20 hole rim replacement

paulbnix
paulbnix Posts: 632
edited June 2015 in Road buying advice
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.

Comments

  • ugo.santalucia
    ugo.santalucia Posts: 28,310
    Archetype is 592-953, close enough
    left the forum March 2023
  • paxington
    paxington Posts: 162
    paulbnix wrote:
    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.

    Have a look at Merlin cycles. A new set of Aksiums (without tyres) circa £120/130 last time I looked.
  • ugo.santalucia
    ugo.santalucia Posts: 28,310
    paxington wrote:

    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
    left the forum March 2023
  • gaanrowl
    gaanrowl Posts: 326
    i have a DT swiss Ra 1 rear wheel that came off my cube i would like to re rim, its a straight pull spoke build 28 hole, what would you recommend ugo? artchtype?
    Cube Ltd Race 09

    Cube Litening Super HPC PRO
  • gaanrowl
    gaanrowl Posts: 326
    i have a DT swiss Ra 1 rear wheel that came off my cube i would like to re rim, its a straight pull spoke build 28 hole, what would you recommend ugo? artchtype? new to this wheel building lark this will be my first attempt. how do you find out the erd? i struggled to find any info on these wheels to set off with.

    sorry for hijacking your thread
    Cube Ltd Race 09

    Cube Litening Super HPC PRO
  • ugo.santalucia
    ugo.santalucia Posts: 28,310
    gaanrowl wrote:
    i have a DT swiss Ra 1 rear wheel that came off my cube i would like to re rim, its a straight pull spoke build 28 hole, what would you recommend ugo? artchtype? new to this wheel building lark this will be my first attempt. how do you find out the erd? i struggled to find any info on these wheels to set off with.

    sorry for hijacking your thread

    They look a bit deeper... maybe the Kinlin 279 will work...
    left the forum March 2023
  • paulbnix
    paulbnix Posts: 632
    A quote from Bicycle Wheel -

    "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. "
  • paulbnix
    paulbnix Posts: 632
    I have now measured the Aksium hub
    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
    4jx98m.jpg

    I think it looks viable but would a rear 20 spoke Archetype rim cope with my 73 kg?
  • cycleclinic
    cycleclinic Posts: 6,865
    Calculating the lengths for straight pull hubs is not simple. The lacing maybe 2x but number you use for the closing is not 2 it is a fractional number between 2 and 3 and there is no way of working that out. You have to work out lengths by trial and error.

    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.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • cycleclinic
    cycleclinic Posts: 6,865
    Calculating the lengths for straight pull hubs is not simple. The lacing maybe 2x but number you use for the closing is not 2 it is a fractional number between 2 and 3 and there is no way of working that out. You have to work out lengths by trial and error.

    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.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • paulbnix
    paulbnix Posts: 632
    I am a bit confused when you say my hub measurement is wrong.
    nfpiev.jpg
    shows the 131 hub length

    1zph1mc.jpg
    shows the 49 DS flange distance

    15rfn7n.jpg
    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.
  • ugo.santalucia
    ugo.santalucia Posts: 28,310
    Just get a rim with the same ERD and tyou won't have that problem
    left the forum March 2023
  • gaanrowl
    gaanrowl Posts: 326
    thanks for the comments Gents.

    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 Ltd Race 09

    Cube Litening Super HPC PRO
  • me-109
    me-109 Posts: 1,915
    Try to find an Aksium with a trashed hub or broken spoke(s). That way you will know the rim fits. :wink:
  • paulbnix
    paulbnix Posts: 632
    Unfortunately buying a 2nd hand Aksium wheel from ebay is how I have ended up with a good hub and spokes.
    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.
  • cycleclinic
    cycleclinic Posts: 6,865
    edited January 2015
    When measuring a hub the centre of flange to the centre of the hub is required for spoke length calculation. You have measured flange edge to locknut wwhich is totally different. Flange pcd measurement is possibly a couple of mm out. Ugo's comment of using a rim of the same erd is the only way this will work for you. You will however have to measure the erd correctly as well.

    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.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • paulbnix
    paulbnix Posts: 632
    I now understand.
    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?
  • ugo.santalucia
    ugo.santalucia Posts: 28,310
    ERD:

    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
    left the forum March 2023
  • cycleclinic
    cycleclinic Posts: 6,865
    Another way is to cut the spokes to 200mm. thread 12mm nipples on so that the top of the spoke is flush or just below the nipple driver flat. You do not want the spoke poking out of the nipple or your ERD will be high and the wheel won't build well. Then place the two spokes with nipples (loctite the nipples in place so they can't move) in spoke hole at opposite end of the rim. When the spokes are pulled together and the nipples seated properly in the rim measure the distance between them and add 400mm. That is your ERD.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • paulbnix
    paulbnix Posts: 632
    I have made an ERD measuring device as described in Roger Mussons book
    27xnzur.jpg

    The spokes were wound in like so
    30iyp11.jpg

    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.
  • paulbnix
    paulbnix Posts: 632
    Bump.

    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.

    308usmw.jpg
    2q1yx3s.jpg

    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.
  • ugo.santalucia
    ugo.santalucia Posts: 28,310
    You made an Aksitype...

    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?
    left the forum March 2023
  • paulbnix
    paulbnix Posts: 632
    I've now ridden some more on the Aksitype and I don't think it is more flexible.

    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.

Categories