Changing tyres!

For discussions about bikes and equipment.
leec27
Posts: 4
Joined: 15 Jul 2020, 11:26am

Changing tyres!

Postby leec27 » 15 Jul 2020, 11:35am

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

tim-b
Posts: 1675
Joined: 10 Oct 2009, 8:20am

Re: Changing tyres!

Postby tim-b » 15 Jul 2020, 3:08pm

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
~~~~¯\(ツ)/¯~~~~

leec27
Posts: 4
Joined: 15 Jul 2020, 11:26am

Re: Changing tyres!

Postby leec27 » 15 Jul 2020, 4:02pm

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

Regards

freeflow
Posts: 1434
Joined: 29 Aug 2011, 1:54pm

Re: Changing tyres!

Postby freeflow » 15 Jul 2020, 4:18pm

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........

freeflow
Posts: 1434
Joined: 29 Aug 2011, 1:54pm

Re: Changing tyres!

Postby freeflow » 15 Jul 2020, 4:20pm

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)

leec27
Posts: 4
Joined: 15 Jul 2020, 11:26am

Re: Changing tyres!

Postby leec27 » 15 Jul 2020, 4:23pm

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.

Jamesh
Posts: 1790
Joined: 2 Jan 2017, 5:56pm

Re: Changing tyres!

Postby Jamesh » 15 Jul 2020, 6:06pm

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

hamster
Posts: 3785
Joined: 2 Feb 2007, 12:42pm

Re: Changing tyres!

Postby hamster » 16 Jul 2020, 1:41pm

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.

leec27
Posts: 4
Joined: 15 Jul 2020, 11:26am

Re: Changing tyres!

Postby leec27 » 16 Jul 2020, 2:13pm

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?

freeflow
Posts: 1434
Joined: 29 Aug 2011, 1:54pm

Re: Changing tyres!

Postby freeflow » 16 Jul 2020, 2:32pm

47c to 28c. Definitely yes.

PhilD28
Posts: 157
Joined: 26 Sep 2016, 8:31am

Re: Changing tyres!

Postby PhilD28 » 16 Jul 2020, 2:39pm

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.

freeflow
Posts: 1434
Joined: 29 Aug 2011, 1:54pm

Re: Changing tyres!

Postby freeflow » 16 Jul 2020, 4:01pm

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.

PhilD28
Posts: 157
Joined: 26 Sep 2016, 8:31am

Re: Changing tyres!

Postby PhilD28 » 16 Jul 2020, 5:05pm

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.

freeflow
Posts: 1434
Joined: 29 Aug 2011, 1:54pm

Re: Changing tyres!

Postby freeflow » 16 Jul 2020, 5:16pm

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

PhilD28
Posts: 157
Joined: 26 Sep 2016, 8:31am

Re: Changing tyres!

Postby PhilD28 » 16 Jul 2020, 6:53pm

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