ed h

Have a recently made Nirve beach cruiser with 7 speed Shimano Mega Range rear freewheel. Where I ride there are some moderate sized hills, would like to reduce the front sprocket size. Used to climbing hills with a mountain bike, just using the middle (32t) chainring. Cruiser bike came with a 46t front sprocket. Here are my questions:


1) Seven speed uses a 3/32 chain correct ? Looking at front sprockets, there are plenty to choose from that are
for 1/8 chain. So far the smallest 3/32 width sprocket I can find is 44t. Not much difference vs 46t.


2) If I cant find a smaller front sprocket for my existing one piece crank setup, any other options ? Could I convert to 3 piece cranks and hopefully find a smaller front sprocket. Ideally would like to use a 32t front sprocket. Speed
is not a concern, getting up hills is the problem.


Appreciate any info or advice

Sci-Fi

Depends on how much you wish to spend. Can buy an inexpensive square taper axle conversion kit that directly replaces the one piece crank. Then buy a single mountain crankset, most will come with a 32t or buy a 2 or 3 chainring crank. Can add a front derailleur to give you even more gear ratios.

There are adapters that are press fit and allows you to use more modern bottom brackets (internal or external) and cranksets. But that's up to you.

I'm collecting parts to convert my 7-speed cruiser to a 1x10 setup...36 or 32t front (still undecided) with 11-36 cassette. The frame/bb came standard with a cartridge bb, so my crankset choices are a lot easier.

ed h

Sci-Fi, Thanks for the reply. May wind up converting to 3 piece cranks so I can go with a 32t front chainring.
I also have some extra MTB cassette wheelsets, looking online see Shimano makes a 7 speed 11-34t which is not mega-range. Seems like alot more option with 7 speed casettes vs freewheels.

ed h

Sci-Fi, Just to clarify your earlier reply, when you say external bottom bracket do you mean the style like used in a Shimano hollowtech ? I have two older mountain bikes that were converted to outboard style bearings for Shimanao Hollowtech, both bikes had the regular European size BB. These cruiser bikes are new to me so just trying to figure out what works and what wont.

Any crankset choices in particular you are looking at ?

Philphine

you can find a smaller front sprocket off ebay pretty easily. I just got a 40, and i think down to 36 wouldn't be too hard to come up with.

Sci-Fi

Ed h...simple answer to your question is yes.

I have a few crankset choices on hand. NOS (hollow tech)Shimano Alfine FC-S500 (130 BCD and FC-S501 (110 BCD). Obviously I'm thinking about using the 110 BCD but 34t is the smallest available. Don't need ramps on the chainring, so Sugino, Shimano Tiagra 4550, or Sram chainring is good enough and the price is reasonable ($16-20). Already have a new/unused Sram 36t ring (10-speed), so might end up just using the parts on hand.

My local LBS has the 4-arm mountain/BMX cranks (no name brand, Taiwan manufacturer) on sale for about $25-30. That would allow smaller ring sizes and give me the low gear inches I want/need (20-23 gear inches). 70-80 gear inches is all I need for the top gear...~19-21 mph before spinning out.

fietsbob

You can look for steel 36t chainrings that have the hole for the pin in your OPC to fit thru..

And, for the new BMX wheels with 9t cog hubs there are even smaller tooth count ones..

Have a LBS? Ask there..





.....

ed h

thanks for all the replies regarding my questions. I'll be dropping off the bike at my LBS for some gearing/drivetrain upgrades this weekend. The LBS I deal with has done drivetrain upgrades on my other bikes so I'm looking forward to see what they can do with my cruiser.

ed h

Wound up going with a 34t chainring/spider combo. Replaced stock wheels with a set of older MTB bike wheels I was not using. MTB wheels use a cassette rather than a freewheel, more choices for gearing. Used a 13-34t Shimano cassette (non mega range) so I don't have the annoying big jump from first to second gear, which was 10 teeth with the megarange freewheel.



Much better gearing now to conquer moderate hills, and more usable gears.

SquidPuppet

That's a nice balance of black and silver components to compliment that great frame color. Looks tough and classy at the same time.

ed h

SquidPuppet - Thanks for the compliment regarding my bike. Funny thing is I purposely ordered this particular model because it was supposed to have silver colored stock rims. Turns out they were black. Had an extra set of MTB rims, so on they went. Look better and also lighter.