'09 MT60 Build
OK Starting this thread for 2 reasons:
Share the build with everyone (I got alot of ideas for many things here on MTBR and the Family section, so returning the favor)
And advise from those that have gone all out on their kids bikes.
My boy is 7 and riding has turned into an addiction for him as much as me!!! Bike started as a $20 CL find with like $20 spent on a bb and then other parts were things I already had. Ill add pics later.
He by "specs" just now fits a 20" bike based on inseam. Been riding it for a year now though. He also helped me go through it prior to him getting it, he does maint on it with my help/supervision, getting quite good.
Also, new son being born any day, so this will likely be a hand me down.
The initial plan:
-Strip, repaint/clearcoat, new decals.
-New grips (ODI makes 90mm lock ons, have locks already)
-convert to 1x8 maybe 1x9 (stock 1x6, current 1x7 on trigger)
- Bottle cage mounts: Found side load bottle cage that will allow use of kids bottle on downtube.
-New air forks: 24" because when he moves up I can transplant forks.
EDIT: Cut out big part of project cause so many say no point on 20" spend the money on a nice 24" build when time comes.
Help I need:
-Crank advise: should I go modded crankset? Thinking of using M590
-*Tires: light weight as possible without being rediculously priced. Bontrager has new version of their race tires in 20" now on their new mt60s
Finally is just any pointers you other Dads learned on the way through your builds that would be good for me to know. Kids bikes though cheaper to build (depending) seem to require so much more thought.
Also no new bike, wife would have my balls over that lol. Goal is lighten this pig up cause I swear it weighs not much less than my 29er, and my 29er aint light by standards (29-30ish lbs), but without spending a ton. Rather drop $1-1.5k into a 24" for him in a couple years when hes ready.
Finished bike probably going to look like a 20" version of my 29er (club sticker and all since hes a member too ) minus second bottle cage (its there to carry his bottle with me)
Last edited by tigris99; 10-09-2013 at 01:34 PM.
Very cool! I've gone through a lot of what you are potentially going through now. You can check out my build thread. I've also included a lot of weights to give you an idea of parts you may want to use. Also in the thread, I did a gear chart which should be helpful.
Originally Posted by tigris99
Just bought my 6yr old a Marin Hidden Canyon 20". Going to put XTR on it.
As for the fork, check out the fork mod thread that I did. I increased the travel and changed spring rates. The fork is now very usable for his weight. I was able to increase the travel to 65mm total with very good action.
Increasing SR Suntour 40mm travel fork to 60mm
I don't recommend using a 24" fork on a 20" bike. The axel to crown measurements on the Spinner 20" is 357mm vs. 410mm (24") vs. 453mm (26"). The 2" height gain will be significant to frame geometry and could make for an awkward handling bike. Save it as the hand me down. Get the nicer fork for the 24" when the time comes.
As for the cranks, how tall is your son? He will most likely need a 135 or 140mm crank. If you plan on going with a 1x setup, you can buy Sinz crank or for 60g lighter and $20 more, you can buy AC mini LE's. You will also drop a ton of weight with a new bottom bracket. Take a look at the Sinz Titanium or Promax Cr-Mo.
Concerning tires, I really like the Kenda folding SB8's. They came in at 373g's and dropped over a pound of weight compared to the stock tires.
Good luck, let me know if you have any questions.
Thnx for the info, kinda replies Im looking for.
As for the fork, can be done just serious slackening of the head angle. Check specialized kids bikes, they have one for just under $700 with 24" air fork and disc brakes... Neat idea but damn thats pricey for a bike for a couple years. Thats where I got the idea. The fork he has is older version, external springs covered by boots. Forks compress and rebound fine, except bouncy do to lack of rebound control.
Right now on outer hole running about 145mm (trek dialed crankset thing with 2 holes for moving pedals out, in outer holes now) but 140 is optimal atm, however that wont last beyond first half of next year. Awesome info on the crankset!!! Be looking around at those.
And tires, omg thank you, folding 20" tires and SB8s on top of it. 200g lighter than the ones from Trek I was looking at.
