Overhaul time: Why is My Bike Soooo Sloooow?

Almost done; Just a little more Dremel action to make room in the chaincase for the Nuvinci hub’s large shifter unit.

Here is a techie tale of real world, long term product testing and what an enormous influence bike maintenance can have on your cycling pleasure. You may recall that I use my own bike to test components and accessories, usually for a couple years unless something just sucks. Then I just remove it as quickly as possible. If I really like something I just call it “mine” and leave it in place until I have a reason to do otherwise.

About a year ago during a several week cold spell I decided that my own Fr8 was deadly, painfully slow compared to others. But I hate repairing my own bikes so I just kept on riding it through the winter, spring, summer, fall and some more winter until a couple days ago. Nothing was really broken nor made even an annoying peep; I just had the feeling I was pedaling pretty hard while grandmas with flowers in their hands and moms on bakfietsen loaded with four kids glided on past. Was I just a little tired… for an entire year? Cycling on this bike just wasn’t as much fun as our others but usually I wouldn’t notice it and if I did notice I’d forget about it shortly after locking up (or not!) and walking inside.

This is exactly why we exhort you to regularly service your bike, unlike yours truly. A well maintained bike is just nice to ride and a crappy running bike is less so, even if you don’t actually notice it. Why sweat more than you need to? Why feel that click, clack or sloppy drivetrain when you can daily enjoy the pleasure of pedaling along silently and effortlessly. This must be one of the world’s cheapest pleasures.

I assumed the abundant friction in my bike had something to do with the NuVinci N360 infinitely variable hub since that’s its most unusual feature. With the bike in the lift the rear wheel required a good tug to turn and it didn’t spin at all. I was totally wrong about the hub but will get to that later. We’ve discussed the Nuvinci friction thing ad infinitum on the @Workcycles Facebook group. Unfortunately a Facebook group can’t be searched so finding those discussions again would mean hours of scrolling. No doubt Mr. Zuckerberg is snickering this very moment while he employs his own powerful FB search engine to scan the Groups for info about Nuvinci hubs and Workcycles Fr8’s.

I spoke to the folks at Fallbrook/Nuvinci. They assured us that that the cold should have little influence on the hub’s efficiency so there must be something wrong with my hub. A replacement hub was quickly dispatched. It then waited patiently for a half year, for the day that I have both the time and willpower to pull my Fr8 apart, build a new wheel and put it back together. The other day the temperature dropped well below freezing and my rear brake and shifter cables froze. After spinning madly to school and work for a few days in the tiny ratio it was stuck in I declared my bike officially “broken”. The operation could commence. I gathered several other new parts to try and stripped my bike.

With the wheel out of the bike and the rollerbrake removed I clamped the axle in the vise and spun. It spun rather well I must say. I mean this ain’t my track bike whose unsealed, oiled bearing wheels will spin for several minutes before gradually stopping, but the Nuvinci wheel did spin almost as well as most other multigear hubs do. Further, spinning axles with my fingers, I couldn’t detect any difference between the 18 month old, ridden daily and stored outdoors Nuvinci and the brand new one. As far as I can tell this hub is as good as new.

monark-centerstand-workcycles-gr8 1
A fresh, clean Monark centerstand, aka “The Mother of All Centerstands” on the same bike when it sported skinnier tires and a single gear.

What then is dragging my ass down? Could it be the Hebie Chainglider, which “glides” along the chain instead of being attached to the frame? It and the chain running through it were both filled with a gritty, slimy paste of oil and dirt. It was vaguely audible while riding and sounds take energy to create. I decided: Away with Chainglider! I only put it on this bike because I was too lazy to cut up a real Hesling chaincase to fit around the Nuvinci’s shifter interface and the Monark “Mother of All Centerstands”. Actually I’m still kinda lazy; I removed the Monark centerstand and installed another Ursus Jumbo. I’d previously tested and broken one of these but it’s apparently been improved since then. Time to try it again, and very convenient that it just barely fits together with the chaincase.

