Bike size advice.

[Skins]

I seem to be in between bike sizes so: is it better to choose the smaller bike with a higher seat height or bigger bike with a lower seat height?
My feeling is bigger bike with a lower seat height. Looking at Boardman SLR 8.9 105 size Medium, I'm 5ft 10.
I consider myself new to cycling so any advice greatly appreciated.
Cheers

[Jamesh]

Im 5'10" and i'd go for a medium which I think is 55cm in the older CB frames

I cannot stand being squashed on a too small frame.

Cheers James

[Jdsk]

Welcome.

Do you have the chance to ride or at least sit on them before buying? With an expert helping?

This isn't a comment on those frames and your size but in general it's often recommended to go for the smaller frame.

Jonathan

[Jamesh]

Welcome to the opinion of forums!

Colin will be along soon to referee!!

Cheers James

[freeflow]

The reach ( distance from headset to the STI) is more amenable to adjustment than saddle position so choose the frame size that best matches your legs.

For the saddle position it is the forward/backwards adjustment that is critical. Height is the much easier adjustment.

[PH]

Do you have a current bike to compare?
It's often the case, particularly with compact frames, that some can easily achieve the same position on two sizes without either being extreme in terms of stem lengths, or saddle position. It then become a matter of preference, when presented with a choice I opt for the larger, but others the same size may prefer the smaller, that only comes from experience. Deciphering geometry charts can be a minefield, it's all related and not fully understanding how one figure impacts on the others can trip you up, has tripped me up. I don't know how Halfords are operating, is it possible to at least go sit on the bikes in a store? I know some are great advocates of test rides, but it takes me a few hundred miles to decide if I like a bike! I'd still like to have sat on one before buying, just to see if there was something obvious I'd missed.

[531colin]

The snag is that even entry level road bikes are made to copy the professionals....but the people who ride the entry level bikes don't train for several hours every day. So, for most of the people, most of the time, the handlebars are both too low, and too far away. (and the saddle is too far forward)
In order to try to mitigate this, have a close look at the geo table...
Here....https://www.boardmanbikes.com/gb_en/products/2341-slr-8.9-2021.html....scroll down

STACK (height of top of head tube above bottom bracket axle) Med = 567mm Lge = 588mm
REACH (horizontal distance from bottom bracket axle to top of head tube) Med = 387mm Lge = 390mm
SEAT TUBE angle Med 73.5 deg Lge 73 deg

So, the Large has the "benefit" of getting the bars 21mm higher at the "cost" of having the bars 3mm further away. (the Large also has the small benefit of a shallower seat tube angle, but only half a degree)
To me, its the Large every time, all day long....just provided you can get your leg over the top tube.

Now, above I'm just looking at frame dimensions....as supplied, the Large has a 110mm stem, and the Med has 100mm stem....you would probably want a shorter stem on the large, maybe try a 90mm as a first guess. (this takes the reach to the bars down to less than the Med bike, as supplied)

As above, reach to the bars is relatively easily changed by fitting a different stem. Bar height is most easily increased by flipping the stem. Saddle height isn't usually a problem, its adjustable over a vast range.

[Jamesh]

It's quite a racey bike, more rave than endurance so you might expect to be a bit stretched out.

How flexible are you?

Do you want to ride fast or piddle about.

Perhaps a adv might be a better buy if the latter.

Cheers James

[David9694]

There is something odd about the seat tube measurements on the boardmanbikes site - the XL is 545mm it says, which would be 21.4” in old money. A XL size should be at least 24” or 610mm, if measured the usual way from the centre of the b/b to the top of the tube.

If you’re starting out, then as has been said, it’s more likely to be the reach, from the nose of the saddle to the centre of the handlebars and the handlebar height that will make the most difference for you.

[Jamesh]

There is something odd about the seat tube measurements on the boardmanbikes site - the XL is 545mm it says, which would be 21.4” in old money. A XL size should be at least 24” or 610mm, if measured the usual way from the centre of the b/b to the top of the tube.

If you’re starting out, then as has been said, it’s more likely to be the reach, from the nose of the saddle to the centre of the handlebars and the handlebar height that will make the most difference for you.

Boardman bikes are semi compact frames so approx 2" smaller than the equivalent traditional level top tube bike.

Cheers James

[Skins]

Cheers for the advice everyone, Maybe I'm looking at the wrong bike? as my intention is mainly for keeping fit, cycling to work (32 miles round trip to work) 2 or 3 times a week with a longer ride at the weekend. Most important thing for me would be riding comfort and half decent bike, not to bothered if it has full carbon or disc brakes just a good all round comfortable bike with half decent kit for about £1000.

Cheers

[leftpoole]

I am 'tempted' to say, "only you know what fits/suits you

[Jamesh]

I'd suggest a more versatile bike to the Boardman listed above.

If you commuting to work you want something a bit more rugged with room for mudguards.

Unless your flushed with cash spending on replacement parts on a 105 bike rather than a Claris spec bike is going to be spendy if commuting on it.

Cheers James

[VinceLedge]

The reach ( distance from headset to the STI) is more amenable to adjustment than saddle position so choose the frame size that best matches your legs.

For the saddle position it is the forward/backwards adjustment that is critical. Height is the much easier adjustment.

Pretty much what I was going to say! Having made the mistake in the past of going for the bigger size, I would always go for the smaller frame, getting the saddle far enough forward can be a real problem on the larger frame, especially with the fashion for layback seatpost. If you can't get the saddle in the right place the bike will never fit properly.

[rmurphy195]

With all the best intentions behind the advice given on this thread, the best - and IMHO the only way - is to visit a bike shop and sit on the bike.

Try with your hands on the hoods, and on the drops, and on the tops. If you feel stretched out (more likley on a sports frame than a touring frame of nominally the same size) then reject that one. If you feel stretched out wearing just a T-shirt in the shop, you'll feel it even more in cold weather with layers of warm clothing and gloves!

If the gears are too high or too expensive, I'd reject that as well. Someone has mentioned Claris spec v 105 spec - I've gone for Claris (3x8) and been very happy with it, though I have a Spa chainset on to get lower gearing than is available with the standard Shimano stuff (the extra 2 or 3 lower gears are far more use than theb ones at the top end, which I rarely use). For an illustration of costs, look at the price of a given 8-speed chain v that for a 10 or 11 speed chain of the same make/quality, ditto sprocket cluster which all wear out.