Overheard about Giant carbon bike...flexy?

[Jeff Potter]

I have a pal who recently bought a 16-lb Giant compact carbon bike.
He's really enjoyed riding it---had a great century on it. But he also
did his first urban crit recently. He's a tall, skinny guy--6'3"
maybe. He said he didn't really like the pack riding in the race. Then
he offhand mentioned that the bike seemed to flex several inches in
the corners. Like it was all over the place for him. He didn't know
this was unusual since he hasn't raced before and didn't even mention
it as a complaint. Well, it's unusual to me for my crit racing back in
the day---I used a Pro Miyata tank and it never budged a bit.

Anyone else hear such a thing about these new compact carbon bikes?
Giants? Maybe a superlong post is involved with all this---with the
big G-forces of a big guy going into a hard turn? He may have the post
up REALLY high as he bought the bike from a guy who's 4" shorter.

He did just fine in the race---very strong guy---but was dismayed at
life in the pack and it made him wonder about it all. I told him that
would be no surprise at all that he had a scary time if his bike was
flexing a lot. I told him that with a rock-solid bike you can be happy
banging around in the roughest crowd or the roughest course. If he
gets a stiff bike I'm sure he'll eat it up and enjoy the packs.

I had a slightly flexy Trek 760 (24" thinwall tube) once that I just
could NOT ride in a pack with---not road race or crit or even big
training ride. It scared me. It was light and nice for TT's and solo
rides, though. But I could muscle thru anything on my Pro Miyata tank.
It made all the difference. To me, a solid bike meant happy racing and
close-pack elbow-bump riding or not doing it at all. Also, the Miyata
was my only race bike that never shimmied on big downhills. I'm
6-1/170.

Anyway, is anyone finding that these new carbon compacts are flexy? Or
that they shimmy on downhills? I thought offhand that they'd be
stiffer yet than my old tank. Is it just a seatpost issue? What about
new-fangled wheels? --I think his have carbon blade 12-spokes or
something like that. Do big guys need stronger wheels? I used to need
a 14-ga rear wheel to hold up. A 15-ga would warp in a week. How stiff
are the new wheels laterally? I've never raced a new-era bike, so am
wondering how they might differ. Thanks.

--JP
outyourbackdoor.com

 

[psycholist]

"Jeff Potter" <[email protected]> wrote in message
news:[email protected]...
>I have a pal who recently bought a 16-lb Giant compact carbon bike.
> He's really enjoyed riding it---had a great century on it. But he also
> did his first urban crit recently. He's a tall, skinny guy--6'3"
> maybe. He said he didn't really like the pack riding in the race. Then
> he offhand mentioned that the bike seemed to flex several inches in
> the corners. Like it was all over the place for him. He didn't know
> this was unusual since he hasn't raced before and didn't even mention
> it as a complaint. Well, it's unusual to me for my crit racing back in
> the day---I used a Pro Miyata tank and it never budged a bit.
>
> Anyone else hear such a thing about these new compact carbon bikes?
> Giants? Maybe a superlong post is involved with all this---with the
> big G-forces of a big guy going into a hard turn? He may have the post
> up REALLY high as he bought the bike from a guy who's 4" shorter.
>
> He did just fine in the race---very strong guy---but was dismayed at
> life in the pack and it made him wonder about it all. I told him that
> would be no surprise at all that he had a scary time if his bike was
> flexing a lot. I told him that with a rock-solid bike you can be happy
> banging around in the roughest crowd or the roughest course. If he
> gets a stiff bike I'm sure he'll eat it up and enjoy the packs.
>
> I had a slightly flexy Trek 760 (24" thinwall tube) once that I just
> could NOT ride in a pack with---not road race or crit or even big
> training ride. It scared me. It was light and nice for TT's and solo
> rides, though. But I could muscle thru anything on my Pro Miyata tank.
> It made all the difference. To me, a solid bike meant happy racing and
> close-pack elbow-bump riding or not doing it at all. Also, the Miyata
> was my only race bike that never shimmied on big downhills. I'm
> 6-1/170.
>
> Anyway, is anyone finding that these new carbon compacts are flexy? Or
> that they shimmy on downhills? I thought offhand that they'd be
> stiffer yet than my old tank. Is it just a seatpost issue? What about
> new-fangled wheels? --I think his have carbon blade 12-spokes or
> something like that. Do big guys need stronger wheels? I used to need
> a 14-ga rear wheel to hold up. A 15-ga would warp in a week. How stiff
> are the new wheels laterally? I've never raced a new-era bike, so am
> wondering how they might differ. Thanks.
>
> --JP
> outyourbackdoor.com

After reading your post earlier in the day, I got on the rollers and flipped
on the 2004 TdF DVD. I happened to watch the stage just before Alpe de Huez
where Ullrich went on his long breakaway. Of course, Ullrich was on his
Giant compact carbon frame. There was a long descent before the last 2
climbs and Jan almost went off the road twice in turns. Now, he's not known
for his descending skills, but Phil and Paul had just been saying how much
he'd improved. Then Paul started talking about the wheels Jan was using.
They were what used to be called ADA wheels. I don't recall what they're
called now. They have very deep carbon rims. Paul said that those rims are
super stiff and super light so they can be very hard to control through
high-speed turns.

FWIW,

Bob C.

 

[[email protected]]

I 'd be inclined to look to really poor fit (seat post and top-tube
stem length).
Personally I've got nothing good to say about compact frames but overly
flexable is not one of the complaints I've heard.

 

[John Rees]

"psycholist" <[email protected]> wrote in message news:[email protected]...
| After reading your post earlier in the day, I got on the rollers and flipped
| on the 2004 TdF DVD. I happened to watch the stage just before Alpe de Huez
| where Ullrich went on his long breakaway. Of course, Ullrich was on his
| Giant compact carbon frame. There was a long descent before the last 2
| climbs and Jan almost went off the road twice in turns. Now, he's not known
| for his descending skills, but Phil and Paul had just been saying how much
| he'd improved. Then Paul started talking about the wheels Jan was using.
| They were what used to be called ADA wheels. I don't recall what they're
| called now. They have very deep carbon rims. Paul said that those rims are
| super stiff and super light so they can be very hard to control through
| high-speed turns.

Those ADA wheels were hand built, and are probably several years old at this point.
Not to mention, the wheels probably cost more than the entire bike the OP was referring to.
You aren't going to be seeing these wheels on any stock Giant or any stock bike of any type.

As to the frame. Guys I know who ridden the compact Giant frames like the stiffness.
The place where you're gonna feel anything is in the long seatpost they often require.

 

[david]

If the seatpost is a low quality post - I'd try upgrading it to a thomson.
The flex is most likely caused by a undersized compact frace with too much
seat post sticking out with a crappy aluminum post.

good luck

david

 

[Jeff Potter]

So do you think the main problem would be the "bad fit." I suspect the
guy has the bike fitting perfectly---but he may be starting with an
overly small frame. That is, maybe he has a superlong seatpost and
superlong stem. Would that do it?

He's a 6-3 guy riding a bike that originally belonged to a 5-10 guy.
Now, the shorter guy does have just about the most stretched out
riding position known to man, so maybe our new tall guy didn't need a
much longer stem, if at all. But he probably raised the seat another
2-3" inches.

Anyway, I used to ride a somewhat small frame with tallish post and
longish stem and this never resulted in the slightest amount of
flex---but it wasn't the new stuff, it was that old 82 Pro Miyata
tank.

The only bike that ever 'wandered' for me in pack-riding was that
thinwall Trek.

--JP