Fr8 Henry 2012
My bike in the spring with the sludgy Hebie Chainglider still installed. I’m very happy to have a real, silent, frictionless Dutch chain case on my bike again.

Still, I couldn’t believe that either the Chainglider or the filthy (but almost new) chain were really causing so much friction. Spinning the crank backwards the friction was negligible, despite the scraping noises. So the Chainglider wasn’t helping the bike’s efficiency but it also couldn’t have been the root of the problem. Nonetheless a real Dutch chaincase is always better if it fits. After half an hour of Dremel grinding and careful adjustments to the brackets the chain ran through the Hesling case silently and with no friction whatsoever.

Eurobike 2009 14
Shimano Rollerbrakes exposed; The IM80 rollerbrake has a much bigger, sturdier brake unit.

Next stop: Rollerbrakes. The Shimano IM80 rollerbrakes on this bike have performed admirably since I installed them. They stop the bike with authority and have good lever feel too. The braking power was confidence inspiring even while cycling in the steep hills of Brussels with two kids and baggage aboard.

Orange Bike Days-2011 14

Little did I realize, however, that my powerful rollerbrakes were braking ALL the time. Once the rear brake was in my hands it was obvious who the real culprit was; A fine paste of Shimano’s sacred, expensive rollerbrake grease and road dirt filled the brake unit requiring serious hand force to rotate it. The front brake was better but not much. Did I screw them up myself by putting too much grease in them? I don’t remember.

With copious quantities of brake cleaning fluid and compressed air I removed every trace of everything from the brake units. Wonder of wonders they spun almost freely now, rather like the name “Rollerbrake” would imply. No way I’m going to sludge these babies up with that stupid grease again! What else could I put in there to keep them from rusting and lubricate the innards? After a quick inventory of the dozens of little bottles and cans on the Workcycles shelves we decided that a thick, clingy OIL ought to work, even if it violates all instructions, death-warnings and warranties. After all these brakes are fairly well enclosed and don’t see any substantial heat here in cool, mostly flat Amsterdam. The most likely problem I anticipate is that they’ll have to be oiled periodically but whether that means monthly or half yearly remains to be seen. Even generously lubed with oil the rollerbrakes spun quite freely. Back in the bike the rear wheel and brake now spun totally normally.

While I was at it I adjusted the front (dynamo) hub cones: They were waaaay too tight, as delivered from the factory. Now my front wheel spins and spins as if it weren’t filled with magnets and coils. Take that, hub dynamo haters!


Of course I also had to fix the problem that pushed me to tear the bike down in the first place: All four cables were removed and given the super special Workcycles anti-freezing treatment. That was when I discovered that the Nuvinci shifter’s adjustment barrels had rusted solid. I just replaced the whole shifter, noting that the new one came with smoother, drawn cables. This is then the only problem the Nuvinci hub has had thus far, an excellent record for a first generation product.

The last update for the day was swapping the older 44T steel crank for the new Sugino 38T forged aluminium crank we’ve begun using. The 44/20 gearing had always seemed a little on the tall side so I figured 38/20 should be about right. Like the Shimano Nexus 8sp hub we fit thousands of, the Nuvinci’s 1:1 ratio is in the upper middle of the range. That is, these hubs have somewhat more undergearing than overgearing, generally quite handy for heavy duty bikes with full sized wheels.

Everything back in place, grips securely glued to the handlebars… and let’s see how it rides. I rolled out the door, pedaled along and Lijnbaansgracht and immediately found myself spinning out in the highest ratio? Huh? I did lower the gearing but not by so much and it was too high to begin with. It was dinner time so I just continued my spinning session for the kilometer home to deal with the gearing later.

That little silver thing next to the chain is the shifter interface and has to rotate most of the way around the axle – thus the cutaway.

