Research & Development

Shirabisu_Pass

Over the last decade-and-a-half, I’ve thought a lot about product development. Long before Bicycle Quarterly and Compass Bicycles, I was involved with several companies as a technical writer and translator. Part of my job was writing instructions, so I got to see product development up close.

From my experience, product development ideally has three components:

  1. Skilled users who are sensitive enough to report what they experience.
  2. Scientists who design tests to confirm those observations and isolate the factors involved.
  3. Engineers who translate those findings into better products.

With Bicycle Quarterly, it didn’t take long until we got involved in No. 1. We rode many bikes over challenging courses, and we noticed differences in how they performed, how they handled, and how they felt.

From those observations, it was a small step to No. 2. After all, our editorial team is made up of scientists, so the question “Why do some bikes ride/perform/handle better than others?” came up quickly. We began testing tires, we tested our hypotheses about frame stiffness, and we rode different front-end geometries.

No. 3 was a logical next step – what good are scientific findings if they don’t lead to bicycles people can ride? So we started Compass Bicycles to translate the results of our research into better bicycle components.

reifen_1005-2

Sometimes, steps 1 and 2 are reversed. That is how our tires came about. I hadn’t thought much about tires, until I saw a tire test in the German magazine TOUR. (By the way, the title in the photo above translates to “Roll Well”.)

Among other things, TOUR tested the tires’ rolling resistance. They found significant differences, but downplayed them by saying that the difference would “only” amount to 138 seconds in a 40 km time trial. That got me thinking: First of all, more than 2 minutes in a time trial is a huge difference. When I raced, 10 seconds over 10 km made the difference between first and fifth place. Could the faster tires have made me a consistent winner? More importantly, speeds are lower for the long rides we now enjoy, so rolling resistance is even more important.

Talking with Mark Vande Kamp (friend, riding companion and fellow Ph.D. on Bicycle Quarterly‘s editorial board), we decided to see whether we could replicate TOUR‘s results, but at lower speeds. We bought a set each of the fastest tire in the TOUR test, as well as a slower one. We scouted a location for a rolldown test, and one Saturday morning, we installed the test tires on our bikes and headed to the hill. I rolled downhill, first on one tire, then on the other (always using the same bike, of course). Mark timed me and found that the differences were quite large: about 10% faster with one tire than the other. We repeated the experiment, and the results were the same. Wow! Tires did make a larger difference than we thought. We knew we had to test this further.

We then went on a long ride and discussed what we wanted to test. Different tire models, obviously, but also different pressures. After all, we always were torn between inflating our tires to the maximum pressure to obtain the highest speed, and reducing the pressure a little to improve comfort. How much speed did we lose if we went for comfort? We also decided to test the same tires in different widths. And worn tires against new ones, to determine how much of a difference tread thickness makes. (Worn tires have a thinner tread, but otherwise are the same as new ones.)

Test_Woodland

The testing took a lot of time and effort, but the results were worth everything we put into it. We found out that the tires I had been using were among the slowest tires in our test. Simply replacing my tires allowed me to stay with previously faster riders during brevets. And when I rode alone, I consistently set personal bests, despite my training being the same as before.

As a positive side effect, the faster tires also were more comfortable. However, comfort was relative: The fastest tires in our test were only 24 mm wide – too narrow for true comfort on backroads.

Our research showed ways to improve these tires. We found that tire pressure did not have a significant effect on speed. This opened up a whole new way forward for tire design. Instead of trying to make wider tires withstand high pressures (which requires strong, stiff casings), wider tires should be made supple casings. Despite running at lower pressures, they’d be much faster.

GrandboisCypres

At the time of our tire tests, we just had started to sell the first-generation Grand Bois tires (above). We were disappointed that they did not score well in our tests. We shared our results with Grand Bois and Panaracer, and they came up with an improved version that had a more supple casing. That was the first product that came directly out of Bicycle Quarterly‘s testing.

Over the next few years, the Grand Bois tire program expanded, and we were able to test our findings on the road. We found that even with 42 mm-wide tires, our bikes were no slower than bikes with narrower tires. And Grand Bois worked with Panaracer to further improve the casings, resulting in the Extra Léger models.

tires_comp_700_28

We felt that further improvements were possible by optimizing the tire tread for performance. The tread on the shoulders of the tire only contacts the road during hard cornering, so it doesn’t wear out. We could make this thinner, so the tires would be even more supple and faster. We tested many tread patterns to obtain an optimum of cornering traction both on dry and wet roads. The result were our Compass tires. Our customers rave about their comfort, speed, cornering grip…

Our tires are just one example of the symbiotic relationship between Bicycle Quarterly and Compass Bicycles. Without Bicycle Quarterly‘s research, we wouldn’t have known that the tires we were using were slow. And without Compass Bicycles, our research would have remained of little use to riders. We would have outlined “ideal” performance tires, but without anybody making them, that knowledge would not have improved our riding experience.

cascade_ride

The main reason Compass components exist is so we can use them on our own bikes! And I truly believe that our riding experience has improved in many ways since we starting riding on wide, supple tires.

