Speed Difference Heavy Bike big tyres.

[Banjo]

I do a 20 km loop from home .Its undulating ,only one steepish hill but none of it is flat.Best thing is I rarely have to stop at junctions.

On my 10kg alloy Synapse on 25c tyres I go round in about 48 minutes without pushing much and about 44 if I get out of the saddle once or twice.

Just tried it on my Jamis 13.5 kg Tourer on 32 c Vittoria Touring tyres, without pushing too much I got round in 53 minutes , about 5 minutes more than on the Synapse for similar effort. (I removed the panniers but left rack mudguards etc on.)

The Jamis was certainly more comfortable on some of the rougher bits though the Synapse is quite a comfortable bike for what it is.

Is there any point to all this rambling? Not really ,just that I expected it to be much slower to be honest.

I have some 32c Racelights In the shed ,I can feel some more time trial experiments coming on soon...

 

[Markymark]

I got me a Trek 6 Domane SLR which has 32c. Massively quicker than my previous bike.

 

[Banjo]

I got me a Trek 6 Domane SLR which has 32c. Massively quicker than my previous bike.

I have looked at them in Evans very tempted ,out of my price range tbh. I think I can squeeze 28 c on the Synapse but have fairly new tyres and need to get some miles out of them first.

Moving up to 25 from the 23c on my previous bike felt like a huge improvement in comfort but definitely tempted to go larger again.Some of the 2018 Synapses can take 32c ,seems to, be the way things are going, probably due in part to crap state of the tarmac on our roads.

 

[Alan Frame]

The main question is , what did you do with the 4 minutes saved?
And does it really matter?
Don't get me started on high speed rail links !

Chill and enjoy the ride, don't get too scientific

 

[Heltor Chasca]

I’ve just put some low rolling resistance knobblies (26 x 2.1 Smart Sam) on my tourer. No difference in average speed to the 1.75 Marathons. In fact Strava awarded me a pocketful of PBs. I’m planning to ride it out to the Brecon Beacons one weekend before Christmas.

My Audax bike (which you haven’t seen yet) is about 3kph quicker over 100-200 km.

Both are comfy.

 

[pawl]

The main question is , what did you do with the 4 minutes saved?
And does it really matter?
Don't get me started on high speed rail links !




A man after my own heart.

 

[twentysix by twentyfive]

low rolling resistance knobblies

Isn't that an oxymoron?

 

[swansonj]

I do a 20 km loop from home .Its undulating ,only one steepish hill but none of it is flat.Best thing is I rarely have to stop at junctions.

On my 10kg alloy Synapse on 25c tyres I go round in about 48 minutes without pushing much and about 44 if I get out of the saddle once or twice.

Just tried it on my Jamis 13.5 kg Tourer on 32 c Vittoria Touring tyres, without pushing too much I got round in 53 minutes , about 5 minutes more than on the Synapse for similar effort. (I removed the panniers but left rack mudguards etc on.)

The Jamis was certainly more comfortable on some of the rougher bits though the Synapse is quite a comfortable bike for what it is.

Is there any point to all this rambling? Not really ,just that I expected it to be much slower to be honest.

I have some 32c Racelights In the shed ,I can feel some more time trial experiments coming on soon...

Is the riding position identical? Increased wind resistance from even a marginally more upright riding position could be just as significant as the change in tyre resistance between the two bikes.

 

[screenman]

My bike is faster with a wind coming from behind.


Behind, not my behind.

 

[Heltor Chasca]

Isn't that an oxymoron?

S’pose. The knobs, mid tyre (only about 10mm wide) are spaced very close together so on the road or compact gravel, running at max pressure (55psi) they are pretty quiet. As soon as you let out some sky from your rounds, or are leaning into sharp turns or uneven ground, they bite rather well. (30psi)

 

[Slick]

I'm not sure it works exactly like we expect for everyone. Admittedly thus is very unscientific, but after 8 or so weeks of commutes with a new lighter and slightly racier bike, I was surprised by exactly how fast and powerful I felt back on the original bike despite full mud guards, rack and pannier. I haven't checked yet, but I'll be surprised if there weren't one or two PB's with what I would expect to be the slower bike.

 

[bpsmith]

The main question is , what did you do with the 4 minutes saved?
And does it really matter?
Don't get me started on high speed rail links !

Chill and enjoy the ride, don't get too scientific

He typed this thread?

 

[Moodyman]

The main question is , what did you do with the 4 minutes saved?

Came on here to tell us about it.

 

[johnnyb47]

I've some Vittora Rubino pro 26x1.50 slicks on my Boardman and tonight I was surprised at how quick I averaged my 18 mile ride. 15.4 mph average. There doesn't seem to be that much difference between them and my 23c on my road bike,,

 

[Alan Frame]

Narrower tyres may be marginally 'faster', but not on our shite road surfaces.
In the real world, springier, wider tyres with more volume and cushioning effect, can often be almost as effective and probably less tiring.