New bike sizing

[e-rider]

I've been out today looking at a giant defy 1 for my new bike, in one shop i was told i should fit a medium in another i was told m/l. Does it matter and what difference would it make if i ordered a larger or smaller frame please?

size is absolutely the most important thing to get right when buying a bike - forget the spec sheet, buy the bike that fits the best, otherwise you'll hate riding it - simple!

as a general comment, you see far more people riding bikes that are too small for them, than the other way round. Funny becasue back in the 1980s it was the opposite (and I'm not just talking geomonetry changes back then), and people would often ride huge bikes. I've seen many tall men ride silly small bikes with their knees hitting their ears - and these are £2K bikes! Don't just trust the shop assistant if you feel something isn't right - get another opinion before spending the cash.

 

[themosquitoking]

Only a slight difference, I guess, but as you're an in between size, it could get rid of the danger of feeling overstretched on longer rides. Marginal though - I've found that the changing the angle of the handlebars so that the tops of the bars are horizontal with the levers higher can make a slightly overstretched position feel more relaxed. That said I only really use the drops as an afterthought when I'm fed up with a headwind or for those downhill whee! moments.

I think this will be me tbh.

 

[themosquitoking]

size is absolutely the most important thing to get right when buying a bike - forget the spec sheet, buy the bike that fits the best, otherwise you'll hate riding it - simple!

What would you do though if you fell right between two sizes? I'd ideally be after a more relaxed position i guess.

 

[e-rider]

What would you do though if you fell right between two sizes? I'd ideally be after a more relaxed position i guess.

I've had exactly that many times - my advice would be to not buy either and look at something different in the correct size. Some brands have huge jumps between sizes so it's easy to fall between sizes. Other brands avoid this by increasing sizes by 1cm at a time (but these are generally very expensive bikes).

 

[e-rider]

manufacturers keep their costs down by producing as few sizes as possible; typically as few as 4 sizes might be on offer, even from leading brands - if you fall between sizes look elsewhere

 

[themosquitoking]

I've had exactly that many times - my advice would be to not buy either and look at something different in the correct size. Some brands have huge jumps between sizes so it's easy to fall between sizes. Other brands avoid this by increasing sizes by 1cm at a time (but these are generally very expensive bikes).

Excellent advice except for the fact i kind of fell in love with the giant today, i think if i bought anything else in that price bracket now i would always wonder if i should have got the defy instead.

 

[e-rider]

Excellent advice except for the fact i kind of fell in love with the giant today, i think if i bought anything else in that price bracket now i would always wonder if i should have got the defy instead.

in love you might be, but you might have a messy break-up once you ride 50 miles on a bike that doesn't fit though

 

[e-rider]

if you really twist my arm (and you are genuinely right between sizes) I'd say go for the larger one.
Make sure you get a proper bike fit as you might actually fit one of the sizes fine afterall!

 

[themosquitoking]

if you really twist my arm (and you are genuinely right between sizes) I'd say go for the larger one.
Make sure you get a proper bike fit as you might actually fit one of the sizes fine afterall!

I'll go back to the lbs tomorrow as the fella i saw today has the day off and see what someone else says i think. Thanks, you've given me some stuff to think about although i think most bikes in the price i'm looking at come in fairly similar sizes.

 

[e-rider]

I'll go back to the lbs tomorrow as the fella i saw today has the day off and see what someone else says i think. Thanks, you've given me some stuff to think about although i think most bikes in the price i'm looking at come in fairly similar sizes.

no that's not the case. They might all say S,M,L or 54cm 56cm 58cm but there are differences between them all. The geometry chnages from one brand to the next and this affects the size. Some might have slighly longer headtubes, some longer top tubes, more relaxed seat tube angle..... it goes on and on. A 56cm in one brand could be quite a different size than a 56cm in another brand as an example. Also, as another example here, you could get a 57cm!!!

 

[e-rider]

Good luck - and enjoy riding whatever you buy!

 

[themosquitoking]

no that's not the case. They might all say S,M,L or 54cm 56cm 58cm but there are differences between them all. The geometry chnages from one brand to the next and this affects the size. Some might have slighly longer headtubes, some longer top tubes, more relaxed seat tube angle..... it goes on and on. A 56cm in one brand could be quite a different size than a 56cm in another brand as an example. Also, as another example here, you could get a 57cm!!!

This all gets quite confusing doesn't it? But from what you say i guess a certain amount of adjustment is available after market, i'm not too concerned if i have to buy a new stem, or handlebar holder, or something else (saddle or seat post maybe, i'm just trying to sound like i know what i'm talking about here) to get the perfect fit if i decide it's needed.

 

[e-rider]

This all gets quite confusing doesn't it? But from what you say i guess a certain amount of adjustment is available after market, i'm not too concerned if i have to buy a new stem, or handlebar holder, or something else (saddle or seat post maybe, i'm just trying to sound like i know what i'm talking about here) to get the perfect fit if i decide it's needed.

there is some scope to adjust the set-up, esp with saddle height etc. but overall perhaps not as much as you might think. For example, handlebar height has very limited adjustment. A decent bike shop shouldn't sell you a bike that isn't a good fit - so find a good shop!

 

[themosquitoking]

there is some scope to adjust the set-up, esp with saddle height etc. but overall perhaps not as much as you might think. For example, handlebar height has very limited adjustment. A decent bike shop shouldn't sell you a bike that isn't a good fit - so find a good shop!

I think the shop i'm hoping to buy from is good, my return visit tomorrow will confirm it. Finger crossed.

 

[Kies]

Have you changed anything since you bought the bike?

Nope, it fits like a glove. 1 year on and i love it more than ever. Upgraded the saddle to a fizik airione as the original was starting to show signs of wear, and recently ordered some blue/black vittora rubino tyres as the originals have done 1500 miles.