[Closed] Specialized Tarmac (well, road bikes in general) sizing help/advice please....

Are you buying new? The shop should do a bike fit for you, getting you the right size based on the brand, as they are all different.

If you're basically 5'10" and have a 34" inseam, (exactly the same as me) unless you arms are outrageously long and you have incredibly good flexibility you probably aren't going to get a satisfactory position on a tarmac with a sensible length stem. Although I am making a lot of assumptions because I can't actually see you/don't have bike fit data.

Cube geometry would suit you well (short top tube/longer head tube) but their bikes aren't great in my opinion, we have them in the shop I work in and the only thing going for them are the components for the money.

Check out a Trek Domane, probably in a 56cm, absolutely cracking bikes, easily 'raceable' and suit people with short torsos and long legs.

Get fitted by a decent bike fitter, you need to work out your 'ideal geometry' and then pick a bike, rather than the other way round.

If guess at 54, but go and sit on some and get a fit.

As the other thread makes pretty clear, you'll be after a 58 in the Cube.

At 5' 10" an inseam of 34" sounds extremely long unless you're a girlie with shorter torso and longer legs. I'm Mr Average and I'm 6' with a 32" inseam; a 56 Roubaix is perfect for me.

Go to a decent Specialized dealer or a Specialized Concept Store and they will measure you up and advise you whether to go for a 54 or a 56. The Concept store will set the bike up and make small changes to the spec to suit you - for example changing from white saddle & bar tape to black if you want.

Tarmac is a superb bike, my buddy has just bought one after ten years on a nice steel Pinarello and he LOVES it - though he crashed last Sunday and wrote it off. New one arriving Tuesday courtesy of his insurance.

I'm six foot and a very important half an inch and I have a size 56 2013 Tarmac which I was fitted for and believe is right for me. On this basis I would expect the 54 to be the best size for you, but as others have said you really need to try the bike to be sure.

My personal bias is that the Tarmac is much more race oriented than the Domane. Don't know anything useful about Cubes...

scotroutes - Member
As the other thread makes pretty clear, you'll be after a 58 in the Cube.

Yes, but its the specialized I'm going for 🙂

And yes I'm buying new, been recommended two different sizes by two different shops up to now.
I've also sat on both sizes and can't really decide, I could imagine riding both to be honest (neither felt outrageously small/large).

By the way, my Tarmac is the sort which I think is one step up spec wise. Cost me £1200 reduced from £1500, I put a decent saddle on it and would like to buy trick wheels, but apart from that it is spot on. Don't think you would regret getting one if it fitted.

Very tough to say without trying them out - and as you say you may be in between and OK on either.

You are buying mail order yes?

Have you compared the top tube and head tube length with your cx bike? (the 2 most significant measurements IMO, albeit the latter may be a bit misleading as the fork and bb height will differ).

I tried a Tarmac, as a leggy 6' 3/4" I'd have gone for the 58, and I suspect the 56 would be better for you.

ollie51 - Member
Cube geometry would suit you well (short top tube/longer head tube) but their bikes aren't great in my opinion, we have them in the shop I work in and the only thing going for them are the components for the money.

I don't have specific experience, but there is GENERALLY no free lunch, and better components means a poorer frame for the same price.

Look flashier, rides worse.

I'm looking at a Cube, what's wrong with them?

Nothing wrong, just not a lot right. Their carbon frames are noticeably flexy too. Brands like Giant for instance can typically match their spec more or less, have a superior frame and hit the same price point.

On a road bike top tube length is what to look for IMHO.

Do you have long arms/reach? If so, the 56cm should be fine, if not then I'd go more typically and say 54cm.

Both my Tarmac and Pinarello have 56.5cm top tubes but the Tarmac has far more stand over. (I'm a shade under 6ft with 34"inseam)

Cheers Al / Ollie, the comparable price Giants and the Planet X RT58 are also on my list to look at so will bear that in mind.

Edit: sorry for the thread hijack!

Thanks for the replies so far.

Normal Man - Member
On a road bike top tube length is what to look for IMHO.
Do you have long arms/reach? If so, the 56cm should be fine, if not then I'd go more typically and say 54cm.

Yes tt length was what I would be basing it on. What would you class as long arms/reach, and how would I go about measuring it.?

I'll nip and measure the cx bike in a bit, ideally I 'think' I'd like a little more reach than my current cx if its for pure road use, is this correct?

