HOT: Active* forum members generally gain 5% discount at starbike.com store!
Weight Weenies
* FAQ    * Search    * Trending Topics
* Login   * Register
HOME Listings Blog NEW Articles FAQ Contact About




Post new topic Reply to topic  [ 21 posts ] 
Go to page 1, 2  Next
Author Message
PostPosted: Sat Mar 14, 2015 9:30 pm 
Offline

Joined: Sat Mar 14, 2015 9:22 pm
Posts: 2
Hi

I am getting my LBC to do a wheelbuild for me using Pacenti Sl23 rims with Tune Mig 70 and Mag 170 hubs and Sapim CX-Ray spokes.

I weigh around 76kg (first thing in the morning). The wheels will be used for spring, summer and autumn use for hilly rides or sportives. Generally I would not expect to use them in grotty conditions – however a lot of the roads round my way are pretty in crap condition. I am looking to keep them as light as possible without compromising robustness and or power transfer / getting load of break rub.

I was hoping to get away with a 20 spoke radial front wheel. Regarding the rear hub I am not sure whether 24 is OK or whether I should go for a 28 spoke build. As for best spoke pattern in radial non drive side OK.

I would be grateful for any advice from you good souls on spoke count and patterns.


Top
 Profile  
 
PostPosted: Sat Mar 14, 2015 9:59 pm 
Offline
User avatar

Joined: Fri Dec 11, 2009 10:38 pm
Posts: 1207
Location: Toronto
I'm heavier than you at closer to 90 kg. IME 20 Radial on front has been fine. My Pacentis are 28 spoke rear and I'm more in favor of a 2x both sides build as it spreads the driving load better. I also have 24 spoke rear wheels that have held up fine, but 28 is the more conservative choice.

_________________
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM


Top
 Profile  
 
Posted: Sat Mar 14, 2015 9:59 pm 


Top
  
 
PostPosted: Sun Mar 15, 2015 12:49 am 
Offline

Joined: Thu Jul 25, 2013 6:42 am
Posts: 141
Location: Copenhagen
First of all, you should have posted this in the wheels section.

Regarding your question, you need to choose between 20/24, 20/28 or 24/28 spokecount.

If you're 76 kg and riding on bad roads, I wouldn't recommend 20/24.

24/28 is the sure bet, and the difference is less than 20 grams between 20/28 and 24/28. I would choose 24/28, and build them 3x rear (both sides) and 2x front. In that case you still have a very light and very robust wheelset, with many many problem free kms.


Top
 Profile  
 
PostPosted: Sun Mar 15, 2015 12:51 am 
Offline

Joined: Tue Nov 11, 2003 9:47 pm
Posts: 1910
Location: Santa Cruz, California, USA
How hard are you on wheels? I'm 66kg but I build my training wheels 28h (on Kinlin XR270s). I'm hard on rear wheels- I do a lot of climbing, a lot of steep climbs in low gear, and a lot of standing on climbs. All those stress the rear wheel. If you do not have a history of breaking spokes and cracking rims, you can probably be ok with 24h. But four CXrays with nipples weigh 20g. That is a small price to pay for added reliability. Are you prepared to do a field retrue so you can ride home when you break a spoke?

Either one will have plenty of "power transfer".

I prefer 2x to radial on the rear NDS. It will result in a better average bracing angle than radial heads out, making a laterally stiffer and thus stronger wheel.


Top
 Profile  
 
PostPosted: Sun Mar 15, 2015 8:50 am 
Offline

Joined: Thu Mar 26, 2009 11:06 pm
Posts: 234
Location: Yorkshire - God's Own Country
Radial front is fine but I'd go 2x both sides at the rear. You'd likely be fine with 20/28 but 24/28 would give a larger margin of security and thus peace of mind.


Top
 Profile  
 
PostPosted: Sun Mar 15, 2015 10:52 am 
Offline

Joined: Mon Jul 11, 2011 11:06 am
Posts: 221
Location: North Adelaide, South Australia
I'm kinda of like eric in terms of being hard on wheels, similar weight at 70. I seem to have a talent for breaking spokes on new factory wheels, handbuilts - just wheels period. I wen't 20/24 and in retrospect would have gone 28 on the rear for more security. One thing that is great about the Pacenti's is that when I've broken spokes, the build is so stiff that you can get home without having to open up the brake callipers. They are my only wheel-set for both training racing (down under cat2 equiv.)

