Chinese carbon frame and wheels thread

clydesmcdale
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Re: Chinese carbon frame and wheels thread

Postby clydesmcdale » Wed Sep 19, 2012 10:41 am

azeng97 wrote:
wow that's really nice :) any more comments on how it rides?
Took it on the first River Loop this morning. Have now got it fitted and tuned how I like it, with the exception of a dropped chain this morning. Rotated the bars up a little from what is shown in the photos. Fit feels good now. Will keep the steerer tube uncut for a bit longer until I’m certain it’s right. Replaced the rubbish squealing brake pads that came with the wheels with a set of Swissstop Yellow Carbon specific pads. Braking is much quieter now and stopping is good. Still getting a little slip on the seat tube. It had been torqued to around 8nm with carbon paste and was not moving, till I adjusted it manually out on the road without my torque wrench, now it has dropped. There’s no nominated torque setting for the seat tube clamp, so I’m trying to be careful.

As for the ride, it feels more comfortable than my CAAD10, but not significantly so. The sound of a carbon frame is very different to the CAAD10 alloy too. Sounds a bit plastic, but I’m told that’s normal. After the 40km or so this morning I feel fresh and not battered around. It’s much more nimble in short sharp climbing.

Haven’t done any big climbs as yet as. I prefer to do big climbs and big descents with the lighter alloy wheels I have. Maybe tomorrow morning I’ll go up Mt Gravatt for a climbing test with the alloys on. It’s a good 2kg lighter than the CAAD10 too, so that should help.

Certainly rolls quicker down-hill, but the biggest difference is on the flat at speed. With the 50mm carbon wheels and the aero frame, when I’m in the drops, I feel as if I’ve got power in reserve when travelling over 40km/h. Acceleration from say 30 to 40 feels much more effortless. Jumping out of the saddle above 50km/h yesterday felt good and if I wasn’t so sloppy on the gear changing I’d have broken 60km/hr with not too much trouble.

Pretty happy with the frame and wheels, and i think it goes without saying the Super Record drive train is superb.

Crawf
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Re: Chinese carbon frame and wheels thread

Postby Crawf » Wed Sep 19, 2012 12:09 pm

clydesmcdale wrote:
Took it on the first River Loop this morning. Have now got it fitted and tuned how I like it, with the exception of a dropped chain this morning. Rotated the bars up a little from what is shown in the photos. Fit feels good now. Will keep the steerer tube uncut for a bit longer until I’m certain it’s right. Replaced the rubbish squealing brake pads that came with the wheels with a set of Swissstop Yellow Carbon specific pads. Braking is much quieter now and stopping is good. Still getting a little slip on the seat tube. It had been torqued to around 8nm with carbon paste and was not moving, till I adjusted it manually out on the road without my torque wrench, now it has dropped. There’s no nominated torque setting for the seat tube clamp, so I’m trying to be careful.

As for the ride, it feels more comfortable than my CAAD10, but not significantly so. The sound of a carbon frame is very different to the CAAD10 alloy too. Sounds a bit plastic, but I’m told that’s normal. After the 40km or so this morning I feel fresh and not battered around. It’s much more nimble in short sharp climbing.

Haven’t done any big climbs as yet as. I prefer to do big climbs and big descents with the lighter alloy wheels I have. Maybe tomorrow morning I’ll go up Mt Gravatt for a climbing test with the alloys on. It’s a good 2kg lighter than the CAAD10 too, so that should help.

Certainly rolls quicker down-hill, but the biggest difference is on the flat at speed. With the 50mm carbon wheels and the aero frame, when I’m in the drops, I feel as if I’ve got power in reserve when travelling over 40km/h. Acceleration from say 30 to 40 feels much more effortless. Jumping out of the saddle above 50km/h yesterday felt good and if I wasn’t so sloppy on the gear changing I’d have broken 60km/hr with not too much trouble.

Pretty happy with the frame and wheels, and i think it goes without saying the Super Record drive train is superb.
I'm building the same frame up at the moment, so haven't suffered the seat post drop issue yet, but I have read about it on this frame. I noticed that sliding the seat post down was super tight so hopefully I wont have that issue.
Try some hair spray on the seat post to increase the tackiness if it continues to slip.

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RobM
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Re: Chinese carbon frame and wheels thread

Postby RobM » Wed Sep 19, 2012 12:51 pm

PawPaw wrote:jheeno, the wobble was classic death wobble, where the front end starts wobbling side to side, then it progressively increases and transfers through the whole frame. The front wheel continues to go through a reasonably straight trajectory. As I said, it was so severe the water bottle was thrown out of its bidon.

