New Rims and Hammered Fenders


Grand Bois has re-designed their rims, so that they offer proper fit and support for tires. The new rims provide a great alternative for riders who don’t plan to run their tires tubeless, since they make tire installation easier and more foolproof.


When 650B tires became popular, we noticed that they often did not seat well on the rims. After some research, we realized that many 650B rims were poorly designed, with wells that were too deep to support the tire. The tires had to float (above), being held in place only by the hook on the rim sidewall. There are ways to mitigate this problem, but we stopped selling the Grand Bois rims when we realized that they were affected by this problem. Other companies continued to sell their rims with over-deep wells, and riders have been plagued with the problems of poor tire seating.


We are happy to announce that Grand Bois re-designed their rims to solve this issue. This required a new extrusion die, which is a considerable investment. The photo above shows the new (left) and the old rims. They look almost identical at first sight…


… but when you measure carefully (or draw a line in the photo), you see the difference: The new one (left) has a slightly shallower well than the old one (right). It doesn’t look like much, but it makes the difference between a tire that floats and one that is supported by the rim bed.

We have tested the new rims, and they fit the tires properly. In most cases, you simply install the tire, inflate it, and it runs round and true, without any further manipulation. With the flexible sidewalls of the tires we like so much, you sometimes have to push the bead in place, but it’s easy. This is how it should be.

The redesigned rims are in stock, both in 650B and 700C sizes, with 32 and 36 holes. They have a classic appearance with a rounded box profile that distributes the stress of the spoke tension well. The rims are polished to a high shine. The sidewalls are a little thicker than those of most modern rims, which means you will get a lot more miles out of them.

Unlike “tubeless-ready” rims, the Grand Bois rims have a curved bed, so the tire slides into position as it is inflated. (On “tubeless-ready” rims, the tire bead needs to clear a shoulder in the rim bed.) When the tire is deflated, it automatically moves to the center of the rim well, making it easy to remove. On the samples we tested, we easily could remove our Compass tires without tire levers. The Grand Bois rims are designed for use with cloth rim tape, so they have a little extra room for the thicker rim tape.


In other wheel news, we finally got hammered Grand Bois 650B fenders in stock. Honjo took a long time to make them, but it was worth the wait. Functionally and aesthetically, these fenders are close to perfect. They envelope the tire nicely, and their diameter is a perfect fit for 650B x 42 mm tires without further “adjustment.” The hammered dimples not only give the fender a nice-looking texture, but they also make dents and scratches almost invisible. Like all aluminum fenders, they are ultralight and the rolled edges keep the water inside.

Click here for more information on the rims, and here for the fenders.

About Jan Heine, Editor, Bicycle Quarterly

Spirited rides that zig-zag across mountain ranges. Bicycle Quarterly magazine and its sister company, Compass Cycles, that turns our research into high-performance components for real-world riders.
This entry was posted in hubs/rims, Testing and Tech. Bookmark the permalink.

31 Responses to New Rims and Hammered Fenders

  1. With Stans No Tube technology, most rims suitable for folding tires can be converted to a tubeless setup. I mounted Hutchinson Secteur 28 tires (700 X 28 mm) tubeless on my wife’s Mavic Aksium rims using Stans No Tube rim tape, sealant and presta valves. I did the same with my Grand Boise Hetre 650B x 42 mm tires and Pacenti PL23 rims. The cost per wheel to make the conversion is about $15. The tires are almost puncture proof providing the sealant is changed every 2-6 months, depending on the ambient temperature of the region. Further, the wheel is about 12% faster than the same tire with an inner tube installed. Mounted tire weight is reduced by about 85 grams. If Rene Herse, were alive today, his team would be using No Tube technology.

    • Jim Thill says:

      Rod: you are correct that it is sometimes possible (to varying degrees) to use non-tubeless rims and tires for tubeless applications. I’m a fan of tubeless tires, too, and have used it on rims/tires that aren’t intended for tubeless. But I’d urge a good deal of caution and skepticism in using tubeless technology on tires and rims that were not made for that application. It sounds like you have had some good luck with your tubeless experiments, but in general the use of non-tubeless rims/tires for tubeless applications either doesn’t work at all, is difficult to set up, or has some significant drawback (sealant leaking through sidewalls at desired pressure, loss of air pressure overnight, etc). And of course, there is a potential safety concern. Tubeless compatible rims and tires tend to have extremely uniform hooks/beads that grip more tightly to each other. A rim with an imperfect grip on the tire bead might be ok for tubed use, yet be prone to rolling off in a corner without a tube holding things together. Anybody who tries one of these tubeless conversion experiments should be aware of that risk.

