SkunkWerX

Just made the jump from 52t up to 56t.
Reason: I was spinning out on downhills (running out of gearing).
I'm not a speed freak, per se, but when trying to build up speed for the next hill, like down and up a stream valley, a few more MPHs meeting the next hill does help.

In order to go higher than 52t, which was mounted on a 110BCD crank, a 130BCD crank fixture was needed.
It didn't take much to convince myself that the stock crank was pretty unimpressive and that a change certainly wouldn't hurt.

Went with an Origin8 ProPulsion road crank 130mmBCD and stayed with my 170mm crank arm length. If anyone decides to upgrade their crank AND lengthen their crank arms, be sure to check clearances, in my case there was clearance, but it was getting close back at the chain stays. Just be aware of this.

Then installed the 56t Origin8 chain ring, and a 42t for the smaller ring.

In stock form this bikes highest gear was a 52t big ring and a 12t rear cog. Now, it is 56t big ring and an 11t small cog.
Pushing a bigger high gear now on this little 20 incher, for sure, but it made a substantial difference. Weak peddlers steer clear of this set up.
This set up is certainly going to make me work more, hopefully as riding season continues I'll get stronger....one can only hope.

Will stop back to this thread to update after some mileage and several trips.

tudorowen1

Would have saved you a pile of money if you had just changed the rear cassette to have an 11 tooth..ie up from 87 gear inches to 94 gear inches..but with the 56 teeth chainwheel you now have a top gear of 101 gear inches...Seems a lot of money to spend just so you can pedal downhill more quickly..to gain momentum to climb up the next hill...Why not just relax ..slow down and enjoy the scenery..You have a 20 inch wheeled folding bike for goodness sake..not a carbon fibre road bike..!

SkunkWerX

I did change to an 11 tooth small cog AND tried it. Was still spinning out going down hill and not while trying to attain warp speed, either.
Decided to go 56t. The money was not as bad as you might think.

I ride for fitness, primarily, so try to keep my heart rate in that zone for the benefit....no matter what bike I may be riding.

blakcloud

Well I am glad you found something that works for you. Moulten in their Speed bike line use a 58 tooth tooth chainring mated to a 10 tooth cog for 107 inches! Pretty amazing stuff if you can push a bike that hard. Have fun with your new upgrade.

prathmann

My Bike Friday (purchased in '94) came with a 60t big chain ring and 11t small cog. Other ways of getting higher gears include using the SRAM dual drive hub with a 3-spd internal in addition to the cassette cogs or using the Capreo cassette (9t - 26t).

12boy

Vuelta makes inexpensive flat chainrings..
[TABLE="class: data-table grouped-items-table, width: 557"]
[TR="class: first last"]
[TH="bgcolor: #F5F5F5, align: center"]Product Name[/TH]
[TH="class: a-right, bgcolor: #F5F5F5, align: center"]Price[/TH]
[TH="class: a-center, bgcolor: #F5F5F5, align: center"]Qty[/TH]
[/TR]
[TR="class: first odd"]
[TD]Vuelta SE Flat Chainring 130mm BCD 38T Silver[/TD]
[TD="class: a-right, align: right"]$21.49
[/TD]
[TD="class: a-center last, align: center"][/TD]
[/TR]
[TR="class: even"]
[TD]Vuelta SE Flat Chainring 130mm BCD 39T Silver[/TD]
[TD="class: a-right, align: right"]$22.49
[/TD]
[TD="class: a-center last, align: center"][/TD]
[/TR]
[TR="class: odd"]
[TD]Vuelta SE Flat Chainring 130mm BCD 40T Silver[/TD]
[TD="class: a-right, align: right"]$23.49
[/TD]
[TD="class: a-center last, align: center"][/TD]
[/TR]
[TR="class: even"]
[TD]Vuelta SE Flat Chainring 130mm BCD 42T Silver[/TD]
[TD="class: a-right, align: right"]$24.99
[/TD]
[TD="class: a-center last, align: center"][/TD]
[/TR]
[TR="class: odd"]
[TD]Vuelta SE Flat Chainring 130mm BCD 44T Silver[/TD]
[TD="class: a-right, align: right"]$25.99
[/TD]
[TD="class: a-center last, align: center"][/TD]
[/TR]
[TR="class: even"]
[TD]Vuelta SE Flat Chainring 130mm BCD 46T Silver[/TD]
[TD="class: a-right, align: right"]$26.99
[/TD]
[TD="class: a-center last, align: center"][/TD]
[/TR]
[TR="class: odd"]
[TD]Vuelta SE Flat Chainring 130mm BCD 48T Silver[/TD]
[TD="class: a-right, align: right"]$29.49
[/TD]
[TD="class: a-center last, align: center"][/TD]
[/TR]
[TR="class: even"]
[TD]Vuelta SE Flat Chainring 130mm BCD 50T Silver[/TD]
[TD="class: a-right, align: right"]$30.99
[/TD]
[TD="class: a-center last, align: center"][/TD]
[/TR]
[TR="class: odd"]
[TD]Vuelta SE Flat Chainring 130mm BCD 52T Silver[/TD]
[TD="class: a-right, align: right"]$31.99
[/TD]
[TD="class: a-center last, align: center"][/TD]
[/TR]
[TR="class: even"]
[TD]Vuelta SE Flat Chainring 130mm BCD 53T Silver[/TD]
[TD="class: a-right, align: right"]$33.99
[/TD]
[TD="class: a-center last, align: center"][/TD]
[/TR]
[TR="class: odd"]
[TD]Vuelta SE Flat Chainring 130mm BCD 54T Silver[/TD]
[TD="class: a-right, align: right"]$34.99
[/TD]
[TD="class: a-center last, align: center"][/TD]
[/TR]
[TR="class: even"]
[TD]Vuelta SE Flat Chainring 130mm BCD 55T Silver[/TD]
[TD="class: a-right, align: right"]$35.49
[/TD]
[TD="class: a-center last, align: center"][/TD]
[/TR]
[TR="class: odd"]
[TD]Vuelta SE Flat Chainring 130mm BCD 56T Silver[/TD]
[TD="class: a-right, align: right"]$35.99
[/TD]
[TD="class: a-center last, align: center"][/TD]
[/TR]
[TR="class: even"]
[TD]Vuelta SE Flat Chainring 130mm BCD 58T Silver[/TD]
[TD="class: a-right, align: right"]$37.99
[/TD]
[TD="class: a-center last, align: center"][/TD]
[/TR]
[TR="class: last odd"]
[TD]Vuelta SE Flat Chainring 130mm BCD 60T Silver[/TD]
[TD="class: a-right, align: right"]$39.99
[/TD]
[TD="class: a-center, align: center"]Out of stock
[/TD]
[/TR]
[/TABLE]

