First time wheel build

[oldie1982]

I have trued a wheel twice now using the wheel in drop out method and zip tie. This has worked well for me. I have always wanted to build a wheel as i found the truing exercise pretty relaxing, it took a few hours but i was in no rush.

I also changed a few spokes a while ago with the help of this forum and it was pretty staight foward.

I have ordered a rim and will measure the ERD when it arrives.

The hub motor I have is a RM G020.250.D which i want to lace into a 700c rim. Currently its laced into a 650b rim.

I have seen a lot of people using 14g spokes which I will also do. Do they need to be double butted or are plain old 14g spokes good enough?

 

[Nealh]

I have always used sapim strongs s/s spokes from spokesfromryan, to date his services have been very good.
He sellls e- stongs or normal 14g/2mm strongs, I always use the 14g 2mm as they have a bit more flex they are 2.3mm at the J bend.
One can find them on page 3.
Other wise double butted.

The truing part I have to agree, it's a great way to chill.

 

[Jodel]

I agree with Nealh above -another vote for Sapim Strong spokes from me. Sapim polyax nipples also give you a bit more angle at the rim if required. Roger Musson's book (PDF) on wheelbuilding is a great reference. The wheelbuilding video on the Grin bikes website is also a good primer - they advocate Sapim Strong spokes in their builds.

Wheel Building - Learn

There are many good print and online references for lacing bicycle wheels. Many will defer to Sheldon Brown, Brandt's Bicycle Wheel Book, and others. However, a lot of the points and details with a conventional bicycle hubs don't necessarily apply to hub motors with their much larger flange...

ebikes.ca

If you get the spoke lengths correct it makes life a lot easier, so you are wise to wait for your rim to be delivered and then check the ERD. Again, I found the Grin bikes calculator to be spot on.

Online Spoke Calculator for Hubmotors and Ebikes

Our handy spoke length calculator allows for easy calculation of spoke length for custom builds - and is the only one of its kind to include paired spoke holes in the flange as is common with many large diameter hub motors. It also creates an automatic side view drawing of the laced wheel and...

ebikes.ca

A heavy duty / touring type rim (I use Ryde Sputniks) is quite easy to build up as they are so strong.

I don't know the diameter of the hub flanges on your motor, but in the case of my Shengyi hub the 156mm diameter really made it necessary to use a single cross lacing pattern to get a decent spoke angle at the rim. I also built the wheel with all spoke elbows out as suggested in the Grin bikes video. So far, it has resulted in a strong enough wheel for the back of my tandem!

The spoke holes in my hub are 3.3mm, so I also used spoke washers to get a decent 'set' in the spokes and hopefully avoid any 'bottle capping'. Smaller size spoke holes shouldn't need washers.

Wheelbuilding is quite satisfying and you'll end up with a wheel as good as, or probably better than, one bought from a shop.

 

[oldie1982]

Excellent advice. Thanks guys.

So double butted is definitely the way to go rather than plain old 14g spokes?

 

[Jodel]

Excellent advice. Thanks guys.

So double butted is definitely the way to go rather than plain old 14g spokes?

The Sapim Strong spoke is single butted and plenty strong (and flexible) enough. I've never tried a motor wheel with double-butted spokes, but if your hub has small enough spoke holes that should be OK.

 

[oldie1982]

The Sapim Strong spoke is single butted and plenty strong (and flexible) enough. I've never tried a motor wheel with double-butted spokes, but if your hub has small enough spoke holes that should be OK.

Sorry I got confused about the spokes. The elbow on the Sapir strong is 2.3mm but the rest is 2.0mm.

The hub motor I have is a Bafang. What size are the flange holes?

If I did go for 14g spokes would I need flange washers? Only reason for 14g is I can get DT Swiss spokes for about 30p each.

 

[Jodel]

I'm not familiar with the DT Swiss range, so can't really comment on their requirement for washers. I can't imagine that DT Swiss would be significantly different to Sapim though, so if Sapim recommend washers for large holed hubs, I suspect DT Swiss will be the same.

I don't have a Bafang hub, so can't help with the dimensions - check the manufacturers website or measure your hub. I used a drill bit to confirm the size of the spoke holes in my hub.

I used washers on my hub following guidance on the Sapim website. The attached checklist should apply equally to DT Swiss spokes I would think.

 

[Nealh]

I never needed washer on my Bafang BPM or CST hub and have never used them on any other hub.

