A few weeks ago, Tim and I were chatting at Leatherhead. He was interested in the Middleburn cranks that I had fitted to my Lynskey. Tim runs a compact on his Pearson, and thought that a lower set of ratios might suit him for the hills. I've fiddled around with this for a couple of years, so here's a quick note of what I've found, for those who, like me, are noticing that the hills are getting steeper ...
There are a couple of fundamental problems. Firstly, triples are getting much rarer, because of lower demand, and in any case they work less well than a double. With lighter bikes and younger riders, even a 50/34 compact is threatened in favour of higher gears, and 34 is the smallest ring you can fit to a standard crank, because of the pattern of the bolts.
So, what can you do? My interest was prompted by a piece by Chris Juden in Cycle. He described 'Compact Plus' cranks that could be had from Sugino. They have a second set of bolt fittings which will take a triple inner ring on a double crankset, so you have a very wide choice of chainrings. I've bought a set, they're beautifully made and have worked impeccably since October 2014 - they're in the picture above. Dave Vine has also bought a set, and his are going well too. 46/30 seems to work very nicely indeed - 11 speed if you need it and works perfectly with Shimano STI.
The problem with these is that they're hard to get in the UK. To get the best choice you need to order from Japan, which, with transport and customs charges is relatively expensive. I used https://alexscycle.com, who gave excellent service. About three weeks, door to door.
The second option I tried was Middleburn. Their system consists of a crank and axle, a spider to which the chainrings bolt and the chainrings themselves. You can mix and match to a considerable degree, and they're great for tinkerers. They're well made and look good for some types of bike, but they are less refined than the Sugino and give a slightly agricultural feel, which doesn't match that well with Di2. It all works, and will probably last forever. Middleburn ceased trading in July, but manufacturing rights were taken over by http://www.mountainbikecomponents.co.uk, and parts continue to be available.
The third option I have tried is Praxis Works. A niche Californian engineering company, they have built a considerable reputation for bearing sets that solve the several problems of carbon fibre race frames, and now appear to be owned by a Taiwanese conglomerate, one of whose businesses is the casting of complex metal parts - you know the sort of things, laptop chassis, or camera bodies. Very tricky stuff.
Praxis have taken advantage of this facility to make cast chain rings, and the strength and sophistication of the shapes available gives real advantage. I've fitted a set to my Mason, replacing the Middleburns originally fitted, and the difference is huge. They're slicker, lighter and work brilliantly with Di2. The main disadvantage is that their smallest set is 48/32 - OK for my use, but you might want lower. And an advantage for many is that Pearson are their local agent and can fit them for you. https://www.praxiscycles.com
There's also quite a lot you can do with the rear mech, of course, but I'll do a note on that another time.
If you're interested, have a word, and I'll show you what I've done.
Mark
6 comments:
Thanks Mark. An extremely interesting summary of the state of play for this equipment. I have to admit that 34 front x 32 rear is not right for me on hills like Tanhouse Lane, White Down, or Combe Bottom to mention a few that I like to avoid. I'll explore those links.
~ Tim
I use Stronglight doubles on most of my bikes and they do a good range of chain rings. Their cranks come in various pcd's.
Good stuff, Stronglight, Tony, and they certainly last. I've had a set on my old Moulton for more than 25 years and it's still going strong. However, it's 110 bcd, as I think all Stronglight doubles are. That means the smallest inner ring is 34 teeth. Stronglight triples are 110/74, and you could certainly make up a compact double from one of those, if you machined the appropriate spacers to replace the outer ring.
I run triples with only 2 rings and can get down to 22 teeth if needed, at present I use 42/26 which is great for touring.
Well the Sugino works just fine on my Condor Fratello, and has taken me up every Surrey hill, even though they are definitely getting steeper. You can go down to a 28T inner ring, though I currently use 30T, so I have something to fall back on. Not sure whether Middleburn go below 30T.
Yes they are expensive - about twice the cost of an equivalent quality conventional compact, but if they enhance the range of riding you can do without straining the knees too much, I think they are worth it.
Put another way, you could enhance your hillclimbing by buying a lighter bike with a conventional compact chainset, but that would be much costlier.
As an alternative Spa Cycles sell a Stronglight triple converted to a double, which gives you a huge range of rings to choose from. Very reasonably priced, though you will need a square taper BB - a bit heavier but durable.
Interesting thread of comments. After much deliberation I decided to replicate the set-up on my Dawes Galaxy, when replacing worn chainrings viz a triple with new Stronglight chain rings (48/38/28) from Spa Cycles, with a 11-34 cassette. This gives 22.2 gear inches - reasonable future-proof for hilly touring and for North Down climbs.
I took this conservative option because I was unsure whether the existing front derailleur and/or shifter would work with a compact. Also I'm comfortable with moving around the small chain rings for hilly work.
However when I get a new custom build - if ever! I would definitely go for a compact with the smallest inner ring. (Or even a single ring with the new range of Shimano cassettes as big as 11-40).
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