I have the same skewers, and I am always careful to tighten them properly, because loose skewers has caused excessive lateral wheel movement in the past.
The wobble has never happened with my heavier wheels so I don't think it is purely the frame.

I'm going to buy a set of alloys around 1500-1600g, and use them for longer rides, and keep the CCs for flat club rides and racing.
I am interested to hear what my mechanic says, and will report it here.
Any feedback from your mechanic? Am thinking of investing in a set of 38mms but want to do more climbing (inc Cootha). Dont want to encounter the same problem as you :shock:
Currently dont experience even a tremble on the Wilier with Fulcrum R5s coming down Cootha front at 65km/h.

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Re: Chinese carbon frame and wheels thread

Postby Crawf » Wed Sep 19, 2012 4:38 pm

punk_rob wrote:
PawPaw wrote:jheeno, the wobble was classic death wobble, where the front end starts wobbling side to side, then it progressively increases and transfers through the whole frame. The front wheel continues to go through a reasonably straight trajectory. As I said, it was so severe the water bottle was thrown out of its bidon.

I have the same skewers, and I am always careful to tighten them properly, because loose skewers has caused excessive lateral wheel movement in the past.
The wobble has never happened with my heavier wheels so I don't think it is purely the frame.

I'm going to buy a set of alloys around 1500-1600g, and use them for longer rides, and keep the CCs for flat club rides and racing.
I am interested to hear what my mechanic says, and will report it here.
Any feedback from your mechanic? Am thinking of investing in a set of 38mms but want to do more climbing (inc Cootha). Dont want to encounter the same problem as you :shock:
Currently dont experience even a tremble on the Wilier with Fulcrum R5s coming down Cootha front at 65km/h.
Could be allot of factors at play here.
I know that my front 38mm CC's are far more planted and better through the corners than my Pro Lite 30mm alloy rims going down Coot tha - so my feelings are quite the opposite. Braking is another matter though :P

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nickobec
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Re: Chinese carbon frame and wheels thread

Postby nickobec » Wed Sep 19, 2012 6:01 pm

No issues with my 38mm CCs on the Del Park Road descent, pushing it at 60kmh to catch the guys in front and not get caught. Or braking suddenly because it looked like the guy in front went into the gravel.

My 60mm CC front scared me big time on a shorter descent at 50kmh when it caught a crosswind, also not so happy hard braking on that rim.

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PawPaw
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Re: Chinese carbon frame and wheels thread

Postby PawPaw » Wed Sep 19, 2012 7:30 pm

clydesmcdale wrote:Maybe tomorrow morning I’ll go up Mt Gravatt for a climbing test with the alloys on. It’s a good 2kg lighter than the CAAD10 too, so that
word of warning.....be very very careful to build your speed up with the 50mm CCs. The first descent I had down the front of Coot-tha I got massive death wobbles. I kid you not, it was the most scarey 20 seconds in my riding life, and I honestly resigned to diving into the bitumen at 65+kph.

The expert opinion is the light front wheel is the culprit. My Trek doesn't get death wobble with my other 2 wheelsets, just the Farsport 50mm carbon clinchers.
Not saying you will get it, but you want to experiment conservatively to find out.
I weigh 84kg and the wobble was so strong it tossed my water bottle out of the bidon.

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twizzle
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Re: Chinese carbon frame and wheels thread

Postby twizzle » Wed Sep 19, 2012 8:18 pm

PawPaw wrote:
clydesmcdale wrote:Maybe tomorrow morning I’ll go up Mt Gravatt for a climbing test with the alloys on. It’s a good 2kg lighter than the CAAD10 too, so that
word of warning.....be very very careful to build your speed up with the 50mm CCs. The first descent I had down the front of Coot-tha I got massive death wobbles. I kid you not, it was the most scarey 20 seconds in my riding life, and I honestly resigned to diving into the bitumen at 65+kph.

The expert opinion is the light front wheel is the culprit. My Trek doesn't get death wobble with my other 2 wheelsets, just the Farsport 50mm carbon clinchers.
Not saying you will get it, but you want to experiment conservatively to find out.
I weigh 84kg and the wobble was so strong it tossed my water bottle out of the bidon.
Methinks you should do your own research rather than relying on "expert opinion". Not saying it wasn't triggered by your wheel, but there are a stack of factors involved with speed wobbles.
I ride, therefore I am. But don't ride into harm's way.
...real cyclists don't have squeaky chains...

