Is this bike suitable for motorization?

Discussion in 'General Questions' started by Yash, Jul 31, 2016.

  1. Yash

    Yash New Member

    Hey guys, new to this hobby. Recently got very interested in this whole thing and have been reading as much as I can on the topic this week. I've found a bike that will most certainly fit an engine inside the frame, but my main problem is that the tubes might be a little thin. The wheels are 28" but I'll probably change 'em to 26". Frame is made out of steel, but the tubes aren't very thick according to some old documentation on the bike, since it's one of those lighter bicycles with thinner tires (which I'll change). It's also made in Russia.

    I'm thinking of mounting a 2-stroke 80cc engine on it, just to clarify.

    [​IMG]
    [​IMG]

    I can upload more pictures, but these should be enough.
     

  2. FurryOnTheInside

    FurryOnTheInside Active Member

    Read about fenders in the newbie threads. Take precautions.
    IMO those caliper brakes are insufficient for stopping the bike if it is to be used on public roads.
    How do you plan to change the wheel size, when you have only the central hole for mounting caliper brakes? Can you find some wrecked old kids' suspension forks and cut the whole arch support and v brake mounts off them and attach to the bike with jubilee clips or something like that?
    IMO it could be easier to start with a newer bike..
     
  3. Yash

    Yash New Member

    I've quickly glanced around, but I now understand they can be dangerous. Thanks for the heads up! I'll definitely read more about them.
    I'll see how well they break, and I can either replace them with new caliper breaks or just tighten them up. I'm not really into coaster breaks and I'm not familiar at all with disk breaks, so I think I'll go with calipers.
    I'm not really experienced with bike modification and repair, only know how to ride them. ;) But I think I'll manage to modify the frame to fit in the caliper breaks for the smaller wheels. If not, I'll have to stick with 28", but I'm not fond of the thin tires.

    I think I'll be buying this bike, out of all the bikes I've found so far this one seems to be the best in terms of functionality and aesthetics. I'm not really into the look of the new bikes (and my budget is tight), and considering I'm in Eastern Europe I don't really have access to the sleek beach cruiser bikes here. We have some similar-looking bikes, but beach cruisers aren't really popular from what I've seen so far. Maybe I'm just missing some store / website though, who knows.

    Thanks for your input, man. Every little bit helps. :D
     
  4. FurryOnTheInside

    FurryOnTheInside Active Member

    IMO and it is just my opinion! I think you need to be familiar with bicycle maintenance and repair before even considering adding an engine to one. Safety is always the most important thing.
    Beware of worn rims. Rim brakes will wear down aluminium rims over time and eventually the rim can split. I had that happen once, 40 miles from home. That wasn't fun!
    Caliper brakes use the central hole mount. U brakes use a pair of posts which are level with the tyre (approximately 1" above the rim). Cantilever brakes and V brakes use a pair of posts approximately 1" below the rim. If a bike has cantilever brakes it can be changed to V brakes with ease. IMO, V brakes are the best rim brakes.

    I would love to see a real Riga motorised bike from the factory that was in Riga, Latvia. They are the original. Perhaps you can even find one to buy. Anyway, don't rush to buy a bike. Something better may come along soon. :)
     
    Last edited: Jul 31, 2016
  5. Yash

    Yash New Member

    Oh, I'm not completely clueless about bikes and their repair / maintenance, I just know the basics - tires, breaks, chain, etc. Mostly because I've never had to repair a bike extensively, just flat tires and screwed up breaks. But I fully agree, safety is number one!

    Latvia is far, far away though, since I'm in the Balkans. Doubt I'll be able to get my hands on one of those. :D

    I know myself too well and I'm quite impatient to start working on this. I'll scour the internet for more bicycles but for now I think I'll settle with this one. I'm still waiting for the seller to respond, and I'll ask him / the delivery company for the option to return the bike if I don't like something about it.
     
    Last edited: Jul 31, 2016
  6. Yash

    Yash New Member

    Learned a bunch about brakes today (and to not write them as breaks :D) thanks to you man, I thought it was just coaster, caliper and disk at first. On my normal bike I've got V brakes and they do a pretty good job.

    Anyways, what's your (and other people's) opinion on the frame of this bike? Is it sturdy / thick enough by the looks of it?

    Also, is it possible to modify a frame for a motorized bike by cutting and welding it, without having the whole thing break down because of the engine vibrations? And is there a recommended tire type, as in wide or thin, for motorized bikes?
     