The following morning I hung the bike up again and pulled the wheel to check that the shifter was installed correctly and reaching the full range of ratios. It was. Then I swapped the 20T cog for an 18T making the gearing almost the same as the old (too tall) 44/20. That was a considerable improvement but bizarrely the gearing is still much too low. Once up to speed on any flat road I just twist it into the highest ratio. Even the steepest bridges require shifting down to only about halfway through the range. So I’ll try 17T and 16T when I find them.

The upshot is that I’ve basically been dragging a plow around behind my bike for at least a year. Fixing the brakes, chaincase and front hub wasn’t just a “marginal gain”. It has improved the bike’s efficiency by so much that it can be ridden much faster with the same effort. I can’t be bothered to do the math but it really must be at least a 25-30% speed difference. That’s huge. Faster is funner and easier is nicer… so maintain your bikes folks! It really matters.

70 Responses to “Overhaul time: Why is My Bike Soooo Sloooow?”

  1. Hulkki Says:

    Hi Henry! Thanks for a great blog! One question regarding the type of levers to use with rollerbrakes: the Shimano techdoc says:
    …brake levers are equipped with a mode switching mechanism. Be sure to use the BR-IM81-F, BR-IM80-F, BR-IM55-F, BR-IM45-F with the mechanism in the C.R. mode position.
    The C indicates the mode position for compatibility with cantilever brakes. The R indicates the mode position for compatibility with roller brakes.

    So not V mode, but you say:

    henry Says:
    February 23rd, 2013 at 18:55
    Hi Brian,
    Yes, you actually answered your own question. The old type rollerbrakes were meant for standard, high leverage brake levers and the new series (IM45, 55, 80, 81 etc) require V-brake type levers. That will fix the problem.

    So witch one is it? Also, how are your brakes doing with the oil? Any problems? I’m considering the same thing for winter, as I’m afraid the cold temperatures will freeze the grease… Do you think the IM81 is considerably more powerful than the IM45? I’m finding the IM45 little weak on my heavy cargo bike.

    How about those pictures about cleaning the brakes? Any chance you might blog them?

  2. Dirk Says:

    Hi Henry, I’ve just got a new Fr8 super cool bike..
    I noticed the front and back wheel free spin only about 2 turns when I give them a push. I’ve read above comments about drag of the roller brakes (im80 I have) and the hub (mine is a: shimano dh-c6000-2r) .

    I’ve on question regarding this remark you made:

    “””While I was at it I adjusted the front (dynamo) hub cones: They were waaaay too tight, as delivered from the factory. Now my front wheel spins and spins as if it weren’t filled with magnets and coils. Take that, hub dynamo haters!”””

    There are only hub cones adjustable on the left hand side, no? .. if not, how do I get to the right hand side cones?

  3. henry Says:

    Hi Dirk,
    You adjust both cones from the left side. It’s just adjusting the distance between the cones on the axle, thus both bearings.

  4. Jonathan Says:

    Hi! Since this article is in part about roller brakes and it seems you guys in .nl have much more experience with those than anybody I can find here … do you by any chance know what the differences between the various Shimano roller brakes are? I’m mostly interested in BR-IM45, 80, 81 and 86, both -F or no -F. There are installation and user manuals available for all of them, but no mention of brake forces or usable braking times at various temperatures anywhere. From what I could gather from the internet so far is that people don’t like the ’45 for being too weak and that the ‘80,1,6 models all seem to be considered “okay”. You describe them as “stopping with authority” and the weight of your bike + you + two kids is probably upwards of 130kg? How much difference in possible braking times is afforded to the IM81 vs. the IM80 in your experience? Not looking for hard numbers here, just whatever you feel you can say about them… Thanks for all the helpful articles in your blog and best regards from neighbouring Germany!

  5. Dan C Says:

    Yes i also wonder about the difference between all the different models, all i can see is that the IM86 is rated for a higher load, 130kg, so presumably that means it can apply more breaking force?

    Also what about hub compatibility? The service manuals suggest only certain models should be used with certain hubs.

    The -F means it’s the front brake.

