# Trek Precaliber 20 Build thread



## slowride454 (Jan 11, 2014)

So I picked up a used Precaliber 20 for my son. I will outline the build in this thread. I didn't realize how heavy and crappy the bike is until I got it home. Oh well, by the time I'm done the only things left will probably be the frame and tires.

I'm still unsure of what I'm going to do about the fork. I can't decide between staying with suspension or going rigid.

Has anyone tried 20" mini velo/folding bike wheelsets? I found a few online. Some of the super deep carbon ones look sweet, but weigh a ton. I found these on Amazon

https://www.amazon.com/gp/product/B01G95J0HS/ref=ox_sc_act_title_1?smid=A1N3NEWYJ4SCRO&th=1


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## SactoGeoff (Aug 11, 2017)

My 2cents. Chinese carbon fork + higher volume frt tire. Save a ton of weight and increase the ability to roll over stuff without the expense/weight of a shock.

Those wheels look pretty darn good for $135! Low spoke count and pretty light.


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## slowride454 (Jan 11, 2014)

I stopped at the LBS that sells Trek. I just ordered a rigid replacement fork for a Superfly. It is a bit more than a chiner carbon fork, but I know it fits and will work.


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## slowride454 (Jan 11, 2014)

I'm just not sure about the width of those wheels, especially if I put a plus tire on the front.


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## oren_hershco (Mar 11, 2006)

I bought a pair of similar 20" wheels for my son's 20" Trek Superfly build. The manufacturer is called "Litepro" at Aliexpress, but I think it's the same manufacturer as the wheels on your link.

Some remarks:

1. Please pay attention to sizing: the rim has to be 406, and not 451 (which is folding road bike size)

2. The hubs should be 100/135 (these are the internal fork/frame size for a standard mountain bike. the other sizes are for folding bikes)

3. The rims are quite narrow, in order to achieve light weight. a "plus" tire won't sit on them properly, I guess, and they are drilled to fit Presta valves only.

4. I bought a pair with *20 *spokes front, *24 *rear. They are truly superlight, the hubs rotate smoothly, and for my kid, who's not very heavy or very aggressive, they're definitely strong enough.


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## slowride454 (Jan 11, 2014)

I tore the bike down to the bare frame and weighed all of the parts as they cam off. Weight as it sat stock was 25.4# I also tore down his modded Hotrock 16 which weighed 16.0# I'll be using some of the parts off the old bike like the carbon bars and hopefully the saddle/post combo.


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## slowride454 (Jan 11, 2014)




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## slowride454 (Jan 11, 2014)




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## slowride454 (Jan 11, 2014)

This is the first thing to be replaced


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## slowride454 (Jan 11, 2014)

and these anchors too


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## slowride454 (Jan 11, 2014)




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## slowride454 (Jan 11, 2014)




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## slowride454 (Jan 11, 2014)

...


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## slowride454 (Jan 11, 2014)




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## slowride454 (Jan 11, 2014)

well that's all the major components. I have all the small stuff too, but until I need grams I'll worry about the big stuff first.


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## mtb1983 (Oct 29, 2013)

We did the same thing to a couple of 20" bikes - which we just sold this weekend - and our current 24" Gary Fisher Precaliber. We ended up with a 18 pound 24" disc brake bike!!!

It is sooo much better than stock! Plus, when it comes time to sell the bikes you can usually get a decent amount back for the upgraded bikes!


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## Crashtestdummee (Sep 14, 2015)

What are your equipment choices for seatpost, seat, handlebars


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## oren_hershco (Mar 11, 2006)

Crashtestdummee said:


> What are your equipment choices for seatpost, seat, handlebars


To whom did you address this question?


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## slowride454 (Jan 11, 2014)

960g!

I'm seriously considering these
https://www.aliexpress.com/item/Lit...id=f1bcb27c-cbae-42e3-aaee-308c35359efe&tpp=1


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## slowride454 (Jan 11, 2014)

The Superfly fork came in today


The LBS gave me the wrong headset bearings so I will have to wait a couple days to find the right ones and start assembling.


