Carbon versus Alloy & appropriate frame size

[briztoon]

Hi guys,

I have a couple of questions.

First up, is there something like a general rule of thumb as to what sized bike fits a person of a certain hieght? I'm 178cm or 5'10" in the old scale.

I've been looking at some of the Avanti bikes, and one store said I should be looking at a size 58, while another store was surprised at this and thought a 56.5 would be more suitable.

As a noob, what should I be looking out for in terms of bike fit?


Next, what are the advantages of Carbon as opposed to Alloy? Obviously wieght and price, but what else. I have a friend who rides, and she is pretty adamant about steering away from Carbon. Her concern is if Carbon breaks, for example the forks, it is expensive or impossible to replace or repair.

I would like some input here as well please.


I know Avanti aren't very popular here, but I like them. And I'm not Kiwi either. Here are the three bikes I am looking at, I would like some opinions on them as well please.

Avanti 2010 Giro
Avanti 2011 Giro 4
Avanti 2010 Quantum 1.0

Oh and why is the Giro 2010 more expensive than the Giro 2011?

I'm approaching 40, and have taken up riding to get fit and lose some wieght. I am only in the early stages of riding, 25 to 30 kilometers at a time, where it's all about the pain. But I am finding it rewarding and would like to get into the sport once I learn how to ride properly. Not at racing level, but definately like to take part in shop rides, other group rides, etc.

 

[Notso Swift]

Your height isn't so much of a critical factor (these days) mainly the length

I guess a lot of the Alloy v Carbon question will be answered by what you want to achieve,
Alloy tends to be Harsh, transmitting more road shock, which is one of the reasons they often are paired with carbon forks.
Alloy is less likely to fail if you crash
Contrary to some opinions it can still fail when riding along (welds), but then neither carbon or alloy seem to fail quite as much as some people will let you believe
Alloy will generally last longer, Carbon does eventually go a bit "soft"

Realistically at this price and with Avanti you will not have to many issues with a frame either way

 

[Black Dog]

Carbon does not go soft. Comfort is a matter of frame design more so than the material that the bike is made from. Go here to see what size you will need.

http://www.competitivecyclist.com/za/CCY?PAGE=FIT_CALCULATOR_INTRO

 

[Night Rider]

You are same height as me and I would go the medium size if I was buying that bike. I would say the bike shop trying to put you on the 58 doesn't know what they are talking about. Unless you have an extremely long torso and need the extra top tube length.

In my opinion if you're in between sizes the smaller one is better.

Re the prices, probably just the difference in original RRP. The 2011 is the better buy (resale value), but spec is almost identical.

 

[DirtyWorks]

The frame material choice isn't important if you can't immediately tell a difference. Carbon definitely does not 'go soft.' It has much better use properties than alloys.

If replacing a carbon frame will not bother your pocket book and you really like the ride more than alloy, then go carbon. If there's not much difference and just want to ride, I would suggest alloy is the better choice.

My personal problem with carbon frames is they fail suddenly and catastrophically. Alloys bend or crack in most crash instances where carbon can shatter. Or, even worse, the laminate fails without an external indication only to fail later catastrophically. Totally personal though. *Lots* of carbon on the road and no problems.

Sizing depends on your inseam. It's impossible to diagnose fit over the Interwebs without lots of personal measurements. Isn't there a site or two that will give him a decent estimate of his frame size if he inputs all his personal dimensions?

 

[dsut4392]

Next, what are the advantages of Carbon as opposed to Alloy? Obviously wieght and price, but what else. I have a friend who rides, and she is pretty adamant about steering away from Carbon. Her concern is if Carbon breaks, for example the forks, it is expensive or impossible to replace or repair.

Your friend is unfortunately ...erm... misguided.
Weight is an advantage but price rarely so.
Carbon doesn't "go soft".
Carbon is not impossible to repair, nor even more difficult than steel. It's easier to repair than aluminium or titanium. As far as replacing, visit a shop; no shortage of carbon frames or parts on the shelves.