Abu Mahendra

my 20" folder tops out at 119 gear~inches thanks to SRAM DD.

SkunkWerX

Thanks guys for the support and the info on the SRAM DD. I'll need to educate myself on such things.

Prathman, 60/11 is huge for a stock bike, that's interesting to know they can be had like that. I guess in your area you could do some fast downhilling!

I used the Origin8 56t chainring because they were going on an Origin8 crank, it was pinned and ramped, but, also because I could get it through Amazon Prime, I had it in 2 days. $44 USD.
The 56/11 combo feels right for my personal power output. On flatland I'll have to work up to turning 56/11 at a decent cadence.

Will report more, later, after rides/miles.

Abu, which of your bikes has the SRAM DD? I would like to see how it looks, and how it installed. Replaces a standard rear hub/width?

Abu Mahendra

It is my Dahon Dash P18 which carries the Sram Dual Drive 2 (28 hole) hub with a Shimano SLX 11-36 10-speed cogset. The SDD hub is standard 135mm O.L.D. width. It gives 19.5-119 gear-inches with a 52T crank.

leoho5

Nice bike, I'm guessing you spend a lot of time in the mountains with that gear range. Had a DD in the past, gear range was excellent but I finally got rid of the bike because I ended up getting tired of it as it was slightly too heavy for me.

BruceMetras

Or look for a Sachs 3x7 .. I like that they use a simple pull chain for hub shifting instead of the later versions with exposed shifter clickbox.. here's one installed on my Montague Paratrooper

leoho5

I once had a DD click box get nudged during shipping and the shifting pin arrived bent. The pull chain seems so much better in absorbing accidental contact. Makes me wonder why SRAM/Sachs changed to the clickbox in the first place.

BruceMetras

Sachs didn't change .. SRAM went with the click box with the introduction of the Dual Drive .. which is a slightly different hub from the Sachs 3x7... I've had/have both .. I prefer the Sachs ..

SkunkWerX

Thanks for the pic Bruce!
I agree about the pull chain being more bomb proof, I was researching and read a few horror stories about the SRAM clickbox.

I rode an 18 mile loop today from my driveway out & back, the big ring worked very well. I was in the 56/11 combo even a little bit more than I had thought I would be.
I had toyed with only going from 52t to 54t...glad I went to 56t after today's ride.

Abu Mahendra

can you provide links to the SDD box 'horror stories'?

fietsbob

well actually Sachs was bought out by SRAM , who unbolted the German production Machinery and shipped it all to their new Factory complex in Taiwan.

SkunkWerX

I would have to go back through my search history.
Two stories of the plastic box cracking, one regarding inability to shift into one particular gear with a couple LBS's unable to solve it. Oh, and bent pin stories.
disclaimer: I may have been in a search loop that was only hitting on problems, so, it doesn't indicate a widespread problem.
What do they say? Bad news travels 10x faster than good news?

When I saw how the box was mounted, sticking out, I wondered about hazards. I tend cause some of my own problems....
(example: fell on my face yesterday hopping a very tall curb abutment)....so, when researching potential gear I look for things I would end up destroying.
I can see myself sideswiping a curb and ripping the clickbox off of its mounting.
Maybe it's not that much of a concern, i need to see one in person.

Abu Mahendra

yes, i think you need to see.and use one.