Author Topic: Evolving views on matching rim width to tire width  (Read 334 times)

Danneaux

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Evolving views on matching rim width to tire width
« on: October 08, 2018, 07:51:48 PM »
Hi All!

My tandem needs some new rims and I've been researching the best match for the new, wider tires I plan to use for loaded touring. So far, the Andra 40s look to be a better match than Andra 30s for my 2.0in Schwalbe Dureme tires in this application due to the greater weight on the tandem resulting in the need for higher tire pressures and as a result, greater jacking forces against the bead seats and possibilities for incurring a split rim if the rim is too narrow for the tires/pressures used.

These two articles cover many of the issues and are thought-provoking...
https://bikerumor.com/2016/08/12/tech-story-match-bicycle-tire-width-rim-width-best-results/
https://www.notubes.com/technology/wide-right
...and might prove helpful to those dealing with similar issues.

I've had no problems using Andra 30s with 2.0 Duremes on my fully loaded Nomad, but even with my extended self-supported desert tours it doesn't carry as much gross weight as my tandem with two riders, panniers, racktop loads and trailer.

Best,

Dan.
« Last Edit: October 08, 2018, 08:06:05 PM by Danneaux »

JimK

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Re: Evolving views on matching rim width to tire width
« Reply #1 on: October 08, 2018, 08:16:15 PM »
yeah if my Andra 30s ever wear out, I've been looking at the Andra 40s to replace them. I kinda doubt it'll ever happen though!

mickeg

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Re: Evolving views on matching rim width to tire width
« Reply #2 on: October 08, 2018, 11:40:06 PM »
I assume your tandem takes 26 inch wheels.

I commented before that I wished I had bought the Andra 40s instead of the Andra 30s for my Nomad.  When I commented before, Dave from the shop commented that the Andra 30 were a better expedition rim than the Andra 40, but I do not recall exactly why he said that.  You might want to ask him for his thoughts.

When I built up my Sherpa, I expected to use tires in the range of 40 to 50mm.  From the chart at the bottom of this web page, that told me that I wanted a rim with an inner width of about 21 to 23mm.
https://www.sheldonbrown.com/tire-sizing.html

I bought the Salsa Gordo rims (now discontinued) for my Sherpa, and am very happy with them.  Inner width is 21mm.  If you expand this photo, you can see a very robust internal bracing.  But they have been out of production for quite a few years now.
https://salsacycles.com/files/components/comp_sm/rims_gordo26_1.jpg

When I built up my Nomad, I did not check the inner width of the Andra 30 because of the high recommendation that Thorn gave for that rim for heavy expedition usage.  It never occurred to me that they would suggest such a narrow rim for the 57mm tires that I was buying at the same time I bought the Nomad frame and the Andra 30 rims.

There have been a few times that I had to run higher pressure in my 57mm wide tires than I wanted to because those rims are so narrow.  I have occasionally thought about buying a pair of CSS Andra 40 rims and switching to them on my Nomad.   I am aware that SJS now recommends against CSS on both front and rear, but I would probably want that.  But the cost and shipping would be quite high, so I am not very enthusiastic about that.

Have you looked at the Velocity rims?  I put the Dyads (for 700c) on my Lynskey.  Before I bought the Dyads, I looked at the Co-Motion website to see what they were putting on the Americano which is a solo touring bike.  Since the Americano comes with tandem strength wheels, I felt that whatever they were using would probably be what I wanted to use.  Their website (as of spring 2017) said that they were having better luck with the Dyads than with Mavic A719. 

I do not know what Velocity model in 26 inch equivalent to the Dyad would be, but that is something I would consider researching if I wanted a non-CSS rim in 26 inch. 

And, as I noted above, I would look for an inner rim width that was appropriate for the tire width I wanted.  The Dyad inner width at 18.6mm is probably too narrow for your purposes, but for my Lynskey where I wanted to run anything from 28 up to 37, that is ideal.

Danneaux

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Re: Evolving views on matching rim width to tire width
« Reply #3 on: October 09, 2018, 12:57:09 AM »
Hi George!

Yes, 26in wheels. Thanks for your suggestions. I'll reply to you by PM as my tandem and its rim issues aren't Thorn-specific beyond my concerns for matching rim width to tire width at higher pressures and the use of Andra 30 or 40 rims, which SJS Cycles supply.

All the best,

Dan.

macspud

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Re: Evolving views on matching rim width to tire width
« Reply #4 on: October 16, 2018, 09:11:07 AM »
I assume your tandem takes 26 inch wheels.

I commented before that I wished I had bought the Andra 40s instead of the Andra 30s for my Nomad.  When I commented before, Dave from the shop commented that the Andra 30 were a better expedition rim than the Andra 40, but I do not recall exactly why he said that.  You might want to ask him for his thoughts.