Ill update what I find, forks will be figured in as whether i can get some rebound control and travel outta these old style and weight vs the 24" air forks (which come in around 4lbs)
Schwalbe Mow Joe tires are some of the lightest available 407mm/20" available suitable for MTB riding;
Mow Joe HS 371 | Schwalbe North America
The folding 20 x 1.85 model at 330gr is a good affordable option. I recently got a pair of mow joes for my daughters 20", big improvement from the stock innova tires that were on it.
If you are interested in trying to make a decently light 20" suspension fork that will not jack-up the front geometry like using an 24" fork, check out the old manitou I modified;
Novara Pixie 20" project
damn guys, dropping more info on me, cant dig up fast enough,lol. Nice, great seeing selection of tires that are LIGHT WEIGHT for 20" wheels and suitable for trails!!! Cool thing, i could do like we all do, more knobs front fast rear (sb8 rear, Mow Joe front for example)
I did find something that made me a very happy person, thought if I wanted to replace hubs or build all new wheelset, custom spokes were in order......
Universal cycles to the rescue there, by per spoke in sizes I would need. Found this doing some digging around for hub and RD options. Oh and yes I can build a wheel, takes FOREVER for me to do it, but im learning, and im a perfectionist.
SO hub choice is m590 hubs since best for price that arent disc hubs. Plus i made the tool to service shimano freehub bodies (clean, regrease, change around spacers, etc as needed) so +1 on a hub that fits what I want, dont have to "settle"
Upon further inspection now, his wheel weight is heavy as shit tires, and rear hub/freewheel assembly. OMG the back is heavy!!! you expect heavier than front but not by 3-4 times,lol. Rims are better than I thought, full aluminum, only single walled but its a kids bike so with 32h its fine. Wheels stay, just new hubs (saves $60)
As for forks, did the measurements outside a bit ago, slackens head angle alot, makes it more like a DH bike geo. Not bad but work in progress.
IMHO, THIS KIDS SECTION NEEDS A GOOD STICKY THREAD WITH LISTS OF WHATS OUT THERE. Make life way easier, then we could skip the long threads and go straight to the build itself lol. Though Im having as much fun doing this (maybe more I think) as I was searching out everything to completely redo my '12 Trek 29er.
Aight use some help here, chainring for the sinz crankset. That crankset as much as ive dug is as you guys said, best way to go. wanting 34t (since I dont think 32t comes in 110bcd). Running no less than 8 speed, considering 9 unless becomes to much of a headache.
You can buy a TA Specialites chainring in 33T but it cost ~$55 vs ~$15 for a std 34t in 110bcd. I decided not to spend the money for the differential. If you go with a 11-36 cassette rear and 34t front, that should be more than sufficient low gear.
Ebay store BMXGURU has ISIS bottom bracket SINZ cranks about 1/2 the cost of square taper. I would imagine that an ISIS BB would hold up fine for kid use.
Sinz Expert ISIS Crank Arms 140mm Black NEW items in BMXGuru store on eBay!
Also note that since the 20" wheel is smaller diameter, effective gear-inches are all lower for them compared to same gearing on a 26 or 29" wheel. You might want to avoid using a 36T cassette that will also need a long cage RD, nearly drags on the ground with a 20" wheel.
If you do really want chainring <34T, you can shorten a 4-bolt 104 BCD or an older 5-bolt 94mm BCD crank to kid length (drill and tap new pedal holes at shorter length).
Last edited by GrayJay; 10-13-2013 at 11:37 AM.
well 34t is fine, just going to run 11-32 or 11-34 cassette. Current gears are 32 front (stock crank system) 14-28 freewheel rear. SO will give him a bit more lower gear (needs it at times on the trail)
OK so took my boy this weekend out to trails, and he did awesome till last couple miles, I ended up carrying his bike out the last half a mile or so. Not fun walking a 29er and carrying his bike down singletrack,lol.
BUT OMG, felt like I was hauling 2 of my bike!!! FFS his bike is heavy for being so small, its insane, WHY IN THE HELL do manufacturers make kids bikes so damn heavy. They make entry lvl 29ers that cost not much more that have lighter components!!!
Felt so bad for him after all that, be like me riding a 50lb + bike through the trails when I first started out.
So, component list done.
Color decided, he wants lime green frame with some blue tidbits.