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## slowride454 (Jan 11, 2014)

Parts I will for sure be using:


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## slowride454 (Jan 11, 2014)

I'm not sure I'll be able to use his UNI saddle/post. It is so freaking light though...


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## slowride454 (Jan 11, 2014)

I'll probably reuse the stock brakes and tires too.

Now I'm looking at cranksets. I used 89mm Spawn cranks on his Hotrock 16. Spawn only has the 127mm which might be a bit big for him and they come with a 32T ring, again a bit too big for him if I'm only going 11-36 on the cassette. Does anyone make a direct mount crank in the 110mm range? I have a 28T Race Face NW ring I took off my Farley that might work.


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## slowride454 (Jan 11, 2014)

these wheels are 1290g

https://www.aliexpress.com/item/201...78f0-45ba-81fb-97d48902e991&priceBeautifyAB=0


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## oren_hershco (Mar 11, 2006)

slowride454 said:


> The Superfly fork came in today.


I'm not sure this is gonna work for you. The Superfly fork is not 'suspension corrected', which means it has a shorter axle-to-crown length than the original Precaliber fork.

This fork is designed to fit the Superfly frame (take a look at the last pic I posted before). I'm afraid that on your frame it will result in a very low handlebar, and too-steep head angle (=sketchy handling)


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## slowride454 (Jan 11, 2014)

I'll take some measurements tonight to see how much A to C is different. I know there are places that make extra tall headset bottom cups and crown race spacers. I really don't want to put the non-functional boat anchor fork back on it.


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## mtb1983 (Oct 29, 2013)

I bought a BMX fork a few years ago and brazed on some cantilever bosses to make it work on my son's 20" Specialized Hotrock bike. However, the A-C measurement being lower caused a few pedal strikes for him, so the suspension fork went back on after just a few rides...The problem was even worse with smaller 20x1.5 tires - so the only way the bike was even remotely ride-able was to use the higher volume 20x2.2 tires we had...

Interestingly, the handling wasn't really a problem, but as anyone who has clipped a pedal unexpectedly knows that is never a good thing!


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## slowride454 (Jan 11, 2014)

The A to C difference is too big. About 1.75" unsagged. I'm just going to put it back together and try to sell it for what I paid. I'm out the $80 for the fork, since I doubt I can return it. What a piece of **** this bike is. I'll start looking again for something that is a better starting point. I wish he was big enough for a 24" bike to make all the effort and money spent worth it.


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## oren_hershco (Mar 11, 2006)

Hold on. There may be some aftermarket options. I don't remember the A-C measurment for a "20 suspended fork, but check out these forks:

1. JAVA Glossy Carbon Fork 20" Rigid Fork For 20" 406 Mini velo Folding Bike V Brake Disc Brake Compatible-in Bicycle Fork from Sports & Entertainment on Aliexpress.com | Alibaba Group

2. JAVA Glossy Carbon Fork 20" Rigid Fork For 20" 406 Mini velo Folding Bike V Brake Disc Brake Compatible-in Bicycle Fork from Sports & Entertainment on Aliexpress.com | Alibaba Group


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## slowride454 (Jan 11, 2014)

https://www.ebay.com/itm/20-Carbon-...hash=item41ce33b4ba:m:mJEus3X4bnnT-BiabfQYl3w


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## slowride454 (Jan 11, 2014)

I found some good ebay deals on a few parts too. Still need to order wheelset and a bottom bracket. What width do I need with the Spawn 127mm crankset?

https://www.ebay.com/itm/Lightweigh...var=562413979062&_trksid=p2055119.m1438.l2649


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## oren_hershco (Mar 11, 2006)

slowride454 said:


> What width do I need with the Spawn 127mm crankset?


I installed a 103 (JIS) Sampson titanium BB on the girl's Specialized Hotrock 12, with a shorter Spawn crankset (89mm). Fits fine. I guess the BB you put on the link is also JIS and not ISO (they don't specify) so you'll get the same result.

All this is based on the assumption that the 127mm crankset will require the same BB as the smaller Spawn cranksets!


