Rim replacement

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subandean
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Rim replacement

Postby subandean » 20 Aug 2017, 3:52pm

Would a Mavic Open Pro rim be a compatible replacement for a cracked Mavic Reflex 700 rim, laced onto a late 80's Campag Chorus hub?
Any other rim recommendations for late 80's audax bike?
Thanks

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Gattonero
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Re: Rim replacement

Postby Gattonero » 20 Aug 2017, 4:01pm

No, you cannot reuse the spokes, Open Pro's are 601mm ERD while Reflex are 612*. I'd still check if the spokes are in GC and if the bike was heavily used may consider to replace them.

The H+Son TB14 are a good choice with their 610mm ERD, shallow profile and very good quality.
They're 22mm wide but you can fit 23mm tyres with no problems at all. Also, the polished ones do look perfect on classic bikes 8)
Image

*= surely someone will disagree with this, and come up with a +-2-3mm on those values. I've built literally hundreds of those rims using such values, and it all comes spot-on as it should be.
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...

Brucey
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Re: Rim replacement

Postby Brucey » 20 Aug 2017, 5:18pm

there is more than one Mavic rim called a 'reflex'; one that is shallow with a large ERD and another with an ERD around 605mm. Which do you have?

If there is enough (~13mm) difference in ERD between the two rims, you could build using the original spokes x4 instead of x3.

BTW IME 605mm is the correct ERD for 700C Mavic Open Pro, unless you like your spokes being about 2mm too short. I like my spoke ends to finish in the slots and I don't mind if they stick out 0.5mm. If the spoke finishes ~1mm below the slot bottom, you get occasional (with brass nipples) or frequent (with aluminium nipples) failure in the nipple.

cheers
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Gattonero
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Re: Rim replacement

Postby Gattonero » 20 Aug 2017, 6:04pm

Brucey wrote:...
BTW IME 605mm is the correct ERD for 700C Mavic Open Pro, unless you like your spokes being about 2mm too short. I like my spoke ends to finish in the slots and I don't mind if they stick out 0.5mm. If the spoke finishes ~1mm below the slot bottom, you get occasional (with brass nipples) or frequent (with aluminium nipples) failure in the nipple.

cheers


Nonsense.
Current model of Open Pro, 32h and 3x, on Shimano HB5700.
On a calculation with 601mm ERD gives 295mm spoke length, this is with 296. Are those "2mm too short"? :wink:
Image
Btw, this applies also for most of the "Open Sup" too, the rim extrusion seems pretty much the same so variations of the ERD are minimal.
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...

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subandean
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Re: Rim replacement

Postby subandean » 20 Aug 2017, 8:43pm

Thanks for the advice.
I am unsure which Reflex rims I have, the stickers are damaged but I am guessing one may have the numbers 622 x 13 on them.
They are not box shape in section.

Brucey
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Re: Rim replacement

Postby Brucey » 20 Aug 2017, 9:12pm

Gattonero wrote: ...Current model of Open Pro, 32h and 3x, on Shimano HB5700.
On a calculation with 601mm ERD gives 295mm spoke length, this is with 296. Are those "2mm too short"? :wink:


well effectively rather than build to 601mm ERD you have both rounded up and at least built to 603mm (or 604mm) ERD in going over by 1mm (plus rounding) on spoke length; they would have finished below the slot bottom if you had used 295mm as indicated. I expect they are DB spokes too, which stretch a bit more. 296mm are fine and 297mm PG (or DB) would have been fine too, just poking out of the nipple top.

FWIW by my calculation HB-5700 front with 605mm ERD 32x3 comes to 296.5mm. With 601mm ERD it calculates to 294.5mm and if you had rounded down to 294mm they would have been too short for sure. If you were to ask me what rim ERD would be correct for that rim on the basis of that build it would be 604 or 605mm, not 601mm.