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PawPaw
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Re: Chinese carbon frame and wheels thread

Postby PawPaw » Wed Sep 19, 2012 10:36 pm

twizzle wrote:Methinks you should do your own research rather than relying on "expert opinion". Not saying it wasn't triggered by your wheel, but there are a stack of factors involved with speed wobbles.
My mechanic/wheelbuilder reckons it is very likely the lighter wheel weight when combined with
- my bodyweight (84kg, 187cm) and position on bike (I had my saddle very forwards from a TT set up).
- the fork angle, rake, and trail (I have a Trek Madone 4.7 with the more relaxed H2 geometry (taller headset).
- larger 58cm frame with seat quite high.

As I said, I've not had the issue with other wheelsets.
A cycling mate is also an automotive engineer who was at the top of his game for decades (motorcycle and F1). He agrees the wheel weight is the most likely explanation, esp considering it doesn't happen with 2 other wheelsets that are heavier.

Anyway, my experience in no way implies the wheels are bad. I've run these wheels down the Gateway Bridge at close to 60kph and not had an issue.
I think the thing about Coot-tha frontside is there's a slight left hand turn just down from the Kiosk where you build speed rapidly. And leaning into the left hander may have started the wobble. On my previous bike, I had wobble twice, both times were when I was accelerating rapidly on curved descents.

I'd suggest anyone with any new wheel set test them carefully on descents - build the speed sequentially over repeats on straight and curved descents.

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bosvit
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Re: Chinese carbon frame and wheels thread

Postby bosvit » Thu Sep 20, 2012 9:35 pm

Paw Paw could you have copped a wind gust at the wrong time?

My Giant Defy Advanced never got the death wobbles until I got a set of 34mm 1.5kg aluminium clinchers. And then it only got the wobbles when descending and I got hit by a side gust. Used to freak the daylights out of me and every time there were bumps or side wind I would tense up and cause the wobbles myself!

It has taken 6 months on the Cannondale Supersix to get the confidence up to attack descents again. Same wheels but less inclined to death wobbles.

Are your other wheels deep profile rims?

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Re: Chinese carbon frame and wheels thread

Postby twizzle » Fri Sep 21, 2012 11:45 am

I ride, therefore I am. But don't ride into harm's way.
...real cyclists don't have squeaky chains...

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Re: Chinese carbon frame and wheels thread

Postby PawPaw » Fri Sep 21, 2012 11:59 am

Bos, it was a perfectly still day.
Twiz, I've read all that, and more. There's some nice utube stuff too, and an excellent one by Murray Walker discussing the same problem with motorbikes.
I'm going to borrow two wheelsets from mates and test on the same hill. I really want to get total confidence back in my frame and forks. I also put my saddle back to a more conventional position.

Baldy
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Re: Chinese carbon frame and wheels thread

Postby Baldy » Fri Sep 21, 2012 12:39 pm

Yeah Twizzle, what were you thinking man!!!

It could not possibly be from user error :lol:

Panic does interesting things to a persons recollection :wink:

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Ross
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Re: Chinese carbon frame and wheels thread

Postby Ross » Fri Sep 21, 2012 3:37 pm

twizzle wrote:Linky 1.
Linky 2.
Interesting articles. My TT bike gets a bit of a wobble going at about 65km/h but it has Zipp wheels and were the same wheels I had on my previous TT bike.

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Re: Chinese carbon frame and wheels thread

Postby twizzle » Fri Sep 21, 2012 3:52 pm

Baldy wrote:Yeah Twizzle, what were you thinking man!!!

It could not possibly be from user error :lol:

Panic does interesting things to a persons recollection :wink:
Dunno about user error, but 'lighter wheels' should equal "less centrifical force", so it's more likely that the frame isn't stiff enough in torsion rather than the fault of a wheel. Ah, carbon - horizontally stiff and vertically compliant... and sometimes as flexy as a wet noodle.
I ride, therefore I am. But don't ride into harm's way.
...real cyclists don't have squeaky chains...

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Re: Chinese carbon frame and wheels thread

Postby PawPaw » Fri Sep 21, 2012 7:18 pm

Baldy wrote:Yeah Twizzle, what were you thinking man!!!

It could not possibly be from user error :lol:

Panic does interesting things to a persons recollection :wink:
hahaha. gee you're a mountain of knowledge Baldy.