As for your example, you'll be very hard pressed to find a good racing bike that doesn't have carbon forks, whether the frame is made from carbon, aluminium, steel, or titanium. It seems to be fairly universally accepted as a better material for making forks.
If you crash a lot, perhaps steering away from carbon is a good idea, otherwise base your choice on something else...

 

[Notso Swift]

Sorry guys you obviously either don't put out the power or have the weight (or both) that I do, you can feel carbon lose its zing, and I shouldn't say the carbon itself, but as I have said many many times the frame bonding does fatigue, If anyone tells me materials don't fatigue I will refer you to a materials engineer - Every material fatigues
Of course I speak from a position of little real knowledge... since I have been riding carbon for about 17 years since my 531P was written off (my first being a 93 8sp 600 equipped Merida 909 Extreme) including Alloy Lugged, carbon lugged and monocoque from various manufactures from Asia and Europe
I have only had one Alloy frame though, a Cannondale, it broke at the BB and down tube, but I don't think that was an issue with the material, just that one frame

 

[Michele]

@notso swift; Ive been riding very soft carbon frames and stiffer ones.
Does all the carbon is the same? Nop, nor the alloy.
Remember that not only the carbon used but also the layup and the glue (? forgot the right word..) makes a big difference.
Obviously geometries, angles etc as well but thats the same for alloy ones too.

 

[Bustedknuckle]

The frame material choice isn't important if you can't immediately tell a difference. Carbon definitely does not 'go soft.' It has much better use properties than alloys.

If replacing a carbon frame will not bother your pocket book and you really like the ride more than alloy, then go carbon. If there's not much difference and just want to ride, I would suggest alloy is the better choice.

My personal problem with carbon frames is they fail suddenly and catastrophically. Alloys bend or crack in most crash instances where carbon can shatter. Or, even worse, the laminate fails without an external indication only to fail later catastrophically. Totally personal though. *Lots* of carbon on the road and no problems.

Sizing depends on your inseam. It's impossible to diagnose fit over the Interwebs without lots of personal measurements. Isn't there a site or two that will give him a decent estimate of his frame size if he inputs all his personal dimensions?

Actually the two most important dimensions on a frame is seat tube ANGLE and top tube LENGTH. Femur length determines seat tube angle and torso length/arm length/flexibility determines stem and top tube length.

The only way is to get a proper anatomic fit, on a fit cycle, with a fit person. Formulas, online guides, etc may be a starting point but that's all. MO places say their formulas will get the right size but what else can they say?

Lastly take an extended test ride on each frame/bike. ALL bikes feel good around the block.

Also, lighter isn't better, just lighter. If it comes at the expense of reliability or crash worthiness, it's a bad thing. BUT remember there are only 2 things you can measure at a bike shop or even MO place, weight and price. Expensive and light, must be good(?), not necessarily.

 

[JayKosta]

Sizing:
1) The frame must allow the seat to be positioned for efficient leg extension and without strain on the knee.
2) You must be able to stand flat-footed on the ground with clearance above the top tube.
3) With the seat in the best position the frame, stem, and handle bars must allow comfortable and efficient riding positions.
a) sitting up with hands near the stem.
b) hands on the upper bends of the bar.
c) hands on the brake hoods.
d) hands on the drops - with wrist in comfortable position.

Frame material:
For all but racing and 'high performance' riding even a steel frame is fine.
Some 'race frames' can be uncomfortable (but fast) on long rides.

Wheels:
Wheels make the most difference to bike feel and performance.
Changing from heavy tires and rims to lighter weight will increase performance and be more fun.
32 (or even 36) hole cross-3 spokes are best for comfort and durability.

