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  1. #1
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    Upgrading hand me down GF Precaliber 20" - Functionality improvements/weight savings

    Hello…

    My daughter is loving trail riding She's six, loved Off the Top in Mammoth and we're finding some local trails she just can't wait to get back on. She's riding her sister's old GF Precaliber and will be for at least three more years and this bike could be potentially be moved onto my 3 year old son with a new paint job too. Really would like to lighten it up and make it a lot easier for her to shift as she climbs like a bat out of hell if she can get it in the right gear. Loves going downhill. Never taken a bike a part but willing to try. So need your help in some smart reasonable upgrades. Been searching and think found a few ideas but please chime in…

    Functionality:

    - Sram X4 Trigger Rear Shifter (8 Speed)
    - Sram X7 Rear Derailleur (Medium Cage)
    - Shimano CS-HG41 11-34 8 Speed Bike Cassette Mega Range MTB. I don't know if she needs this as she climbs normally in the second ring? Going to be climbing with her older sister and friends so just thought maybe a good idea. But could use stock(?) and spend that money on something to lighten the bike up or upgraded fork?
    Rear hub when it spins is grinding and not very smooth. Swap the hub? Whole wheel?
    Am I missing something or do I need a tool to make this happen?

    Lightening the bike up:

    - Love to get her some lighter wheels as rolling mass but not sure it's smart money?
    - Find some used carbon riser bars (OK to cut down right?)
    - Suggested headset? Carbon?
    - Carbon seat post? Does anyone know what size?
    - Sinz Expert ISIS Crank Arms 135mm
    - Sinz Expert BB
    - Salsa Front Chain Ring 34T
    - Kenda Small Block 8 tires with lightweight BMX tubes (this saved two pounds) Once she destroys the current treads.

    - Always wonder with us going to Mammoth is it smart money to upgrade to disk? My bike's v brakes worked just fine but? Or would it be better money to put it towards lighter cranks or wheels?

    Light set suggestions? We do a lot of riding for frozen yogurt at night and wondering if there's a cheap light set stocking stuffer you guys like? Doesn't have to last more than 30 minutes or so?

    Anything else throw it at me

    Thanks for your help in advance,

    Smkntrls

  2. #2
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    The folding bead schwalbe mow-joes are an even lighter 20" tire;
    Mow Joe HS 371 | Schwalbe North America
    Dont wait until current stock tires are worn out, they likely will outlast your families use of the bike and be a constant source of heavy weight.

    Your current rims are probably as light as you are likely to find for a 20" rim, there are not really appropriate kid-weight rims made, just adult rim extrusions rolled down to smaller size. You might want try try re-building using the existing rims with better hubs and using fewer spokes for weight savings. See my wheel re-build (and a light shock modified as a 20") at thread ; Novara Pixie 20" project

    Disk brakes will make a kids bike heavier compared to V's. I would start with lightening the crank and wheels as you have suggested.

  3. #3
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    Wholly smokes GrayJay your Novara Pixie 20" project is awesome. I'm going to have to pull up a frosty one and sit down for an in depth read. Any thoughts on the Spinner Air 20 Fork? Tearing apart a fork kind of scares me and I definitely don't have the confidence in telling my wife I know what I'm doing ;-) The Spinner is expensive but it will stay with the family for at least six or seven more years. I'm assuming swapping it out won't be too much trouble and I can move it to a different bike if need be. Biggest concern is serviceability and related parts to do so. Any thoughts would be appreciated.

    Any thoughts on the capability of the Mow Joe's on the trails in Mammoth? The first set my oldest wore out so I upgraded the tires to a Specialized Spanky up front and Kenda rear tire that's very beefy/aggressive and I'm sure heavy for the trip to Mammoth. They worked well and she pretty much stops on a dime which is what I was hoping for. The weight I may just live with but get some lightweight BMX tubes.

    Thank you again for sharing,

    Smkntrls

    Anybody have experience swapping cranks on the GFP? What kind of BB would I use. Thank you...