  7. FurryOnTheInside

    FurryOnTheInside Active Member

    Yeah idk where everyone is.. I like new project threads. :)
    The frame is probably quite sturdy enough. Hard to tell the guage (wall thickness) of the metal from a photo, but age and being made as transport rather than racing makes me think it will be fine. The wheelbase is long so should help it to be stable at motorised speeds. The bend in the fork will absorb some high frequency road bumps so that your hands don't tire. It is taller than necessary as you are not going to be pedalling.. But idk if that would be a problem. It's forward slanted rear dropouts should be good for getting the correct chain tension with less fuss. I quite like it in a lot of ways.
    Yes you should be able to weld that frame as it is steel, unlikely to be any kind of special heat treated or whatever, just high tensile steel. It really needs tig welding or brazing (I think I can see in the photo it has the sleeves at the joints because it is brazed, not welded). I had someone MIG weld a bike frame repair for me once and though it worked it was not pretty by the time he finished filling the holes back in that he burned in it! I hope you would look into getting the mounts for v brakes if you are going to modify the frame.
    I never read about brazes failing due to vibrations, and it has survived this long, I think it is really okay as it is apart from the old style caliper brakes.
    You should still think about making some modifications to your engine to reduce vibration for better comfort (and the health of the engine at higher engine speeds) anyway.
    Frames built to take wider tyres generally have more clearance to get the motor chain through.. They can have a straighter return (lower) side of the chain, which means less strain on the idler pulley when you bump start the engine.
    It looks like the rear wheel has already been replaced, that is good. Spokes should be stainless steel (shiny) not cheap wire (grey).
    The tyres look like maybe 622x32mm which is fast and economic, but they (32mm) are the size I use on my touring bicycles, on roads and being careful and pumped up to 70/80psi, but loaded up with a lot of weight.
    I think there's a happy medium on the tyre size you actually use, but that depends on your weight, your roads, your riding style.. 622x47mm might be preferable for motorising if there are unavoidable bumps in the roads, but only you can know that. You might need a 3" tyre mountain bike to protect the rims and your spine but it would get many less miles from the tank of fuel- what suits you will depend how you ride and where!
     
  8. Yash

    Yash New Member

    Cheers man! Many thanks for all the advice, I'll be ordering the bike soon and I'll try to get it in shape for motorization while I get ready to purchase the engine kit.

    Also, how can I reduce the engine vibrations? I'm guessing I'll have to tinker with it a little, or maybe put something soft where the engine is mounted to absorb some of the vibrations? I'm not really sure the latter will help, might even be more dangerous actually if it obstructs the engine mounting, but I'm definitely up for some engine tinkering, it's quite interesting to me.

    Oh, by the way, is there any way to bring the bike a bit lower to the ground other than resorting to smaller wheels and modifying the frame? You know, similar to those 1910's motorbikes / board trackers.

    I'll be sure to post updates on my progress, might be useful to someone new like me (or entertaining for experienced members :D ).
     
    Last edited: Aug 1, 2016
  9. Yash

    Yash New Member

    Weird, my previous post is waiting to be approved by a moderator, but this one got posted instantly, so I'll just copy over what I said to avoid confusion.

    Cheers man! Many thanks for all the advice, I'll be ordering the bike soon and I'll try to get it in shape for motorization while I get ready to purchase the engine kit.

    Also, how can I reduce the engine vibrations? I'm guessing I'll have to tinker with it a little, or maybe put something soft where the engine is mounted to absorb some of the vibrations? I'm not really sure the latter will help, might even be more dangerous actually if it obstructs the engine mounting, but I'm definitely up for some engine tinkering, it's quite interesting to me.

    Oh, by the way, is there any way to bring the bike a bit lower to the ground other than resorting to smaller wheels and modifying the frame? You know, similar to those 1910's motorbikes / board trackers.

    I'll be sure to post updates on my progress, might be useful to someone new like me (or entertaining for experienced members :D ).

