KitN

Hi all,

I need higher gearing on my current commuter. It has a 48t crankwheel. I've found someone that can upgrade it to a 53t crankwheel.

My question: Will the 53t crankwheel be noticeably faster than the 48t crankwheel?

Thanks.

BTW, I already looked into changing out the freewheel but no dice. My only option is to upgrade the crankwheel.

envane

https://www.sheldonbrown.com/gears/

Sixty Fiver

Is this for a folder ?

weavers

thats pretty pricey going from 48t to 53t because typical you can't just buy a new crank that will fit, you offten need a whole new crankset. add the cost of instaltion or buying the tools then you might need a new bb too.

what gears do you run on your cassette, in the back? a 12-25 should be plenty of gears with a 48t. if its a 14 or a 16 in the back then thats not enough. cassttes are alot cheaper and easier to install than a whole new crankset. proper gearing helps alot for speed and steep climbs, but stronger legs makes a bigger differnce.

JeffS

It will be approximately like changing two gears in the rear - like shifting from a 13T to an 11T.

Will it make you faster? Only if you're severely gear limited now. Very few multi-gear bikes are truly gear limited on anything but a big downhill.

KitN

Hi guys! Thanks for the replies. To answer your questions:

1. Yes, it is a folder. It has 16" wheels.

2. Currently it has a 14t - 28t six-speed freewheel. I've looked online and tried several bike shops. I wanted 11t or less but no one has a 6-speed freewheel with anything less than 14t!

3. I've looked at the Sheldon Brown gear page. I'm even more confused with all that stuff.

Question: Can I switch the freewheel out for an Internal Hub like a Strumey Archer 8 speed? If I can, then what would I need to do?

ibcrewin

If I may be so snarky.. How about pedalling faster?

envane

You put your wheel size (16"), chainwheel sizes to comapre (53 and 48), and your smallest rear cog (14), then sellect "MPH @ 90 RPM" to get your speed at a normal cadence. I get:

____53_____ 48
14 16.3 mph 14.8 mph


So, it will give you 1.5 more mph at top gear.
Dear lord, you really do need higher gears.

jyossarian

So according to Sheldon's site, your highest gear results in 58 gear inches (4.3 gain ratio). The 53t ring would raise that to around 64 gear inches (4.8 gain ratio). For comparison, my FG is at 72 gear inches (5.6 gain ratio). Switching to the new chain ring will move your bike 1/2" farther for every inch the pedal moves over the old chain ring, or around 21" further per crank revolution, assuming 170mm cranks.

KitN

Snarky indeed!

Of course I'm pedaling faster. Duh! I'm pedaling faster than the wheels can keep up.

KitN

Yep. Higher gears are definitely needed.

Ok, I'm going with the larger 53t crankwheel. Next up: Does anyone know if I can change out the 6-speed freewheel for an Internal Hub? If so, do I need to buy anything else like a new chain or a new wheel to go rim/wheel to go with the Internal Hub?

Thanks!

envane

You need to get a whole new wheel built around the internal hub. I don't know if this is even possible for a 16" wheel.

AEO

how's the ground clearance on the current 48T?

Torrilin

I'd ask in the mechanic's forum for advice. If the bike will take a 7 speed freewheel, you have more options. The problem is, because the bike was so cheap to begin with, it may not be worth upgrading. Folding bikes don't always use standard components, and finding something nonstandard can end up... expensive. Worst case, it can be more expensive to do the upgrade than the bike's original cost!

In that situation, it might be better to bite the bullet and spend the money on a better designed folder.

KitN

Thanks for the reply.

I did some poking around the official SA site: https://www.sturmey-archer.com/hubs_8spd_XRF8_A.php#

155 mm hub = 28 spoke holes
170 mm hub = 36 spoke holes

My 16" wheels have 28 spoke holes. So it's a match for the 155 mm hub's 28 spoke holes! Yay!

Where do I measure to see if I need the 155 mm hub or the 170 mm hub?

Thanks!