  4. #4
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    1500gr for the air spinner 20" is a lot of weight for a 6-yr old to lug around;
    Spinner Air 20" Fork

    If you don't want to DIY convert a fork to 20" then finding a lightweight rigid fork might be a good alternative and could easily save couple of pounds.

    Pretty sure the GFP would just have a standard british/ISO (Euro in BMX speak) bottom bracket shell. If you are using an ISIS spline crank, then a MTB width ISIS cartridge bottom bracket (with british/ISO threading) should work fine in the frame. The bottom bracket you can use is more dictated by the crank than by the frame.

    See Jordans other recent GFP 20" thread for more on the BB and crank;
    20" Custom Build Project

  5. #5
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    Awesome GrayJay. So I'm sorry to say I didn't get to review your thread on the link above last night but will be tonight. I thought the Spinner would be much lighter than the standard rst and used all it's travel and therefore xxx but now I'm tempted...

    Please let me know what you'd think would be a reasonable to nice upgrade for a fork. My main concern now is adjusting the angles to much on the bike, and serviceability. I don't mind tinkering and learning about how a fork works and improving her ride exponentially. I'd actually like to get into it so I can service the rest of our family's bikes shocks. I've serviced/torn apart my KTM but never the forks/shocks so I'm a little intimidated.

    Is there another thread I should also get into tonight on this that you suggest reading? And thanks for the link to Jordan300 build. Don't know how I missed that one.

    Also is it tough removing the rear cog from the wheel? Any of those upgrades I mentioned you think I should adjust up or down a level? Again this bike will be used for at least six/seven more years.

    Thank you so much and have a great day. PM me if you'd like.

    Smkntrls

  6. #6
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    Hi...

    Took a quick minute to figure out how to measure some things and ran into a couple posts and saw that potentially GrayJay I may not need to do any spacing adjustments with the rear cassette? Did I read that right?

    Also NYrr496 did you swap the rear hub for the XT as a necesity? Do I need to do the same to achieve this build? Was your hub going bad? Mine is starting to grind and maybe I should buy a cheap shimano replacement and have some fun trying to build up a wheel for the kids?

    FYI my goal is to tear this down and build it up in front of about 15 neighborhood kids + parents who are starting to get into MTBing. So any and all feedback will be for the benefit of not just me but for all of them as parents are skeptical about what I'm preaching to them about the fun of the sport and it's positive attributes.

    Also here's some measurements I took of the bike that I think are relevant. Someone please share with me a good tear down/measurement/build thread I'd be happy to read it to learn about what I should have on hand to do so. Anyone please confirm my measurements for accuracy and how to and if it was necessary that would be great. As I certainly don't want to buy the wrong components. Thank you. Smkntrls

    Fork is 1' 10" from top to bottom
    bottom bracket to bottom of fork wheel tabs 1 ' 3"
    8" from the top of the fork crown to the top of the stem where the cap goes

    BB width is 66.675 mm
    Fork stem diameter is 1 1/8 or 28.575

    Seat Post circumference is 1.5" or 38.1 mm

    Stem (from middle of fork tube to middle of the handlebar) is 63.5 mm
    Bar thickness is 79.375 mm
    Bar length is 558.8 mm

  7. #7
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    Sadly, a new, ready to purchase lightweight suspension fork for a 20" bikes simply does not exist. Spinner air or else a White Brothers are probably the best available options but are still overweight for a kids bike. See the the suspension vs rigid discussion at;
    Kids 20inch MTB's

    Viable light option to heavy front suspension might be a lightweight 20" BMX fork without front brake, like the 16 pound marin shown in thread; KTM 20" MTB Build 19.6lbs

    Good new is that the GF frame you have is a great starting point for your kids build.

    Your bike likely has a thread-on freewheel, not a cassette. You will need a shimano freewheel remover tool to get it off. Good plan would be to replace the junky threaded hub with a cassette hub, rebuild the wheel around the new hub. Working on bikes definitely takes a few specialty tools and knowledge that is not always obvious but there is plenty of good info out on the net. Shocks are not terribly hard to service.