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PawPaw
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Re: Chinese carbon frame and wheels thread

Postby PawPaw » Fri Sep 21, 2012 7:23 pm

twizzle wrote:Dunno about user error, but 'lighter wheels' should equal "less centrifical force", so it's more likely that the frame isn't stiff enough in torsion rather than the fault of a wheel. Ah, carbon - horizontally stiff and vertically compliant... and sometimes as flexy as a wet noodle.
Why would frame torsion vary between wheelsets?

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twizzle
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Re: Chinese carbon frame and wheels thread

Postby twizzle » Fri Sep 21, 2012 9:18 pm

PawPaw wrote:
twizzle wrote:Dunno about user error, but 'lighter wheels' should equal "less centrifical force", so it's more likely that the frame isn't stiff enough in torsion rather than the fault of a wheel. Ah, carbon - horizontally stiff and vertically compliant... and sometimes as flexy as a wet noodle.
Why would frame torsion vary between wheelsets?
It doesn't - read link 1 again. Maybe your wheel has some lateral flex, or you hit a stone, or there was a gust of wind... after that, it was the frame.
I ride, therefore I am. But don't ride into harm's way.
...real cyclists don't have squeaky chains...

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Re: Chinese carbon frame and wheels thread

Postby Baldy » Fri Sep 21, 2012 10:22 pm

PawPaw wrote:
Baldy wrote:Yeah Twizzle, what were you thinking man!!!

It could not possibly be from user error :lol:

Panic does interesting things to a persons recollection :wink:
hahaha. gee you're a mountain of knowledge Baldy.
I am full of something :mrgreen:

I have had it happen once. On my steel touring bike, fully loaded coming down Bust me gall hill on the east coast here. The wind started it, the speed kept it going and increased it. If you try and chase the wobble at this point you will just make it worse, I knew this from motorbikes. You need to un-weight the saddle and have soft hands on the bars, enough to hang on but not more. Trail the rear brake if you need to reduce speed.

Its pretty unsettling, specially if its your first time tankslappin :lol: You are forgiven for carping yourself :wink:

My point I dont think its got a lot to do with light wheels. It happens on different bikes for various reasons and is made worse by the nut attached to the handlebar...

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Re: Chinese carbon frame and wheels thread

Postby beij » Sun Sep 23, 2012 8:54 am

http://i1251.photobucket.com/albums/hh5 ... 65b2f1.jpg" onclick="window.open(this.href);return false;

Had my first ride on the new wheels, got the 38mm tubulars with ceramic bearings from FarSports. They are way stiffer than my Stan's Alphas and lighter (AT) 1096grms with skewers. I haven't done any timings but feels faster and accelarate at least on par with the Alphas. Total cost was $646 including shipping so very happy with the purchase. All up brings the total weight down to 14.5 pounds. I have to say it was a pain installing the tyres - literally. Nearly lost a thumbnail. Probably due to my little thumbs so will definately get my lbs to do it next time. Never ridden tubulars before so looking forward to the regular group ride to compare, have injected the recommended 2oz of Stans so hopefully won't get too many flats. I have also changed the stem to a Ritchey WCS, noticeable improvement in stiffness and confidence descending.

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Re: Chinese carbon frame and wheels thread

Postby Magpie » Sun Sep 23, 2012 9:55 am

Some thoughts on speed wobbles
Tank slappers/ speed wobbles occur when the natural frequencies of all components coincide =resonance frequency
But generally the system needs some trigger to get the whole thing moving
On a bike this could be a bump,wind gust or swerve

Small forces at resonate frequencies can produce large motions,
As an example it only needs a small effort pushing a swing to produce a large oscillating motion which is hard to stop.


Natural frequencies are predominantly determined by geometry but are affected by stillness,mass and damping

Crawf
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Re: Chinese carbon frame and wheels thread

Postby Crawf » Mon Sep 24, 2012 9:10 am

Finished my FM098 build, just need some time to ride it - http://www.bicycles.net.au/forums/viewt ... 41#p856841" onclick="window.open(this.href);return false;

mike95
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Re: Chinese carbon frame and wheels thread

Postby mike95 » Thu Sep 27, 2012 10:38 am

Well I have had my Farsport 50mm clinchers on for a week & have a few rides on them now.

I have 2 issues with them .

I have bad rear brake pulse / vibration when braking. ( only on the rear )
The front end feels a bit twitchy & nervous over undulations/ road surface changes.