 

[oldie1982]

I never needed washer on my Bafang BPM or CST hub and have never used them on any other hub.

Were these builds using the Sapim strong spokes? Or plain 14g spokes?

My rim arrived. Measured the erd using two spokes. Repeated it 4 times to make sure and I got a number of 604.5 erd.

The rim is double eyeleted. I don’t know if this makes a difference.

I used the grin spoke calculator.

I got spoke lengths as follows.

Left Spoke Length 250.2 mm

Right Spoke Length 251.2 mm

Do I just go for 251mm spokes?

Can someone please double check the figures. I wasn’t sure on a couple of things on the calculator so did a few searches and I think I got it right.

Please see the pictures.

 

[Nealh]

My early hubs used cheap 14g spokes and I used to get some broken ones but that might have been down to poorer early builds, after the first couple I found the Sapim strongs and never had an issue since.

 

[Nealh]

Imv you will be better building the larger hub with a 1x lacing as the nipple entry will be straighter.

For a 2 x the spokes lengths are about right the calc I use says 251.6 L & 250.5 R.

I use the same spoke length.

 

[oldie1982]

Imv you will be better building the larger hub with a 1x lacing as the nipple entry will be straighter.

For a 2 x the spokes lengths are about right the calc I use says 251.6 L & 250.5 R.

I use the same spoke length.

I take it I go for the longer of the spokes? 251mm or 252mm depending on mine or your calculations?

I went and checked the erd again to be as sure as I can be and as it turns out I now get a different erd. This time I got the following figures from different parts of the wheel. I even taped a marker so the nipples would be in the same place every time.

607.2
607.7
607.9
607.1
607

Last time I got 604.5

 

[Jodel]

I'd be inclined to go for a 1 x cross lacing pattern too. Even the Sapim Polyax nipples will only give you about 9 degrees maximum entry angle.

I had a few failures of my hub motor spokes at the rim (on a tandem) when laced as a two cross. The spoke entry angle was too great - even after I 'Bruceyed' the rim: https://forum.cyclinguk.org/viewtopic.php?t=118625&hilit=sputnik

I laced as a single cross and its been fine since.

 

[oldie1982]

1 x lacing it is. Cheers

 

[oldie1982]

I found the dishing offset from another post which I entered on the grin calculator. How do we work this out from the picture?

 

[awol]

I have trued a wheel twice now using the wheel in drop out method and zip tie. This has worked well for me. I have always wanted to build a wheel as i found the truing exercise pretty relaxing, it took a few hours but i was in no rush.

I also changed a few spokes a while ago with the help of this forum and it was pretty staight foward.

I have ordered a rim and will measure the ERD when it arrives.

The hub motor I have is a RM G020.250.D which i want to lace into a 700c rim. Currently its laced into a 650b rim.

I have seen a lot of people using 14g spokes which I will also do. Do they need to be double butted or are plain old 14g spokes good enough?

I would recommend this wheel building book. The author has put years of experience into it. Plus he has a spoke calculator on the website too.

Wheel Building book for cycle wheels

Wheel Building, by Roger Musson. A complete guide to building and repairing wheels with over 90 color photos and CAD drawings.

www.wheelpro.co.uk

 

[oldie1982]

I would recommend this wheel building book. The author has put years of experience into it. Plus he has a spoke calculator on the website too.

Wheel Building book for cycle wheels

Wheel Building, by Roger Musson. A complete guide to building and repairing wheels with over 90 color photos and CAD drawings.

www.wheelpro.co.uk

Thanks. I have done a lot of reading on that site. It’s also another calculator in using but I get stuck on the part where they ask for the flange offset?

 

[Nealh]

Wheelpro is the calc I use.

 

[Sturmey]

I found the dishing offset from another post which I entered on the grin calculator. How do we work this out from the picture?

On the front hub dimensions (picture) you attached, the dishing offset is 'Dimension F = 8.2mm'. Also note WR =58 & WL =42, which gives the 16mm difference which requires offset of 8mm. Note that if you have to make any axle adjustments with washers afterwards ( e.g. to line up with disk brake) and need to re-dish, this alters the offset slightly.

 

[oldie1982]

I really appreciate that.

What a mistake i have made, the hub i have is a rear hub but i posted the picture i found on the net and did not realise it was a front hub.

The correct picture is now attached.