Seat:
Find a comfortable one - they do exist.
Adjust the angle to it is 'just right'.
Don't be concerned about weight or style - just how it feels.
My seats are old - a Stella Italia TURBO, and Brooks B72.
And use proper cycling shorts - avoid wearing anything that has a big or rough seam in a 'sensitive area'.

Jay Kosta
Endwell NY USA
age 63, cycling since early 1970's

 

[ustabe]

First up, is there something like a general rule of thumb as to what sized bike fits a person of a certain hieght? I'm 178cm or 5'10" in the old scale.

I've been looking at some of the Avanti bikes, and one store said I should be looking at a size 58, while another store was surprised at this and thought a 56.5 would be more suitable.

As a noob, what should I be looking out for in terms of bike fit?

56.5

You should be able to sit comfortably in the saddle with decent leg extension and your center of gravity roughly over your feet or the bottom bracket. Barring extraordinary physiological limitions, you should be able to set the handlebar at the same height as the saddle or a bit lower, and you should be able to support your upper body in the hands-over-the-hoods neutral position without leaning on your hands and arms. From this neutral sitting position you should be able to pull yourself up to a standing-on-the-cranks position without the sensation of crawling out of the back seat of a small car.

 

[Benotti69]

Hi guys,

I have a couple of questions.

First up, is there something like a general rule of thumb as to what sized bike fits a person of a certain hieght? I'm 178cm or 5'10" in the old scale.

I've been looking at some of the Avanti bikes, and one store said I should be looking at a size 58, while another store was surprised at this and thought a 56.5 would be more suitable.

As a noob, what should I be looking out for in terms of bike fit?

the canyon bike website has a measuring tool. if you know your dimensions check it out and see what it says.

canyon.com

look for calculate framesize

you'll get lots of different answers from different bike builders and LBS but source the bike you want first and then find the correct frame size of that bike for you.

 

[DirtyWorks]

Actually the two most important dimensions on a frame is seat tube ANGLE and top tube LENGTH. Femur length determines seat tube angle and torso length/arm length/flexibility determines stem and top tube length.

How many people listen long enough for that to sink in though? And then you've got Giant confusing the situation with compacts. Hence, "What's your inseam" makes the customer feel like they are a part of the process.

 

[briztoon]

Well I have been looking online to see what bikes are in my price range and what group sets they come with. Tomorrow I go on a LBS crawl to checkout the bikes I have shortlisted, hopefully go for a test ride on each.


Avanti Giro 4 56.5cm (2011)
Scott Speedster S20 (2011)
Giant Defy 1 (2011)
CAAD8 5 105 (2011)

Merida Road Race 904-Com (2010)

Avanti Quantum 1.0 56.5cm (2010)

The Avanti Giro, Scott, Giant and CAAD8 are all alloy frames with carbon forks, with Shimano 105 5700 group sets, but the Giro has some slightly better Shimano parts in place of 105 5700. The Giro and Giant also come with pedals included.

The Merida comes with Shimano 105 5600 group sets. So to the Avanti Quantum and it's breaks are Avanti Tiagra, not 105's.

So first question is, is there a big difference between 105 5600 sets and 105 5700 sets?

Is the Avanti Quantum made from good quality Carbon and does this make it a better buy than the alloy frame bikes.

 

[DirtyWorks]

Is the Avanti Quantum made from good quality Carbon and does this make it a better buy than the alloy frame bikes.

The Asian sources for your Avanti have to build product that complies with engineering safety standards in many different markets, so they build to the highest standards to be able to sell the product everywhere. It's all good product.

How about abandoning the whole notion that there are important differences between alloy and carbon? Because really there isn't any difference on frame material alone. Getting a good fit is important. Frame material isn't.

Before anyone jumps down my throat for that last statement, argue the merits of alloy/carbon on your local ride with your buddies. If the parent poster actually hangs around the sport long enough to get another bike, we all know it will be a better one.

