April 23, 2018
Shimano Altus FC-M311 175mm 42x32x22 Crank Mechanism With Black Cover
Crank mechanism belonging to the ALTUS group. Made of durable steel. Designed for quiet tourist driving. Smooth and accurate gear change-the crank mechanisms use chain lifting ridges, special teeth profiles and guide ramps to ensure fast and precise change of gears
– individual shields have 42-32-22T teeth
– arm length 175 mm
– steel discs Hyperdrive SG-X
– compatibility with 6, 7, 8-row drives
– co-operating with DUAL SIS
– Chain line: 50 mm
– Average weight: 945 g
Shimano Altus 28x38x48t 7/8spd 175mm Square w/ Guard by Shimano
Shimano Altus M311 7/8s 42x32x22 175mm Chainset 2016
- Already installed the BB and the rear gear cassette several days ago which were almost exact duplicates.
- It arrived yesterday and I quickly noticed that the OEM crank set are all flat gears and the new set has about 4 mm offset to the inside.
- Also the new unit had four prongs poking from the gears to the inside that interfered with the BB shell.
- Since this is an education project and not a lot of money is involved, I removed the offending prongs with a Dremel tool.
- I realized that the offset to the center would change the front/rear chain alignment slightly but that could be accommodated.
- After installation and a lot of adjusting, I now realize that the clamp-type derailleur linkage mechanism interferes with the seat tube when I try to make it shift to the inside small gear.
- The small gear is inside the outside edge of the shell.
- For the time being I will be one of the progressive riders switching from three to two front gears.
- My complaint is that the specifications do not address that this unit has an offset to the inside.
- To be fair, I Googled this problem and found others have complained about the same thing for internet purchases.
- The pricey solution is to visit your LBS and look at the crank set before you buy.
- I am impressed with how well it shifts compared to what I have on my mountain bike.
- With the mountain bike, I have to hold the shift trigger until the crank makes a little more than a half rotation.
- With this crankset, it shifts reliably up and down with a quick shift-lever motion.
- Update: Ordered another to replace the worn out Suntour crankset on my Motobecane 529HT.
- Now, the smaller gear allows me to go snail, maybe slug slow, in comparison and the larger gear is better for those trails hardpack or paved so that I’m not pedaling faster than the wheels can spin.
- In all respects the set is an upgrade over the original while having the same name.
- Here are the pros and cons:
-Great powder coating material does not scratch easily.
- I weigh a lot so I needed something sturdy
-matching nut covers.
-The pretty facing on the outside is made of plastic and comes of easily on the trails.
- I ended up super gluing it to the outer sprocket after I clipped it back in.
- Overall I think this it’s a great crank set and if you’re ok with the facade on the outer sprocket needing to be either removed or glued on then this is for you.
- Aluminum just like the oem ones I had on my bike before I stripped the pedal threads.
- The replacement and installation was easy-peasy, though it is VERY helpful to have a crankset puller tool.
- This crankset comes pre-greased, but it doesnt hurt to add more if you want to.
- Since I installed them, my bike has been running great as new.
- The only downfall I can think of for this crank set is that it did not come with covers/clips to prevent debris from entering the bottom bracket.
- I didn’t want to pay more for the replacement crank than I did for the old bike.
- A bit of work to get the derailleur re-aligned with the new crank, but that’s more of my lack of experience.
- Before removing the old crank, make sure you identify the crank type and buy an appropriate crank-puller.
- Unless you are upgrading, you’ll probably want to make sure that the length and gear ratios are the same as your old crank.
- Very easy to fit, including coming with a few dabs of great for the bottom bracket and pedals.
- Very smooth shifting and way more solid than the original basic parts on my mid-range hardtail.
- Fit and finish is good and it’s fairly light for an inexpensive crankset.