M590 Hubs for sure, DT Swiss spokes, Sram 8s cassette 11-32. That with about any decent tire choice should save 1.5-2 lbs off wheel/tire wieght.
Sinz Crankset with aluminum 34t Chainring. Save another 1.5+lbs getting rid of forged steel crankset.
Bontrager Kids size ssr seat, save ~.25lbs there
Bars I have will shave off a little bit, not much but every little bit helps. Same with going to Avid speed 7 levers etc. All the extra changes should save .5lbs maybe more.
Forks I dont see saving much weight any route I go. Research has weights pretty similar accross the board unless I go spinner 20" air, which will save about .5.
But overall pretty close to 4lbs savings on what I want to say is 28lb bike. Be nice if a company would actually put a little more common sense into a kids frame, the top and down tubes could be hella smaller, shave close to pound off frame weight alone.
Now fun begins, stripping it down and such, getting it ready for paint and new parts to come over next several weeks.
To save some weight, when you re-build your wheels with better hubs just use 1/2 the spokes (16 per wheel). Still plently strong for a kid bike, 32 spokes is complete overkill.
Dont overlook modifying an old manitou fork into a 20" kid fork if you want a suspension fork that is cheap and lighter than any currently available production 20" suspension fork. I probably have less than $20 in my daughters 20" manitou (sourced used from co-op) and these can be .75 pound lighter than the 1500g spinner air 20".
FAQLoad - 20" front fork build
Actually just did some measuring, found some how current hubs are same dimensions as m590s... I checked it 3 times against QBP hub specs from shimano. So no need for new spokes. Nice cause saves me $65 in spokes (dt champions in black).
Being that I can get blue spoke nipples for like $15 I may do that for him for some added bling factor.
16 spokes makes sense but going to look odd, with all the extra holes and really going to save maybe 1/4lb total across both wheels. Every little bit helps but with single wall wheels dont think im going to take that route. If it was double walled than I would.
Forks idea is AWESOME, but no lathe and good luck finding those forks around here, live out in the middle of BFE on the Miss. River in Ill. Closest big city is chicago 2.5 hours away.
Originally Posted by tigris99
See post #4 of my build thread Novara Pixie 20" project for more detailed description of how I shortened a Manitou to 20" using just hand tools, no machine shop tools. Not hard to find an old manitou on e-bay for <50$. I've sourced several old Manitous cheap from local bike co-op in Alaska, how is that for remote!
End of same thread has some updated pictures and weight savings examples of reduced spoke count wheel build.
I was thinking more on the spoke matter, did some reading and could see benefits far outweigh the look of unused holes.
Just now trying to figure out what lacing pattern, going to need new spokes but being half the cost of full sets it doesnt bother me. I know for me being a clyde 4cross lacing is best, figure standard 3 cross would be plenty for this use. Planning to get hubs/spokes next week to start on the wheels hopefully.
Ill do some digging to see what I can find for the forks, if you can find in alaska i shoulf be able to find there here,lol. Thnx
I wouldn't worry about the unused holes. I relaced my daughter's 24" front wheel using a 16h road hub I had spare, using every second hole in the 32h Velocity aeroheat rim. I actually got the idea from GrayJay's thread. I went with radial lacing because the road hub can handle it and I'm not using disc brakes on my daughters bike.
If the hub flanges can handle it, radial lacing the front will be the easiest and save the most weight because of the shortest spokes. On a 20" wheel you will have difficulties with spoke angle where it meets the rim with 4x, and even sometimes 3x. Also with a low spoke count wheel higher cross patterns will have the spoke heads interfering with other spokes. For 16 or 18 spoke counts on a 20" rim you can really only go 2x max. GrayJays approach of radial DS with the half the spokes and 2x NDS is a good one.
One problem you may have is sourcing short length spokes. I was lucky enough to pick up a Hozan spoke threading machine which has saved me a lot of time and aggravation in the time I've had it. Otherwise, danscomp usually has a range of shorter spoke sizes (but only in straight guage).
@ Gray- checked ebay, seems those forks are common enough and can go about the same price as a new set of coil forks for a 20" on the high end. Reading more into everything to said to look at, I can do those mods fairly easy. And better thing being I can set geo by deciding what axle to crown length I want (so i can slacken it a bit) and cut forks accordingly. Very nice idea and thnx for pointing me towards that.
