I'm using a Shimano XT 760 32 spoke front hub, matched to a 32 hole Sputnik rim.
Can anyone with more experience advise if a spoke length of 297mm seem about right ! (NB. I've been trying to work it out all evening
)Spoke calculators!
Spoke calculators!
I wouldn't ask, if it wasn't for the hub / rim being so generic! And I can't get my head around spoke calculators!
I'm using a Shimano XT 760 32 spoke front hub, matched to a 32 hole Sputnik rim.
Can anyone with more experience advise if a spoke length of 297mm seem about right ! (NB. I've been trying to work it out all evening )
I'm using a Shimano XT 760 32 spoke front hub, matched to a 32 hole Sputnik rim.
Can anyone with more experience advise if a spoke length of 297mm seem about right ! (NB. I've been trying to work it out all evening
)Re: Spoke calculators!
https://leonard.io/edd/
That site gives 293.9mm for a standard Sputnik and 297mm for a Sputnik CSS rim.
That site gives 293.9mm for a standard Sputnik and 297mm for a Sputnik CSS rim.
Re: Spoke calculators!
32x3 build
38mm hub flanges, 68mm separation
606mm ERD
predicted spoke length = 297mm
607mm is also used as a Sputnik ERD (you need to measure your hubs/rims to be sure) and this would make the predicted spoke length 297.5mm
cheers
38mm hub flanges, 68mm separation
606mm ERD
predicted spoke length = 297mm
607mm is also used as a Sputnik ERD (you need to measure your hubs/rims to be sure) and this would make the predicted spoke length 297.5mm
cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
Re: Spoke calculators!
Hmmm, that calculator has “Rigida Sputnik” ERD as 600mm, is that just wrong or is there a different version or something? CSS rim ERD matches Brucey’s info.
Re: Spoke calculators!
Many thanks to both, I'll go with 297mm.
Have to admit I gave up on calculators and relied on direct measurements and guesswork, using an existing 36 spoke Sputnik / LX rear hub and a 32 spoke Giant front hub. My original guess ranged from 294-298 and I was inclined to hedge my bets and go for 296mm!
Have to admit I gave up on calculators and relied on direct measurements and guesswork, using an existing 36 spoke Sputnik / LX rear hub and a 32 spoke Giant front hub. My original guess ranged from 294-298 and I was inclined to hedge my bets and go for 296mm!
Re: Spoke calculators!
gbnz wrote:I wouldn't ask, if it wasn't for the hub / rim being so generic! And I can't get my head around spoke calculators!
I'm using a Shimano XT 760 32 spoke front hub, matched to a 32 hole Sputnik rim.
Can anyone with more experience advise if a spoke length of 297mm seem about right ! (NB. I've been trying to work it out all evening
FWIW, I build the Sputnik 29er (600mm ERD I measure) with Shimano M756 (60mm flange) on 3x I use 290mm for the Rear Lh and 288mm for the Rh.
297mm seems way too long, and how can you get 606mm ERD?
It is by riding a bicycle that you learn the contours of a country best,
since you have to sweat up the hills and coast down them.
Thus you remember them as they actually are...
since you have to sweat up the hills and coast down them.
Thus you remember them as they actually are...
Re: Spoke calculators!
ElCani wrote:Hmmm, that calculator has “Rigida Sputnik” ERD as 600mm, is that just wrong or is there a different version or something? CSS rim ERD matches Brucey’s info.
I measure them. 600mm it is.
It is by riding a bicycle that you learn the contours of a country best,
since you have to sweat up the hills and coast down them.
Thus you remember them as they actually are...
since you have to sweat up the hills and coast down them.
Thus you remember them as they actually are...
Re: Spoke calculators!
What I do, is buy the rims and hubs .......... and measure myself.
Then, use a few online spoke calculators with your own measurements and look for a consensus.
IME, they all vary. That is, what the websites say about hub dimensions, rim ERDs and spoke lengths.
When you have your figures, round them up and then buy your spokes.
