28mm tyres on Galaxy...for more "Audax" style ride

melw1 · Post by **melw1** » 18 Aug 2007, 8:50am

Sorry to keep asking questions the whole time but I was thinking last night about how to speed up my Galaxy...... an rather obvious thought struck me (I'm not techie minded!) how about I just put thinner tyres on it - say 28mm? (It's on 32 at the mo)

I don't use it for serious touring at the mo, but for trailering (2 kids) plus at the most panniers with shopping. (There is a limit as to how much I want to pull with a trailer on the back too!). Very rarely would I have 4 panniers on it.

So, would skinnier tyres make much difference to the ride (I aim to go out with a local group sometime - not a fast group I understand, thank goodness!) and would it still be suitable for my use as described above?

Sorry if this is a rather basic question.

Melanie

reohn2 · Post by **reohn2** » 18 Aug 2007, 9:00am

Melanie
I have a Galaxy,I've ridden it with 28mm and 32mm tyres and the only appreciable difference is comfort levels.I does help to have the right tyre pressures though about 75/80psi for 28mm and 70/75psi for 32mm.

I'm afraid the only way to make it go faster is to pedal harder :wink:

melw1 · Post by **melw1** » 18 Aug 2007, 9:06am

...pedal faster...thought that might be the case :wink:

! If it's just comfort levels then i guess I won't bother. I fancy some swalbe marathon puncture proof tyres but as they're so expensive and I can't buy 2 sets, I'll prob get the 32mm size then... I'll also check my tyre pressures.... I tend to forget about them!

reohn2 · Post by **reohn2** » 18 Aug 2007, 9:26am

melw1 wrote:...pedal faster...thought that might be the case ! If it's just comfort levels then i guess I won't bother. I fancy some swalbe marathon puncture proof tyres but as they're so expensive and I can't buy 2 sets, I'll prob get the 32mm size then... I'll also check my tyre pressures.... I tend to forget about them!

Wait a minute,the Marathon plus tyres are a heavy and stodgy tyre to ride, if you want a more nimble ride I'd go for either the ordinary Marathons or Marathon Supremes they are both very puncture ressistant.
But if you want to go faster don't buy Marathon Plus.

Post by **Mick F** » 18 Aug 2007, 10:35am

My understanding is that tyres can make a huge difference to rolling resistance.

Wider tyres have more contact with the road, narrower ones less. Less contact equals faster ride. This is assuming the tyres are inflated to the correct pressure.

Some tyres have harder rubber, some softer. Therefore the fastest tyre would be narrow, high pressure with hard rubber. Trouble is, the faster the tyre, the worse the ride quality!

I'm lucky. I have a superbly built Mercian in 531c. It's springy, light and comfortable - that means I can ride 20mm racing tyres and still have decent ride quality.

melw1 · Post by **melw1** » 18 Aug 2007, 10:55am

So what to do??? I've decided on the Marathon Kevlar tyres rather than the plus as per reohn2's advice, but still in a dilemma re the size. Would rather have a slightly speedier tyre but still want a comfyish ride..... How great is the comfort difference between 28 and 32? In the balance between comfort v speed , which way do the scales tip? Is it a slightly less comfy ride but worth it for extra speed?

Mick F - I want a mercian! Just better start buying lottery tickets first!

georgew · Post by **georgew** » 18 Aug 2007, 10:59am

It makes little difference in the whole scheme of things I feel. The 32's do give a bit more cushioning but it's not worth agonizing over.

Post by **Graham** » 18 Aug 2007, 11:01am

reohn2 wrote:Melanie
I have a Galaxy,I've ridden it with 28mm and 32mm tyres and the only appreciable difference is comfort levels.I does help to have the right tyre pressures though about 75/80psi for 28mm and 70/75psi for 32mm.

I'll second that. As a longtime Galaxy owner I would say 32 is right for the bike.
However, it is not a big deal if you try a 28 instead. All rather marginal for speed and comfort.

melw1 · Post by **melw1** » 18 Aug 2007, 11:04am

Right, that's it then. I'll quit stressing about it and go for the 32 version! Thanks for all you help.

glueman · Post by **glueman** » 18 Aug 2007, 1:39pm

It's a bit more complicated than thin vs fat. All things being equal, on a billiard table smooth road the narrower tyre is easier to push, there's less contact area and marginally better aerodynamics though spokes make more of a difference to the latter.
In the real world of gravel, bumps and potholes fatter tyres can be quicker because the wider tyre absorbs surface inconsistencies rather than deflecting over them which absorbs energy. More noticable is the effect a hard narrow tyre has on the rider, increasing fatigue and stress on wrists and bum. There aren't enough wide, well made, fine threaded tyres imo, though Panaracer Pasela's seem to hit a high note between road holding, responsiveness and durability.

I may be a bit old fashioned (and have everything from 20mm to 1.75" tyres on different bikes) but a good quality 32mm tyre takes some beating for general use. Marathon's and other new generation tyres are excellent for commuting and long tours but I wouldn't dream of putting them on a Sunday or club bike.

Post by Si » 18 Aug 2007, 5:09pm

melw1 wrote:So what to do???

I think that most people, in their first few years of riding (forgive me if you aren't) tend to try out all sorts of things to make their bike go faster. I know that I did (back in the bad old days of drilling components).

But after a while, many decide that a lot of kit is much of a muchness and although slight advantages might be possible by upgrading to so-and-so from what-not, it's often not worth the hassle and the worry. Best to just get out and ride with what you got if it all works OK

melw1 · Post by **melw1** » 18 Aug 2007, 7:29pm

Best to just get out and ride with what you got if it all works OK

Very sensible words - I shall stick with the 32 and be done with it. Until the next thing I fancy changing.... :wink:

meic · Post by **meic** » 19 Aug 2007, 12:34am

Dont forget to pump them up hard. The Marathons have a max of 95 psi on the 32mms my wife has. If you want to go faster it is best to have the tyres at that sort of pressure. If you dont have a guage it is when the tyre is almost rock hard. Probably as hard as you can get it!
Thats my opinion, lets see if it generates some opposite views.

reohn2 · Post by **reohn2** » 19 Aug 2007, 12:52am

meic wrote:Dont forget to pump them up hard. The Marathons have a max of 95 psi on the 32mms my wife has. If you want to go faster it is best to have the tyres at that sort of pressure. If you dont have a guage it is when the tyre is almost rock hard. Probably as hard as you can get it!
Thats my opinion, lets see if it generates some opposite views.

If you put 95psi in a 32mm tyre you're going to get your eyeballs or your fillings (or both)shaken out,I weigh 85kgs and ride 32mm at 70psi,they roll well at that pressure anything above and it just becomes uncomfortable.

We have 32mm Marathons on one of the tandems,for day rides with an all up weight of 148kgs, we run them at 82psi again anything above and things just get uncomfortable.

We've been riding a tandem for about ten years and in that time I've fiddled about with tyre pressures starting at 110psi but gradually we've found 80to82psi to be just right.When touring we add an extra 5psi (we don't camp) so only carry about an extra 8kgs.

horizon · Post by **horizon** » 19 Aug 2007, 12:53am

melw1: I am not sure that whatever you do will make much difference. In fact I am not sure that you really want to go faster. What you might be looking for is less effort for the same speed. Once you are trailoring or carrying shopping then weight versus hills is the biggest factor. If you have any hills at all to go up locally then I would suggest lower gears to make life easier. I would also keep the Galaxy as a good all rounder and if you want to go on speedy club runs just get a second hand racer for Sundays (eg Dawes Giro) - there's loads of them out there. (BTW I currently have a Marathon Plus 38 on the back but even I think that that is overkill.)