20 hole rim replacement
paulbnix
Posts: 628
I have a worn out Mavic Aksium rear rim with vgc spokes and hub,
I measured the rim ERD as 594.
Where and how do I look for a 20 hole rim with a 594 ERD?
I don't want to spend too much in case the project fails but I thought it might be worth a try.
I measured the rim ERD as 594.
Where and how do I look for a 20 hole rim with a 594 ERD?
I don't want to spend too much in case the project fails but I thought it might be worth a try.
0
Posts
Have a look at Merlin cycles. A new set of Aksiums (without tyres) circa £120/130 last time I looked.
It's a project... some like a project, others like ready meals
Cube Litening Super HPC PRO
sorry for hijacking your thread
Cube Litening Super HPC PRO
They look a bit deeper... maybe the Kinlin 279 will work...
"The effective rim diameter is measured by dropping a nipple into a rim hole and finding how far its head lies below the outer edge of the rim. This value is doubled and subtracted from the outer rim diameter. "
NDS Flange Diam 38 Distance 29
DS Flange Diam 38 Distance 49
Hub Length 131
using 594 as the ERD the spoke lengths are calculated as 280 NDS and 278 DS for 12mm nipples.
The spokes actually measure 283 NDS and 298 DS.
The nipples are 14 mm so the NDS looks ok.
The DS spokes come off the hub at a tangent as shown so I don't know how to check what their length should be
I think it looks viable but would a rear 20 spoke Archetype rim cope with my 73 kg?
Simply don't bother unless you have a stock of straight pull spokes to experiment with.
If you have one side radial you need to measure the pad from where the spoke side in the flange easy to get this measurement wrong by a couple of mm.
Simply don't bother unless you have a stock of straight pull spokes to experiment with.
If you have one side radial you need to measure the pad from where the spoke side in the flange easy to get this measurement wrong by a couple of mm.
Also your hub measurement and spoke lengths are definitely wrong.
shows the 131 hub length
shows the 49 DS flange distance
shows the 29 NDS flange distance
I measured the flange diameter for the NDS between the ends of two spokes.
I agree the DS flange is difficult to measure because the spokes are offset.
Perhaps i may just start fresh for my first go.
unless i can find a rim as you say with the same erd, then i guess i just measure the spoke length.
is there any way to find the erd with out dismantling the wheel as hte wheel is still in use?
Cube Litening Super HPC PRO
The wheel looked ok when I collected it. When I got it home I compared it with the wheel on my bike and noticed the spokes were loose.
While I was tightening a spoke it pulled right through the rim.
Although the rim looked good on the surface internally it was heavily corroded.
This is just an idea that I won't bother with if the chance of success is low.
My new bloody tablet can't spell why can't it just let me spell the words the way I want to. It's edited now to make sense. Really how do you turn of predictive spelling on a tablet.
The measurements I described above were taken and fed into an Android app called Wheeler.
Those are the parameters it takes to calculate spoke lengths.
I have remeasured to get the values needed by http://www.wheelpro.co.uk/spokecalc/ and NDS flange from centre =36.5, DS flange from centre =16.5.
Feeding these into the calculation gives NDS spoke=278.9, DS spoke=277.0.
These are within a mm of the lengths I calculated earlier.
I think I am left with 2 questions :-
1. Have I measured the ERD correctly?
2. Will a 20 spoke Archetype rim rear wheel support my 74kg?
Take two shortish (270-280 mm) J bend spokes and two 12 mm nipples. Insert the nipples with the threaded spoke into opposite holes. Take a rubber band and join the two J part of the spokes together. Measure the distance between the two extremities at the point where the spoke enters the nipple. Then add 20 mm and that's your ERD
The spokes were wound in like so
I measured the ERD in a few spots and it was 595.
I also tried it by dropping a nipple into the hole and measuring from the rim to it = 18mm.
Subtract twice this from the diameter of 633mm gives 597 for the ERD.
I decided to try replacing the Mavic Aksium rim with an Archetype after gaining confidence successfully building my first set of wheels. They are 24/28 Miche Primato, Sapim Laser/Race with Archetype rims, all parts supplied efficiently by The Cycle Clinic.
It took me quite a while to re-rim the Aksium because the Mavic nipples can't be driven on with a nipple driver as they have no slot and are filled with a blue grip material. I had a couple of goes and ended up having to count the turns as I put the nipples on the spokes.
I haven't got a tension meter so I used the Iphone app to record the tensions of the old wheel and duplicated them on the new one.
I think it looks quite mean except I ended up with the rim label facing the wrong side
I did a 15 mile loop to try the wheel and all seemed ok except I could get the rim to touch the brake block when standing on the pedals. I'm not sure if that is a problem I can fix or just live with.
Not sure why you find it less stiff than the original... could it be that the brake blocks have not been adjusted for the extra width?
While the brake track was still anodised any contact between rim and brake block made a loud noise.
Now its had an outing in the wet the brake track has been ground down removing the anodising so it no longer makes an obvious noise when touching the brake block.
Its probably still touching but I can't hear it.