Bike Forums

Bike Forums (https://www.bikeforums.net/forum.php)
-   Fatbikes (https://www.bikeforums.net/forumdisplay.php?f=336)
-   -   Spoke Lacing question (https://www.bikeforums.net/showthread.php?t=1157575)

Speedway2 10-09-18 12:08 PM

Spoke Lacing question
 
I posted this pic/question over in the Cruiser Bikes in my thread (Speedway2).
I was wondering why the spokes are lined up on one side instead of cris-crossed (like my front wheel). The bike's a 2spd with coaster brake and the spokes are lined up on the same side as the drive (chain). The tire is 4" wide.

I'm guessing its to manage the torque of accelerating and braking?

https://cimg4.ibsrv.net/gimg/bikefor...9e87a9ad86.jpg

HerrKaLeun 10-10-18 06:40 PM

Did this come with a bike or where did you get this wheel?
is the rim off-center in relation to the fame?

May be one of those wannabe fatbike when they sued 135mm hubs and off-set.

Speedway2 10-10-18 08:15 PM


Originally Posted by HerrKaLeun (Post 20610388)
Did this come with a bike or where did you get this wheel?
is the rim off-center in relation to the fame?

May be one of those wannabe fatbike when they sued 135mm hubs and off-set.

I bought the bike new at the LBS and they did not know why either. The wheel looks in-line with the seat post (looking from the rear) but I do notice it about a 1/4" closer to the fork on the non-chain side.
The LBS had another Felt Fat tire Cruiser with an internal 2-spd and it was laced the same way....

dabac 10-11-18 03:48 AM


Originally Posted by Speedway2 (Post 20608126)
I was wondering why the spokes are lined up on one side instead of cris-crossed (like my front wheel)?

You mean the front wheel is built in lateral cross?
(spokes cross some distance inside the rim when viewed from ahead)
That has a (mostly) theoretical advantage - if the nipples can be made to align with the spokes. A lateral cross will improve the bracing angle, making the wheel stiffer sideways for a set gauge and spoke count. So either you get a stiffer wheel for (nearly) the same weight/air drag. Or you can build an equally stiff wheel with less spokes/thinner gauge.
However, if you have the nipples pointing vertically, and the spokes angling away as soon as they exit the nipple, I'd think that this will be a bigger disadvantage than the increased stiffness. I've killed a couple of rear wheels due to optimistic builds causing an angle right at nipple top.

Speedway2 10-11-18 05:06 AM

dabac.....thanks for the explanation. Makes sense.
As you can see in the pic of my front wheel the spokes are staggered using holes on both sides of the rim....unlike the rear. I'm guessing the rear is done this way because its geared internally with a coaster brake(?).
I haven't seen a Fat bike with the same configuration with a similar rear wheel (yet)
https://cimg2.ibsrv.net/gimg/bikefor...b8ca0c2ad3.jpg

dabac 10-11-18 05:42 AM

So your front spokes aren't in lateral cross. Each flange's spokes use the corresponding side of rim holes b/c that gives a good enough sideways angle w/o causing the spoke to bend at nipple exit.


Originally Posted by Speedway2 (Post 20608126)
I was wondering why the spokes are lined up on one side..The bike's a 2spd with coaster brake and the spokes are lined up on the same side as the drive (chain).

Best assumption I can come up with from the pic:
Your rear hub is probably not entirely symmetrical, with one flange being further inboard than the other. If they'd laced the most inboard flange to the same side row of rim holes, maybe the spokes had ended too close to vertical for a reliable build.
So they laced the most inboard flange to the opposite side of the rim to get a better lateral (sideways) spoke angle.


Originally Posted by Speedway2 (Post 20608126)
I'm guessing its to manage the torque of accelerating and braking?

Spokes are crossed tangentially(leaning fore/aft) to let the hub transfer either drive or brake torque to the rest of the wheel. Strictly speaking, they don't need to cross, it's possible to build a wheel where all spokes on one side leans forward and all spokes on the other side leans aft. But the every 2nd spoke approach has proven itself over time to be a good lace pattern.

Speedway2 10-11-18 12:06 PM

dabac....thanks again for the great info! I had no idea installing spokes on a rim could be so technical.
I'm relieved that the integrity of the rear wheel isn't compromised.......but it does look odd.

Speedway2 10-11-18 12:12 PM


Originally Posted by dabac (Post 20610840)
Best assumption I can come up with from the pic:
Your rear hub is probably not entirely symmetrical, with one flange being further inboard than the other. If they'd laced the most inboard flange to the same side row of rim holes, maybe the spokes had ended too close to vertical for a reliable build.
So they laced the most inboard flange to the opposite side of the rim to get a better lateral (sideways) spoke angle.
.

I think you may be onto something. The gear side does look off-set. There's at least the width of a locking bolt (or 2) difference from the "other side"....perhaps to gain some clearance from the fork(?)
https://cimg6.ibsrv.net/gimg/bikefor...a6361918ba.jpg

CliffordK 10-11-18 01:45 PM

That looks absolutely bizarre.

For multi-gear bikes, off-center rims are common, generally with all of the spokes going to the left (non-drive side) of the rim, and thus improving the spoke angle on the drive side.

Yours has the IGH, so less dishing needed, but the offset is opposite from what would normally be expected.

It is easy enough to check the wheel dishing with a dishing tool (your LBS should have one).