Your best buy should be the 2010 product. The model year distinctions are largely a joke inside the industry where consumers never fail to be fooled at middle/lower price ranges. My understanding is the 'new' 105 5700 is lower quality to meet the SRAM prices.

If the 2010 bike feels good and the price right, then it seems like a good idea to consider it.

 

[Notso Swift]

I would definately want to go "full 105" over mix with Tiagra, the quality is a major step, as is Ultegra, while Dura ace is only incremental

The Asian sources for your Avanti have to build product that complies with engineering safety standards in many different markets, so they build to the highest standards to be able to sell the product everywhere. It's all good product.

How about abandoning the whole notion that there are important differences between alloy and carbon? Because really there isn't any difference on frame material alone. Getting a good fit is important. Frame material isn't.

Before anyone jumps down my throat for that last statement, argue the merits of alloy/carbon on your local ride with your buddies. If the parent poster actually hangs around the sport long enough to get another bike, we all know it will be a better one.

Your best buy should be the 2010 product. The model year distinctions are largely a joke inside the industry where consumers never fail to be fooled at middle/lower price ranges. My understanding is the 'new' 105 5700 is lower quality to meet the SRAM prices.

If the 2010 bike feels good and the price right, then it seems like a good idea to consider it.

No argument, hence my question initally to the OP, what do you want to achieve and the most likely senario is a good reliable unit that lasts and Good Alloy is way better than bad Carbon, that said , none of those brands are bad, they are all supported resonably well, which is more important.

I would also suggest they look at any second hand units out there, but some times they are too dear for what they are from a shop (as opposed to ebay, which can be pot luck in itself)

I wouldn't assume the 2010 is better value automatically, it may have a bigger discount but from the Avanti links that the OP put up the actual price was close to the same, the spec was the same and only the graphic changed.

Since you are linking Bikeexchange I am guessing you are in Australia, that being the case I would also look at cyclingexpress.com, they have some decent specials and you can get them delivered (and set up right) through a bike shop

 

[briztoon]

OK I made the mistake of trying out a couple of different Carbon bikes just for kicks today, as well as the alloy bikes, and subsequently threw out all the alloy bikes I was looking at, and added $500 on to my budget. Seriously, if you are looking at top of the line Alloy bikes, DO NOT test ride a Carbon bike. WOW I never new what I was missing out on.

So at the end of the day I am down to two bikes. The 2011 Roubaix SL2 Elite for $2000* or a 2011 Scott CR1 Comp for $1800.

*Yes I know the add says $2499, but if you ask nicely, you can get it down to $1999 and still get the Speed Freak pack valued at $499 included.

OK, time for some bike comparisons.

The Roubaix has SRAM Apex components. You can get the same bike with Shimano 105 5700 components for an extra $100, but seriously I like the SRAM bits better. The Roubaix has a longer wheel base than the Scott, so doesn't handle as well in the corners. The Scott does not have all Shimano 105 5700 components, it has Shimano R600 crank and generic Shimano brakes (I would love someone to look at the add and tell me whether the add says they are 105 5700 cranks and brakes). The Scott has a shorter wheel base and definately corners better and feels more responsive. Both have very comfortable seats, but I think the Scott just edged it.

Ideally I would have the Scott with SRAM Apex components.

I already have an Avanti helmet, Spelialized shoes, Shimano 105 pedals, a n.e.r.d computer, lights, etc. So the extras pack isn't essential, though it would be nice.

At this stage I am leaning towards the Scott, mainly because I liked how it handled, and it felt like a better ride. However I would still like to hear peoples opinions and/or reviews of the two bikes. Especially for people who can read the specs lists for both bikes and tell me if one represents better value for money over the other.

 

[RDV4ROUBAIX]

The Roubaix has SRAM Apex components. You can get the same bike with Shimano 105 5700 components for an extra $100, but seriously I like the SRAM bits better.

Spend the extra $100 and get the Shimano grouppo. SRAM road stuff is junk.