Click here to learn more about Compass tires.

 

About Jan Heine, Editor, Bicycle Quarterly

I love cycling and bicycles, especially those that take us off the beaten path. I edit Bicycle Quarterly magazine, and occasionally write for other publications. Bicycle Quarterly's sister company, Compass Bicycles Ltd., turns the results of our research into high-quality bicycle components for real-world riders.
This entry was posted in Testing and Tech, Tires. Bookmark the permalink.

43 Responses to Research & Development

  1. Do the Kevlar beads of the Compass Stampede Pass fit tighter on the rim than the Grand Bois Cypres? I stopped using the Cypres on our tandem as they came off too easily when I repaired a flat.

    • The tire fit is the same – there are internationally recognized standards on bead seat diameter that all tires should adhere to. Unfortunately, some rim makers no longer adhere to these standards, so you get some rims that don’t fit any tire well. Some of these rims, like the Velocity Synergy, have overly deep wells that make it difficult to seat the tire well. I wrote about that here.

  2. Paul Knopp says:

    I’m glad you are taking real-world approaches to making bicycles more safe, reliable, comfortable, and efficient. You may also want to explore why people who ride on platform pedals never complain about knee and foot problems.

    • Really? I switched from platforms to clipless precisely because of knee and foot problems! On the advice of my physiotherapist, I might add – I’d never have thought of it myself. And she is not a competitive cyclist so the various performance stereotypes and assumptions did not factor into her thinking.

      I am happy for people who specialise in cycling injury treatment and prevention to explore such issues…. and leave the bicycle testing to Jan and Co.

      • Daniel M says:

        I will chime in here as another data point. I switched (back) to platforms after using SPDs for years and my knees and Achilles tendons seem much happier as a result. I’m not convinced that our legs are optimized for pulling rather than pushing.

  3. Paul Ahart says:

    Your testing, and the development of tires that reflect the results, have completely changed the way I sell to customers and what I use on my own bikes. When a customer asks for a recommendation, I respond with a few questions: “Do you want performance and comfort, or is puncture-resistance all that matters? There are trade-offs. Are you willing to put up with the occasional puncture, but enjoy riding much more?” I then explain that using the largest section tire their frame will allow lets them decrease pressure for more comfort and probably fewer flats. Thanks to the research of BQ, the heads of many cyclists have been turned around on this.

    Now, if we could just get major bike manufacturers (and many well-regarded smaller ones) to utilize your findings on frame flex and how it affects riding efficiency. Far to many still subscribe to the “stiffer is better” mantra.

  4. Martin says:

    Do you plan on releasing tubeless versions of these tires at any time in the future?

    • Tubeless technology is still in flux. With our small production numbers, we cannot afford to make a new mold every time there is a small change, so we have to wait until we are certain that the specifications for tubeless beads are not going to change anytime soon.

      Also, true tubeless tires (which can be used without sealers) must have a rubber membrane on the inside, which makes the casing comparatively stiff. A better option appears to be a “tubeless-ready” tire that seals well on a tubeless rim, but relies on sealant to keep air from leaking through the sidewalls.

      • Christophe says:

        Tubeless Ready versions of Compass (or Grand Bois) tires would really be appreciated. I do not think any supple, light and wide (at least 32mm) tubeless tire exists on the market, you could be the first !
        I am even considering trying to mount Compass Stampede Pass tires without a tube (if I can find them in Paris, France): has anyone ever tried that ? Do you think it would be safe enough ?

      • Several riders have used the 38 and 42 mm-wide tires with tubeless setups. However, the tire pressures are relatively low – less than 3.5 bar (50 psi). With 32 mm-wide tires, like the Stampede Pass, you’d have to run higher pressures, and I cannot recommend that with a tubeless setup unless you have a tire bead that is specifically designed for this.