Come to think of it, I think I may even have 604.5mm written down in a book somewhere based on an average of the rims I have built.

cheers
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Brucey
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Re: Rim replacement

Postby Brucey » 20 Aug 2017, 9:20pm

subandean wrote:Thanks for the advice.
I am unsure which Reflex rims I have, the stickers are damaged but I am guessing one may have the numbers 622 x 13 on them.
They are not box shape in section.


Are they sprints for tubs and if so do you want to stick with those?

One thing that might help is you eyeball where the spoke ends finish in the nipple and then remove and accurately measure one (or two for a rear wheel) spokes, [pref an 'inside' spoke since the J bend will be less deformed] measuring from the inside of the J bend to end. With this information we can calculate the ERD of the rims you have and we will know what spoke lengths you have too, and thus assess whether the spokes can be re-used or not with another rim (if we can agree on the ERD of that rim.... :wink: ).

cheers
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subandean
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Re: Rim replacement

Postby subandean » 22 Aug 2017, 3:01pm

Brucey wrote:
Are they sprints for tubs and if so do you want to stick with those?

One thing that might help is you eyeball where the spoke ends finish in the nipple and then remove and accurately measure one (or two for a rear wheel) spokes, [pref an 'inside' spoke since the J bend will be less deformed] measuring from the inside of the J bend to end. With this information we can calculate the ERD of the rims you have and we will know what spoke lengths you have too, and thus assess whether the spokes can be re-used or not with another rim (if we can agree on the ERD of that rim.... :wink: ).

cheers


The rims are clinchers and it is the rear that needs replacing.
I measured an inside spoke; on the drive side 31.2, on the non drive side 30.5

Brucey
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Re: Rim replacement

Postby Brucey » 22 Aug 2017, 4:24pm

is the wheel 32 or 36 drilled, and how many crossings are there?

cheers
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subandean
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Re: Rim replacement

Postby subandean » 22 Aug 2017, 5:20pm

They are 32 drilled and 3 crossings. I have had them for about 20 years so they have done well. The spokes look OK.
Reading a few forums I noticed the Ambrosio rims such as the Excellight often recommended.
Thanks for your helpful responses.
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Brucey
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Re: Rim replacement

Postby Brucey » 22 Aug 2017, 7:57pm

I am somewhat baffled by your spoke measurements; that looks like the 700C 'reflex' rim with about 605mm ERD to me, which 32x3 built onto a campag small flange rear hub ought to use ~294 and 296mm spokes.

A double-eyelet rim with ~605mm ERD will often measure around 18.5mm section depth.

If it is as I suspect then an old (rather than new) model Open Pro rim may be a straight swap, but there are heavier/stronger rims than that if you want something more durable.

cheers
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subandean
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Re: Rim replacement

Postby subandean » 22 Aug 2017, 8:34pm

On measuring again 296 takes me from the J to 4mm inside the rim, the rim section depth is 18mm.
I use the bike for day rides so would like to have a responsive, fast wheel, not looking for heavy duty on this bike.
Difficult to source an older Open Pro. CRS say the newer version has ERD 602. Would the Ambrosio Excellight with ERD 600 be a recommended option?
If neither are a straight swap then hey some new spokes!
cheers

Brucey
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Re: Rim replacement

Postby Brucey » 22 Aug 2017, 9:29pm

slightly baffled by LBS comment

https://www.sjscycles.co.uk/rims-tape/32-mavic-open-pro-c-700c-622-rim-cd/

'old' model Open Pro (as per above) is continuing in production for now, they say...

cheers
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Vetus Ossa
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Re: Rim replacement

Postby Vetus Ossa » 22 Aug 2017, 9:35pm

That H+Son TB14 rim looks nice I think.

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subandean
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Re: Rim replacement

Postby subandean » 9 Sep 2017, 5:49pm

Brucey wrote:slightly baffled by LBS comment

https://www.sjscycles.co.uk/rims-tape/32-mavic-open-pro-c-700c-622-rim-cd/

'old' model Open Pro (as per above) is continuing in production for now, they say...

cheers


I finally have my new pair of wheels, OpenPro rims as you recommended. They look good and ride well.

Cheers