    -----

    Actually, I won't be buying that bike, its owner said he has used it quite a lot every day and it's got some considerable wear, so I'll be buying this one instead -
    [​IMG]
    It's the absolute same model, but this one hasn't been used as much, it's in a pretty good condition. The rear wheel is a bit older, front one looks okay but overall it's got less rust and less wear on the whole bike. Well, it will be sent tomorrow and I'll probably receive it tomorrow or on the 3rd. Wish me luck! :D
     
  10. FurryOnTheInside

    FurryOnTheInside Active Member

    Yes I am sure it will be an interesting thread. And yeah I thought it looked like the same bike! :) It does have the original wire spoked wheels so to drive it from the spokes (kit rag joint) you should really be replacing/rebuilding with high quality spokes.
    You have time to read all the newbie/sticky threads and don't forget to use the search function (up in the top right) with words like vibration reduction and crank balancing as there is lots of great information already posted. :)
    You will read about fender dangers, the need to mount solid to the frame, and the basic upgrades that "all" generic 2 strokes need.
    I'm sure if you can/decide to take brake mounting posts (aka lugs) from scrap/wrecked bikes/forks then you can use any wheel size you like to lower the bike. The quill stem should be able to be dropped quite a bit too, but not too far (mind the taper). Also see if you can get the Sheldon Brown site to work on your device as there are some great tips on bicycle repair/setup/standards there.
    http://www.sheldonbrown.com/handsup.html

    Good luck! :)
     
  11. Yash

    Yash New Member

    Wonderful advice, you've been lots of help man! I'll definitely continue reading about the stuff you've mentioned, but I'll mostly focus on the bike until I get the engine kit. Much thanks again! :)
     
  12. Yash

    Yash New Member

    Hey guys, I've got the bike and now I've started planning on what to do. So, first up I've got to change the wheels completely (they're in a bad shape, rusty and beaten up), decided to stick to 28" so I don't have a bunch of problems to fix if I go to 26", and I've found some new rims for a very good price. However, I'm wondering if there's anything specific to know about the wheels themselves when it comes to motorization of the bicycle. The rims I've found are aluminum and I wonder if that will be a problem.

    I'm also interested if there's anything I should know about picking the tires for the bike.
     
  13. Frankfort MB's

    Frankfort MB's Well-Known Member

    Id try to stick too double wall rims.... I've never had a bike with aluminum wheels so I can't answer your actual question
    Thick spokes help with sidewall strength
    A heavy duty hub is a must!!! Coasters will work but aren't efficient:)
     
  14. FurryOnTheInside

    FurryOnTheInside Active Member

    Okay first thing I have to say: Double wall rims are always aluminium. (Frankfort, get a magnet and tell me if im wrong! Lol)
    Aluminium rims can be single or double wall. You definitely do want double wall rims.

    Your wheels are (or appear to be) 700c which is also called 29" (but 29" generally refers to wider rims meant for mountain bikes) or ERTRO size 622. ERTRO is the modern standard sizing / name and will ensure you get tyres to fit. Be careful to not end up with a weird old standard size by using the 28" name.

    Spokes are either wire or stainless steel. Wheels with either can be machine built but the wire ones are always machine built and are common on cheap bikes. You do not want wire (grey) spokes like the ones currently on the bike. It is impossible to get the high tension you need with low quality spokes.
    You do want high quality stainless steel shiny spokes. (The black ones can be high or medium quality, it is difficult to guess the quality based just on appearance when it comes to black spokes.)
    A wheel can be seen as an arch. Your weight hangs from the spokes at the top and the strain is transferred to the sides of the arch which are held in shape by the spokes at the sides. The bottom of the arch is supported by the spokes at the sides. The spokes at the very bottom are not loose and bending because they are pre-tensioned and because the spokes at the sides are not prone to stretching so the arch stays in shape. It is spoke tension that keeps the wheel in shape.

    I believe the kit "rag joint" sprocket attachment method does not help the wheel to function correctly. I believe this is why a lot of riders prefer the heavy guage (thick) spokes. I am no structural engineer and only have a basic understanding of how a wheel functions, but I really can't agree with the kit system, to my mind it just doesn't make sense!
    Anyway, it is cheap, but a custom or tandem wheel with heavy 12 guage spokes is expensive especially outside the USA. You certainly need high quality spokes IMO (in my opinion).

    So, IMO a complete ready built wheelset is possibly the economic choice.
    It should have 36 high quality spokes per wheel,
    deep section (deep/aero profile) rims in case a spoke does break,
    and a hub which fits your rear dropouts.

    What is the width of the space between your rear dropouts? The common multi speed bike dropout width is 135mm and most common wheelsets have a rear hub to fit this.

