Road Cycling

[Drollic]

System six is a race bike?? How wide a tyre is needed?

It's whatever road bike you want it to be providing you can make it work. If the geo works, fast bikes such as the system six are free watts even at slower speeds. 28s roll faster under what most speeds people ride at in all but racing, and not lower end racing. There is no reason not to use 28s at lower pressure unless you race regularly. That or all you do is climbing or target strava koms. Comfort plays a part also. People ride 25s as that's what the top tier ride. The difference is most people would be faster on 28s as well as more comfortable. It's only above around 23-24mph that 25s are slightly faster. I personally wouldn't buy any bike now unless it can run a 28 at 30-32. Just look at the latest tarmac to give you an idea of where clearances are going. Madone supports them, just not officially as they go off 6mm clearance, 2mm above legal requirements. Easily clear. I'd bet the new aeroad supports them as well. How often is a rider of anything around 4w/kg going to be riding above 23-24+ mph average, not often.

I should just add that a lot of bikes have been designed in a cross over phase between 25 being normal with a move to 28s coming. This is why they state 28-30mm clearances in the paperwork - 25c coming in at 26-29mm on wide ID rims like 20-21mm. Cervelo s5 just the same and list goes on.

 

[Jonny ///M]

I get the trends and the science of it being faster but purely going by feel a 23mm tyre feels magic to me.

Lower pressure 28s feel sluggish to me but as you say whatever you make work for you is best.

Why make a synapse if a super six or system six can be super comfy? The lines are so blurred now with race bikes having such high stack heights and being so low geared compared to 6-8 years ago.

Maybe I have too many old dinosaurs around me using 53-39 11-25/28 and 23mm tyres

 

[Drollic]

I get the trends and the science of it being faster but purely going by feel a 23mm tyre feels magic to me.

Lower pressure 28s feel sluggish to me but as you say whatever you make work for you is best.

Why make a synapse if a super six or system six can be super comfy? The lines are so blurred now with race bikes having such high stack heights and being so low geared compared to 6-8 years ago.

Maybe I have too many old dinosaurs around me using 53-39 11-25/28 and 23mm tyres

You must ride on glass like roads, shorter distances, not long hours in the saddle or just be used to discomfort for little to no benefit. 23s are bordering on silly for UK roads. People think they should ride what the pros do, not saying that's you, but it's almost laughable with what's available now. Just look at the current uci worlds course and the quality of road compared to what we ride on, and I say that having ridden all over the country. 25s on anything like that course at those average speeds are 100% justified. Why would you want extra discomfort for less speed here though?! The lines are blurring you're right, but the aero bikes still have the weight penalty, it's just getting less.

As for the geo, perhaps more companies will offer partially hidden pro aero geo options and then the default aero fit. Trek do this through project one. Specialized also do this with the roubaix, the team geo is nasty in 57 which is what sagan has used amongst others. Interesting that they don't fully promote Pro geo bikes as they know average Joe can't hack it, yet when it comes to tyres, no no, average Joe will be fine on 25s riding cut up roads all day

 

[Berger]

Sure it feels fast, because you’re getting more sensations through the bike which makes your brain think it’s fast. Compare an old car or a track car to a new Mercedes at 70mph. The Mercedes will be effortless and quiet. The others, one will be on the limit of its capabilities, the other you’ll feel each bit of tarmac and hear everything working.

I’ve worked up from 23-28mm. No slower, guaranteed. If anything faster on the fatter tyre, better grip, less bouncing on poor surfaces, easier to keep the power down as your not controlling the bike so much.

My TT bike feels incredibly fast on 22mm tubs on a super smooth bypass. It’s truly awful on a rough road, going from 23mm is much the same just the differences aren’t quite as noticeable. I wouldn’t go back to a 23mm tyre, a 25 run for fast road/racing perhaps.

I used to ride 53/39 too. 52/36 on my bikes now and that’s made no difference to me apart from I’m better up the steep climbs as can keep my cadence up better!

 

[Saytan]

The lines are so blurred now with race bikes having such high stack heights and being so low geared compared to 6-8 years ago.

I think the manufacturers have realised the best way to sell expensive race bikes is to aim them at wealthy cycling-is-the-new-golf types.

 

[UTmaniac]

I've been running a 23mm GP5000 on the front this summer, first sub 25mm tyre I've bought in over twenty years (had a 20mm Conti "Grand Prix" model on my ridiculously underused Principia RSL from around '97), on my Hunt Aero Light Disc front wheel. Sometimes with a 25mm GP5000 rear, other times with 28mm (really 31mm+) GP4000S II. Despite my post-Covid fitness rollercoaster, I've ridden my first two sub 4 fairly hour hilly Strava "Gran Fondo" rides ever in June and July.

On a high stack sportive like my Cube Attain, there's so little weight on the front, the 23mm gives no perseptable comfort loss while giving a much smoother transition to the wheel rim (which are hardly deep at ~28mm). Butter smooth tarmac in the South Downs lanes, such as Longwood Dean Lane near Owslebury, are a rarity.