I havent ridden them yet in strong winds but even light winds seem to make the bike feel unstable.
I am really cautious with these wheels when descending down hills.
I dont have the confidence yet to bomb down the descents.

Previously i had mavic aksium wheels on the bike & it felt much more stable & predictable on descents.


Now im attributing the rear brake pulse to a slightly uneven surface on the brake track.
Im using the supplied blue pads.

The twitchy front end has me a bit stumped. Could it be the reduction in weight?


Otherwise the wheels are great on the flats, & really fly.
Image

clydesmcdale
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Re: Chinese carbon frame and wheels thread

Postby clydesmcdale » Thu Sep 27, 2012 2:02 pm

mike95 wrote:Well I have had my Farsport 50mm clinchers on for a week & have a few rides on them now.

I have 2 issues with them .

I have bad rear brake pulse / vibration when braking. ( only on the rear )
The front end feels a bit twitchy & nervous over undulations/ road surface changes.


I havent ridden them yet in strong winds but even light winds seem to make the bike feel unstable.
I am really cautious with these wheels when descending down hills.
I dont have the confidence yet to bomb down the descents.

Previously i had mavic aksium wheels on the bike & it felt much more stable & predictable on descents.


Now im attributing the rear brake pulse to a slightly uneven surface on the brake track.
Im using the supplied blue pads.

The twitchy front end has me a bit stumped. Could it be the reduction in weight?


Otherwise the wheels are great on the flats, & really fly.

Got the same issue with pulsing in my front wheel. Blade X 50mm Clincher (made by Farsports, sold under a different banner)
The wheel is in the LBS now seeing if it can be rectified. Initial inspection potentially shows a 1mm out of true. Can certainly feel the pulsing when braking, more prominent when slowing to a stop.

Will report back on what they've done and whether it can be rectified.

mike95
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Re: Chinese carbon frame and wheels thread

Postby mike95 » Thu Sep 27, 2012 3:54 pm

clydesmcdale are you using the supplied brake pads?
Im using the ones that came with the wheels that look a bit like the reynolds Blue Pads, but are probably a inferior pad.

Im considering trying some different pads, either Swiss Stop yellow or Zipp cork to try a remedy the brake pulse.
Also going to have the lbs take a look & check the trueness of the wheel & brake surface.
Image

clydesmcdale
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Re: Chinese carbon frame and wheels thread

Postby clydesmcdale » Thu Sep 27, 2012 4:17 pm

mike95 wrote:clydesmcdale are you using the supplied brake pads?
Im using the ones that came with the wheels that look a bit like the reynolds Blue Pads, but are probably a inferior pad.

Im considering trying some different pads, either Swiss Stop yellow or Zipp cork to try a remedy the brake pulse.
Also going to have the lbs take a look & check the trueness of the wheel & brake surface.
They supplied me with generic brown things that;
1. didn't have a slot in the back specific to campy so slid out if waiting on a hill and olled backwards, and;
2. disentegrated very quickly
3. squealed very loudly

After less than a 100km i've changed to Swissstop Yellow Carbon specific. Stops the bike nicely, without squealing, but i'm still getting the pulsing. Possibly partly due to the residue it leaves on the brake track inconsistently around the rim.
Just got a message that the bike is ready, so i'll pick it up shortly. Have also got some zipp cork pads on order from wiggle, just in case.

Edit: Got the wheel back now. Mech at the LBS did an inspection on the rim surface, checked the spoke tension etc and cleaned off the brake pad residue.
First issue, held up to the light and spinning the wheel he said he could see some inconsistencies in the carbon. Some areas of the weave are closer to the surface than others, whilst not a cause for the pulsing, something to keep an eye on.
Second, the wheel did have a slight buckle and he trued it a bit to take some of it out, but it's not completly gone. Said the nipples they used are soft and easily rounded off when adjusting. Did what he could, but suggested replacing the nipples if it becomes a further issue. Qualified that the wheel is safe, fine to ride and not likely to get any worse.
Third, the residue was adding to the pulsing effect and suggested I clean it regularly with non-acetone based cleaner.

Will ride this evening and tomorrow morning. The pulsing was really never that bad to begin with, just slightly annoying. I'd think with what has been done and possibly trying the cork pads it will be less of an issue.

If I had dropped upwards of a thousand dollars or more, I'd be rightly pissed. But with what I payed (around $450 delivered) I'm not expecting pristine quality and am happy enough with what I've got.

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