      • Jim: The Pacenti PL23 rims are a tubeless design. The Grand Boise Hetre tires seated and held pressure without sealant when I initially set the tire on the rim. This was also the case for the tubeless Secteur 28 tires when I initially seated the tire on the Mavic Aksium rims. As a retired chemist/engineer, I do not jump into these experiments without prior research. I already knew the above combinations worked from my research. We have never experienc sealant leaking through the sidewalls. Perhaps because we use low tire pressures. The Hetre are inflated to ~40 psi (F) and ~45 psi ( R). The Secteur’s are inflated to 70-75 psi (F) and 75-80 psi ( R). The tires do leak off pressure over a period of a few days but the low pressure makes them easy to maintain.

        Stans No Tube has excellent product support and I recommend cyclist venturing into tubeless tires consult with Stans support personnel. Stans is not the only company manufacture tubeless tire technology and all have support personnel.

        By-the-by, the tubeless Secteur 28’s were developed for teams competing in the Pari Roubaix race. Before installing these tires, My wife Lenora rode on Specialized 23/25 tires with a tire pressure of 100-110 psi. With the Secteur 28, the bike appears to be faster and ride comfort is significantly improved. Lenora’s first ride on these tires was a metric century and she was very pleased with the speed of these tires and the ride comfort. As reported in Bicycle Quarterly, wide supple tires set a lower pressure can be as fast or faster than narrow high pressure tires and ride comfort is significantly improved.

  2. Cory b says:

    These fenders seem like a much closer repro of the hammered Lefols. They do look like they cover a better profile of the tire, allowing nice fender lines and very good clearance. Jan, what is the distance from your rear axle to seat stay bridge ? Your Herse is very well designed with great clearance.

    • Yes, Grand Bois went through a lot of effort to get these fenders right. They re-made the tooling for the hammered dimples several times until it was “just so.”

      The fender clearance on my Herse is about perfect – the dimension was copied from a 1952 Rene Herse. Perhaps we should do a BQ article on the optimal clearances for various tire sizes. I still see way too many brand-new bikes where the fenders are much too close to the tires. It’s not just an aesthetic problem, but it also greatly increases the danger of the fender crumbling into the fork crown.

      • Cory b says:

        It seems riders like the tight aesthetic of a racing bike and maybe the chunkiness of a proper fender clearance is unappealing to some. If you could measure that distance mentioned, that would be great. I’m pondering a conversion and am trying to gauge clearance. Great idea for an article ! What about a blog post on efficient pedal stroke as well?

  3. charliewhite says:

    Any chance of getting 40 and 48 hole rims? Although it seems like overkill, the builder of our tandem suggested that we run the higher spoke count rims. We have gone through several Velocity Deep V rims and I am really disappointed with their lifespan. We are currently trying Velocity Chukker in hopes that they last longer. On average I am replacing rims after 2500 miles. Not much longer than the tires are lasting. I have no idea what the thickness of the braking surface on the Velocity wheels are, but at this point I am looking for alternatives. Switching to a 36 hole rim would be costly as I would have to replace both my Schmidt hub and a Phil Wood rear hub, not something that I want to do.

    • I think 40 holes on the rear wheel of a tandem is a good idea, even with wide 650B tires. On the front 36 holes are sufficient.

      The Japanese don’t ride tandems much, and these rims mostly are made for Grand Bois’ own bikes. So it’s unlikely there will be a 40- or 48-hole version soon.

    • Bill Gobie says:

      Charlie, Are you using a drag brake on your tandem? If you’re braking a lot to control downhill speed a drag brake will take a lot of the work off your rim brakes.

    • Doug Wagner says:

      You might try DaVinci V-23 tandem rims. They are quite robust, and come in 700×40. We use them on our tandem, and have 10 years of wear on our 26″
      Doug Wagner
      North Port Fl and Ky

  4. Tobin Henderson says:

    This is great to hear. I’ve nearly worn through my old set of Grand Bois rims, and I’m so tired of fighting with them.