Then, use a few online spoke calculators with your own measurements and look for a consensus.
IME, they all vary. That is, what the websites say about hub dimensions, rim ERDs and spoke lengths.
When you have your figures, round them up and then buy your spokes.
Mick F. Cornwall
Re: Spoke calculators!
as several people (including myself) have suggested you really need to measure for yourself because rims can vary a little from batch to batch. This is good advice.
However I can tell you for a fact that the measured 'drop' from the bead seat to the nipple seat is ~10mm, i.e. if the rim is built to the correct size the nipple seat diameter (NSD) is 622 -10 -10 = 602mm. Normally you would add on about 4mm to convert NSD to ERD, suggesting ~606mm. I have never measured the ERD of sputnik as small as 600mm. Spa cycles build (and sell) lots of sputniks and they say 607mm on their website.
The last pair of sputniks I built (a few weeks ago, SF 36x3) measured at 607mm ERD and the front spokes (14G PG) ended up 0.25mm proud (out of the top of the nipples), the NDS rear (again 14G PG) about 0.5mm proud, and the DS rear (14/13G SB) 0.5mm below flush, i.e. mid-slot. I can check my records but IIRC I used 'stock' spokes (rather than ones cut and threaded to length) so they would probably have come in 2mm increments rather than 1mm increments. I could have gone with NDS spokes 2mm shorter but there would have been a good chance of ending up with some of the spoke ends being shy of the bottom of the nipple slots (which is certainly not preferable to them being slightly proud IMHO).
A Brucey top tip; Sputniks are not angle drilled (there is only a virtually imperceptible stagger to the spoke drillings, and BTW they can be left or right handed.....) and the eyelets are a snug fit with most nipples, and don't allow easy articulation of the nipple. So, if you are intent on making as good a job as possible of it you can 'tweak' the eyelets slightly so that there is no angle (kink) at the nipple. This has only a small benefit if you are building on conventional SF hubs (you might only bother on NDS rear spoke holes in fact) but on larger flanges it is A Very Good Idea.
cheers
However I can tell you for a fact that the measured 'drop' from the bead seat to the nipple seat is ~10mm, i.e. if the rim is built to the correct size the nipple seat diameter (NSD) is 622 -10 -10 = 602mm. Normally you would add on about 4mm to convert NSD to ERD, suggesting ~606mm. I have never measured the ERD of sputnik as small as 600mm. Spa cycles build (and sell) lots of sputniks and they say 607mm on their website.
The last pair of sputniks I built (a few weeks ago, SF 36x3) measured at 607mm ERD and the front spokes (14G PG) ended up 0.25mm proud (out of the top of the nipples), the NDS rear (again 14G PG) about 0.5mm proud, and the DS rear (14/13G SB) 0.5mm below flush, i.e. mid-slot. I can check my records but IIRC I used 'stock' spokes (rather than ones cut and threaded to length) so they would probably have come in 2mm increments rather than 1mm increments. I could have gone with NDS spokes 2mm shorter but there would have been a good chance of ending up with some of the spoke ends being shy of the bottom of the nipple slots (which is certainly not preferable to them being slightly proud IMHO).
A Brucey top tip; Sputniks are not angle drilled (there is only a virtually imperceptible stagger to the spoke drillings, and BTW they can be left or right handed.....) and the eyelets are a snug fit with most nipples, and don't allow easy articulation of the nipple. So, if you are intent on making as good a job as possible of it you can 'tweak' the eyelets slightly so that there is no angle (kink) at the nipple. This has only a small benefit if you are building on conventional SF hubs (you might only bother on NDS rear spoke holes in fact) but on larger flanges it is A Very Good Idea.
cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
Re: Spoke calculators!
When I rebuild my rear 406 CR18/SA, I will "tweak" the nipple alignments. Not just a large flange, but a small wheel. Worst of both worlds.Brucey wrote: ...............but on larger flanges it is A Very Good Idea.
Leaving the wheel as it is until the new rim is required .......... two or three months yet.
Mick F. Cornwall