So...just about to buy a lovely ti gravel bike and went down to get myself sized up. I am 180cm tall with longer legs than body (if you get what I mean) and they reckon I'm a medium (55cm effective top tube) but my current road bike (which has always felt like it might be a tad small) seems to measure up at 56cm.
To be fair they did say I was on the cusp of a medium and a large (57cm) but that medium would work better. Does that 2cm really make a huge difference? Would I be better off going large and shortening the stem or sticking with medium and lengthening the stem?
Would you say a smaller frame is better for 'gravel' duties? It's a big purchase so I want to make sure I get it right 🙂
I'm 6', ride a 58 road bike and a 56 gravel bike, works for me
So it does make sense to go a bit smaller for somethIng you'll take off-road?
Another consideration is that a slightly longer post will be a little comfier. As above, I'd usually be a 58 for most road bikes, but 56 for the gnarmac [s]rig[/s] [s]whip[/s] [s]steed[/s] bike.
It just feels a bit less stretched out, feeling more like an old school MTB than cross/road, which i like.
Might be worth demoing if you can..
The top tube is a poor guide when the seat angle might not be the same. Look up the stack and reach for both. I'd err towards smaller provided the seat post isn't going to be silly long, and provided you can get the stem stacked high enough.
Sounds like the medium might be the best bet. He did say if it ends up being too small he'll change without any problem but be good to get it right first time. He did also size me up very professionally (measuring legs, core, shoulders, difference between arms lengths etc) so he should probably know better than me!
A short seat tube also allows more room for a dropper.
6ft here and 55 ett on gravel and the cx bike.
Depends on how tall the head tube is, how high you want your bars (higher for off road & drop use) how many headset spacers you can live with and associated flex
You tend to move around a lot more on a CX bike offroad vs road in the quest for grip, eg. Off the back for descents, so having a bit more room makes sense. Bit more toptube clearance also aids getting your foot down when traversing slopes.
Hmmm, bit confused. Some folk saying smaller but Doverbiker, are you suggesting it would be better to be a bit bigger? Difference between two sizes is only 2cm Effective top tube - so would I be safer to go large?
If in doubt go for the smaller frame.
I read it as smaller being better - and I'd agreebut Doverbiker, are you suggesting it would be better to be a bit bigger
Would you say a smaller frame is better for 'gravel' duties?
I’d say it depends on the brand, and possibly model too.
I’ve got a Specialized Sequoia and I wouldn’t size down in those as they size like an MTB. Spesh road bikes always look smaller than they are too.
Before that I had a Croix de Fer and I did size down but wished I hadn’t, I should have got the correct size and a shorter stem.
You’ve really got to try one out and get some advice from somone who knows the brand. Like a dealer, who will know the brand better than anyone on here.....
Try speaking to other owners who've bought through the same place and see how they've got on with the bike.
Just to add to the mix - I'm 5'8" and ride 565TT road bikes and 545TT CX and 'mixed surface' bikes. All with 100mm stems. I have a short upper leg and relatively long arms...
Depends on how tall the head tube is, how high you want your bars (higher for off road & drop use) how many headset spacers you can live with and associated flex
This is the bit that makes most difference to how my frames fit. Sometimes the difference in headtube between a 54 and a 56 can be 30mm
Its really a road bike so size accordingly. However it's pointless to compare numbers unless the geometry is the same and it won't be so every bike will be different. So are people so comparisons are not much use. If one puts you between sizes look at another.
IMO It's all about stack, reach and your back.
I'm 5'10", ~32.5" cycling inseam with a back that has played up on and off for coming up to ten years.
My 58cm frame Cube road bike has 620mm stack and 388mm reach. This puts the bar tops as good as level with my saddle top (which is ~73cm BB to saddle top).
If I had chosen the 56cm frame, reach would be 385mm, but the stack would be 591mm. More pressure on my lower back, because the bars would be 2.9cm lower by default.
To clarify, IME size-down if between sizes and also you don't really need such a big bar to saddle drop as it only serves to pitch your weight forward which you don't want when riding steep and loose.
Note if comparing head tube length that some gravel bikes have shorter head tubes than road but have a longer fork to provide good tyre clearance.
So I measured up my current road bike...the fork length and head tube is about equal to the proposed purchase.
But the top tube is 570 with effective top tube of 580 and I run a 140mm stem (which is probably a bit long tbh) but everything pointing me towards thinking a 570 gravel Bike May be better...
As above, the general theme is to drop a size. But the fork length / stack etc doesn’t always comply with that logic.
In now using this little [url= http://gearinches.com/blog/misc/bike-geometry-comparator ]geo comparison visualiser[/url].