yumseyo

Hi All, I just bought a Tern Link D8 and wanted input on gearing. I want to install a 12-34 kcnc cassette and a xtr med rear derailleur with a 53/39 crankset of some kind. (I am looking for something light). Would this be adequate gearing for the 20 inch wheels?

I also have a XTR tripple that I was going to take the granny gear off and just run it as a double, but the large gear is only 44 teeth.. Would the XTR 44/32 be too small? Or does anyone know if I would even be able to install it?

I plan to do light recreational riding. This is more of a build it toy...hee hee..

I've just ordered a rear derailleur hanger and front derailleur adapter from Thor in hopes to be able to install the XTR goodies..

Plans are also to install a titanium seat post, new lightweight specialized saddle, easton carbon handlebars, dura ace thumb shifters with Paul White adapters, alligator cables, and light weight foam grips. (had a bunch of goodies I was saving for a carbon hardtail I never built..)

It already has Kinetix Pro wheels and Kojak tires, and a alloy fork...

Please give me any advice possible, since I am at the planning stages, all if it can change..

fietsbob

I have a preference for IGH, so this is the path not taken.. by yourself.
with my Bike Friday Pocket Llama and it's short chain tensioner ,
the lower pulley is quite a long distance from the ground ..

probably , assuming the wheel in use is small

I have 2 16t cog Rohloff Hub Bikes with same ratio range ,
the 26" wheel~38t chainring; with 20" wheel~53t chainring ..

So in your case Ultegra triple, or Dura Ace road race crank (or 'lowly' 105)
perhaps one with a 55t big chainring

Shimano made a small wheel 9~26t cassette-hub combo, Caprio,
but you already bought what you bought.

your 44:12 in a 20" 451 wheel would spin out your crank cadence,
at a fairly low rate of speed.




I love my Rohloff hub, disc brake Bike Friday [its a 16:53, turning a 406 wheel]
Even More when the rainy season returns .. As it Has..

yumseyo

so, the larger the better on the crankset and the smaller the better on the cassette? how about the larger cassette for hill climbing? or would the 12-34 still be too big?

fietsbob

do the math? formula .. front (tooth count) divided by rear x wheel diameter .
2:1 x 20"= one pedal rotation, 2 wheel rotations.

44:11, wheel rotates 4x.

dynaryder

For small wheel bikes,yes. Here is Sheldon Brown's gear calculator:
https://sheldonbrown.com/gears/

You can plug your numbers in there to see what your gearing will be. Granny gear for an average MTB is about 17 gear inches,top gear on a typical road bike is about 120-something. If you own another bike,you can plug those numbers in for a comparison.

Sixty Fiver

The gear range you get with that set up is 21 - 83 gear inches.. it is the same as what I run on my touring folder and although I'll spin out on hills and at speeds of 50kmh it works well for it's intended purpose and if you ran an 11-34 you's bump the top gear to around 90 gear inches.

Bike Friday's NWT comes with a 39/53 and an 11-x cassette for touring as you really don't need to exceed 100 gear inches unless you are racing.

sunburst

44/12 is OK for me for just putting around on flat roads, but I'm no powerhouse (my son actually laughs when he sees me in bike shorts). For a normal rider I'd say you'd run out of top end gears before you even got started.

yumseyo

I may just install the xtr and see how it rides. At least if I use the gxp bb its easier to switch later..

And thanks to you sixty fiver. I am right at that age to!.. The faster I go the more I could get hurt if I spill...

bhkyte

I tend to think 53 front and 11 teeth is about right on a folder for top gear with 20 inch wheels. You can go bigger front but it gets expensive. Used 53t are ok to get cheap from roadies on ebay.

20 inch folders need gearing up generally ime.

Low gear, 28 or 24 should be fine with a 53 only, but it depends on use, fitness, and preferences. Certainly should be ok with a douLbe for low gears range.

Shimano Cespro is a 9 tooth rear hub .but its hard to justify when a large chain ring is so much cheaper.

I would go 53 with 11 -28. With the 42-44 double front you would have plenty of granny gear range.

yumseyo

I just saw a Pulsion 50/34 with CT2 chainrings and a FSA titanium BB....The seller called it jewelry, and for the price he is asking, I probably would agree. Any thoughts? 76.8 on the 50/12...

cplager

You'll be able to change this up later if you want. At the end of the day, it depends on what you want and you may not know that until you try it out.

For what it's worth, I've got a range of 17" to 106" on my 20" bike (I've got the Capreo hub with 9-26T and a 50/39/24 triple). I'm more aerodynamic than most folders, I end up using my top end fairly regularly. I'm a crappy climber, so I end up using my low end very regularly. It works for me.

fietsbob

reads like the OP is on a folding bike weight weenie quest.

yumseyo

ha ha, yup "fietsbob", I resemble that remark !! yup, I was going to build a carbon fiber mountain hard tail weight weenie , but found that having to buy a bike rack and having to lock them up every where I went was a pain. I am learning what cool things can be done with folders these days...So, I wanted to use a lot of the collected parts for this folder and build the hard tail ? I just turned 60, and lifting a bike to the top of a car is not as easy as it used to be..

sunburst

59 1/2 here. I ride single speeds mainly, so am used to living with one gear, but I got my BF partly for San Francisco and I use my whole range (18-80) up there. Plus the NWT is surprisingly capable off road and you know how quickly altitude can change in the dirt. In fact, based on my restoration (grim!), I'm 99% sure the previous owner mostly used it on trails.