  6. henry Says:

    Basically Shimano has made three levels of rollerbrakes for many years. There are the el-cheapo units that are permanently attached to a dynamo hub, the less expensive units with flat brake track, and the higher end models with the V-shaped brake track. Within each type there are no meaningful differences. The brake unit and hardware is always the same but the cooling disk varies in size and shape.

    All of the replaceable units fit the same shimano rollerbrake hub splines. Other, non Shimano hubs are also made with rollerbrake compatible splines: NuVinci CVT and some front hub motors are the most notable examples.

  7. Dan C Says:

    Thanks, so where does the 45 and 8x series fit in this categorisation?

  8. henry Says:

    Shimano changed the rollerbrake numbering system a year or so ago but in the old system the 4X and 5X were the cheaper models and the 7X and 8X were the high-end models with V-shaped brake track. WorkCycles only fits the 8X models (and now the differently named but basically the same models that replaced them).

  9. Chris Schafer Says:

    Thinking of buying a used WorkCycle Kruisframe bike here in the states. It is an 2006 serial number purchased in 2008 at Clever Cycles PDX. Very well taken care of but I am pretty big and I intend to carry near capacity loads and perhaps use a trailer with it. So I would like to know if I can upgrade the stock brakes to the the newer larger systems. I won’t do it right away but I want to know I have some options as there is pretty much no where I can purchase these locally. I notice they aren’t in stack anywhere right now. Is Shimano changing the model out or discontinuing them? Either way they a a great deal at $50 each. I just want to make sure I don’t end up with something that I can’t maintain without a trip to Europe. 🙂 Though perhaps there are worse things.

  10. henry Says:

    Chris, Yes, all of the roller brakes fit the same mounts on the hubs. The IM80 has been renamed the BR-C-6000 but seems to be exactly the same brake. They’re still in production and we still build most of our bikes with them.

  11. Paul Says:

    Hi There,
    This is a very interesting read. We have a fleet of hire bikes here (2500!) all with roller brakes. The newer ones have nexus which work fine but we have older new bikes being commissioned after being in storage for three + years with inter m brakes on. The brakes on the bikes after storage are very poor with little or no stopping power. We are greasing from new with no difference. have you any thoughts on this? could damp be an issue? We have checked and the grease looks okay.
    Thanks in advance.

  12. henry Says:

    Paul, Even after fitting and maintaining many thousands of rollerbrakes through the years their inconsistency remains a mystery. We’ve discussed the issue with Shimano dozens of times but they either don’t know or care.

    My guess is that the old grease in those brakes is the root of the problem. I’d try cleaning them out as well as possible with solvent and/or ultrasonic and then re-lubricating them just enough. Too much grease in a rollerbrake is also unhelpful.

  13. Paul Says:

    Very much appreciated Henry.
    There is a mountain to climb!! We will have to devise a way of cleaning them as part of the commissioning process. Any thoughts on a safe / efficient method. currently our commissioning procedure runs at circa 2 hrs. We have about 300 bikes to get through!

  14. henry Says:

    Paul, Maybe get a parts washing station and let the brakes first soak for a couple days. Seems like great work for some teenagers!

  15. Kuno Says:

    Hi Henry
    I feel like my bike does brake all the time – and I found your post with a possible solution. How is the longterm result with only oil instead of grease? How often and how much refill necessary? And what oil?
    Additionally to the constant breaking (or additional exercise) I have the problem that my roller brake “lever” (rotating part of the brake) hits the housing before I get normal brake power. I don’t know if this is a sign of total wearing out of the pads, which would probably make a full replacement necessary. Do you have experience with this issue? (I have the bicycle for about 10 years, probably 15-20’000km, with one short, steep downhill every day. Could send a picture to explain.

  16. henry Says:

    Hi, Actually it sounds like your rollerbrake is simply worn out. Ten years and a couple tens of thousands of kilometers in hilly terrain is far beyond its normal life expectancy.

    In the end we decided that cleaning and only minimally greasing the rollerbrake offers the best balance of wear and resistance. Too much grease just gums everything up and gathers more dirt… which turns into a thick paste causing friction.

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