  8. #8
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    I replied to your private message but I'll go into more detail here. The hub that came on my son's bike was the freewheel type. I could not swap the cassette on it and I had an XT hub, 8 speed cassette, shifter and derailleur. The hub was 135mm wide. The frame was 130 or 132... Slightly narrower. I did get the hub in but I figured it would be bad for the frame to ride it that way so I had the LBS fool with the axle and the spacers to get it to drop in. I also used Vee brakes since these were not disc hubs. I used old Ringle quick releases that weigh almost nothing.
    I never weighed the bike but it was lighter for sure. Every component I replaced was lighter than the part it replaced.
    Every part adds up.
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  9. #9
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    Oh yeah... I believe the seatpost on those is 27.2
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  10. #10
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    Wait a second this isn't plug and play. What are we dealing with Windows 95

    Thanks GrayJay and NYrr496 (thanks for the measurements and PM reply; I sent a response) for your help. The fork may just have to wait since I'm looking at hub and build. Is it possible to find a good trigger shifter for this bike and not have to go through this trouble? Gears are good for her the shift is just to hard?

    Wow my eyes are wiped from checking out a lot of sweet rides. Thinking I may need to shorten up the stem as she is leaning pretty far forward with this 20" top tube.

    Thanks again guys.

    Smkntrls

  11. #11
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    How many gears does it have now and what kind of derailleur? For my daughters 20", she was unable to twist grip shift but did fine when I switched to an old 6-speed indexed thumb shifter (to match 6-speed freewheel). Shifter was sourced used at local bike coop for cheap.
    A new SRAM derailleur will need a SRAM shifter, ratio is different than shimano derailleurs. I dont know if SRAM ever even made 6-speed shifters (if it now has a 6-speed freewheel?) Might be easier to find shifter that is compatible with the current freewheel tooth count by using a shimano derailleur instead of a SRAM.

  12. #12
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    Hi GrayJay,

    I may have made a mistake when I first bought it years ago and asked the LBS to install a trigger shifter type. It's just to hard to push the big lever on this poorly designed one.

    The trigger shifter is a Tourney which the big lever to get to the taller gears is just impossible to push.
    It's a Shimano Sora six speed.
    The cassette is a Shimano MFT220.

    Is there a way to improve this system? I read one place that you can have a higher geared shifter that will just have a dead shift if it doesn't have the matching cogs, true?

    Interestingly the rear frame measured 133.3 so I'm now real curious about a normal hub slipping in/forcing it just a bit :-)

    There's what looks like disk tabs on the back of this frame. If I go the point of rebuilding the rear wheel is it possible to go disk? I've read how it's easier on long descents to squeeze the disk brake equipped bike. Kind of like that idea.

    Watched that epic 5 part rebuidling thread on you tube and thinking I can manage it. Then set me up to build my own set for my ride down the line...

    Thoughts always appreciated,

    Smkntrls

    Thanks everyone,

    Smkntrls

  13. #13
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    Quote Originally Posted by SMKNTRLS View Post
    Interestingly the rear frame measured 133.3 so I'm now real curious about a normal hub slipping in/forcing it just a bit :-)
    Smkntrls
    Manufacturing tolerances. Just pull the rear stays apart when you put the rear wheel in. I had the same issue with my son's Marin Hidden Canyon.

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    Thanks Stom_m3. Seen a lot of nice bikes over past day. Have you posted your build? Sorry brain's turning to mush looking at all these parts.

    Figure forget the rear disk and brake upgrade and focus on drivetrain. Everybody happy with their Paul's Chain Keeper? Seen some posts with the use of an extra front derailer as a stopper.

    Curious if anybody uses shimano dual controls for their applications? Looks really big and bulky and maybe harder to use?

    Smkntrls

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    Quote Originally Posted by SMKNTRLS View Post
    Thanks Stom_m3. Seen a lot of nice bikes over past day. Have you posted your build? Sorry brain's turning to mush looking at all these parts.