As for doing that on wheels, radial bothers me (based on fact so many manufacturers void warranty on radial lacing). Bike is currently 3x on v brakes, im sticking with v brakes and plus side became much easier time with building the wheels, Universal cycles has sizes I need for this route. Being as you guys went radial route, figure 1 or 2x will be plenty. To gain more weight loss, Im going to aim for lighter spokes, instead of champions.
I would have actually started stripping this down and started on everything but weather has been staying in rideable range for him so dont wanna tear his bike apart and take out riding for a while till weather puts a stop to it anyway lol.
For those wanting to lace up wheels for 20" bikes spokes in length: I used DT spoke calc (seems t be insanely recommended and easiest IMO to use). Next is that Universale Cycles and Prowheelbuilder.com sell spokes in singles at about any length you can need. PWB is nice cause more selection including colors without paying $3 a spoke.
Last edited by tigris99; 10-19-2013 at 02:42 PM.
Finally an update on this. Been busy with newborn baby and overtime at work.
Started getting parts ordered in, bike is almost tore down to bare frame. Cant beleive the weight of the frame (BB still in it but thats it) still heavy for the size but after im done will be alot lighter regardless, extra weight will just make him stronger for when he moves up.
You are going to find it hard to get lighter spokes in the short lengths you need. To go lighter you need to use butted spokes and most spokes have the butted part longer than the short length you need. DT Swiss Comp spokes are sometimes available in short lengths and CX-Rays too (but maybe not short enough).
Originally Posted by tigris99
The lightest will be to use some 2.0mm straight gauge titanium spokes which you can have shortened to whatever length you need. This will be expensive.
im going 16 spokes instead of 32 instead off the recommendations of others, save weight and money at the same time.
Last edited by tigris99; 11-23-2013 at 05:30 PM.
Alright time to resurrect this thread. Some things arose that delayed this including me getting hurt at work (lost overtime needed to catch up bills from having new baby).
But its in full swing, some details have changed to preserve budget but still accomplish goals I set out to do.
Colors finally decided polished aluminum with red decals, kids have issues deciding but told him what he says now is final lol. Polished aluminum or black will be frame color (he has till next weekend to decide)
Parts bought thus far: can thank trek for releasing new 20" superfly for some parts
-origin 8 anodized red urban bars (narrow, light, red)
-55mm aluminum stem
-bontrager xr1 20" comp tires. Very light compared to stock, about same as any other of the lightest 20" mtb tires. New release from trek for '14
- replacement crankset for new superfly 20". Part specced as 2010 precaliber. Same ring just aluminum crank arms and only 1 hole for pedals.
-bontrager ssr seat is on next order from lbs.
-I upgraded my 29er to Shimano hydros, so he's getting my speed 7 levers to use on his v brakes.
Total spent: $145
Yet to buy:
Rear hub, cassette and 8s shifter. $75
Seat post, well that's a if he still needs 0 offset or not.
red cable ferrules and new cable housings.
Forks are working decently, some thicker oil and good servicing have them dampening well, just wish they were lighter but he wants them not a rigid fork.
Next weekend we strip the frame, I strip the paint and polish or repaint. Well run current 7speed freewheel setup for a little bit yet as I put cash together to set him up on 8s in the rear. Also cutting the cable stops open on ends to run solid housings to rear brake and rd.
Also wife has friend with Camio crafting cutter, she cut custom trek decals, his name, and a tiny club logo sticker for his bike for me. Also cut custom stickers for my commuting used trek I just bought that im going polished aluminum frame.
Pics coming soon
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And finally pics as promised!
Start the final build (he decided on polished aluminum with the red now) this weekend.
Decided not to move it to 8 speed, too much money/work, at least right now. Hes happy with what hes got, well excited with what hes got!!! Less spent here, more to put aside for when he moves to a 24". Did this whole thing pretty cheap considering. Just hunted and waited for deals. Only thing I paid retail for was tires and crankset, which $25 per piece there, cant complain.
Had custom vinyl stickers made
0 offset seatpost, new pedals, and new crankset. Crank they use on new superfly 20" with aluminum crank arms. huge weight loss there.