What are the overall pro's/con's of a slightly shorter or slightly longer frame when it comes to a road bike (eg. how does it affect the handling, climbing, descending etc)?

😀

I'll nip and measure the cx bike in a bit, ideally I 'think' I'd like a little more reach than my current cx if its for pure road use, is this correct?

Yes

What are the overall pro's/con's of a slightly shorter or slightly longer frame when it comes to a road bike (eg. how does it affect the handling, climbing, descending etc)?

It's getting it to fit you if it's too big or small, it just doesn't feel "right". You have a fair bit to play with in terms of swapping stems and moving the saddle back and forth though, so not the end of the work in your case, I think.

Watch out for sizing on tarmacs, they come up long for given size.

I am 5'10", 32" in seam and long arms. my 56cm allez was too long, my 54cm tarmac much better but I'm using 90mm stem to get comfortable reach. I've been fitted using BG fit on number of occasions, have played with stem lengths (I work in a bike shop so that's easy...)

Don't size a bike using fore/aft saddle position it has a critical effect on pedalling efficiency and comfort; Get the saddle right and then setup bike using stem/bar

Have ridden 52cm tarmac, it's probably a better fit in hindsight. 54cm Roubaix with the longer headtube has shorter effective reach, feels more comfortable. What i've found with my tarmac is going slow the reach feels wrong, up to speed and sitting forward into the hoods feels great!

Thanks for that esher.

Well I've just (re)tried measuring my inseam again (its a 2 person job!), with a spirit level this time and not as much upward pressure. I'm coming out at 33" inseam, I assume that's more in keeping with my height.

Just measured up my current cx bike (ridley xbow);

Top tube c-c = 53cm
HT length = 130mm
Seat tube c-c = 52cm
Seat tube c-t = 55.5cm
Stem length = 110cm
Standover = 805mm
BB centre to saddle top = 760mm

😀

@jackal

Get the smallest bike that fits. It's easy to resize a smaller bike, much more difficult to resize a bike too large as once stem drops below 90mm handling tends to suffer whether climbing or more interestingly descending where steering feels too sharp and front wheel too light.

On my 56 allez I used a Thompson in line seat post as this was only way to shorten reach but it screwed up my pedalling and caused hip/knee pain. With 54cm tarmac I moved to regular lay back post and got this sorted!

I played with 75 and 80mm stems on my 56 allez and 54cm tarmac and found them detrimental to handling, with 75 I would catch my shorts on tip of saddle when moving to stand up off saddle

esher shore - Member

Get the smallest bike that fits. It's easy to resize a smaller bike, much more difficult to resize a bike too large as once stem drops below 90mm handling tends to suffer whether climbing or more interestingly descending where steering feels too sharp and front wheel too light.

I played with 75 and 80mm stems on my 54cm tarmac and found them detrimental to handling, with 75 I would catch my shorts on tip of saddle when moving to stand up off saddle

Cheers esher, that's just the sort of advice I'm after.
Its totally at odds with my mtb experiences, I'm now running the shortest stem I can (well always did on the dh bike), with a longer top tube as it's better for DH and will still climb. A longer stem = better for climbing not descending in my mtb head....

Get round some shops and try a few,no shortcuts with this I'm afraid. Don't buy from anywhere that doesn't do full fits or that won't let you test the bikes on the road.
I've just bitten the bullet and got a carbon synapse but only after trying about a dozen different bikes from Specialized, Trek, Bianchi (very nice), Focus (really really nice and great value), Cervelo, Felt and obviously Cannondale.
I'm 5'8" with 31 inside leg but needed short seat tube and longish top tube with highest head tube I could get, Cannondale just fitted best and was best around ride, although Focus ergoride was a bit racier. Ended up with a 54 but was in between size really.
For what its worth wasn't impressed by the Roubaix at all, too short and dead feeling. Tarmac was better but too low and bit too stiff. Domane was nice but wanted internal cable routing for later Di2 upgrade and that costs bloody fortune. cervelos are lovely but start at £3K.
But really love my Synapse, got the 105 and upgraded to a pair of Ksyrium elites which are brilliant and also 11 speed for when I get round to upgrading.

54 Tarmac

Hi fella, I really think you need to go and sit on your chosen bike before buying online, they vary in size a lot. I just got a giant tcr 1 composite fro pauls cycles online for an amazing price, I ended up buying a much smaller frame than I would have done had I not gone and sat on one in a shop first.

Happy hunting