    Figure forget the rear disk and brake upgrade and focus on drivetrain. Everybody happy with their Paul's Chain Keeper? Seen some posts with the use of an extra front derailer as a stopper.

    Curious if anybody uses shimano dual controls for their applications? Looks really big and bulky and maybe harder to use?

    Smkntrls
    Here's my son's 20" build for when he was 6;

    Just bought my 6yr old a Marin Hidden Canyon 20". Going to put XTR on it.

    Here is my son's 24" build that I just did now that he's 9;

    Scott Scale RC Jr w/ mods and weights

    As for the front chain keeper, a Pauls, or N-Gear Jump stop with a BBG bash ring will work. I did combinations of both on the two different builds.

    Let me know if you have any questions.

  16. #16
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    Thumb shifters are pretty easy for kids to use, for example;
    Amazon.com: Shimano SL-TX30 Tourney 6 Speed Shift Levers: Sports & Outdoors

    6 speed freewheel (or cassette) needs a 6-speed specific shifter as the cog spacing is different for each # of gears. 7 and 8 speed are close to same spacing but still not exactly the same. See; Shimergo | CTC and/or Sheldon Brown's Bicycle Frame and Cassette Spacing Crib Sheet

    Switching to disks brakes with new hubs is a possibility but they also add weight. Well setup V-brakes can be plenty strong and are lighter.

  17. #17
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    stom_m3 Awesome build there and love the expressions on your sons face. Well worth the time and money spent. Have to spend a little more time reviewing them and thanks for sharing Have to check out the fork mod and see how that works out for the bike.

    GrayJay Thanks for the links. Yeah I must have the older or crapier version as it's hard for me to move that big thumb one. Pretty much decided go for a complete driveline overhaul for the future years of abuse. V brake overhaul will be next year's presents.

    Curious if someone can help me figure out what stem size I have so I can figure out what stem/handlebar combo I can shop for. I again have measurements above but not sure if I did them right. Also I think I want to shorten the reach but not sure what size would be just right. Saw M-dub went with 35 mm with some rise. How's that working out for him? The current one has a rise to it so probably keep the rise. Anyone know what degree rise I probably have? Looking on ebay Trutive looks pretty nice and reasonably priced. Suggestions would be helpful.

    Also should I be thinking about a new headset? Is it really necessary?

    Thank you,

    Smnktrls

  18. #18
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    I have one of those Ebay Truvative stems on my son's current bike. A little heavy but the price is right.
    The Uno stuff on Ebay is pretty light for the price. I think that's who made his handlebars.
    I like turtles

  19. #19
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    Quote Originally Posted by SMKNTRLS View Post

    Curious if someone can help me figure out what stem size I have so I can figure out what stem/handlebar combo I can shop for. I again have measurements above but not sure if I did them right. Also I think I want to shorten the reach but not sure what size would be just right. Saw M-dub went with 35 mm with some rise. How's that working out for him? The current one has a rise to it so probably keep the rise. Anyone know what degree rise I probably have? Looking on ebay Trutive looks pretty nice and reasonably priced. Suggestions would be helpful.

    Also should I be thinking about a new headset? Is it really necessary?

    Thank you,

    Smnktrls
    Stem, crank length, bar width, seat position, seat height are all fitting type components or settings. Kids are a little more generic in fitting because they are growing so fast. Without knowing your daughter's height and reach but assuming a 6 year old with growing potential, I would look for a 60-75mm stem, 0-6 degree rise, 31.8 handlebar clamp. Usually Jenson's, Pricepoint, or Cambria bike have good sales on previous model stems. Find the cheapest lightest option. Same with the Handlebars. Find an inexpensive 31.8 aluminum or even a previous model carbon fiber bar.

  20. #20
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    NYrr496 and stom_m3 THANK YOU. My response last night was pretty winey Thanks for putting up with it.

    Great Stom_M3 I almost bought the wrong size handlebar. I'm obviously very uniformed on measuring bike components. Love it if someone pointed me to a place where I can become informed. If not I'll look into that next.