  5. Mark Fisher says:

    Thanks for filling the void with great products and reading for those of us who don’t do the Tour. I do have to ask that you start putting some more solid engineering behind your products. I’m sure the tires are fine since Panaracer is involved. That said, when I see decisions like chrome plating chrome moly steel rather than using stainless like 17-7 or 17-4PH, I have to wonder. I feel similarly about the lack of anodizing on cranks rather than using modern high strength anodized alloys like 2024 or 7075. If these decisions are for aesthetic reasons and for engineering reasons, that is fine. With proper treatment, chrome plated bolts can work fine (post plating baking needed), but no one would do it for engineering reasons. Similarly, a product developer would not recommend a single crank length to better maintain the strength of a mid-strength aluminum alloy that isn’t anodized. Corrosion protection and alloy selection are critical to fatigue strength. As a 30+year product developer/mech. engineer, it pains me to see such great product ideas (and they are great) not being implemented as well as they could be.

    • We have an engineer on staff, so your concerns have been addressed. Unfortunately, most of the changes you suggest would make our products less strong…

      Anodizing cranks protects the finish, except where the cranks get scratched and the raw aluminum is exposed. However, scratches are the places where cracks can grow, so anodizing doesn’t make the crank stronger. And you cannot polish anodized cranks, so you cannot sand out small nicks. Yet sanding out the nicks allows you to see whether they are just superficial or actual cracks. So a polished crank actually is as strong as an anodized one, and safer, because you can easily distinguish between nicks and cracks. (Powdercoated cranks are worst, because the cracks can grow undetected underneath the powdercoat.) As far as alloys go, 7075 aluminum suffers from stress corrosion cracking, so it’s a poor choice for bicycle cranks. 2000-series aluminums have been used for cranks since the 1930s, and they work fine. It’s a bit stronger, but also is a little more prone to corrosion.

      Regarding our chrome-plated CrMo bolts, they are far stronger than any stainless steel ones. Even companies not known for shiny components, like Race Face, insist on using plated CrMo bolts for their stems. You expressed concern about the potential for rust on CrMo bolts, but that is only superficial. I have never seen a bolt fail from rust, but I’ve seen plenty of stainless bolts snap. Furthermore, our bolts are triple-plated, with a layer of waterproof nickel under the chrome, unlike many classic bolts that only had a single, (porous) layer of chrome. So they are less likely to suffer from cosmetic rust, too.

      There are solid engineering reasons for the choices we make. They make our products stronger and more reliable. We also subject our components to tests by independent labs, and we are proud that our René Herse cranks are pretty much the only classic cranks that meet the EN “racing bike” standards for fatigue resistance.

      • Mark Fisher says:

        Regarding stainless bolts, there are many precipitation hardening alloys like 17-4PH that allow for strengths similar to grade 8 bolts (plenty for a bike application) and similar to 4130. They are available as a catalog item in english threads in McMaster Carr. Socket head cap screws have more options, though, and metric bolt suppliers have options. When I designed products for the aerospace and industrial tool industries, precipitation hardened stainless was the choice for this sort of thing. Honestly, though, strength isn’t as critical as you’d think unless you torque them up properly. Bolts I’ve seen fail on bikes are either due to corrosion or not using the correct wrench size. I also disagree on the crank length issue. Personally, I’d add a bit of material to make up for the strength reduction to get proper crank length…..I do have a vested interest here since I am quite short! Perhaps the existing forging could be drilled and tapped shorter. Honestly, the ultimate/yield strength of the material in a crank isn’t that critical. It is the fatigue resistance and notch sensitivity. I went through this same exercise with a 10,000 psi hydraulic cylinder and ended up with 2024T4. I believe 2014 is the forging alloy equivilent. That said, if you aren’t anodizing (as the marine and aerospace industries almost universally do), it might be worth considering the 5000 series of aluminum. It has similar strength as the 6000 series and better corrosion resistance.
        All this said, the offering you have is unique and fills an important niche that few other companies are addressing.

      • Thank you for the pointers regarding high-strength stainless. We may explore that for future projects. Most of our bolts are specially shaped for their applications, so we can’t just buy off-the-shelf bolts.

        The bolts on most of our components are relatively small to save weight, so fatigue resistance is an especially big concern. Most stainless steels don’t do too well there. The thought of a bolt that holds a brake pad snapping off during hard braking is not something I want to entertain.

        I agree that cranks break due to fatigue, unless you do big jumps. However, having a good grain structure is important there as well. We may offer additional crank lengths in the future, but they’ll each use a dedicated net-shape forging.

