First build is this a good frame?

Discussion in 'Photos & Bicycle Builds' started by FLAMINGxORPHAN, Jan 12, 2014.



    Howdy folks, this is my first time building I have a diamond back Sherwood mountain bike frame. It says 21"is that the seat height? that has no back wheel. Is this a decent frame to use? Could someone respond with any specific info relating to this frame maybe? I have been reading for a few hours and I think I want to use a 2stroke motor with the kit that let's you use the existing gears on the bike.

  2. Bzura

    Bzura Member

    I'm not familiar with that model, but after looking it up online it appears to be a standard size/shape mountain bike frame that would easily accommodate a 2-stroke kit.


    Thank you for reply can u recommend a kit? I weigh about s 190 so I probably want as big a motor as I can fit? Can spend about 250 but the less the better. Thanks again for reply.
  4. wheelbender6

    wheelbender6 Well-Known Member

    The 21" is measured from the center of the crankset to the intersection of the seat tube and top tube. A 21" frame is considered large. I think you need to be 6' tall or better to ride a 21" frame. I am 5'9" and ride a 17-19" mountain bike frame.


    I'm just under 5 11 but I like this bike and really want to keep it. So what kit tout and where from? I have an eBay account is that the best option?
  6. Bzura

    Bzura Member

    I've used quite a few kits from different vendors (a few from ebay too) and I haven't noticed any major difference in quality of engine/components in them. That is for. Basic 66cc China 2-stroke (Happy Time, HT, etc.)

    That being said, these kits aren't for the person who wants to just bolt it on & ride without any maintenance or tune-ups every now & then. And by "now & then" I mean it could be now, then in 5 minutes, then in 10... But, if you are the type to like working on mechanical things & you are somewhat handy then these engines can be a great thing. They really are pretty simple, and after a while of riding, working on the engine & reading the forums you can quickly figure out what the engine needs or how to identify & fix problems along the way.


    Ya I get it I have been half assed mech for a wile and don't mind it plus I have access to a friends small engine/ motor cycle repair shop I guesse I was just hoping someone could point me to a specific kit I know I want a 2 stroke and I have about 250 to spend. Do I need better brakes? Also this bike has no back tire at the moment as ain't no wheel , nothing , my son who is 6'2" destroyed it completely so is there a certain type of wheel/ tire I should or could buy online ? Maybe one with the the appropriate sprockets already mounted on both sides? Again thanks to everyone!
  8. HeadSmess

    HeadSmess Well-Known Member

    steel frame preferable. 21" is huge but if you could ride it fine when it was in one piece, use it. i got a 24" that is just silly...but hey... it rides smoother! longer distances make it slightly more flexible/springy which does wonders for vibration! tiny frames vibrate more.

    less clearance between seat and the top bar can make a grown man cry :joker:

    helps if the tubes are skinny, rather than these massive oversized tube frames that need mounting modifications. dont drill holes through the frame! use clamps etc...

    make your son buy new parts. show some spine and teach discipline. im sure you worked to pay for it in the first place... well, beanpole can now return the favour.

    v-brakes(linear pull) or cantilevers are good enough. some may argue but if a v-brake can lock the wheel with one finger...what more do you NEED?

    the engines...can be anything from frustrating to a marvel of modern mass manufacturing... all down to luck apparently. personally, i say skyhawk makes the best engine. and again, i only use the 48's. convenience, mostly. except the skyhawk has different internals, be warned! i only have one for that reason mainly. everything else has just been generic HT 48cc china engines...

    a handlaced wheel is far superior to any machine laced wheel, but you will pay! ignore that advice! just use the one that fits. do you want all those gears? havent had cables on my shifters since motorizing, just locked them off in an easy pedalling gear for when the engine has its moments... and you can always push if the worst happens.