 

[Bustedknuckle]

How many people listen long enough for that to sink in though? And then you've got Giant confusing the situation with compacts. Hence, "What's your inseam" makes the customer feel like they are a part of the process.

We only sell after a complete anatomic fit, with a fit guy, on a fit cycle. Don't sell bikesinboxes, buy a frame, build here..they listen. Are there those that rely on formulas? Order a frame/bike thru the interweb, get the wrong size? Sure, we do fits on existing bikes all the time and see this again and again. Some are a correct size frame, can be corrected with seatpost/stem/handlebar but some are so far off it's laughable(but I told them my inseam and standover?)

 

[Bustedknuckle]

Spend the extra $100 and get the Shimano grouppo. SRAM road stuff is junk.

Well said, concise, to the point. I had a customer who bought a sram apex Specialized, road it once, the RD was so sloppy, it was a joke. I installed a 105 group on it a week later. Thankfully some 'sucker' bought the apex stuff..really poor, even when new IMHO.

 

[Notso Swift]

See at $2000 you are all of a sudden getting it to a MUCH more serious bracket of bikes
You are even looking at the run out Ultegra bikes or very good 105's


With Brands, well there are going to be a lot of Scotts around next year with GreenEDGE, and there are already a lot of Specialized. Also look at brands like Cell, Felt and you are at the begining of the BMC line, Focus Cayo, Orbea

Here you go BH!
http://www.bikeexchange.com.au/bicycles/bh/road/bh-speedrom-105/mona-vale/nsw/100320192

 

[ustabe]

At this stage I am leaning towards the Scott, mainly because I liked how it handled, and it felt like a better ride. However I would still like to hear peoples opinions and/or reviews of the two bikes. Especially for people who can read the specs lists for both bikes and tell me if one represents better value for money over the other.

The handling of the Scott is much snappier than the Roubaix. The riding position is also a considerably more aggressive while still classifiable as "recreational." To me the Roubaix is just too over-the-top comfortable. Not that I have anything against comfort, but if you want that kind of comfort get an Electra Townie.

By the way, Scott's Speedster S10 and S20 are a first-rate execution of the CR1 in aluminum. Same geometry, different material, just a little heavier and a slightly different road feel.

 

[briztoon]

OK, well I've settled on a Specialized Tarmac Elite Compact (2011)* but got it for $2300. I also got a few minor upgrades to the bike compared to the specs in the add. Full set of 105 5700 components (the crankset and front and rear brakes weren't 105, they are now. Plus I already have 105 pedals), with Mavic Aksium wheels, Toupe Gel Saddle, 2 water bottles and 1 cage.

Then add in the Specialized promotional package that's on offer; SPEED FREAK PACK OFFER - receive the Speed Freak Pack for free, which includes the following products from Specialized: Propero Helmet, Comp Road Shoes, Rib Cage and Mini-Wedgie (valued at $499 RRP).

I think (hope) this is a good beginner carbon bike package.

Final full fitup tomorrow. I've been through most of it before I took the bike out for two rides, yesterday and again today. They're just going to add the upgrade components I asked for, then we'll do a final fit up and I ride it home.

*Note for Brisbane readers. I did not get my deal from the Paddington store, but from one on the Southside. Thier add did not show the free pack offer, but they include it as well.

 

[briztoon]

The handling of the Scott is much snappier than the Roubaix. The riding position is also a considerably more aggressive while still classifiable as "recreational." To me the Roubaix is just too over-the-top comfortable. Not that I have anything against comfort, but if you want that kind of comfort get an Electra Townie.

By the way, Scott's Speedster S10 and S20 are a first-rate execution of the CR1 in aluminum. Same geometry, different material, just a little heavier and a slightly different road feel.

Haha, the road feel is like night and day. I tried the S10 then the CR1 Team and that was it, I didn't think about alloy again.

 

[Notso Swift]

Cool Enjoy the ride!