Hi all..
I'm after a bit of advice on bike sizing for a road bike as I'm doing a bit more of that these days.
My current bike is an Orbea Orca which I like but it's time for a change. Also anything over 1.5hrs to two hours it really starts to do my lower back and my neck - So I'd like to ensure I get a bike that will be more comfy for long rides - however I still want to get a fast bike that feels snappy and I can race on.
I'm figuring I've got one last bike like this in me before I go to an endurance frame.
What I can't get my head around is people saying a bike with a taller head tube will be more upright. When going for a larger frame size, although the larger frame has a longer head tube it also has a greater reach/top tube so I guess the latter negates the effect of the former.
Any pointers as to if I should go 56 or 54 will be welcome.
Orca SL654 SL656
Top Tube (Eff) 545mm 540 562
Head Tube: 145mm 143 163
Reach: 380mm 384 395
Stack: 552mm 544 565
Thanks in advance!
That was supposed to be a table in my post comparing my 53 Orbea and a Tarmac SL6 54 and 56 frame.
Formatting hasn't worked but hopefully you get the drift. Thanks.
I think they mean some frames, especially more endurance have a longer head tube than a racier frame but the same length, essentially reach and effective tt length stay the but stack gets bigger. So you end up with a more upright position, obviously a bigger frame will also have a bigger stack but it will get longer as well. Obviously spacers or a positive rise stem will have the same effect but looks a bit nicer with less spacers and a flat stem.
Wouldn't be looking at a tarmac, Roubaix comfier or look at a Domane or a Synapse. Anything racy will more than likely not solve your problems without playing around with position a lot, which you could do to your current bike.
Wait till you can and go and test some bikes, you might not want an endurance model but in actual speed they're not really slower.
If the reach on your Orbea frame is right for you and you have a normal sized stem, then the 54 and 56 Tarmacs are probably too long and/or too low.
In the Cube Attain range, you would probably want a 53cm, which has 376mm reach and 561mm stack. Or maybe the 56cm frame (385/591 reach/stack) and then make sure the stem is flipped upward.
The geometry geeks website is quite handy for comparing stack and reach between different makes / sizes:
I can't see changing for either frame will actually do anything for you, would point to checking your position first.
One thing going up a frame size - if you ran spacers on the smaller size you are reducing horizontal reach due to head angle being tilted back. If you go up a size you have a taller head tube so less spacers so gain more reach than the ~10mm the frame itself offers. As most road bikes have a 25mm or so top cap the reach is never what is advertised unless swap that out.
If you went to a 54 Tarmac you would probably lose some of the 4mm 'extra' reach by adding in 10mm of spacers - difference is therefore naff all.
Go to a 56 and you will 'gain' 15mm reach but also run less spacers so that will in reality be more.
There is option of coming down 10mm on stem, within reason and depending how you like a bike to handle (noting trail, HA, wheelbase)
Bike sizing for a *ahem* bike
I thought with that title you were going to talk about something dirty. Like an eMTB.
Lol! Some blokes in the forest tried to sell me the idea of an ebike last week. Didn't realise you can set training zones on them. But I still spat on their shoes and rode off.
Thanks for the info all👍
I'd suggest playing around with your existing bike to find out what position makes things comfortable before buying your new one.
Your discomfort could be due to all sorts of things, not just reach and front end height (including saddle height, saddle fore and aft). You should be able to simulate the effect of a taller head tube with a riser stem; that's a cheap way of testing things out.