    So are the fork tubes from different brands/models that the stem attaches to all one general size for all mtb's?

    Trying to learn as I hope to build my next bike.

    Thanks everyone,

    Smkntrls

  21. #21
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    The steerer tube which you refer to as fork tube is measured via diameter.

    Here is a short list of some measurement items;
    Steerer tube = diameter (typical 1 1/8")
    Seat post = diameter x length
    Stem = Steerer tube diameter, length (C to C), handlebar diameter (typically 31.8 but older use 1")
    Crank length = C to C
    Bottom Bracket = thread type (yours should be Euro 68mm) by length of spindle (108-118mm)
    Seat tube = diameter (for ordering a chain guide)
    Chainring BCD = Diameter (5 bolt = 110bcd, 4 bolt = 104/64bcd)

    Of course there are huge variations and standards but the above will be applicable to your bike.

    If you are buying a new fork, you will need to ensure that you purchase a 1 1/8" steerer fork (of course this assumes your stem and headset match accordingly).

  22. #22
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    Thank you stom_m3.

    Looking at some of the weight savings comparisons people have made and the stem doesn't seem to be such a big difference so I may just hold off on that.

    When you get a second could you please define C to C for me? Is that center of circle to center of circle?

    One of my measurements match's up ;-)

    Smkntrls

  23. #23
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    First purchase:


    EASTON EC70 XC CARBON HANDLEBAR HIGH RISE

    Specifications:

    Brand: EASTON

    Model: EC70 XC

    Length: 685mm

    Rise: 40mm

    Sweep: 5 degree upsweep, 9 degree bend

    Clamp Diameter: 31.8mm

    Material: UD Matte Carbon

    Color: Black

    Weight: 159g

    Retail Price: $140.00 (not what I paid though)

    The sweep makes me think of lowriders but hopefully it's to the kids liking

    Thanks everybody. Keep you posted (pun intended)

    Smkntrls

  24. #24
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    SMKNTRLS, I'll take the pics tomorrow and send them out Monday. Sorry, but I can only access my e mail from work or on my blackberry.
    The pics will come out better if I take them with the camera and not the bberry.
    I like turtles

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    NYrr496 no problem my friend and thank you

    I'm kind of waiting for a few things to come through and have moved on to what to do for my older daughter. Probably start a new thread on that one.

    What do you guys think about a bash guard for the 20". Just learning about them and like the fact it will protect their legs from the teeth. Along with maybe stopping inadvertent pants/laces from catching? Suggestions on which one with Sinz Cranks and I think I want a Salsa 34T? Need one with five holes

    On that train of thought (if I have one ) for those of you newbies checking out my thread here I found gold! You all owe me

    Sheldon Brown's Bicycle Glossary Ca--Ce

    And pretty obvious guess ha stom_M3

    Thanks everybody!

    Smkntrls

  26. #26
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    You'll see when I send you the pics, I have the Salsa chainring and bashguard on the Sinz cranks. It works perfect.
    The only other thing I had to add was an N Gear Jumpstop to keep the chain from dropping to the inside.
    I like turtles

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    Quote Originally Posted by NYrr496 View Post
    You'll see when I send you the pics, I have the Salsa chainring and bashguard on the Sinz cranks. It works perfect.
    The only other thing I had to add was an N Gear Jumpstop to keep the chain from dropping to the inside.
    Agree with the jump stop. Put it on my son's Scott and it works well which is to say he has yet to drop a chain. He also uses the BBG bash guard. Cheap and effective. I don't know how much the salsa chainring is but it seems like it would be expensive. For reference a MCS or Sinz chainring sells for $15 at JR bicycles and Danscomp.

  28. #28
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    15 dollars is cheaper than a Salsa ring.


