WalksOn2Wheels

After some great advice from the board here (see my previous thread asking about components and compatibility), I've decided to save my pennies and keep an eye out for a good used Specialized Tarmac. I'm rolling on my cheapie special with STI shifters and Sora derailleurs, and after becoming addicted after my return to cycling, I think it's time to lay some serious money down on a long term bike.

Anyhow, looking at the Specialized website, I see different version of the bike, usually with different components, but then they list the same basic bike in "compact" and "double" versions. What is the main difference in these frames?

silversx80

Compact, double and triple refers to the crankset in most cases. A compact has a 50-tooth big ring and a 34-tooth small. Double refers to two chainrings on the crankset (usually a 53/39T or the compact, 50/34), triple refers to three (53/39/30 or 52/42/30 most typically). There shouldn't be any difference in the frame unless noted in the specifications under "frame."

haimtoeg

The double has a standard double crank (53-39) and the compact has a compact double crank (50-34), the rest seems to be identical.

edit: beaten by silversx80

under18cyclists

The more expensive either the better the components or the better the carbon. They have 7r

carbon, 10r carbon, and alot more. The higher number of the carbon the better it is as in stiffness

and other things. The diff. in compact and double is that compact uses smaller gear ratios, it's hard

to explain. And if you didn't know Tarmac is more of an aggressive race bike and the roubaix is more

of a century bike with more comfort in mind.

WalksOn2Wheels

You guys need a smiley of a guy smacking himself in the head... Or at least I need one.

So yeah, just read in another thread and realized the difference. Like I said, I'm an idiot. Or a n00b anyway.

WalksOn2Wheels

Good suggestion on the Roubaix, but my current setup has a 52/42/30T chain ring and a 11/28 cassette. As it is, the double is 53/39 (I don't spend any time on the 30T on my current setup) so I wouldn't want to go smaller. Most, if not all, of the Roubaix models seemed to have smaller chain rings. In fact, it looks like even most of the Tarmacs have 12-27 cassettes. I'd probably want to change over to 11-28 later on, but not spend the extra grand on a "better" groupset.

Fullforce

My take:

https://www.bikeforums.net/road-cycling/568811-specialized-tarmac-comp.html

icyclist 

>Most, if not all, of the Roubaix models seemed to have smaller chain rings.<

I'll educate you! All Roubaix models are available with either compact or triple options. Top of the line model offers only a a compact set-up.

Roubaix triples come with a 52 chainring, while Tarmac doubles come with a 53 chainring.

Roubaix compacts and Tarmac compact doubles have the same , 50/34 chainrings.

Tarmac: for racing and for those who want to feel like racers

Roubaix: long rides, rough rides, mountainous and/or monotonous rides

Tapeworm21

The Tarmac line is pretty easy. Figure out what you want to spend on a bike and you'll get every penny worth of bike. Comp and Elite have the same frame.... expert is totally sick this year, pro is better, and S-works will make you cream your pants.

silversx80

It isn't that you're going smaller, you're just changing your gear ratios. How much time have you spent in the 52/11 combo? Probably too little to make a difference. Most compacts come with a 12-25 cassette. Your 52/11 is a 4.73:1 ratio. The 50:12 is a 4.17:1. That's roughly a 10% change. If you get an 11-28 cassette with a compact, you'll have a ratio of 4.55:1. That's less than a 4% change, almost too little to notice.

I considered switching from my 12-25 to 11-28 after coming from a triple to a compact. It isn't worth it to me because after my longest rides, I never come out of the big ring and never use either the 12, or the 25. I may still switch to the 11-28 the next time I head to UT, but the compact crankset is fantastic.

WalksOn2Wheels

I actually use the 52-11 combo quite a bit. I'm in Texas, so there are a lot of flats. When I approach anything resembling a climb, the lowest I go is about the third to biggest gear on the cassette (it's actually an 8-speed) and the second ring, but that's on a bad day (headwinds, etc.).

Anyhow, I'd rather get the 53 big ring and put an 11-28 on there. It won't be a huge difference, no, but I'd rather push myself a little more than go a bit smaller.

umd

Wow, you can push a 52x11 on the flats? That's impressive, I wish I could do 40mph on flat ground...