  6. Hi Jan,

    I have been using the Barlow Pass with standard casing for about 8 months now, and it is clearly the most comfortable/fastest wide slick you can get in 700C; just fantastic ride quality overall. However, I was wondering if you can speak to the possibility of Compass developing essentially a Babyshoe Pass tire in 700C? I think the Barlow with the 15% greater air volume you’ve cited before would be the ultimate gravel tire for an all-road bike.

    On the often washboarded and loose gravel here in Eastern WA, I think the extra float and shock absorption of a 42mm tire would be a huge upgrade, though I know many road bikes don’t have clearance for this size, which may limit the marketing possibilities too much. I have been intrigued by tires like the Soma Cazadero and Bruce Gordon Rock N’ Road, but I don’t think those would be supple enough for my taste, in addition to the “compromise” tread pattern.

    • The 15% extra air of a 42 mm tire does indeed make a big difference over a 38. However, it’s difficult to make a 700C frame that fits 42 mm tires, without resorting to wide mountain bike cranks. That is one reason why we prefer 650B wheels for bike with 42 mm tires. For us, making a tire that fits only few bikes is difficult to justify.

      By the way, you might want to try the Extralight casing. It’s yet another big step forward with respect to comfort and speed.

      • Also, in reference to your mention of wide mountain bike cranks, I’ve had great results using the White Industries Eno crank paired with their double-ring VBC setup on a 121mm bottom bracket on my Sam Hillborne. It seems like a good Q-factor for road biking and I’ve had no issues with clearance or chainline.

      • What is the tread (Q factor) with that setup?

        In many cases, it’s not the cranks that cause a wide tread (Q factor), but the bike’s chainstays that are splayed outward and necessitate a longer BB spindle. That is the case on many Rivendell bikes, starting with the Atlantis. Of course, this also moves the chainline outward to the detriment of shifting performance. With smaller wheels and careful shaping of the chainstays, you can use a standard 43.5 mm chainline, so you don’t only get narrower tread (Q factor), but also perfect shifting.

  7. Jan, Take Mark Fishers comments seriously. Many of us feel similarly. Many of your products are great but some are just good waiting in line to be great. Constructive feedback that you take to heart can help you do that.

    I found inconsistencies in both of your comments. For instance. I agree that steel bolts are often rated higher in strength than standard stainless steel varieties and the corrosion aspect is of no great concern. There are stainless bolts that are stronger than 4130. It is just that they are not commonly available. Saying they (4130) bolts are far stronger than any stainless is not accurate. The fact that they are 6 point hex nut in this day in age with far better standards (12pt, torx, etc) is less than optimal IMHO. If you want to make 1950’s recreations than fine. If you want to do what Mr. Herse would have done had he our materials and technologies you would make different engineering choices.

    http://arp-bolts.com/p/technical.php

    They will make whatever you want.

    Chrome cannot be plated directly to steel so at the very least there must be a nickel strike before. If you are saying that you have a better, thicker plate job done than I believe that. Electroless nickel with chrome would be much better than a traditional triple plate (thinner, stronger, more durable)

    • Take Mark Fishers comments seriously.

      Of course, we take every comment seriously.

      There are stainless bolts that are stronger than 4130. It is just that they are not commonly available.

      You are right – there are some very specialized stainless steels that are very strong. However, we need to work with bolt manufacturers who offer certain materials, and not others. So I should have said that 4130 CrMo bolts are stronger than any stainless bolts we (and others in the bike industry) can get. I think the main issue should be whether our bolts are strong enough. The answer is yes, they are as strong or stronger than any used in the bike industry.

      Allen and torque bolts are appealing, mostly because the wrenches are less expensive and less likely to slip. However, the bolts require thicker heads, since the wrench needs to fit inside. That makes not only the bolts bulkier and heavier, but also the parts into which the bolts fit. I don’t think it’s a coincidence that today’s brakes and derailleurs are so much heavier than many classic ones, despite offering no better performance. The Compass brakes weigh less than a short-reach racing brake, yet they span a 42 mm tire with fender, and offer similar braking performance.

      When we develop our components, we look at every part and think about how it could be improved. Through my previous work as a technical writer, I also have many contacts in the bike industry who are willing to help out, since they like our projects. We also are always open to suggestions and ideas for improvement. However, suggesting that anodizing our cranks would make them better, or substituting unobtainable stainless steel for the industry standard 4130 CrMo isn’t going to improve our products.