    Plus, I don't think Salsa makes chainrings or bashguards any more. Geniuses.
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    Wow I created a two page thread

    Thanks Stom_M3 and NYrr496 for sharing. I just got in from a long day of soccer and tonight it's a cards night with the boys so I'll be going through MTBR withdrawals in about a few hours

    Time to type up another thread for another family member . She's the curaitor of this refound passion and one hell of a rider at nine. Charged down a seroius manmade concrete 30' almost vertical drop with a three foot swoopy drop at the end that wasn't even level with her Dad in front screaming get back on your seat as I charged down it before her. Thank God for her safety and for me being smart enough to buy her a real bike with real equipment. Of course she couldn't hear me and of course this was in Mammoth on a side trail. Note to self. Always prerun a trail without the kids along. Or stop at every blind intersection top of a hill. But she pulled it off. Scared her though. Which is a good thing .

    Thanks again and look forward to checking out those pics and looking into your guys suggestions

    Enjoy your evening or maybe catch ya in the Giant Forum

    Smkntrls

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    Quick suggestion on cards night... Make it on Friday. Makes the weekend feel longer and doesn't mess up your Sunday morning group ride.
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    Friday night was last weekend Lucky guys or ladies

    Totally agree. I definitely need the extra recovery time as these guys just can't get enough. I enjoy the comrodery more than anything else. Hopefully I can get out with some change in my pocket so I can feel better about my shopping spree here

    Can't wait to join a Sunday morning group. Tough with kids and trying to keep them active. But fortunately I've got a built in group with rides as nice or soon to be nicer than mine

    Thanks for your help and enjoy your ride tomorrow if you get out

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    Help...

    I've got a lot of cool stuff on the floor next to me/on order and I'm stuck trying to figure out what hubs I should be buying. Obviously I'm looking budget in the low 30's for each but everything I'm reading so much stuff is unreliable on the back end. Certainly don't need disk compatibility but durability is a must. Hate to spend all this time building two new wheels and have to tear them apart in six months. Should I buy some old school used ones? Not going to bode well with the wife if this build starts to take a negative turn . Be better to bight the bullet on better grade stuff vs dealing with well xxx. But the XT stuff reads like a horror story

    So I would love to know what you guys think. Should I just get a deore front and a sram rear?

    Also GrayJay, NYrr496 and stom_m3 love to get your thoughts on lightweight spokes. There's no way the wife will be happy if she sees holes where she thinks spokes should be so I'm thinking supper light all around.

    Can't wait to post some pics and get this works PC on the dirt

    Thanks guys,

    Smkntrls

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    SMKNTRLS - Sounds like you need to take your pants back, start by telling your wife to stay out of the bike garage and get back in the kitchen!

    Durability of the hubs will not be a big concern for a kid rider, even the lightest hubs you can buy will be plenty strong for the amount of abuse and wear that a 50 pound kid can dish out. Are you planning on threaded freewheel or a cassette hub?

    Butted spokes in appropriate lengths for a 20" wheel are going to be tricky to find (if they even exist) try calling dans comp BMX store. Most likely you will just need to use plain 14 gauge spokes that have be cut and threaded to the correct length needed. Lack of suitably lightweight rims and spokes for 20" wheels really only leaves you with option of reducing the # of spokes if you want to lower weight of the wheel a bit.

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    Shimano HB M737 Rear Hub Parallax Deore XT Used | eBay

    This hub listed above is what's on my son's GF. If you don't win that one, my all time favorite Shimano low cost indestructable hub is the M529. Costs about 45 bucks for the rear.
    I could be wrong but I believe I laced those wheels up with DT Swiss Comps. Use alloy nipples which will let you add color as well. If you set up tubeless you save a little weight as well.
    I like turtles

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    Quote Originally Posted by SMKNTRLS View Post
    Help...

    I've got a lot of cool stuff on the floor next to me/on order and I'm stuck trying to figure out what hubs I should be buying. Obviously I'm looking budget in the low 30's for each but everything I'm reading so much stuff is unreliable on the back end. Certainly don't need disk compatibility but durability is a must. Hate to spend all this time building two new wheels and have to tear them apart in six months. Should I buy some old school used ones? Not going to bode well with the wife if this build starts to take a negative turn . Be better to bight the bullet on better grade stuff vs dealing with well xxx. But the XT stuff reads like a horror story

    So I would love to know what you guys think. Should I just get a deore front and a sram rear?