The 25mm on the rear might a fraction quicker, but at ~85PSI for my ~80Kg heft, discomfort kicks in noticably quicker than running the "28mm" at ~75PSI.

 

[RoboCod]

80kg = heft? I'm 95kg!

Cycling is one of the rare occasions I wish I was short.

 

[UTmaniac]

80kg = heft? I'm 95kg!

Cycling is one of the rare occasions I wish I was short.

I was ~95Kg in June 2016; got down to ~73Kg by August 2017 after taking up this cycling for fitness malarky in Jan 2017; back up to ~78Kg by April 2018; back up to ~84Kg by August 2019; down to ~76Kg by Feb 2020; as high as ~82Kg since getting Covid in late March...

I like my food too much, massive carb cravings in winter like many SAD sufferers (plus I got addicted to choc raisins and hot cross buns) and if I don't do enough cycling I pile the weight back on. Now a lot closer to 11% fat according to our Salter scales than the ~9.9% I used to see!

 

[RoboCod]

I was ~95Kg in June 2016; got down to ~73Kg by August 2017 after taking up this cycling for fitness malarky in Jan 2017; back up to ~78Kg by April 2018; back up to ~84Kg by August 2019; down to ~76Kg by Feb 2020; as high as ~82Kg since getting Covid in late March...

I like my food too much, massive carb cravings in winter like many SAD sufferers (plus I got addicted to choc raisins and hot cross buns) and if I don't do enough cycling I pile the weight back on. Now a lot closer to 11% fat according to our Salter scales than the ~9.9% I used to see!

If you don't mind me asking, what's your height?

 

[UTmaniac]

If you don't mind me asking, what's your height?

A measly ~178cm.

 

[Jonny ///M]

Maybe I'll try 28s long term and have my mind changed.

Roads are really rough round here. The old road beside the motorway is sooo rough but I just get on with it. 3 of us on 23s today.​

 

[Drollic]

Well worth trying but I should add, it really needs to be on wide rims otherwise they don't handle like they should. 20-21mm ID with an outer around 28-30mm or even more. New roval rims ideal or the knots.

The fatigue and discomfort on long rides really does play a part. On ultra endurance it's why aero bars are normally used to reduce road vibration and of course pressure through the wrists. The studies on rolling resistance and pressures should have also been done years before they were. It wasn't as most things just filter down from the top and they aren't needed there outside of Paris-roubaix.

 

[Berger]

Struggle to buy a “narrow” rim now!

Beautiful day today, I did a few hours but could have easily done more.

Hard to dress for, I went out to the shed came back and got changed. Started off with the jacket on and swapped to base layer, jersey and arm warmers.

 

[SoliD]

2 rides today, this morning out in full winter bins and top with a light long sleeve baselauer, plenty warm at 7.30 then out again and at 4 in knee warmers, normal shorts, short sleeve baselauer and perfetto, but got a bit warm that time. Hope this northerly wind does one.

 

[xdcx]

Maybe I'll try 28s long term and have my mind changed.

Roads are really rough round here. The old road beside the motorway is sooo rough but I just get on with it. 3 of us on 23s today.​

Don't be lured in by their peesh min.
25's tops.

I love the "everyone wants to be like the pro's" stuff flung about all over the shop. Nobody is riding about on tubs everywhere. and 25mm is absolutely perfect for a lot of people..... 25mm at 80-90PSI is fine but suppose if you are 80-100KG's you need to run 28's to run at PSI like that. So is this really a discussion on which tyre size is more comfortable or more so what PSI is more comfortable depending on how much you weigh?

 

[RoboCod]

I weigh 95kg and have 25s at 100psi. Am I doing it wrong? seems comfy to me.

 

[xdcx]

I weigh 95kg and have 25s at 100psi. Am I doing it wrong? seems comfy to me.

Nope, doing nothing wrong. Worked for decades but apparently a 28mm tyre is a must have and will just make your life wonderful so maybe you should spent lots of money on wheels and new tyres It's all about speed/comfort and advancement of course. Nothing at all about brands changing something because something to extract cash out of folk who mostly don't need be spending pennies.

 

[Saytan]

I was using 28s on my commuter/winter bike before it was cool, and before you could get wide rims. my "best" bike won't take more than a 23. It definitely has more zip, though I am using racier tyres.

 

[SoliD]

25s are best sweet spot between feel and comfort for me, once you go above this yes you get more comfort but you get less feel as to what exactly is going on through that front tyre with that bit more sidewall squish.

 

[mrthingyx]

I have 32s on my aluminium commuter and 23s on my TT. As I am 88kg, I generally have the formers set up between 90-100PSI (normally have panniers on), and the latter at 115-120PSI.
The TT bike is a bit like having an orbital sander against the top of my skull on the roads around here, but I prefer the position to my roadie...

But then the last comfortable bike I rode was my Carrera LRS3 with dual suspension - I have never ridden a comfortable road bike.