Anyway, I've got 52/42/30 up front, 12-30 in the back. I think you could actually work with that 44/32, especially if you could get an 11 cog on your cassette.

fietsbob

I've been a bit less Bike-weight conscious , some stuff that's cool, and functional, to my mind ,

was worth what they weighed , irregardless ..
[Brompton M3L, 6, With 2x Mountain drive , Hub dynamo Lights.]

Sixty Fiver

A 44 with an 11 on a 20 inch wheel is a really low gear... the granny on my touring folder is a 40 tooth chainwheel with a 34.

fietsbob

Yea add 9~10teeth to the chainring.. a 53 or 54., the road crank.

chaadster

Yeah, a 44t with a 12-34 won't be going anywhere quickly.

How much gearing you need, however, depends on how you ride. If you ride leisurely and slow, maybe the 44t chainring would work. If you ride aggressively or like to ride fast at all, it's not going to work at all.

My feeling-- and I should mention that I run 60t with an 11-28 8spd on my minivelo-- is that you'll want to select your gearing so that you're running on the middle of the cassette most often. That way, you've got a couple of options on either end for the rarer circumstances, whether it be due to terrain, wind, or your legs.

I've also got a stock Dahon Mariner, which I find under-geared in general, but I've found that it works well for some types of riding nonetheless, and I enjoy the bike. I think that's equipped with a 53t and 11-32 7spd (whatever the stock setup is).

yumseyo

I've noticed that there are a lot of 50/34 compacts available now, I guess that's what's popular. I think I will look for a 53/39 !! I would like something light and cheap...(200.00?) Any advice? Quite a few 53/39 Ultegra 's out here...Kinda heavy though..

fietsbob

given gram counting priority, eliminate the $200 cost ceiling ,and you can find more parts to meet the desire

53-39 is a common Roadie crank .. cheap or super light, pick one.

crankarms are another place that Carbon fiber has come into use.

somebody has to physically put the Carbon Fabric in the mold , a labor cost.

and the race to the bottom is about cutting labor cost , and worker's Income.



are you thankful yet?

pacificcyclist

I have a similar bike like yours which is my Dahon Mu SL -- an old but light weight reliable steed. I wouldn't call it light weight ahem, cause I've got the Thudbuster seatpost installed as well as a pair of fat Big Apples. But still it goes fast! With a 53/39 FSA and a 9 speed rear 11-34 using a SRAM X9 RD, I could keep up with the Madones and the Cervelos at up to 25 mph top no problem. Well at least drafting behind them. My front end is set up to be a little lower than normal to give me a more road aero riding position. Yours I think is a bit higher. The most important thing to consider is whether you are strong enough to push those big gears to even consider having them. There's no point in having big gears if you don't have the lungs, core muscles and the legs to push them yet. They'll be just dead weight. Better consider a 50/34 option so you can have some high, more medium and lower gears which are ideal for a recreational rider like yourself and saving a little bit on weight. Anyhow, I keep my Dahon Mu SL for travel because it is only slightly heavier than my Trek carbon bike which is really light and this works well with maintaining the 50lbs weight restrictions when travelling light on airlines which gouge you on excess weight!!!

In regards to Thor adapter for my Mu SL. I would highly advise that you do not use a click shifter if you want to maximize usage of all the gears at the rear. You really need trimming with his adapter, cause the acute chain angle (short wheelbase) which can rub against the front derailleur guard which you may if you cross chain which I think you will (cause you'll only have 16 gears and the ratio themselves from 53 to 39 with a mega cassette can have big jumps). I use a Shimano 105 FD, but better stick with a Tiagra front to allow better trimming.

chaadster

Another cool and lightweight crank option would be the Tune Bigfoot. They're silly light, like sub 400gm, and square taper, so straight bolt-on (assuming Tern uses same square taper BB, but I'm not sure). The only problem is that they're over the budget by about $125, but you won't get anything lighter I don't think: https://www.bike24.com/p211362.html

EDIT: Too bad we missed these! https://www.ebay.com/itm/Storck-Power...p2047675.l2557

Old Storck Power Arms are wicked light, too, the one above 470gm with 53/39! Went for a little above $100 over budget, but maybe you can track down another set. Carbon would look cool!

yumseyo

Geez, you hit my situation almost dead on ! I was planning to use some Paul White shifter adapters that I bought some Dura Ace 105 bar end shifters for so I wouldn't have to deal with "click" shifting. Kinda "Old School" but effective. With regards to the front derailleur, what do you think of an XTR 960 front deraileur? and I might just go with the 50/34 compact gearing..

Where would I have to trim on Thors rear adapter if I wanted to use that cool KCNC 12-34 I have? If not, what size would I be able to use with his adapter comfortably?

Well, more later, got to start cooking my bird for the 30 people after thanks giving inlaw dinner tonight :=(

yumseyo

Wouldn't I be better off just replacing the bottom bracket with something lighter and newer? Though that Storck-Power is sooooo cool its kinda old school? Yes, I am going to try to find a FSA or SRAM carbon unit..

yumseyo

I guess $$$ is part of the game. though, I still don't know what might
pop up on CL in my area...Thanks for your expertise fietsbob..I am finding more 53-39 on EBAY than on
CL...Craigs has more 50/34..I guess thats what sells. Maybe I should put in a "wanted" ad and see what
comes up...