    Also GrayJay, NYrr496 and stom_m3 love to get your thoughts on lightweight spokes. There's no way the wife will be happy if she sees holes where she thinks spokes should be so I'm thinking supper light all around.
    Smkntrls
    I don't know of the horror stories that you are talking about but I haven't had an issue with my son's XT hubs. Also, remember that your kid will be pedaling the bike and not some clydesdale power house. Here are the parts and prices of my son's wheel build;

    Hubs F/R: Shimano XT M775 ($47.68, $65.88 @ amazon)
    Rims: Sun Envy Lite ($37.99 @ Dan's Comp)
    Spokes: Sapin Dbl Bttd ($36/wheelset @ Dan's Comp)
    Nipples: Alloy gold ($22/wheelset @ Dan's Comp)

    I drop shipped the Hubs straight to Dan's Comp and they built them up. Give them a heads up that the hubs are coming and it was no big deal. If you buy everything from them, they lace for free. Unfortunately they don't carry mtn bike hubs or at least the last I checked. They charged me $10/wheelset to lace. Cheap enough where I wasn't planning on doing it myself. At $250/wheelset, that's pretty cheap. Looking back, I should have tried skip lacing with only 18 spokes or some other variation. The wheel is pretty stout. The total weight F/R was (739/906) Using half the spokes would have dropped another 140g.




  36. #36
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    Good morning everyone,

    GrayJay thanks for the laugh Depended on the hubs I was able to get.

    NYrr496 Thanks for the extra time in looking. Love it if you'd eliminate your info. Got it saved...

    stom_m3 Looks familiar and awesome. Looks like I'm going to be lacing. Have to contact them for the additional stuff. Went through BMXhub for the SRgls.

    Have to run but wanted to say quick thanks!

    Smkntrls

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    Hello Gentle people.

    My mind is now mush. Can anyone help me determine if any of these Shimano rear hubs can accomidate 8 /9 /10 gears. Be it spline or threaded. Don't really care either way just would like to move past this point. And the toughest point is finding a seven speed quality shifters/derailleurs for some of these.

    I'm assuming anything with a shorter length than 130 mm is not going to fit either. Or will a spacer do the job with a longer QR?

    If they all can take a cassette described above your suggested best to worst or top two and gravy would be a suggested cassette:

    Deore LX FH-M563
    FH M-732
    FH-MC12
    ACERA X PARALLAX
    FH-M 452

    Thanks for your help in advance.

    Smkntrls

  38. #38
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    On the 24" bike (the blue one in the pics I sent you), I used a Deore hub. I have a ten speed cassette on it. I suggest sticking to 8 on the 20". The chainstays are so short you won't have a good chainline at one end of the cassette.
    On the 24, it was VERY difficult to get the last small cog on the outside. I finally tapped out and made it work well in nine gears and locked the last one out. My son can't even tell.
    I like turtles

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    Hi NYrr496,

    Thanks for hanging in there with me

    My concern is reading about some of these hubs they say you can't get anything past this type of cassette, ie. 7 speed. Maybe that was more of a threaded set. But I couldn't tell if a spline just in general can take any number of geared cassette.

    So if I find a spline hub should it be able to accommodate 8 or 9 spline cassette?

    Then any spline cassette should be able to fit on any spline hub. Doesn't matter which manufacturer?

    Thank you very much,

    Smkntrls

    BTW $60 for your 24 what a crackin deal . Pretty much decided I'm going to sticker up the Cypher and leave it in one piece until I build up my own bike. Let me be the true ginny pig.

  40. #40
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    Sram or Shimano will fit on a splined Shimano hub.
    I like turtles

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    Hi NYrr496,

    I just read why you had to remove the inner sprocket.

    I can't believe how much time this is taking.