_________________
Norwood & Adelaide Uni CC


Top
 Profile  
 
PostPosted: Sun Mar 15, 2015 12:50 pm 
Offline

Joined: Thu Jan 08, 2004 10:11 pm
Posts: 734
I have 3 wheelsets with radial lacing nds. Two have 28 spokes and were manually built. They are both very flimsy, I can definately feel this when cornering hard.
The third one is an Easton EC90 RT (20/24) and it is stiffer then the handbuilt ones, but still not as stiff as my other wheelsets that have 2 or 3x lacing nds.

I would not recommend radial lacing nds. The difference in weight between radial and 2x is insignificant.

I have a set of Pacenti SL23 laced up with Hope Mono RS hubs and 20/24 Sapim CX Ray/Sprint spokes. The rear is laced 2x both sides and the front radially. I would have liked 2x front too, but I bought them secondhand, so didn't have much choice. Both front and rear are very stiff, so I can't fault them. But for peace of mind I would have propably gone for 24/28 and 2x lacing all round.

I weigh 70kg.


Top
 Profile  
 
PostPosted: Sun Mar 15, 2015 1:18 pm 
Offline

Joined: Sat Jun 16, 2012 3:12 am
Posts: 271
+1 on 2x lacing all around and 24/28 for longevity/durability. That is what i would do; i weigh about the same (76kg). I also would do Laser spokes at 1/3 the cost since there is no point in squeezing any miniscule aero benefit from spokes laced to a shallow rim IMO. Unless you want cx ray for aesthetics.


Top
 Profile  
 
PostPosted: Sun Mar 15, 2015 1:43 pm 
Offline

Joined: Sat Mar 14, 2015 9:22 pm
Posts: 2
Thanks for the replies - some good advice there.

Apologies for posting in the wrong spot - thanks to who ever moved the thread.


Top
 Profile  
 
PostPosted: Tue Mar 17, 2015 6:28 am 
Offline

Joined: Fri Jun 19, 2009 6:46 am
Posts: 18
I was tossing up the same issue re spoke count on a wheelset as you but went with HED Belgiums, not the Panceti but have heard great things about these rims.

I was tossing up between a 20/24 or a 24/28 build with radial front and 2x rear. I'm 154lbs (70kg) and consensus that 20/24 would be fine for me. You probably would be ok with 20/24 that but the extra spokes gives a little more security in the build. You could also look at different (stronger) spokes for the drive side.


Top
 Profile  
 
PostPosted: Tue Mar 17, 2015 8:31 pm 
Offline

Joined: Sat Jun 16, 2012 3:12 am
Posts: 271
Spoke *stiffness* for driveside may be a factor/concern, but AFAIK the forces that you care about for stressing a wheel are not from pedaling torque (they are from rider weight, impact etc.), so little value in *stronger* spokes on DS. Someone correct me if physics says I am wrong.

Personally, I have not had problems with stiffness of 28h (shallow alloy or deeper carbon) CX-Ray/Laser or even 24h (50mm) CX-Ray rear wheel builds. I know some people prefer Race spokes on rear DS; I just haven't noticed any flex with the more elastic ones.


Top
 Profile  
 
PostPosted: Wed Mar 18, 2015 4:54 am 
Offline
in the industry
User avatar

Joined: Sun Jul 29, 2012 2:59 pm
Posts: 655
Location: Ruidoso, NM
SgtRock wrote:
I would be grateful for any advice from you good souls on spoke count and patterns.


I'd suggest 20f and 24 or 28r. CX-Rays or similar.

Crossing spokes adds nothing to lateral stiffness. It's only good for torque transfer and putting less stress on hub flanges.

Radial front and NDS rear is fine, but you can cross them if you wish.

The reason to use heavier DS spokes is increase the amount of radial load your wheel can take before the NDS goes slack. It might make sense sometimes but isn't necessary.

