50mm Carbon Clinchers...500 mile review pg. 7

Discuss light weight issues concerning road bikes & parts.
AZR3
Posts: 688
Joined: Wed Sep 12, 2012 9:00 pm
Location: Az USA

by AZR3

Did my first mountain descent this morning and wheels/tubes didn't explode lol
Braking obviously was not as good as my alu wheels but being cautious on my first descent everything went well. Then I pushed it a bit the second time down and giving the brake levers a couple quick grabs drops enough speed without over heating brake track, just the really steep stuff can be a bit scary.
I still have the pulsing issue but its really only a problem at slow speeds.

User avatar
roadytracky
Posts: 94
Joined: Fri Sep 21, 2012 3:58 am
Location: Southern California

by roadytracky

AZR3 - Thanks for the review. I'm seriously considering the Farsports 38's, 50's, or 60's so this is a very helpful thread.

Your Cervelo looks great. Apologize for veering off-topic, but, how do you like your C7 brakes? I've been considering them for the weight and quick-release, but some of the posts comparing C7's with Planet-X's bash the C7's. I see there's quite a passionate WW Planet-X fan club so I have to take the posts with a bigger "grain of salt" than usual. Thanks.

by Weenie


AZR3
Posts: 688
Joined: Wed Sep 12, 2012 9:00 pm
Location: Az USA

by AZR3

The C7s are nice and light but they do flex a little. With that being said I'm 160lbs so not a lot of weight to stop, if you're a lot heavier they might not be a good choice. Another thing is I think the Planet X are single pivot vs the C7s dual pivot, never had a problem with having them needing to be re-centered although I've read that as a common complaint for the Planet X.

Then you have the price, Planet X being much cheaper.

If I had to choose I'd buy the C7s again.

User avatar
roadytracky
Posts: 94
Joined: Fri Sep 21, 2012 3:58 am
Location: Southern California

by roadytracky

Nice. Thanks.

addictR1
Posts: 1350
Joined: Sun Jun 10, 2012 1:11 am

by addictR1

AZR3: the pulsing issue you mentioned, I read through all the posting here on this thread and didn't hear people mention it on the 50cm version. could it be it's stiffer on the 50cm as compared to the 38cm version?

anyone descending with a 50cm care to chime in?

AZR3
Posts: 688
Joined: Wed Sep 12, 2012 9:00 pm
Location: Az USA

by AZR3

addictR1 wrote:AZR3: the pulsing issue you mentioned, I read through all the posting here on this thread and didn't hear people mention it on the 50cm version. could it be it's stiffer on the 50cm as compared to the 38cm version?

anyone descending with a 50cm care to chime in?


This is my first experience with carbon wheels and in all the threads I read about these wheels pulsing rarely came up and when it did no one seemed to have an answer. Other searches I've done mentioned switching brake pads sometimes helped. I'm going to try Reynolds blue pads to see if they help, I'll report my finds.

addictR1
Posts: 1350
Joined: Sun Jun 10, 2012 1:11 am

by addictR1

ok.. hopefully the new pads will fix the pulsing.

i was discussing it with my friend over Togos today about it and they said it could be because of overheating so the pad doesn't seem to grip as evenly on the braking surface?

or, they suggested maybe the pad is too soft, so it's gripping too good or too sticky to the braking surface.

eric
Posts: 2196
Joined: Tue Nov 11, 2003 9:47 pm
Location: Santa Cruz, California, USA
Contact:

by eric

I have some rims that pulse. It's because the rim width at the braking surface varies. I measured some rims that pulse and some that don't, and the ones that pulse have greater variance in width.

One of my 50mm FarSports pulses a little. The 24mm FarSport tubulars are dead smooth.

I think that it's due to individual production variation- for example some of my KinLin XR270s pulse and some don't. I had some pulsing Open Pros back when I used them.

If it's rim width like I think, then theoretically one could gently sand down the thicker parts. I've never heard of someone trying that so I'd want to experiment on cheap rims. And keep in mind that you could be thinning the rim walls and making the rim weaker. Measuring the inside and outside of the rim walls would tell.


