phoshizzo

After being out of cycling for close to 6 years, I getting ready to get back into it. I've got back on the trainer and am hitting the gym to loose some unwanted weight .

Being that my current road bike is worn out and outdated, I've decided to shop around for a new bike. My old bike was a DEAN made from Easton Tubing w/ DA and had a standard geometry.

Seems like many of the new high end bikes are CF w/ the sloping down tubes of the compact frame. I notice that most these frames slope back (down from the head tube to the seat tube). The Trek appears to be the opposite w/ the slope going from the seat tube down to the head tube.

Can someone explain how the slope of the top tube would change the handling of the bike?

BTW, I've test ridden the Giant TRC1 and Trek Madone 5.2SL. Of the two, the Trek handled much better for me when going into/out of turns and out of the saddle. The Giant seemed to have a bit more flex and felt loose in and out of the turns.


I'm not really into the brand names or labels, but would I look like a Lance Armstrong poser if I bought the Madone 5.2SL in the 06 Midnight Blue Its the only color it comes in
https://www2.trekbikes.com/bikes/bike...id=1468000&f=1

Saturday I hope to ride the Specialized bikes and the Cannondales. Input on all the mentioned bikes are welcome as well as advice on other makes I should consider. My price range for a complete bike is $2500-$3000. I'm a hard sell and want to make sure I look at a good number of bikes in my price range before I make up my mind.

Lastly, I'm new the forum and have enjoyed many of the threads as well as the search function. I hope you guys/gals don't mind too much if I ask questions that may have already been discussed

thanks

khuon

A DEAN is worn out and outdated? Personally I'd consider upgrading it if I were you. I would think the frame is definately worthy.


Short generic answer: It doesn't. A sloping toptube may be dictated by other factours such as height of the headtube or attempting to create a smaller frame size with a relatively long top-tube length. Often times it's mainly aesthetic.

mingsta

Hi Phosshizo, welcome back to the cycling fold! You should be able to find a lot of old posts on this if you do a search as its a frequent question on the forum.

Its possible to have a sloping top tube without changing any of the angles or fit points on a frame. As such, having a sloping top tube does not necessarily affect the handling of a bike.

There's been a big movement towards compacts over the past few years, but this isn't necessarily because it is "better" per se. From a manufacturors POV having a sloping top tube eliminates standover issues. This means that you can get away with manufacturing frames in just 4 or 5 sizes (Giant, for example). Not necessarily a good thing IMO.

There's been lots of debate about ride quality...some people feel that compacts are stiffer (due to smaller triangles) yet more comfortable (due to longer seatpost), but others feel that it makes not a bit of difference.

phoshizzo

The wheels need rebuilding, the cog and chainrings are worn, etc...... I figured it out and I get a better deal if I sell my old ride and put that money toward a new bike.

The frame is not Ti or CF, its aluminum so it has a number of dings and scratches. It seems to have lost its "snap", but then again it might be that fact that I gained 30lbs since last I rode it competitively No matter, nothing motivates more than a new bike

khuon

Note also that Giant and other companies that use the compact sloping toptube design strategy also include in their fit philosophy the idea of adjusting the stem to compensate for more granular sizing. Personally I can't ride Giants simply because their sizing scheme doesn't work for me. I'm sort of "between sizes" and don't feel that just changing out stems will promote good frame fit. However, if you happen to hit right in Giant's frame sizing sweetspot then great if not then you may want to consider how far off you are and what the tradeoffs will be.

Also note that just because a manufacturer uses a sloping toptube on their bikes does not necessarily mean they only offer limited sizes. It doesn't seem like you were implying that but I just thought I'd clarify for the OP's and other readers' sake. For the most part, it's aesthetics. One doesn't really have any large advantage over the other. I personally prefer horizontal toptubes but I don't necessarily consider sloping toptube bikes to be ugly.

khuon

That's okay. I can understand new bike lust and there's certainly nothing wrong with that. I'm not necessarily trying to dissuade you from getting a new bike. I'm just trying to point out that just because something is old doesn't necessarily make it worthless or unusable. My suggestion if you get a new bike: don't get rid of the old one. You can always use a spare bike. I regret giving away all the perfectly good bikes in the past and wish I had held onto them.

