 24" to 114" range with sensible gaps between ratios. The front mech is totally reliable, with the dropped chainstay design I've not had any chain slap, I've not yet needed to use the clutch mech, and to be honest if I did, I suspect my teeth would be falling out well before chains were jumping. The weight saving of losing the front mech and front ring compared to having an enormous stack of steel dinner plates at the back is negligable. And this is on a gravel bike, not a road bike.

I get a 1x for a TT bike, but for real world riding, what is so wrong with a front mech?

Watchman

6,391 posts

244 months

Thursday 29th October 2020
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okgo said:
Without wishing to be rude, most people do not have chains falling off, ever, let alone every ride!
I don't either but there's likely a lack of mechanical sympathy in operation there. Seems to happen a lot to her friend too (also female). I look after both bikes and I can never make it happen on my stand or brief test rides.

If I could afford it, I would buy her an electronic gearset.

okgo

37,858 posts

197 months

Thursday 29th October 2020
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Watchman said:
I don't either but there's likely a lack of mechanical sympathy in operation there. Seems to happen a lot to her friend too (also female). I look after both bikes and I can never make it happen on my stand or brief test rides.

If I could afford it, I would buy her an electronic gearset.
Electronic doesn't stop that sort of thing, sadly.

I know what you mean, the same reason I see more ladies grinding up a hill with many more gears to use, or churning a huge gear on the flat, funny one.

loudlashadjuster

5,082 posts

183 months

Thursday 29th October 2020
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Yeah, I maybe drop a chain once a year. If that.