How much differnce do tyre sizes make

[Steve N]

I picked up a new Dawes Sportif on Friday. It seemed ok during the various trying and testing I did at the dealers.
Yesterday I gave it a bit of a run on familiar roads and was surprised how hard the ride was compared to my ancient tourer.
I know the Sportif has slightly different geometry which probably has some affect but I thought Sportifs are designed for comfort too ?


Would changing the tyres make a significant difference ?

My old Tourer has 700 x 28s whereas the new Sportif has 700 x 25's

 

[Grasen]

more air = more comfort

 

[Alien8]

Maybe a bit but I would have thought that the difference in frame/fork materials and frame geometry etc would have more of an impact - guess your tourer is steel.

Read this for more background.

 

[Sittingduck]

Before shelling out on new tyres, make sure the bike has adequate clearance for 28's. Might very well only take 25mm...

 

[PpPete]

Less air = more speed

 

[Steve N]

Less air = more speed

more air = more comfort

Priority towards comfort at the moment - If I'm to regain the ability to walk properly

The combination of the harder ride and the Brooks saddle was sheer torture.
Am on the lookout for a comfy saddle first. The holy grail, I know. But - The Brooks has got to go.

 

[potsy]

I would imagine that going up 1 tyre size would only make minimal difference to the ride comfort,I went down a size from 25 to 23 and didn't notice any difference tbh.
32's might make more sense but like Sittingduck says your frame might not have the clearance so check 1st.
My bike (Secteur) will only take up to 25's.
As for saddles I'm on my 3rd since I bought the bike last October,and this is currently the best yet (Charge Knife) have never tried a Brooks but was getting close to buying one before I got the Knife.

 

[asterix]

My audax bike has 23's whereas I've always been used to 28s. It also had a new Brooks B17.

It was painful..

So I took off the new Brooks and put an old well used Brooks on (off the Brompton) and the bike has been magically transformed. The new Brooks is being broken in on the Brompton which has suspension.

I like the 23's but might try 25's when they are need replacement.

 

[Steve N]

My audax bike has 23's whereas I've always been used to 28s. It also had a new Brooks B17.

It was painful..

So I took off the new Brooks and put an old well used Brooks on (off the Brompton) and the bike has been magically transformed. The new Brooks is being broken in on the Brompton which has suspension.

I like the 23's but might try 25's when they are need replacement.

Strangely enough I tried several bikes before deciding and one was a Dawes Galaxy which had a Brooks B17 which I found quite comfy.
I decided to buy the Dawes Sportif and upgraded the saddle to a B17 on the strength of this, but joking apart it's literally unbearable.
Maybe the Galaxy had been well auditioned breaking in the Brooks a bit.

 

[MacB]

Have you got the aluminium Sportif or the steel?

 

[Steve N]

Have you got the aluminium Sportif or the steel?

Titanium

LINK

 

[palinurus]

Another thing that can make a difference is the wheels. In particular deep section rims can feel harsher than "traditional" ones, although other aspects of wheel design and spoking etc. have an effect too.

 

[MacB]

Titanium

LINK

well, it's certainly a thing of beauty, we need to get this comfort thing sorted out, far too nice a bike not to.

It's traditional geometry and you can straddle the top tube, by going with the biggest size then you give yourself the best chance of getting the handlebars high enough. but I can't see a geometry chart for it, do you know the detailed specs, ie HT/ST angles, lengths etc?

 

[PpPete]

My guess is that geometry is a sharper than on the Galaxy...( they always used to be 72deg parallel in the old days ). Moving the saddle back a few millimetres might help. Exactly which bit of your nether regions is uncomfortable BTW?

 

[RecordAceFromNew]

I picked up a new Dawes Sportif on Friday. It seemed ok during the various trying and testing I did at the dealers.
Yesterday I gave it a bit of a run on familiar roads and was surprised how hard the ride was compared to my ancient tourer.
I know the Sportif has slightly different geometry which probably has some affect but I thought Sportifs are designed for comfort too ?


Would changing the tyres make a significant difference ?

My old Tourer has 700 x 28s whereas the new Sportif has 700 x 25's

Why not swap front wheel, back wheel (or tyre if not possible) and saddle with your old tourer to eliminate/identify potential offending variables?