biker7

Listen to khoun's advice because he is very knowledgeable but I will preface what he writes above a bit.
Mfr. paradigm shift in recent years to sloping top tubes has much more than an aesthetic contribution...but a utilitarian function. It allows for a reduction in frame size offerings that can effectively be tuned by stem length and rise. Yes you can fall in between frame sizes as khoun mentioned. Why are sloping top tubes conducive to reducing no. of frame sizes? Simply because a highly sloped top tube takes stand over height out of the equation or makes it less critical to choosing an incrementally larger frame size based upon fewer frame size offerings when a corresponding horizontal top tube bike would hit your private area when standing flat footed. The further benefit of a sloped tube bike is less frame material which generally translates to a very modest weight reduction that is somewhat offset by a longer seat post which incidentally offsets any perceived advantage in frame stiffness that many associate with a compact frame which is largely a myth....it is more a function of frame tube material and section.
George

Brahman Bull

A few months back when I was in the market for a new ride, my bike "fitter" gave me a great piece of advice when looking for that special bike. He said to test ride EVERY single bike you can (in your price range). Make a day of it. Bring your pedals, cleats/shoes and a pair of cycling shorts to make the ride more realistic. Any shop worth their salt will put on your pedals and make all the adjustments to make your test ride comfortable. If they are bothered by your request, walk out. Test ride standard geos along with compact frames. Forget about brand names b/c that will make your decision more difficult. He said not only buy a bike that feels good but buy one that speaks to your heart. Follow your gut when adding a new ride to the family. That may sound a little too spiritual but in all honestly it worked for me. Good luck on your purchase and welcome (again) to the fam. BTW, I bought a compact geo composite Giant TCR and switched all the components. Great bike, super stiff all around and climbs like a mountain goat.

ronbridal

^^^ Great advice! I would second the notion of test riding every bike in your price range that is possible. I was considering buying a Giant TCR or Trek Madone 5.2 Sl and test rode both. The shop I went to that sold the Trek allowed me to take a much longer ride and even sent me on a route that had a huge hill, which I liked. The Trek seemed like a much better fit to me and I felt more comfortable on it. I still ride it today and am very pleased with it. Regardless, the advice to ride each bike and simulate the conditions that you will be riding in is the best thing to do. Enjoy! Ron

Ramjm_2000

+1 on test rides. Consider bringing in your wheels if your trying to compair frame vs. bike differences.

mingsta

Yup agree with all of that.

Ideally frame sizes should be offered in 1cm increments, regardless of whether compact or trad. You should be able to pick a frame size that gives you the correct top tube length, which should in turn give you the correct stretch when mated with a 10-11cm stem (what I'd ballpark as a normal stem length nowadays). The problem with only having a few sizes is that you start lengthening or shortening the stem to compensate if the TT length isn't ideal, which will effect your centre of gravity and handling.

...and yup, wasn't implying that all compact frames are only offered in a few sizes, I know that Giant and Spesh work like that, but plenty of manufacturors offer compacts in 1cm increments. Of course, you should really bypass the whole sizing game and go get a custom Seven. I like the semi compact look and specc'd mine with a 6 degree slope.

johnny99

Your first paragraph only applies to companies that offer limited sizes in compact frames (e.g., small-medium-large). Specialized offers their compact frames in 7 different sizes, which should fit most people. Giant offers 5 sizes, though that is a big improvement for them since they used to have only 3 sizes.

Your second paragraph is kind of confusing. I'm not sure if that is a disclaimer for your first paragraph or just a rant.

mingsta

Khuon's reply made perfect sense to me. Bear in mind that he was replying to my post...prolly makes more sense if you read the two together.

In a nutshell he was saying; compact frames allow manufacturors to produce fewer frame sizes. However, thats not saying ALL compact frame manufacturors chose to do this, some offer a full range of sizes. Where you have limited frame sizes, you end up having to tweak the reach using saddle fore/aft and stem length, which is a dubious practise as it can change the balance of a bike.