  5. Andy says:

    Can you clarify the weight? On the sidebar it lists a 650b rim as 468g, but the pdf tech info lists 488g. For comparison, I see Velocity claims 435g.

  6. Greg says:

    Jan, this is excellent news. Also, they added some lightness, if I may paraphrase the late Colin Chapman. Even better! I’ve held off trying the GB rims in the past, but it sounds like now is the time to go for it. I like the look, the shape, and now the tech. details sound great as well.

  7. Andrew says:

    What’s the inner width of the rim? Also, what are the recommended minimum an max spoke tensions?

  8. Conrad says:

    I’m curious, who manufactures the grand bois rims?

  9. cbratina says:

    Any chance of wider rims? I have switched to 24 and 25 mm outside to outside.

    I would second the 40 hole request for tandems not many there.

    • Alex says:

      I, too, wonder why the chance to make the rims wider was not taken – especially since the extrusion die had to be remade, and given recent findings regarding the benefits of wide tires paired with wide rims. In both 584 and 622 a wider rim would have made sense (although admittedly mostly for the 622 paired with generally narrower tires), and involved only the one new die. Admittedly, 17mm is ok, but over 20mm, such as the HED Belgium Plus, is even better, n’est-ce pas?

      • The rims are mostly used for Grand Bois bicycles, which use tires from 28 to 42 mm. Hence the choice of rim width… It also keeps the rims interchangeable for riders who have several wheelsets, albeit I doubt that is the case for many people with randonneur bikes.

  10. vladluskin says:

    The rims very nice, but at $98 per rim seem quite steep.

    • It depends what you use for comparison. Most Pacenti rims costs about the same, so does the Velocity A23, the HED Belgium is $ 150, and that one isn’t even polished. I wish we could offer them for less, but between the cost for the new die, the labor for hand-polishing, and the high price of shipping small batches of rims, we actually don’t make much money on them. If we could order a containerload, the price would drop significantly.

      On the other hand, I know that every time I don’t have to wrestle with my tires when mounting them is worth quite a bit to me.

  11. Paul Ahart says:

    I and I’m sure many other professional bike mechanics, appreciate the attention Compass Bicycle and Grand Bois pay to the fine details that make the difference between rims that mount tires easily and correctly, and those that have either too deep an interior or too shallow, making the tires impossible to seat, or impossible to install. Same with your Honjo fenders, with their exactly correct dimensions, minimizing any bending or stretching. As they say, the devil is in the details, and I’m glad you give them the attention they need. Well worth the price.

  12. TomT says:

    I have a set of wheels built with the 1st version rims, and use wide cloth tape, haven’t had any difficulty with mounting or centering the tires, including different Grand Bois – 32-42 and Pacenti P.M. My guess is that the thicker cloth tape built up the rim’s well to its proper depth.

    • Glad the original Grand Bois rims are working for you. They never were as bad as the “improved” Velocity Synergies, which were (or are – I think they still make them!) too large in diameter: The line on the tire sidewall had to seat on the hook of the rim sidewall, which it didn’t want to do…

      I haven’t had problems seating the tires on the original Grand Bois rims, either, but it’s nice if they seat automatically without having to mess with them.

  13. Chuck Hoefer says:

    I find myself wondering how the tandem commenter would be wearing out the Velocity Deep V rims in 2500 miles. That does not seem like something that would be happening unless there is something wrong.

    I would go along with the recommendation of 36 hole rims on the front of a 26″ or maybe a 650B tandem but for the larger diameter 700c wheel, I think more spokes make for a safer wheel. I say this because as a tandem turns, it “pushes” the front wheel, whereas a single bike does so to an insignificant degree. This can be validated by the fact that front tandem tires wear out much more quickly (even in relation to the rear tire) than do those on single bikes.

    While I recognize the desire for light weight in bicycles, most tandems are used in a way that sends me to the conservative side of the fence. A couple who goes out for a ride together will be better served by a bicycle that does not let them down. Racing is another matter and it is not what I am addressing here.

    Chuck Hoefer

  14. Sean says:

    I was wondering if the rolled edge of the fenders have a ‘tunnel’ of sorts with sufficient space to thread a dynamo wire?

    Thank you!

Comments are closed.