Bontrager Xr1 20" tires, another very noticeable weight loss. New but left on floor, got dirty lol.
THen bars, stem, grips, red ferrule kit, red spoke nipples and pieces I need to run full cable housings for everything.
Ordering his seat, Serfas kids gel seat ( $20 on amazon for anyone looking) and a BBG outer bash in red, next week. Oh and a Side access bottle cage. I bought rivet nuts to put cage bosses in since this bike doesnt have any.
Expect to have finished pics by easter weekend (the next weekend Ill have him instead of his mom)
Last edited by tigris99; 04-05-2014 at 02:17 AM.
Wow, this is gonna look really good.
I still gotta see what I can do with the forks to make them look better. Work well but will look like ass. Thinking if I can't mod to internal springs going to strip the current fork lowers and paint red or something to clean up the look a little
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OK so my son said he wanted to work on his bike, so I let him strip the frame. I had to pull the crankset and BB but he did the rest while I was finishing stripping paint off my commuter frame.
Start on frame tomorrow. Strip the paint, modify cable stays so full housing can run through. Then Standard tune up stuff all the bearings and such as things go back together. Oh and noticed new crank (directly from Trek so I didnt expect this) doesnt have holes drilled for bashwich that is used on all geared kids 1x bikes. Be fun drilling that steel lol.
Was the trek crank just $25? How many teeth and how much does it weigh? can you post more pictures of the crank?
Aight heres where im at.
Crankset isnt right!!! Trek has it listed for the new superfly but looking further the 2010 Precaliber is SS!!!! So 8s chain obviously wont fit..... Calling my lbs tomorrow to see what we can do cause the only difference is it has a ss chain ring, crank arms are the same as the Superfly 20". And I already drilled holes for bashwich. As for specs, weight I have no idea, dont have a scale accurate that small but it weighs half what the stock dialed steel crankset does roughly. Its same too, 32T steel ring. And yes $25, 127mm which is middle of what trek 20" dialed crankset pedal holes are.
Now onto the work. Started the day with bare frame needing stripped of paint. Thank god they only put one layer and primer on kids bikes, no heavy dip like my commuter (that took me a week to strip clean) sunlight while applying stripper paint came off 30 secs after brushing the stuff on, kept having to rinse my brush out,lol.
Frame stripped, ok polish job (hands got tired and boy is happy so good enough)
And where I am at with assembling new parts as of now:
Even serviced ALL accessible bearings, used my new love called marine grease (used to use automotive grease). ANd hard to see but even red spoke nipples installed. THE STOCK NIPPLES WERE GALVANIZED STEEL or some ****, they were rusty inside the rim and stuck to magnetic screwdriver tip on my drill,lol. cut spoke nipple weight literaly by over half lol.
Yet to do:
Get new seat
modify cable stays for full housing and get new housing.
Run all cables, install RD and chain.
Deal with crankset problem.
Change rear axle to QR.
Dial in cockpit for him (bars are 520mm not sure if they will be too long for him)
Ok crankset update. Trek hasn't gotten that sorted yet, joys of poke and hope.
So, to my fathers shop it will go. This weekend I'll take it over and thing the ring down where the chain rides. Take a bit of time to do but better than $25 for this crank (im stuck with since I drilled it) and the another $50 or more after digging to find a BMX crank the right size that's still as light.
Except for that bike is rideable. Cut cable stays to allow for full housing idea didn't come out as clean as I had hoped but it is what it is for the moment. Looks ok and works.
True up wheels tomorrow hopefully, Saturday take care of the crank issue and seat will be here in the morning.
Think im as excited about this build as my son will be lol.
Edit: seat is on now, matches bike well too. And better padding than his old seat, not to mention actually looks like a kids seat, not going to still be on the big side like the old on.
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Last edited by tigris99; 04-09-2014 at 12:53 PM.
Aight first ride today, didn't think about pics cause boy was enjoying himself too much. Amazing how much more confidence he has in a bike that he can handle instead of a lead sled.
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This thread is a godsend. I just wish the pictures would show up. This is amazing. Im trying to etch up a part list for my kids bike but man, there are so many threads between the specialized and the trek. So confusing.
Ignore the manufacturers of the bikes. Means almost nothing as parts are pretty standard across all these size bikes.
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