Cycling UK Forum

Hello all! I've recently started long distance cycling (90km my current record) and I'm wondering to get more speed and better times from my bog standard Carrera Subway 1 with the usual
650 x 48b tyres if I were to change them to slick road tyres would I be able to get a bit more out of the bike? I seem to max out at 28-30kmph on straight roads. If this is possible what size should I be looking at?

Thankyou

Lee

Hi
Stick around the size that you have, you might find that a slicker tread will feel a little better on-road but will struggle more off-road. Experiment with tyre pressures too.
I commute on 650Bx47 at 55psi rear and 45psi front and there's little difference speed-wise between those and my old 700Cx28 commuter at 85psi and 75psi
Regards
tim-b

Ok Tim thank you for the advice I'll have a look at some tyres and play around with the psi

Regards

Have a look at

https://www.bicyclerollingresistance.com/

Its likely you have tyres similar to marathon greenguard. (21 watts)

Then decide if you can afford to switch to a pair of 28C GP5000. (10 watts)

If the speed gain due to 10watts is not worth the cost of the tyres........

Also, if you are interested in Long distance cycling take a look at Audaxing. For Audaxers, 90km is what you do before your first tea break (cheeky smile)

Lol first tea break! I took my first break for a minute or so about 50km! Needed to refuel a little! My goal is 100km.

Despite what people say I think going for 28mm tyres will make you faster and still preserve some comfort.

I doubt the stock tyres are particularly light either.

Cheers James

freeflow wrote:Have a look at

https://www.bicyclerollingresistance.com/

Its likely you have tyres similar to marathon greenguard. (21 watts)

Then decide if you can afford to switch to a pair of 28C GP5000. (10 watts)

If the speed gain due to 10watts is not worth the cost of the tyres........

Agreed GP5000 are wonderfully fast and supple tyres. I love them.
If you ride roads with lots of trash and flints be warned that they may not last well. I typically get around 1000 miles out of one before it gets terminally cut. For me it's a summer-only tyre. Michelin Pro4 Endurance is not quite as fast, but way tougher in my experience and a bit quicker than Conti GP4Season.

hamster wrote:

freeflow wrote:Have a look at

https://www.bicyclerollingresistance.com/

Its likely you have tyres similar to marathon greenguard. (21 watts)

Then decide if you can afford to switch to a pair of 28C GP5000. (10 watts)

If the speed gain due to 10watts is not worth the cost of the tyres........

Agreed GP5000 are wonderfully fast and supple tyres. I love them.
If you ride roads with lots of trash and flints be warned that they may not last well. I typically get around 1000 miles out of one before it gets terminally cut. For me it's a summer-only tyre. Michelin Pro4 Endurance is not quite as fast, but way tougher in my experience and a bit quicker than Conti GP4Season.

Ok, thankyou for your information much appreciated. I take it these will fit without any issue, would I need to change my current inner tubes?

47c to 28c. Definitely yes.

Remember these are 650b wheels not 700c. Going down as small as 28 from 47 will change the trail figure and make the bike less stable.

For 650b wheels the smallest tyre I use is a 37mm and often ride 42's (normally compass tyres). Good quality supple tyres 37-42 are at least as fast as 28c tyres and I regularly ride bikes with both. No problem riding 100 plus miles on 650 x 37's as fast as my audax bike with 28's and a lot more comfortable.

The rolling resistance data shows a 15W difference between GP5000 622 28C and Vittoria Hypers 622 37C. What that 15 watt difference means in terms of speed difference is rider dependent.

Those are totally different tyres and both are 622, 650B are 584mm. If you look at something like Compass extraight 37mm in 650B you would find they have extremely low rolling resistance.

I can assure you that the tyres I'm suggesting are as fast as GP5000 in 28, I regularly ride bikes with both.

That's why I was very clear about posting reference to the numbers and specifying the tyre sizes to which I was referring. I look forward to you posting references to similar data for the compass tyres. If you can't provide numbers or a link to numbers then what you are claiming is just hearsay

Yep just hearesay. I'll not bother posting my experiences, I'll just leave it in your capable hands.