When I built up my Sherpa, I expected to use tires in the range of 40 to 50mm.  From the chart at the bottom of this web page, that told me that I wanted a rim with an inner width of about 21 to 23mm.
https://www.sheldonbrown.com/tire-sizing.html

I bought the Salsa Gordo rims (now discontinued) for my Sherpa, and am very happy with them.  Inner width is 21mm.  If you expand this photo, you can see a very robust internal bracing.  But they have been out of production for quite a few years now.
https://salsacycles.com/files/components/comp_sm/rims_gordo26_1.jpg

When I built up my Nomad, I did not check the inner width of the Andra 30 because of the high recommendation that Thorn gave for that rim for heavy expedition usage.  It never occurred to me that they would suggest such a narrow rim for the 57mm tires that I was buying at the same time I bought the Nomad frame and the Andra 30 rims.

There have been a few times that I had to run higher pressure in my 57mm wide tires than I wanted to because those rims are so narrow.  I have occasionally thought about buying a pair of CSS Andra 40 rims and switching to them on my Nomad.   I am aware that SJS now recommends against CSS on both front and rear, but I would probably want that.  But the cost and shipping would be quite high, so I am not very enthusiastic about that.

Have you looked at the Velocity rims?  I put the Dyads (for 700c) on my Lynskey.  Before I bought the Dyads, I looked at the Co-Motion website to see what they were putting on the Americano which is a solo touring bike.  Since the Americano comes with tandem strength wheels, I felt that whatever they were using would probably be what I wanted to use.  Their website (as of spring 2017) said that they were having better luck with the Dyads than with Mavic A719. 

I do not know what Velocity model in 26 inch equivalent to the Dyad would be, but that is something I would consider researching if I wanted a non-CSS rim in 26 inch. 

And, as I noted above, I would look for an inner rim width that was appropriate for the tire width I wanted.  The Dyad inner width at 18.6mm is probably too narrow for your purposes, but for my Lynskey where I wanted to run anything from 28 up to 37, that is ideal.

Quote
When you get things sorted out and have a chance to try out the Andra 40 rims, let us know what you think of them. 

Looking at the Ryde site for the Andra 40 rims, it states:
   OPTIMUM TYRE WIDTH (MM)   37-62

That would be perfect for me, I mostly use 50 or 57mm wide tires on my Nomad, but occasionally use tires as narrow as 40mm.  Thus the range of tires I use is centered right in the middle of the recommended Andra 40 range.

I got the Andra 30 rims in part because the Thorn Nomad brochure said it was a great expedition rim, but it really is too narrow for the tire sizes I primarily use.  Since my tour a few months ago, I have been considering changing to different rims.  I probably would not have ordered the Andra 30 rim if I knew that they were that narrow - unfortunately I trusted the sales brochure where it touted it as a great expedition rim for the Nomad.

I am not too enthusiastic about a rim change, the time to put different rims on the hubs would be several hours, and I am sure that a new set of Andra 40 CSS rims shipped to USA would be quite costly too.  But, the Andra 30 rims are just too narrow for my purposes, which frustrates me. 

Slightly confused by your post, the Andra 30 is for 25-57 the biggest Tyre we fit is 55, you say the biggest Tyre you fitted was a 57 so your rims are fine for your tyre choices, I doubt a bigger tyre tan 57 would clear in a Nomad.

We looked at the 40 but the floor is wider and slightly thinner, we know from examples of overloaded Grizzly rims that this isn't a good idea.  So for now we still believe the 30 is the best touring rim for a Nomad.

Back to the OP its certainly not the best join, cosmetically not ace but in practice it would probably work just fine so if the seller gave you say 50% discount I would just use it and have it on the front.

Hope this helps, Dave.

Above is the post by Dave that you mentioned.
Going by the information on the Ryde website https://www.ryde.nl/andra-40   https://www.ryde.nl/andra-30, the Andra 40 is the only Andra rim that has max load 180kg classified as optimal, all the other Andra rims classify max load 180kg as not advised. Take from that what you will but it suggests to me that the Andra 40 is a very strong rim, though it weighs 825g compared to 740g for the Andra 30.
« Last Edit: October 16, 2018, 09:39:33 AM by macspud »

martinf

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Re: Evolving views on matching rim width to tire width
« Reply #5 on: October 19, 2018, 09:29:33 AM »
yeah if my Andra 30s ever wear out, I've been looking at the Andra 40s to replace them. I kinda doubt it'll ever happen though!

Same here. Andra 40s should theoretically suit the tyres I have better than my existing rims, but I already have enough 26" rims to see me out.