Replacing rims

Discussion in 'Bicycle Mechanics and Repairs' started by BillyS79, 31 Jan 2018.

  1. BillyS79

    BillyS79 Active Member

    I need to replace some Pacenti SL25 disc rims -


    My wheels have a 32 spoke count front and rear.

    Is it possible to change the rims without buying all new spokes as well?

    If so, can people recommend other rims that would work?

    The SL25s are discontinued so I can't seem to find them anywhere in a 32 hole drilling (though if anyone else knows where to source some please do shout up). The Pacenti replacement rim is the Forza but I'm not sure if these would work as they are asymmetrical so presumably spoke lengths would need to be slightly different?



  2. Yes it’s possible, but why would you want the old spokes and ( presumably hubs ) with new rims? Wheelbuilding / spoke threading etc. is a black art, it’s fine if you want to go down that road, fair play to you, but it’s just a whole lot easier to go for factory built wheels.
  3. derrick

    derrick The Glue that binds us together.

    I have replace wheel rims and hubs without fitting new spokes. Never had a problem as long as the spokes are not damaged.
    BillyS79 likes this.
  4. Velochris

    Velochris Active Member

    Nothing wrong at all with reusing spokes if they are in good condition.

    In terms of reusing the spokes on a different rim, it is difficult to say.

    A quick search shows the effective rim diameter (basically the width of the rim from opposite spoke holes to where the spoke ends up in the nipple) is very similar, maybe 1mm difference.

    In general, you can build a wheel using the same rim but spokes could be different lengths. So the same rim and wheel design could be built for example with 291 or 292mm spokes. Depending on the length used on your existing wheel the spokes may be okay on the new rim.

    The offset may further complicate things but if the old spokes can be used then on any offset rim you would probably get away with only having to change one side of the spokes.

    You really need an experienced wheel builder for a definitive answer.
  5. OP

    BillyS79 Active Member

    Sorry, perhaps my OP was not so clear. All the components are brand new but unfortunately the rims I have been sent are no good, so I need to replace them. So I have the hubs and spokes I need for the build, but now can't find anywhere else stocking the rims! So I hoped to find another rim that would work with the same spokes, rather than having to order a whole new set of spokes and being left with some that are no use to me.

    Do you know of any who use this forum that might be able to advise?

  6. vickster

    vickster Legendary Member

    Spoked Wheels likes this.
  7. Velochris

    Velochris Active Member

    Not sure if he uses this forum but I have seen him post elsewhere

    He sells the Pacenti so may be able to advise. If so try to buy from him. Service and delivery was very good when I used in the past.
  8. alecstilleyedye

    alecstilleyedye nothing in moderation Moderator

    out of curiosity, why do you need to replace rims on a disc-braked bike?
  9. gaijintendo

    gaijintendo Über Member

    You can ding them, just the same.
    I replaced a rear wheel after there was fatigue on the rim beside the spokes.
    Other than that, perhaps aesthetic reasons - so many disc rims are black, and given it doesn't make a difference to braking - I would love a retro chrome rim on my steel bike...
  10. davidphilips

    davidphilips Über Member

  11. si_c

    si_c Veteran

    Replacing the rims without changing the spokes is relatively easy. You do however need to be aware of a few things, firstly the ERD of the rim, this is the internal diameter where the spoke is seated, this (along with the hub flange diameter and the lacing pattern) dictates how long the spokes need to be. In this case (according to this link) the ERD is 607mm, so you will need to find a rim of the same ERD for it to be a direct swap, otherwise you are looking at replacing the spokes as well. For example, the Forza above has an ERD of 591, so would require shorter spokes.

    If you do have to replace the spokes, you won't go wrong if you try JRA, I found them to give excellent service.

    Edit: Just looked at the PX link again, and the picture shows an ERD of 589/590.
    BillyS79 likes this.
  12. Ajax Bay

    Ajax Bay Veteran

    East Devon
    With respect, @si_c , have you read the OP's two posts? I think it's reasonable to assume he is "aware of a few things" already. He has not got built wheels. He has bought new rims, new hubs and new spokes but the rims are unusable. The OP has asked which alternative rims he might procure which would require the same spoke lengths as the Pacenti ones (see OP). I'm afraid I don't know if there's a sensible way of finding out the options, but @Spoked Wheels has already been paged. I wonder if @I like Skol might be able to add value?
    How about these: (ERD 589) H-Plus-Son/The-Hydra-Disc-Clincher-Rim
    BillyS79 and winjim like this.
  13. I like Skol

    I like Skol Hold my beer and watch this....

    Just two points that occur to me.

    The Forza states it has a machined brake surface so are these actually a replacement for the disc brake specific SL25?

    Could you uses the front Forza rims Fr & Rr? Presumeably the rims have the same strength and amount of metal in them as the claimed weights are the same for both? If you thought usisng the asymmetric rim would cause problems then just buy 2 x front 'normal' rims.
  14. Tenacious Sloth

    Tenacious Sloth Über Member

    Huntingdon, UK
    Hi Bill.

    If it makes you feel any better I’ve also carried out a fairly extensive internet search for SL25s in a 32h drilling and can’t find them anywhere. Plenty available in 24h for the the racing snakes including £19.99 at PlanetX. :eek: Hell of a bargain, but no good for you.

    I’ve built wheels with both SL25 and the asymmetric Forza and while they are both excellent, I do prefer the Forza as they give you a much more even spoke tension between DS and NDS.

    It may be worth you comparing the SL25 against the Forza on an Online Spoke Calculator as they may come out with similar spoke lengths?

    If not, the H Plus Son Hydra Disc specific rims have an identical ERD of 589 which would mean you could definitely use your existing spokes. Their internal width is also identical at 20mm. I haven’t built with the Hydra rim, but have previously built a couple of wheels with the H Plus Son Archetype rims and found the build quality of said rims to be excellent.

    I’m also interested in why you need to replace your existing SL25 rims as I’ve found them to be bullet proof?

  15. Tenacious Sloth

    Tenacious Sloth Über Member

    Huntingdon, UK
    You can get the Forza rims in a Disc specific version.

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