I did the Everest Challenge stage race this weekend. It features very long climbs and long high speed descents. In the past I have had trouble keeping up on the fast straight descents since I am tall but light. I used the wheels I built on the 50mm clinchers. This is the first time in this race that no one has passed me on the high speed parts. I had no trouble keeping up with the riders in my field and even gapped the group I was with on a couple descents. I'm sure there are more aero rims but I was quite happy with the FarSports rim's performance, especially for the price and weight.

plpete
Posts: 534
Joined: Thu Dec 22, 2011 12:39 pm
Location: DC

by plpete

How was prolonged breaking with the higher speeds?

AZR3
Posts: 688
Joined: Wed Sep 12, 2012 9:00 pm
Location: Az USA

by AZR3

plpete wrote:How was prolonged breaking with the higher speeds?


That's something I tried to avoid, just hit the brake hard a few times to scrub speed before final braking for the corner. The only time I got on the brakes hard for a prolonged time the pads started screaming but braking was still consistent, but I was afraid of glazing the pads as I still had a few miles of the descent left so didn't do that again.

eric
Posts: 2196
Joined: Tue Nov 11, 2003 9:47 pm
Location: Santa Cruz, California, USA
Contact:

by eric

I went over 50 mph both days but from a brake heat standpoint the race is the least risky of any I've done. There aren't many turns that require braking and most of those are fast so you don't need to slow much.


I was pleased with my descending speed, and since the wheels are the only major change on the bike since the last time I did the race, I think they were much of the improvement.

AZR3
Posts: 688
Joined: Wed Sep 12, 2012 9:00 pm
Location: Az USA

by AZR3

eric wrote:I went over 50 mph both days but from a brake heat standpoint the race is the least risky of any I've done. There aren't many turns that require braking and most of those are fast so you don't need to slow much.


I was pleased with my descending speed, and since the wheels are the only major change on the bike since the last time I did the race, I think they were much of the improvement.


That was one of the worries I had/have with new wheels, you never know how they're going to behave Ina fast descent. I've read in a few threads about high speed "death wobbles" with these wheels. Now the situations weren't full explained (winds, road conditions etc) and any wheel can wobble at high speeds. So far I've maxed mine at 45mph and they were only very slightly less stable than my alu wheels but there was no hint of wobble at all. My handle bars just seemed a little more sensitive to road conditions.

eric
Posts: 2196
Joined: Tue Nov 11, 2003 9:47 pm
Location: Santa Cruz, California, USA
Contact:

by eric

They are more sensitive to side winds and more prone to shimmy than low profile wheels. My bike shimmied all the way down the descent after the first stage. I was wearing a heavy jacket and the sleeves flapping were enough of an input to get the bike to shimmy. Being dead tired probably didn't help. But the shimmy was not strong- I could damp the shimmy with knees on the top tube or by bending my elbows so the sleeves didn't flap so much.

The bike was stable during race descents.

Roger9
Posts: 9
Joined: Thu Sep 13, 2012 9:19 am

by Roger9

I'm keen to get opinions on the effect of reduced wheel weight on rolling speed. I'm currently on fast forward 40/60 combo coming from long time mavic SL usage. I was sceptical about te FF wheels given they are almost 400g heavier, but in the real world the FF are a faster wheel. A bit slower to spin up but so much easier once up and rolling.
Even on the uphills I really don't feel the extra weight, but like the added stiffness at the rear.

I've been researching this thread for a while and find the prospect of the farsport 50M clincer very appealing at around 1300g. My main concern is that they may roll a little slower on th flats due to reduced inertia/momentum of the lighter rims.

Is my concern unfounded? I'd appreciate any feedback...

by Weenie


User avatar
prendrefeu
Posts: 8610
Joined: Wed Oct 31, 2007 10:32 pm
Location: Los Feliz, Los Angeles, California
Contact:

by prendrefeu

Roger9, there's plenty of threads that cover/debate the merits of weight vs. aero, inertia issues and so on. Try doing a search for 'inertia' or 'momentum' or 'light wheels aero vs.' and see what comes up.
Exp001 || Other projects in the works.

Post Reply
  • Similar Topics
    Replies
    Views
    Last post