Tell them to use washers on the DS nipples.

_________________
formerly rruff...


Top
 Profile  
 
PostPosted: Wed Mar 18, 2015 4:05 pm 
Offline

Joined: Tue Nov 11, 2003 9:47 pm
Posts: 1910
Location: Santa Cruz, California, USA
It's not the spokes crossing that add lateral stiffness vs radial laced heads out, it's lacing half the spokes heads in that adds stiffness.
You could lace radial spokes that way, or all heads in for that matter. But half in/half out radial would look funny.

The additional stiffness from half or all the spokes laced heads in is due to the increased bracing angle. (I know you know all this Ron, I'm explaining for people who may not)

This article has a good study of various lacing patterns: http://www.williamscycling.com/assets/i ... Lacing.pdf


Top
 Profile  
 
PostPosted: Wed Mar 18, 2015 4:53 pm 
Offline
in the industry
User avatar

Joined: Wed May 09, 2012 12:39 am
Posts: 27
Location: San Diego, CA
I generally shy away from doing heads-in with most hubs, as it tends to put too much stress on the flanges and diminish hub life. At 70KG, you can get away with a 20/24 build without much difficulty, if the wheel is built well. If I were asked to do the build, I'd probably build them 2X all around, CX rays/Aerolites front and rear non drive side, and a thicker round spoke like the Race or DT Comp for the rear drive side, which is subject to greater abuse than elsewhere. Be aware that the SL23 is a pretty tricky rim to build, and it takes a really quite good wheelbuilder to get a good wheel out of it, especially at low spoke counts.

_________________
Hermes Sport, San Diego CA
Handbuilt Competition Wheel Systems
http://www.hermes-sport.com


Top
 Profile  
 
PostPosted: Wed Mar 18, 2015 6:23 pm 
Offline
in the industry
User avatar

Joined: Sun Jul 29, 2012 2:59 pm
Posts: 655
Location: Ruidoso, NM
eric wrote:
It's not the spokes crossing that add lateral stiffness vs radial laced heads out, it's lacing half the spokes heads in that adds stiffness.


They meet in the middle, so it's like having spokes come from the center of the flange. It might gain you a couple mm but then you have to consider that the spokes are longer, too. So it's really insignificant. Plus the trend these days is to have wider flange spacing on the front wheel, so radial elbows out is unnecessary. And it occasionally causes issues by distorting the bearing bores.

_________________
formerly rruff...


Top
 Profile  
 
Posted: Wed Mar 18, 2015 6:23 pm 


Top
  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 21 posts ] 
Go to page 1, 2  Next


Who is online

Users browsing this forum: Maxxis85 and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

   Similar Topics   Author   Replies   Views   Last post 
There are no new unread posts for this topic. Pacenti SL23 hole offset

in Everything wheels

lennyk

9

1005

Wed Jul 09, 2014 4:59 am

Rush View the latest post

There are no new unread posts for this topic. Custom Alchemy Elf / Orc + Pacenti SL23 + CX Ray Wheelset

in For sale - Pictures are mandatory 22-3-13

geedawg

0

344

Sun Dec 28, 2014 2:12 am

geedawg View the latest post

There are no new unread posts for this topic. Pacenti SL23 Issue - Update with solution in first post

in Everything wheels

Mr.Gib

2

422

Mon Nov 03, 2014 4:58 pm

Mr.Gib View the latest post

There are no new unread posts for this topic. Enve 3.4 clincher vs. Pacenti SL23: ride quality difference?

in Everything wheels

Lugan

12

1659

Sun Jun 08, 2014 12:19 pm

r_mutt View the latest post

There are no new unread posts for this topic. all-round Pacenti build: BHS 20/24 or DT240 28 2x?

in Everything wheels

hmai18

5

587

Tue Apr 22, 2014 5:41 pm

hmai18 View the latest post


It is currently Sat Mar 28, 2015 3:13 am

All times are UTC + 1 hour




Advertising   –  FAQ   –  Contact   –  Convert   –  About

© Weight Weenies 2000-2013
hosted by starbike.com


How to get rid of these ads? Just register!


Powered by phpBB