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## slowride454 (Jan 11, 2014)

Parts ordered

https://www.ebay.com/itm/451-406-Bi...var=471571787184&_trksid=p2060353.m2749.l2648

https://www.ebay.com/itm/Light-full...var=521622775179&_trksid=p2060353.m2749.l2648

https://www.ebay.com/itm/Children-K...var=591044327781&_trksid=p2060353.m2749.l2648

https://www.ebay.com/itm/ESI-30mm-R...e=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2648

https://www.ebay.com/itm/Mountain-B...var=470916947688&_trksid=p2060353.m2749.l2648

https://www.ebay.com/itm/MTB-Road-B...e=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2648

https://www.ebay.com/itm/Sram-Gx-Ty...e=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2648

https://www.ebay.com/itm/20-Carbon-...var=581826101666&_trksid=p2060353.m2749.l2648

plus the Spawn 127mm crankset

I think I just need a lighter saddle, bottom bracket, and a gold chain


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## slowride454 (Jan 11, 2014)

I used a regular Shimano square taper BB on my son's Hotrock 16 with the Spawn 89mm cranks. It was a pinch wide for him.


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## slowride454 (Jan 11, 2014)

Now there is a problem with the wheelset. I got a message from the seller that the red rims and hubs are out of stock. My son was pretty dead set on wanting red wheels. Ahhh the joys of custom built bikes.


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## slowride454 (Jan 11, 2014)

well my son decided that red hubs and black rims will be ok. The wheelset is on its way.


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## johne5ive (Mar 15, 2017)

Thanks for the informative posts. I'm enjoying watching the progress and looking forward to seeing the result.


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## slowride454 (Jan 11, 2014)

The crankset and rear derailleur showed up yesterday. I think the only thing left to order is the BB, and maybe a saddle.


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## slowride454 (Jan 11, 2014)




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## slowride454 (Jan 11, 2014)

ordered this tonight

https://www.ebay.com/itm/Lightweigh...var=562450550796&_trksid=p2057872.m2749.l2649

I got shipping confirmation within an hour.


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## slowride454 (Jan 11, 2014)

ESI grips and the cables/housings arrived today. It's going to be a while until the fork and wheels show up.


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## slowride454 (Jan 11, 2014)

Seat post and cassette arrived. The wheels and fork are coming from China so they will not be here for a while. I still need a chain, and would like to get a lighter saddle and some grippier pedals.


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## slowride454 (Jan 11, 2014)

Here are the costs so far:

Bike $175
Fork $134.99
Wheels $189.96
Brake levers $3.42
Grips $14.98
Bottom Bracket w/ Ti bolts $43
Spawn crankset $74.47
Cassette $24.79
Rear Derailleur $47.49
Seat post $14.98
Cables/housings $10.99

The rest of the parts being used are from the stock Trek or from his modded 16" Hotrock or were in the parts bin.

Grand total as of now $734.07

He wants a gold chain to match the gold cassette. I like the Velo saddle I posted in another thread, but it might be heavier than the stock one. I've got analysis paralysis with the pedals.

According to my weight weenie spreadsheet it looks like the bike will be about 17.5 to 18 pounds when complete. I sure hope so.


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## slowride454 (Jan 11, 2014)

a little on the heavy side, but it is GOLD!


I'll compare this one to my other carbon 27.2 posts before I cut one of them down for him.

A different kind of weight management...I gotta make it 0.2oz heavier


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## slowride454 (Jan 11, 2014)

Wheels came in today. I guess they found some red hoops at the factory. My son was extremely excited.


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## slowride454 (Jan 11, 2014)

brake levers arrived. I'm not impressed with their quality. The plastic feels soft and they are not all that smooth. I'll try to make them work better. They are a bit heavy too.


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## slowride454 (Jan 11, 2014)

The fork and BB showed up over the weekend. I'll try to get weights tonight.

Still need to decide on pedals, saddle, and chain.


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## slowride454 (Jan 11, 2014)

I'll be trimming a whole lot off the steerer tube and seat post. I picked up some tubes at the LBS, but didn't like the 60mm valves. I'll return them and order some proper 406 presta valve tubes with something more reasonable around 30mm long.