    Thank you,

    Smkntrls

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    Smk-
    See the explanation of freewheel vs casette hubs at;
    Freewheel or Cassette?

    SRAM and Shimano splines and spacing are cross-compatable, (campagnolo is not).
    95% of cassette hubs are built to work with any of 8, 9 or 10 speed cassette (all same width). Tere is new road 11 speed that is different but not needed for a kids bike. The oldest (and some more recent low end) cassette freehub bodies were 7-speed only and were 5mm narrower. (or can be used with 8 of 9 cogs of a 9-speed cassette). 7-speed works fine for a kid bike, a 20" wheel rider is unlikely to use all the cogs anyway as their speed range is fairly narrow with low power and low skill level. My daughter would start braking anytime she was on a downhill that would have needed anything more than about a 34x18 gear to go any faster.

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    Hi GrayJay,

    Yep that's where I found out about why NYrr496 removed the one sprocket so this would work on his 24".

    So it seems if I go with a older Shimano FH with a 9 speed cassette and 9 speed derailer/shifter I should have 8 speeds.

    Does the locking nut normally come with the cassette and will I need some tool to remove the locking nut and related first sprocket (which means a little less top speed but that's OK).

    Thank you,

    Smkntrls

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    Ok forget my question about tools to install/remove a cassette as I finally figured out the picture and that it isn't two different sprockets (one with a nut to hold it onto the frame; which I saw a couple of rear hubs that way last night). So I'm curious if someone has a good general tool kit they could refer. Obviously will need it and maybe a good sprocket key. I'll try and build and true the wheel on the bike I think...

    Will definately need assistance on spoke length...

    Looks like you guys are here hard at work. Or laughing. One or the other

    Thanks and keep those thoughts coming...

    Smkntrls

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    Hi Guys,

    I'm thinking I can't use my current chain as it will be to short.

    If I create a 8 speed system with a 9 spd medium cage rear derailleur do I get an 8 or 9 speed chain?

    Also I'll need some new cables too.

    Thank you,

    Smkntrls

  46. #46
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    No... I didn't remove a cog. I locked it out via the derailleur. The spacing on the cogs relates directly to the amount of cable movement controlled by the shifter. So... If you have a 9 speed cog, you need a 9 speed shifter and derailleur. 8 speed needs all 8 speed parts and so on.
    Also, the chains are different widths, not lengths. An 8 speed chain is wider than a 9 speed chain and a 9 speed chain is wider than a 10 speed chain.
    Since more gears are crammed into the same given space on the hub's spline, the cogs get closer together and the chains get narrower. You'll get it.
    I like turtles

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    Thanks for letting me know that NYrr496. That all makes sense.

    Smkntrls

  48. #48
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    Quote Originally Posted by NYrr496 View Post
    No... I didn't remove a cog. I locked it out via the derailleur. The spacing on the cogs relates directly to the amount of cable movement controlled by the shifter. So... If you have a 9 speed cog, you need a 9 speed shifter and derailleur. 8 speed needs all 8 speed parts and so on.
    Also, the chains are different widths, not lengths. An 8 speed chain is wider than a 9 speed chain and a 9 speed chain is wider than a 10 speed chain.
    Since more gears are crammed into the same given space on the hub's spline, the cogs get closer together and the chains get narrower. You'll get it.
    One clarification, same rear derailleur can be used for 6-7-8-9-10 speed so long as it is matched to correct shifter, no need to get different RD specific to # of speeds.

  49. #49
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    Quote Originally Posted by GrayJay View Post
    One clarification, same rear derailleur can be used for 6-7-8-9-10 speed so long as it is matched to correct shifter, no need to get different RD specific to # of speeds.
    I believe 8 and 9 is interchangeable. Ten is not. Not sure about 6 and 7.
    I like turtles

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    Thanks guys. I'm just shooting for a nine speed then I can at least transfer everything to a 24" or 26" after the baby rolls on it and grows out of it. Hope you guys are out enjoying an epic ride!

    Smkntrls

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