    The 622 rims need to be suitable for at least a 40mm, up to 47mm tyre. (ERTRO 622x40, 622x47) Anything larger will almost certainly not fit in that frame. You might not even have clearance for a 47mm tyre.
    Wheelsets sold as "touring" wheelsets have the right width. Those sold as "road" or "racing" may be too narrow, and such a large tyre may not stay on the rim.
    The ERTRO measure of rim width is the internal width in millimetres. The ERTRO tyre width should be around 1.4 to 2 times the ERTRO rim width.
    For example: IF the largest tyre that fits your frame is 622x47 then the largest rim you can use is 622x35 but that would mean you can never use a smaller tyre (you can but it is risky). The narrowest rim you can (sensibly) use with a 622x47 tyre is 622x23 and that would allow you to also use tyres as small as 622x32

    Switching to the ERTRO 590 rim size (aka 26") would give you more clearance for the tyres if you want larger tires, but then you really do need to find a way to mount brakes.
    Smaller diameter wheels really are stronger wheels (all other things being equal).

    Tyres should be as "slick" as possible if you are riding on paved roads. A "tread" is only needed for dirt and gravel roads, and will not have as much traction on paved roads as a slick tyre. The tyre should be able to hold enough pressure to allow a drop (in depth) of only 10-15% of the tyre depth/width when you load it (put your weight and the bike's weight on it). An online bicycle tyre pressure calculator will be helpful. Always check the maximum pressure on any tyres you are thinking about buying and see if it is wide enough to support your weight at that pressure. The wider the tyre, the less pressure is required (and the 15% is also a higher number so you have a smoother ride).
    22-30mm is common for road bikes (lightly loaded, just a skinny cyclist with no cargo), 32-40mm is common for touring (moderately loaded, cyclist + water + tent + sleeping bag) and 40-47mm is preferred for heavily loaded touring (cyclist+food+water+full camping equipment+spare parts+clothing+etc). I would think that the wider tyres are best for motorising but you are going to be limited by the clearance in your frame.
    Weigh yourself, your bike, add 10kg for the engine kit and 2kg for fuel.

    That is the most I have ever written about wheels in one go, lol.
     
    Last edited: Aug 5, 2016
  15. Frankfort MB's

    Frankfort MB's Well-Known Member

    Thanks for your clarification!
    My double wall rim is a Alloy wheel (which I'm pretty sure is the same as aluminum:))

    I know that double wall rims are a lot stronger but I do not know what they are made of or what the best material is.


    Also adding to your post, your tires should be slick but if you ride in the rain you need a tire with channels....

    I specially ordered 12g spokes with a double wall rim.... Hopefully that will take to torque of a torquey little motor:p
     
  16. FurryOnTheInside

    FurryOnTheInside Active Member

    I was/am pretty sure that any wheels made this century and sold separately (as in not on a bike or cheap trailer) have an aluminium alloy rim. I have seen steel rims only on ancient bikes and the worst 16" trailer wheels.

    I disagree about the channels, (unless you have a flat tyre) the round shape will not aquaplane until you are going well over 100mph.

    I'm sure 12 guage will help with the stress that the rag joint /_spoke driven system puts on the spokes but idk if this is the best way down the rabbit hole for our Baltic friend. There are no MB shops in Europe, so 12g ready built wheels probably don't exist and so using 12g spokes means building a wheel.. Rose bikes in Germany does a good mail order service and could have a decent 36 (high quality) spoke 622 touring wheelset. I have not checked.
     
  17. Yash

    Yash New Member

    Wonderful information, much appreciated.

    Here are the rims I'm interested in - http://olx.bg/ad/kapli-28-ili-29-za...yah-tioga-schwalbe-ke-ID5yqD0.html#81d18e565f

    It's in bulgarian but you can just scroll down and look at the pictures. I'm interested in the Schwalbe Road Cruiser 42-622 tires that the guy is offering with the rims, since they seem pretty good. The rims have aluminum hubs JOY TECH XRP, from what I've read.

    By the way, I'm in the Balkans, not the Baltic. It's way down in Southeastern Europe. :D
     
  18. FurryOnTheInside

    FurryOnTheInside Active Member

    Oops! I apologise for the mistake. I'm baking plastic pedals in my oven and fumes are probably starting to affect my brain. :oops:

    Okay I will take a look at the link. I think I have a Schwalbe road cruiser on my trailer. It is pretty nice.
     
  19. Yash

    Yash New Member

    No problems, they sound quite similar! :D

    I'll be messaging the seller if he knows if the rims are double walled, or for the model of the rims since I can't find it on the website he posted to.
     
  20. FurryOnTheInside

    FurryOnTheInside Active Member

    Sorry but the spoke pattern on that wheelset is more fashion than function and you will find it difficult or impossible to fit the sprocket that comes with the motor kit. You really need 36 spokes in an even and very normal looking pattern.
     
    Frankfort MB's likes this.
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