I have to get some threaded V-Brake bosses for the fork. I still need to decide on pedals and a saddle. I also need to get a gold 10 speed chain.


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## slowride454 (Jan 11, 2014)

Chain is ordered. I picked up some pedals and I'll use the stock saddle for now. I still have to cut down the seat post and steerer tube. I also have to do the cables and housings.


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## slowride454 (Jan 11, 2014)

The bike is put together. I stopped by the LBS last night to get it weighed on an official bike scale. According to the Feedback scale it is 17.24 pounds.

Shaved 8.16 pounds off. Not sure if it was worth spending almost $700 to do so.

Total investment $838.07 including the cost of the used bike.

I'll post some pictures soon.


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## RMCDan (Feb 28, 2008)

slowride454 said:


> According to the Feedback scale it is 17.24 pounds...Total investment $838.07 including the cost of the used bike.


A tip of the hat to you sir, that's pretty solid work.


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## svinyard (Aug 14, 2017)

Dang man, that is just awesome.I only with bike companies would freaking start doing this. I wouldn't feel bad in the least @850$ with a bike at that weight and quality. Well done.

How much was that Superfly fork and where did you get it? (sorry if you posted earlier). Id like to see a fork like that in 20" and 24" for nice bikes stuck with a heavy spring fork.


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## slowride454 (Jan 11, 2014)

I got the Superfly fork from my local Trek dealer. $80, but not suspension corrected, so it was 1.75" too short axle to crown. I had to return it.

I got the Chinese carbon fork off eBay. It is for minivelo and recumbent bikes. Has both disc and v-brake mounts and is super light. Luckily, the axle to crown is about 10mm longer than the sagged stock suspension fork spec. I paid $119.99 plus $15 for shipping.


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## slowride454 (Jan 11, 2014)




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## RMCDan (Feb 28, 2008)

Murdered out! That thing is sick. Personally, I'd ditch that steel bashring that comes on the Spawn cranks. It weighs nearly half a pound and it will look better without it. If he's dropping chains get a red ano'd NW ring to match the rest of the build, but he may not need it with the clutch RD.

edit: You might need shorter chainring bolts if you remove the bashring. That was the case with with the 102mm Spawn cranks I had.


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## slowride454 (Jan 11, 2014)

I will do that. The chairing is already a NW.


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## svinyard (Aug 14, 2017)

RMCDan said:


> Murdered out! That thing is sick. Personally, I'd ditch that steel bashring that comes on the Spawn cranks. It weighs nearly half a pound and it will look better without it. If he's dropping chains get a red ano'd NW ring to match the rest of the build, but he may not need it with the clutch RD.
> 
> edit: You might need shorter chainring bolts if you remove the bashring. That was the case with with the 102mm Spawn cranks I had.


What size chainring bolts do you recommend? Our Spawn 16" Yoji has the ring gaurd on it, but yea its heavy and dumb.


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## RMCDan (Feb 28, 2008)

svinyard said:


> What size chainring bolts do you recommend? Our Spawn 16" Yoji has the ring gaurd on it, but yea its heavy and dumb.


6 mm


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## nepbug (Sep 3, 2004)

Looks good, I'll have to make sure but son doesn't see that gold cassettes are a thing. Lol, it'll make it harder for me to use my old XT cassette.

I've also gone with that fork to replace a suspension fork. I've also ordered some wheels, pedals and tires, but this thread is giving me good options for other areas to save some weight. Seems like the other big place to save might be crank/BB, gonna have to look into that.

Let us know how the kid likes riding it!

Sent from my VS986 using Tapatalk


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## ghabe (Mar 7, 2015)

What BB spindle length did you end up using?


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## slowride454 (Jan 11, 2014)

ghabe said:


> What BB spindle length did you end up using?


103


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## ghabe (Mar 7, 2015)

Thanks! How’s the chain line?