WalksOn2Wheels

Morning, UMD.

Heck if I know, but yes, I spend a good bit of time using the big chain ring and the smallest gear on the cassette. But no, I'm not hitting a cadence of 120 rpm or something. More like 80 to 90. If it's kicking my butt, then yeah, I'll switch down a couple of gears, but for the most part, I do spend a good bit of time in the 52-11 combo.

On one section of road, it's hilly, but mostly downhill and I can push it over the inclines in top gear, but every now and again I'll switch down a couple of gears. At most, though, I'm doing maybe 27 or so mph. That's on a fast, mostly downhill section, though.

In fact, just the other day I actually did hit 40 mph for the first time on a very steep downhill. I usually just take it easy and hit 30, but I decided to really spin it up and see what I could do. 40.2 mph was the best I could manage and I was hitting quite a quick cadence at that point.

What, is a 52-11 combo supposed to mathematically equal 40 mph at all times?

umd

Sorry a 52x11 is only 35mph at 90rpm... still not necessary for flat ground.

I do like my 53x11 for downhills though...

KiddSisko

50x11+8%@100=40mph

or something like that

kneed2wrydemore

Heck, I'm happy if I can maintain 20mph on flat ground.....50x12.

WalksOn2Wheels

I have been looking at picking up a computer with a cadence monitor as well, then I could actually see what I'm doing.

Just for fun, I manually counted the teeth on my gears and they are indeed 52-11 for top gear. I guess as a qualifier, I should mention that it is pretty windy in North Texas, so If I hit a head wind, I'm usually two gears down on the rear using the big ring on the front and with a tail wind, plugging away in top gear is fine. With no wind, I can usually do top gear, but after a long stretch, I might click it down a gear if I find myself slumping to bring my cadence back up.

silversx80

You might want to pick up that cadence sensor. You'll realize you're probably not spinning as fast, or much faster than you thought.

Spinning on a 52-11 is pretty rough, considering today that I was on my 50-19, 17 and 16 for about a 21 - 25 mph cruising speed.

umd

Walks, I feel bad for your knees.

unterhausen

I thought I heard something screaming

Sinn

This is not on topic, but everytime I'm in DFW -- specifically the mid-cities area -- all I see in bike shops are Specialized, Trek, and Orbea. I haven't looked hard, but the shops with a selection of bikes different from these staples seems hard to find. Its sad that there is not greater selection out there bc there are some really awesome places to ride your bike.

WalksOn2Wheels

Tell ya what, I'll pick up a computer with a cadence monitor in the next couple of months and report back. I could very well be running too low of a cadence, but I definitely did the when I first started and was riding "seriously" a few years ago. I made it a point to make myself suffer as much as possible. I'd be pushing top gear over hills just because I was convinced that that's what everyone should be able to do.

When I read a little bit more about cadence, I made a point of counting out my rpms and watching a clock a few times just to get a feel for what I should be doing, but without a computer, that's just a guesstimate, really. But I know when my legs are feeling the burn up a hill. I know the feeling of lactic acid building up, and I'm not getting that on the flats, so I ASSume I'm doing a decent cadence. It certainly feels good anyway. And like I said, if I feel like I'm having to push too hard, I do switch down a gear or two to keep my legs spinning.

umd

Well 60 rpm in a 52x11 is about 23mph

WalksOn2Wheels

UMD, I just looked that same rpm up in an online calculator. Just imagining myself on a bike, I can definitely see me doing 60 rpm. Strange. I thought as long as it felt easy and I wasn't burning my legs up, I was spinning fast enough. Oh well. I'll have to start counting again and see what it takes to get me to do a solid 80 or so rpm in a lower gear.

silversx80

I always shoot for a solid 90, so that leaves me between 80-100 most of the time. Everyone's different though

My girlfriend has started riding recently, and I'm trying to edumacate her on all the intricacies like braking, clipless pedals, shifting... the basics. One thing I hound her about is her low cadance. I equate it to the gym. A low cadance is like doing a lot of weight, for a longer period of time and with longer breaks in the repetitions. A faster cadance is a lower weight, quicker and shorter breaks.