KitN

There's a metal "foot" on the bottom of my folder to protect the crankwheel when folded down. There's about 3/4" between the crankwheel and the ground when folded so I don't see a problem at all with the 53t crankwheel's clearance.

envane

An 8 speed internal hub will run you about $150. You will need to pay a bike mechanic to build the wheel around it. So you're looking at $200+ to upgrade a cheap folder. As Torrilin noted, you're better off with a new folding bike.

KitN

I was initially going to do that but I recently rode a Brompton and, less than a week ago, a Downtube NS. I also checked out a Bike Friday Tikit, a Xootr Swift and three Dahons in a bike shop. Unfortunately, they aren't the bike(s) for me.

I love the bike that I currently have. It fits me perfectly. I love riding it. It makes me happy. It just needs to go faster. I know it's doable. I've seen other people modifying their folders in similar fashion.

I don't mind spending the extra money to make it faster. It's better than dropping $2,000+ on a bike that I'm not happy with and will wind up right back on these forums asking how I can modify it to make it suit me better. No dice.

I'm sticking with what I've got. All I need is to upgrade the gearing and I'm set!

KitN

Thanks for the input. I'm very much aware of how much the hub costs and the mechanic costs.

I'm keeping what I've got and upgrading the gearing, thanks!

muccapazza

13x28 6 speed freewheels are available https://sheldonbrown.com/harris/freewheels.html#6 here, for one, a 53 ring with a 13 low freewheel cog would help your speed. I'ld look into seeing if a 7 speed freewheel, the 11x28, would fit, they are just a smidge wider than a 6 speed.

RI_Swamp_Yankee

I love the bike that I currently have. It fits me perfectly. I love riding it. It makes me happy. It just needs to go faster. I know it's doable. I've seen other people modifying their folders in similar fashion.

OK! You have options. A 53t crank will improve top speed, but make going up hills murder... if your daily ride doesn't include a lot of the steep stuff, this may be just the upgrade you're looking for. If not, then you still have options. Sclumpf and Truvativ make internally-geared cranks that have a "high" and "low" setting you change by tapping a button at the crank with your heel... no front derailleur needed. Also, there are places that will make freewheels with custom cogs. Between those two options, you will probably achieve a good clip with your little bike... but be aware that other bikes with bigger wheels will go faster by nature. There's no substitute for wheel diameter when it comes to go-fast.

JiveTurkey

53x28 on 16" wheels (assuming 16x1.5" tires) is an easy gear. It's lower than a 1x1 ratio on a 700x23c-wheeled bike. My triple-crank road bike doesn't even go that low (30x27 is the lowest gear and I can get over pretty steep hills on the road).

prathmann

Does anyone really make a freewheel that takes an 11-tooth cog? If so then that would be a good solution since dropping the 14 to an 11 would increase the gearing by over 21% whereas going from a 48 to a 53 chainring only increases it by about 10%.

My Bike Friday came with a 60-tooth chainring and an 11/28 cassette to give reasonable gearing - and it has 20" wheels vs. the OPs 16". So I agree that he certainly does need higher gearing. If a freewheel is available with an 11-tooth cog then that would be easiest. Otherwise he'll need to change the hub (i.e. rebuild the wheel) using either an internal gear or one that takes cassettes with smaller cogs.

Just changing the front ring from 48 to 53 teeth (i.e. 10% larger) doesn't seem like enough of a change to make it worthwhile.

muccapazza

^^^^Well, they used to recently, Shimano went to the trouble of improving the engineering of the 7 speed freewheel, first with a 11x34 alpine gearing megarange model, which I have, and later an 11x28. I'm having trouble locating one now though at the usual suspects (Harris and loosescrews,for a couple).

KitN

Thank you all for your input. I appreciate it.

A few more questions about options and general pricing:

1. Can I change to a 6-speed CASSETTE with 11t by rebuilding the wheel? If so, approximately how much do you think it would cost?

2. Can I somehow squeeze a 7-speed CASSETTE with 11t? What would I need to do to accomplish this since the 7-spd takes up slightly more room than the current 6-spd, I assume?

3. Taking into consideration the option to put in the SA 8-spd Hub and the two options listed above, which is the best or easiest option?

Thanks in advance!