      Quite a few of our products do go against the current trends, but there are good reasons for what we do. We offer only one crank length, so we can use a net-shape forging, which makes the cranks much stronger. We don’t anodize our crankarms – but we do anodize our chainrings, which are made from 7075 aluminum for wear resistance. We don’t put ramps and pins on our chainrings, because that would eliminate the ability to customize your chainring combinations. And we don’t put puncture-proof belts into our tires, because that would ruin their ride, comfort and speed.

      As a result, our components offer true alternatives to the offerings from the mainstream makers, rather than just boutique items that offer snob appeal, but often are functionally inferior to the mainstream offerings.

      As an aside, from what I understand, it is possible to chrome-plate steel without other layers. It’s not commonly done any longer, except for hard plating to improve wear resistance, because chrome by itself isn’t corrosion resistant. Those old 10-speed bikes with chrome-plated hardware that rusted and peeled off are a case in point. With good triple-plating (copper to give a better shine, nickel to improve corrosion resistance and chrome to eliminate tarnishing), a part will be quite corrosion-resistant, unless you expose it directly to salt (sweat).

  8. I figured the very limited market share would be in the way. The bike I’m referring to is my Rivendell Sam Hillborne, and I know these clearances are rare in the road bike world. Your views and research on wider tires and how comfort and speed are not mutually exclusive had me see 38mm tires the way I used to see 28mm tires– too skinny! While Rivendell is far ahead of the pack in terms of wide + fast adaptability, I have chosen to get a Jones Plus as my next bike, and I am eager to see how this bike fares as a fast gravel bike with 60mm Schwalbe Super Moto tires.

    I still plan on keeping my Rivendell, and I was planning to upgrade to the extralight casing when my standards wear out, to maximize this as the “go-fast” light(er) duty bike. Looking forward to the reviews of the wider prototype tires in BQ!

    • marcpfister says:

      Limited market share? There’s 15+ years of Surly Cross Checks out there, which by themselves must dwarf 650b bikes by at least an order of magnitude.

      And now that “Gravel Bike” is a market category and the majors won’t dip their toes into 650b for a few more years at least, there should be plenty more 700c bikes that could take a fatter faster tire.

  9. Glad to hear a 700C X 42mm is in the realm of possibility. I neglected to include the legions of Cross-Checks and LHT’s that Marc mentioned. If 700X41 knards have mass appeal, I don’t see why a fatter Barlow wouldn’t be sought after, since those tread blocks presumably do nothing for you on gravel.

  10. John Duval says:

    After 25 years in product development myself, I find your process refreshing and exciting. The ideal is seldom reality. Ultimately you have to feed the sales engine either with the product the customer asks for, or some compelling sales story to convince buyers to change their minds. BQ is your sales engine, and the 4th necessary element in the product development cycle. Otherwise, no product.

    One positive thing that came out of component design in the 80s and 90s was the ability to hit the road or trail carrying one hex key and a flat bladed screwdriver. Now I find myself carrying a full set of hex keys and a couple torx. Throw Compass components into the mix and I am carrying several wrenches once again too. My parts may be lighter, but the tool kit is getting heavier.

    • I carry three tiny, superlight Mafac wrenches, which can handle almost everything on my bike. We are thinking of reissuing those… Most of all, our components are designed so the bolts don’t come loose. I have yet to use the wrenches on my custom bikes in seven years and over 50,000 miles. I carry them just in case…

    • BQ is your sales engine, and the 4th necessary element in the product development cycle.

      Bicycle Quarterly is an integral part, but less as a sales engine than as a way to explain what we are doing and why we are doing it. You may have noticed that BQ articles come years before the product, not after we introduce them. We first test tires, then make some. We first write how great centerpull brakes are, then develop them. It’s about sharing our findings, and then acting on them.

      Bicycle Quarterly‘s independence is very important in our R&D process. Otherwise, we might have acted like TOUR (whose biggest advertisers made tires that did not perform very well in their tests) and downplayed the performance differences, since the tires we sold at the time did not perform very well. Instead, we worked on improving those tires… Perhaps not a smart move economically, but Compass never has been about maximizing returns.

  11. Ford Kanzler says:

    Glad you’ve exploded the myth of skinny/high-pressure tires being the only “performance” solution and giving people a more comfortable, durable and even safer way to ride. The idea will likely take quite awhile to percolate down into the racer-wannbee set.
    I’ve been using somewhat wider tires (25 and 28mm) at well below max pressure for the last couple of decades with great comfort and speed. I recently rode a friend’s bike equipped with 23mm tires pumped all the way up and what a disconcerting experience. Reducing the pressure for my ride and returning the bike to him with the lower pressure, he was aghast. I suggested he just try it and I referred him to your tire test. We MAY have a convert! 🙂
    I look forward to soon building myself a bike that can use 32mm tires for a wider range of roads.

