Road Bicycle Hubs
There’s no doubt disc brake system are very well on the method to the trail cycle marketplace. A few major brands like Colnago and Specialized recently launched production designs, Volagi built their brand together with them from outset, and disk brake cyclocross bikes tend to be pouring in.
Exactly what does all this mean for opposite side regarding the wheel? We’ve covered a few of the technical difficulties and problems of utilizing disc brakes on roadway bicycles and also the modifications required for tires. Nevertheless conversation’s been lacking one important element of the change. Virtually everybody that’s making or planning a disc brake road or cyclocross cycle has 135mm backside hub spacing regarding attracting board.
That’s 5mm wider than what road-bike structures have been made for. 5mm broader than what decades of drivetrains being created around. Yes, that is only 2.5mm per side, which does not seem like a great deal. Before you give consideration to that Shimano just required 1.8mm to include an 11th cog.
We spoke aided by the engineers and product managers at FSA, SRAM, Shimano, Specialized, Parlee and Volagi to observe how this can impact string range, shifting performance and heel approval on which might be your after that road bike…
CHAIN LINE & SHIFTING
One of the greatest problems we heard in the beginning ended up being the way the string line could be affected during the extremes, specially when cross chaining from the small band into littlest cog. Given, the majority of us know a lot better than to drive such as this for lengthy, but it takes place. When it does, the sequence could snag from the huge ring, causing a mis-shift, jammed chain or worse if you’re really cranking.
Above is a regular 53/39 Ultegra crankset and cassette to my Moots cyclocross bicycle. This has 135mm rear spacing and disc brakes. We place the camera’s focus during the chainrings (left) and cassette (right), click to expand.
What I within this equipment combination had been that my chain was dangerously close to the huge ring’s teeth (showcased in yellow). Simply click to expand and you’ll notice it better. You may see how close the string will be the front derailleur’s cage. It’s maybe not rubbing, thankfully, but -and this is certainly a large but- my ‘cross bike features fairly lengthy 423mm chainstays.
Where this becomes a genuine issue has been race-oriented road bicycles with very quick chainstays. The Specialized Tarmac has 405mm stays for most framework sizes, including. It’s these types of a potential issue that FSA has established and given a technical consultative bulletin aided by the after recommendations to assist make sure appropriate shifting and clearance:
At top, the chart reveals OK’d chainring and chainstay combinations for standard 130mm hubs. Below it, the same thing for 135mm hubs. The increased limits become pretty obvious with that purple.
Also it’s not only the big ring’s teeth that could catch the chain. Shift pins are used to help guide the chain up during an intentional move. But, obtain the chain too close also it may help on unique.
While Shimano wouldn’t get into much information when it comes to product designs and research regarding this matter, they performed send over their standard statement in terms of compatibility. Dave Lawrence, Shimano road item manager, had this to say:
“Shimano happens to be a frontrunner in cycling component manufacturing. Element of that success is because of Shimano’s ongoing interaction with frame manufacturers. With Shimano’s CX75 and R515 technical disc brakes for cyclocross and road bicycles, Shimano is well-aware of this industry-wide proceed to wider back spacing for roadway and cyclocross bikes. Although this does impact chainline, presently Shimano is certainly not changing its 430mm chainstay length guideline for ideal Shimano element overall performance. Be Confident though that Shimano will continue to talk to framework manufacturers.”
So, what does everyone have to say? I asked some standard concerns, responses from each brand follow. What’s interesting is that a lot of them don’t see this just as much of a challenge, and others talked about things we hadn’t even looked at.
Including, we believe roadway and ‘cross bicycles are only switching to 135mm hub spacing to make space for the rotors. Perhaps. Not. As with many things in life, this will depend on who you ask. Fortunately, we ask a lot of people a lot of questions. And similarly thankfully, they don’t get fed up with it! Here we go…
THE QUESTIONS & RESPONSES
We talked with Omar Sisson (mind auto mechanic) and Robert Choi (Co-owner) of Volagi and Tom Rodi (item supervisor) at Parlee before assembling our formal concern number. Our conversations together tend to be transcribed further down. For those concerns, we reached out to the businesses mentioned and Colnago, but performedn’t hear back from their store. For other individuals, the replies are from Jason Miles (FSA, Engineer), Scott McLaughlin (SRAM, lead drivetrain engineer), Charles Becker (SRAM, road product supervisor) and Ty Buckenberger (Specialized, carbon road-bike task supervisor).
BIKERUMOR: exactly how ended up being chain range and drivetrain function (ie. shifting, cross chaining, etc) impacted by increasing the back hub width to 135mm? Just what steps did you decide to try make sure appropriate overall performance?
FSA: One problem we’ve seen is when you have got really brief chainstays and a large difference between chainrings, like, state, a 53-39. In the event that you struck a bump, the big ring can grab the string and trigger a bit of ghost shifting in the event that derailleur is trimmed so that its cage isn’t massaging the chain when you’re regarding smaller cogs, too. It may additionally cause the string to drop to a smaller equipment a little slowly than you’d anticipate.
We’re taking care of solutions, and our chainrings will have to transform. The string rub you could encounter today won’t be there forever. Meanwhile, we make the RD460 wheelset that’s a 130mm road disk brake wheelset. MSRP is $499.99 and will come in at 1830g. It’s been spec’d using one associated with the Redline Conquest bikes in past times, we’ve been making it since 2006.
SRAM: First, it’s really worth discussing that Road/CX bicycle rear hub spacing would not differ from 130 to 135 to support disc brakes. Bike frame and wheel manufacturers decided that they could make stiffer frames and stiffer wheels with 135 rear spacing. And because they had a need to design new road/CX wheels and road/CX frames to allow for disc brakes they chose to use the occasion to also change to 135OLD. Nevertheless, forward and rear shifting are effected because drivetrain is optimized for 130OLD. We recommended a solution that individuals aspire to implement quickly.
SPECIALIZED: We’ve done considerable screening to guarantee that the shifting had beenn’t affected on our existing disk bicycles (Roubaix and CruX). The chainstay length on those two models helps. The small/small gear combo on Roubaix with 135mm dropout spacing isn’t any worse than a shorter chainstay cycle with 130 spacing.
BIKERUMOR: exist particular gear combinations that don’t are really or don’t just work at all in this arranged?
FSA: See charts above.
SRAM: It depends regarding the cycle framework measurements but cross chaining whilst in the tiny chainring is affected many.
SPECIALIZED: All the equipment combinations can be obtained, although not always suggested. Similar to bicycles the small/small gear isn’t perfect. It works, you could get some chain/front derailleur contact because combo. Equivalent contact takes place of all overall performance roadway bikes with 130 spacing and brief chainstays.