• This topic has 16 replies, 9 voices, and was last updated 9 months ago by Bez.
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  • Just stuck 32mm GP5000 tyres on the Tempest
  • Premier Icon igm
    Full Member

    And did the commute with panniers (laptop and change of clothes, shower stuff etc) at and average of 16.2 in 16.7mph out for 21 miles each way.

    Quickest I’ve done that run is 18.2 on the posh road bike without any luggage.

    I’m liking that bike set up.

    PS yes I know you could knock off 21 miles far faster. I’m old, an ex-rugby forward and actually so can I if I choose the route. 😉

    Premier Icon mattbee
    Full Member

    I run 41mm G Ones on mine (on Stans Arch rims) and I find it around 1-2mph slower than my fancy pants road bike on 25mm tyres, mid section rims, etc was. Much comfier to ride though! I do think that the higher front end and flared bars are one of the biggest contributors to the slight speed drop too as I’m definitely catching the wind a bit more.
    No regrets about the Tempest replacing 2 bikes though, I’ll keep this one until it snaps! (As all Ti frames reputedly do…)

    Premier Icon roverpig
    Full Member

    I’ve recently picked up a “gravel” bike (with almost slick Byway tyres) and have been trying to get a feel for the “penalty” on the road compared with my road bike. I’d agree that it seems to be around 1mph on average (that best time presumably had some help from the wind). It’s not evenly distributed in my case though. I hardly seem to be losing anything on the climbs and it’s mainly on the fast road sections where I’m losing, presumably because of the high wide front end. It’s soooo much more comfortable though and because of that can end up being faster overall on a long ride.

    Oh, and I’d be very happy with those average speeds 🙂

    Premier Icon tpbiker
    Full Member

    My croix de fer with road tyres was about 1-1.5mph slower than my tcr.

    My gravel bike with 650b byways was considerably slower than the tcr. Well over 2mph I’d say.

    Premier Icon roverpig
    Full Member

    It depends on terrain of course. My road bike would kill the gravel bike on a smooth A road, but the difference is much less on a crappy lane (and the gravel bike wins once you get off the road altogether of course).

    Premier Icon onewheelgood
    Full Member

    My Gradient with 43mm Panaracer SKs is about 1.5mph slower than my Defy with 28mm GP5000s. Very comfy though, even on the disintegrating lanes I usually ride.

    Premier Icon igm
    Full Member

    Oh, and I’d be very happy with those average speeds 🙂

    My new best friend roverpig

    Premier Icon dudeofdoom
    Full Member

    My gravel bike with 650b byways was considerably slower than the tcr. Well over 2mph I’d s

    They’re surprisingly fast when rolling considering they’re probably 47’s .

    I do think the gp5000s in 32 are a seriously good fast commute tyre (apart from the iffy puncture protection)

    Premier Icon igm
    Full Member

    gp5000 32mm tubeless

    Premier Icon Frankers
    Free Member

    I just fitted GP5000 TL 32mm to Cannondale Synapse, very comfortable and seem pretty rapid. What pressure are you using?

    Premier Icon igm
    Full Member

    What pressure are you using?

    At 15st plus panniers full of laptop and change of clothes, I’ll be near the limit on any given tyre – so 85psi on the Bonty track pump gauge for this 32mm one.

    Premier Icon Bez
    Full Member

    Out of all the variables, the panniers are going to have by far the largest effect on times, so I don’t think this tells us anything about the tyres or the bike 🙂

    Premier Icon igm
    Full Member

    Bez – the move from Vittoria Revolution tubed the week before to the GP5000 tubeless took a 14.7mph round trip average to 16.5mph. Otherwise the bike was the same, as were the panniers.
    Yes the wind will have been different, but that’s the two way average.
    And there was a fair amount of frost on the cycle path for the morning run on the faster average.
    So that’s a fair comparison I think.

    But yes panniers make a difference between the commuting bike and the road bike.

    Premier Icon Bez
    Full Member

    Right, so comparing the same bike with different tyres gives you a basis for comparing the tyres.

    I’d want more than just one commute on each to mitigate for the many confounding factors, though: you’ve shaved over 10% off your ride time for an average speed where rolling resistance will only account for something like 20% of energy loss, even without factoring in the additional air resistance of panniers. I mean, it’s not impossible, but it’d be an eyebrow-raisingly huge drop in rolling resistance to cause that increase. When I rode my commute more frequently, I didn’t even find that 3kg of extra bike weight and 7W of drag from a dynamo hub added 10% to my ride time.

    Premier Icon igm
    Full Member

    Don’t disagree.

    I suspect belief has a lot to do with it.

    The tyres felt good, I felt faster, morale was up, so I was willing to work a little harder.

    That said, I started off by saying that I liked that set up for a decent length commute.
    And that I’m very willing to stand by that statement.

    Premier Icon Bez
    Full Member

    Yeah, I think that’s a lot of it. When the bike feels more responsive to power you put more power in. Of the two bikes I alluded to above, although I could get their fastest times over a 48km commute to within a couple of minutes of each other, one of them was psychologically much easier to get in that ballpark than the other, so a lot of the time the difference was more than a couple of minutes.

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