    • I used to ride 19 mm tires when I started racing in 1989… A few years back, I saw an old bike with 19 mm tires, and I couldn’t believe how narrow they are. 23s already are a lot wider, and the racers all are going to 25 and wider.

      For my own bikes, it’s hard to contemplate anything narrower than 38 mm now. 32s still will not be optimal on chipseal and other rough pavement, to say nothing of gravel.

  12. Were is the professional racing teams in terms of tire size and use of more supple tires?
    and what would be your guess three to five years out.
    I realize that bicycle racing frames would need to resized to accept say 32c racing tires
    Charles Nighbor architect

    • Based on our testing, on smooth roads, you don’t gain significant speed by going beyond 25 mm-wide tires. So there isn’t any reason for the pros to go wider, at least for the great tours.

      For the classics and especially Paris-Roubaix with all the cobbles, I think much wider tires would provide a significant advantage. With the big manufacturers pushing gravel bikes, it’s conceivable that they’d equip their riders with 35 mm tires… After all, racers don’t ride what is fastest, but what their sponsors want them to ride.

  13. Re: White Industries Eno Crank Q-factor: I measured the tread on my White Industries VBC crank with 48/32 rings on a 121mm BB and it was 153mm +/- 2mm. I had to eyeball to the edge of the other crank with my maxed-out caliper, and it was right at about 153-154mm. I looked up the TA Carmina triple on Peter White’s page and he lists the tread at 156mm.

    My plan with this was to have a “mountain crank” for the road, and this has worked really well. The principle in my thinking was in the same way Surly has gone with 2 rings for the O.D crank, to maintain a narrower stance with a bike with bowed out chainstays. It also makes sense from the standpoint of not having gear overlap by having a true off-road inner ring and a long enough high gear.

    • Thank you for the measurements.

      The tread (Q factor) of a standard Campagnolo double is 146 mm. The René Herse doubles we sell are 142 mm. 153 mm isn’t hugely wide, so my main concern would be your chainline. If it was moved outward by 3-4 mm, that would affect shifting, especially in the “big-big” gears that one tends to use a lot when running a compact double.

      • As long as I don’t fully cross-chain (48 to 34-30t) the bike shifts smoothly, but I do have to be careful to go down to the small ring on most hill climbs here in the Palouse. When you’re in a seriously hilly place, it’s quick training to learn to go to a lower gear than you need and work up (after nearly snapping my front derailleur off the first week mid-hill. . .)

      • Every setup entails compromises, so yours makes sense. I tend to shift late to maintain momentum on hilly terrain, and I use the “fully cross-chained” gear quite a lot, so I set up my bikes with a slightly narrower chainline than standard. That requires great skill from the framebuilder, because the chainstays have to be bent with great accuracy to provide clearance for the tires on one side and the cranks/chainrings on the other.

      • If only an innovative builder could come up with a no-compromise way to eliminate chainstays. 🙂

      • Mike DeSalvo build me a frame that will take 700 x 42c tires with a 68 mm BB shell and 43 mm long non-idented chainstays which gives me a 155 mm Q Factor with a triple or a 143 mm Q Factor with a double. It is not that hard.

      • It gets a lot harder if you want 42 mm tires, round chainstays and fenders with sufficient clearances (20 mm around the tire, except 8-10 mm at the chainstays and fork blades).

      • cbratina says:

        Fender clearance is 10 mm each side with 35c tires.

  14. I would like to add that I would have gladly gone to 650B wheels in my recent wheel re-build, if not for the brake issue on my Rivendell. The Paul Motolites were already bottomed out, so I couldn’t justify getting new brakes and wheels, I guess. In any event, it would be worth it to me to be able to go to a 650B X 42mm (or 50mm!) tire on my Sam Hilborne, as the 38mm tire size is just below what you’d be comfortable riding Eastern WA gravel in mid-summer. A Sam with 42-50mm fast, supple tires would be awesome.

  15. Michael says:

    I am glad BQ/Compass does all this research and develops better cycling gear.
    I am enjoying the tires they sell. Also the Decaleur for Pearl stems. Cleanest design for a decaleur in the world right now that I can find. And very fine tolerances for the bag pins/receiver interface. Very smooth and snug fit.

    I also like the ideas built into the Herse cranks. Removal of both rings without needing to remove the crank arm sounds convenient.

Comments are closed.