    yes, you can get a special hub with the sprocket mount on the other side... the rag joint works fine for most people but. how much money do you want to throw at it? less than 250....hmmmmm. possibly already laced, even, but a wheel isnt that hard to relace. takes less than an hour. need correct length spokes for relaces if any dimensions are different, such as hub flange diameter or the distance between flanges...

    weakest link in the rear wheel, only thing that gives me grief, is the tensioner. cus if that slips and catches a spoke... at best, you walk home! unexpected lockups at any speed are nasty :wacko: best to, once its all decided on and in final position...screw through it into the frame or tack weld it on...
  9. butterbean

    butterbean Well-Known Member

    190 lbs is not heavy enough to need "as big an engine as you can fit". Also, when it comes to the kit two strokes, there isn't much difference power-wise between the 49cc and the 66cc, but if you want the 66cc, go for it. At your weight, either size engine should make decent power for you. With a shift kit (the kit that allows you to use the bike's gears, you will definitely get decent power. $250 is not going to buy you an engine kit and a shift kit, but $350 probably would.
  10. Bzura

    Bzura Member

    FLAMINGxORPHAN - I don't really feel comfortable recommending a specific bare-bones Happy Time engine from a company or seller that offers no customer support or warrantee. You're going to find your least expensive engines from these operations. It can be a crap shoot as to how one engine is assembled compared to another - both from the same factory. They are usually just fine, but I've seen some weird stuff slip through Chinese quality control. I am willing to take that risk, and every engine I've dealt with gets stripped down & rebuilt so I know it's right.

    There are some good, reliable vendors who advertise on this forum. has some really solid American built engines with balanced cranks, upgraded bearings & he's a real stand up guy who will stand behind his product.

    As far as just getting a bare-bones engine kit, check ebay & pull the trigger on one if that's what you want. They all vary slightly, but they are all still very much the same thing. No one stands out as being the go-to engine for having any advantage over others.
  11. butterbean

    butterbean Well-Known Member

    Dax's engines come from the same factory in China. American REbuilt or American upgraded would be a better description.
  12. KCvale

    KCvale Motorized Bicycle Vendor

    If it is one of these models maybe not a very good choice for easy...

    Most of the those models I see there are really tight and have a fat down tube but then again a 21" bike is huge.

    Diamondback's are fine bikes and though it takes a different front mount (I use the SBP universal front mount) they can come out nice like this Sorrento.


    Assuming your back wheel hub and sprocket set are intact you can have a bike shop re-lace into a new rim with 13 or even 12g spokes for ~$60 and you'll have a new sturdy drive wheel.

    For a rag joint spoke mount many 7-speed wheels have an ideal diameter so the sprockets hole fits over it and darn near aligns itself, what you don't want is a hub to fat or sprocket with a hole so small the sprocket won't fit right or you have a whole of slop to get aligned for the dreaded vertical movement that causes your drive chain to get loose, then tight, then loose again on every wheel rotation.

    I always have to smile at the guys that rig spring loaded chain tensioners to combat this opposed to just making the rear sprocket true.

    As for 2-stroke engine kits I have only bought Grubee Skyhawks the last 50 or so 2-stroke builds because they go together well, start right up 95% of the time, and don't come back with problems.

    The Chinese YangDung engine factory (China Gas) and Nationwide Access ( 2010-2012 EPA status was not renewed in 2013 due mostly to the government shutdown so NO Chinese MB 2-stroke assembled engine kits are legal to import now but that's OK with me, gasbike is selling their 2013 2-stroke 66cc kits with the engine partially taken apart (you need to attach the piston, jug, head and magneto).

    Personally I love the new kits as I look inside there anyway, they are not burdened with EPA requirement parts, and a few other subtle improvements like the new 2.5L gas tank and petcock fitting, it has a double long tank screen and outer ring attachment so you put the on/off lever where you want it with a good no leak gasket and not where the internal threads bottom out.

    Just my 2ยข worth.
    Last edited by a moderator: Dec 18, 2015