I’ll be ordering the Spawn 127mm cranks like you did for our Superfly 20. The stock BB is 130mm and looks very similar to the one you had on the Precaliber. I initially planned on getting a 110mm BB...


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## slowride454 (Jan 11, 2014)

ghabe said:


> Thanks! How's the chain line?
> 
> I'll be ordering the Spawn 127mm cranks like you did for our Superfly 20. The stock BB is 130mm and looks very similar to the one you had on the Precaliber. I initially planned on getting a 110mm BB...


Chainline looks good.


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## slowride454 (Jan 11, 2014)

Final weight = 17.17

I took the bashguard off and added a bell.


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## Floyd1715 (Apr 20, 2019)

I know this is an old thread but was hoping to see how that Minivelo fork has worked out?

I picked up a used Precalibur for my son (Same model as yours I believe). I've made some minor upgrades to it, Tires, Shifters, grips, etc, but that stock fork is horrendous. If I can talk him into a rigid fork, I was curious if you thought it would be worth the ~ $120 I can grab it on ebay? I couldn't pull up the older pics so I wasn't able to see the weight savings, but I can imagine it was pretty significant bc the current fork is a tank.

Plan is for the bike to last through his younger brother and sister so I can justify the expense fairly easily.

Any better options at this point as its nearly 1.5 years?


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## slowride454 (Jan 11, 2014)

The fork was the best thing I did for this bike. it saved many pounds off the bike and works better than a poor suspension fork. It was worth every cent.


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## Floyd1715 (Apr 20, 2019)

Picked up this fork for our build. Really happy with it out of the box. Got everything set up on the frame with no problem. Went to throw on the wheels and.... realized I didn't factor in the solid axle/bolt on wheel of the stock wheels. Doesn't fit with the replacement fork. Going to drop by the LBS to see if they can fit in a QR setup. I don't think it should be a problem, but I'm still new to a lot of this.

The difference in weight of the garbage coil and the new fork in my hands was absurd.


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## dernbiebs (Nov 24, 2016)

Sorry to resurrect this thread. I picked up a used Precaliber 20 just like this one recently and am looking to make some modifications. Primary focus right now is changing out this crappy fork. It looks like the links to the carbon fork used in this thread's build are no longer active, and I can't seem to find it anywhere else online. I did come across some aluminum alloy forks that I think might fit, but wanted to see if anyone could confirm if these forks work? My understanding is that the hub spacing should be 100mm. The axle to crown of the suspension fork is ~350mm and these two aluminum forks say the a-to-c are 325mm and 330mm, so just under 1" shorter. Is the shorter a-to-c going to be a problem as far as geometry is concerned or is 1" shorter a-to-c not likely to have a significant impact to geo and handling?

Here are the two forks. If anyone else is aware of other options I'd be grateful to know.

Fork 1

Fork 2

Many thanks


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## nvancyclingman (Jan 30, 2021)

slowride454 said:


> and these anchors too


thanks for weighing this, its helpful. Stupid heavy.


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## nvancyclingman (Jan 30, 2021)

dernbiebs said:


> Here are the two forks. If anyone else is aware of other options I'd be grateful to know.
> 
> Fork 1
> 
> ...


*_edit, noted later the one fork only has 143mm headtube, this is too short for the precaliber which has a headtube length of about 155mm. 180mm minimum would be probably be a good choice, you can however buy an extender if you want to go with that fork. *_

_original post_
I'm looking at exact same two options, which seem to be about it(I've spent hours looking). Some 20" forks are 74mm axle width, these are both 100mm so thats good. Headtube diameter and length looks fine. Forward axle offset is about 40mm, and these forks look about similar there too. I came to the same conclusion, the axle/crown length is about 25mm shorter. Its going to make the head angle a touch steeper. I noticed as well the cheaper fork has no posted weight, its almost certainly lighter than the stock suspension fork.

If a superfly fork is available, it may be a better choice as the axle to crown may be closer to Precaliber fork.

Another option could be getting a 24" rigid fork, but the brake mounts would be higher. If you are updating the wheelset to disc brake, with a 24" wheel rigid fork with disc mounts then that would be an option.


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