You cold shove a rod or something through the spokes to compare right and left centering of the hub.

I would think you would get a stronger wheel with a normal cross pattern, or I have wondered about crossing the right flange to the left side of the rim, and visa-versa.

Speedway2 10-11-18 05:38 PM

I sent FELT an email. I'll share it here if/when they respond.

Speedway2 10-12-18 03:53 PM

I received a response from a Felt representative. Here's what they had to say....
No this is not an issue. Lacing a wheel this way has to do with hub spacing, spoke tension, chainline and rim/tire width.

Having a fat tire with a regular width hub, spokes need to be laced this way to keep the wheel centered and the spoke tension similar on both side of the hub flange.

Sincerely,
L


Makes sense?

dabac 10-17-18 07:32 AM


Originally Posted by Speedway2 (Post 20613578)
I received a response from a Felt representative. Here's what they had to say....
No this is not an issue. Lacing a wheel this way has to do with hub spacing, spoke tension, chainline and rim/tire width.

Having a fat tire with a regular width hub, spokes need to be laced this way to keep the wheel centered and the spoke tension similar on both side of the hub flange.

Sincerely,
L


Makes sense?

It aligns with what I suggested:"Your rear hub is probably not entirely symmetrical, with one flange being further inboard than the other. If they'd laced the most inboard flange to the same side row of rim holes, maybe the spokes had ended too close to vertical for a reliable build.
So they laced the most inboard flange to the opposite side of the rim to get a better lateral (sideways) spoke angle."


As far as providing a (theoretical) reason, it works.

However. I'm not sure I buy the execution of the idea. The DS spokes seems to run at a very shallow angle, near vertical.
There's NO way that rear has similar DS-NDS spoke tension if I'm interpreting the picture right.
And I don't like the look of the bend of the NDS spokes right where they exit the nipple.
But maybe it's good enough for the purpose. It doesn't seem like it'll be a high-mileage bike.

dabac 10-17-18 07:46 AM


Originally Posted by CliffordK (Post 20611669)
That looks absolutely bizarre.

Agreed.

Originally Posted by CliffordK (Post 20611669)
Yours has the IGH, so less dishing needed, but the offset is opposite from what would normally be expected.

Agreed.
Last IGH I built up ended up with about 10% spoke tension difference DS/NDS due to one flange being farther inboard. Don't remember which one.
On this, with the extra axle nut I'd assume it was the DS that's further in, which would make the build reversed from ideal. Some simple measuring should be accurate enough to say if the build design was the right compromise.

Originally Posted by CliffordK (Post 20611669)
It is easy enough to check the wheel dishing with a dishing tool (your LBS should have one).

OP hasn't said anything about any chafing/clearance issues, so I don't think there anything to learn there.

Originally Posted by CliffordK (Post 20611669)
I would think you would get a stronger wheel with a normal cross pattern.

The cross pattern is normal, it's only shifted sideways.

Originally Posted by CliffordK (Post 20611669)
.. I have wondered about crossing the right flange to the left side of the rim, and visa-versa.

Lateral cross. Has been done. Brings a small improvement. Rim has to allow for the nipple to align with the spoke. The bends on the NDS spoke here doesn't look promising for longevity. Having DS and NDS equally bad isn't an improvement.
I'd be tempted to center-drill the rim, see if it'll hold.
But only if I started getting spoke failures.

Speedway2 10-17-18 12:13 PM

dabac....that's a lot of technical detail! Thanks for that.
As you've alluded this bike will not be a "high-mileage" bike. It's for those lazy days when I just want to casually ride around the neighborhood and sight-see.

Felt Canada Rep also followed up with another email indicating the rim was spoked this was because the Sturmey Archer is a 135mm spacing hub.

By all accounts it may look weird but doesn't seem like an issue.

trailangel 10-18-18 04:11 PM

Right. Spoke angle at the nipple NDS looks terrible. I would have just built it like the front wheel. I wouldn't be able to sleep at night know that is in my garage.....

Speedway2 10-19-18 04:59 AM

Thanks for you opinion(s) folks! Really appreciate it.

I know nothing about spoke lacing but at this point can a LBS simply ``move` the``NDS spokes to left side of the rim. Or would they have to break down the wheel at start over....

Forum Moderator(s) please feel free to move this thread into "Bicycle Mechanics" if its more appropriate.

dabac 10-22-18 07:46 AM


Originally Posted by Speedway2 (Post 20623647)
I know nothing about spoke lacing but at this point can a LBS simply ``move` the``NDS spokes to left side of the rim. Or would they have to break down the wheel at start over....

They'd have to pull tire, tube and rim strip off to be able to move the nipples over. And they MIGHT prefer cutting the old spokes out rather than unscrew and relocate one by one. Even if the shop is OP with reuse, I'm not sure about the impact of the change in geometry on the required length. Spokes might bottom out on the nipple threads and need to be replaced anyhow. Adding washers under the nipple is doable, but not quite seen as proper build technique.

For the time being, I'd go with good old "ain't broke, don't fix".
Sometimes there's precious little to be gained by going from "good enough" to "better".
Unless you're planning to use that bike for a long unsupported ride, the time to consider a rebuild is when you start breaking spokes.

unterhausen 10-22-18 08:12 AM

I'm pretty sure the spokes wouldn't be long enough to swap sides

I would move the thread, but it seems fine here


All times are GMT -6. The time now is 03:03 AM.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.