Bike with 29" wheels?

[tidelipop]

I've just realized that my bike isn't that suitable to convert to an ebike. The reasons is, it has an alu-fork, which makes a front motor a bad choice. It does also got 8 speeds in the rear hub and therefore no place at all to fit the rear derailleur.

So I'm thinking about what bike to buy and convert to an ebike. I think I do want a rear motor, so an alu-frame would be fine. I have now found one rather affordable that I like. It's a MTB with 29" wheels, is that a problem? I've not seen any ebike-kits with 29" wheels, why is that? It does also got the brakes and the gear shifters in one package on the handlebar, is that a problem? Do I need to use the included e-brakes in the kit I'm buying? If that's not a problem, what do I need to do? Is it just to mount the rear wheel with another set of freewheels and the old gear shifter will work as long as I don't try to change to a higher gear that I have on that new freewheel kit? Is it just to put the chain on and it's fine or? I'm a newbie on this...

Thanks!
Andreas

 

[dogman dan]

Actually, your 8 speed bike will take a rear motor with a 7 speed freewheel good enough. It won't index perfect, but it should be ridable in whichever 3-4 gears you actually use. You just won't be shifting much, if at all with a good motor. Just set it for the middle, or towards the high gears, and at least 5 gears will index good. You will also adjust your derailur stops on the top and bottom to fit the new cluster. So you don't go for the 8th large gear, and send the chain into the motor housing.

You don't need the ebrakes. Well, you do to be legal some places, but who on this forum sweats legal? Unplugged, the motor runs. Close the circuit, and the motor stops. You can use that same plug to install a handlebar kill switch.

29 er motor wheels aren't so common now, but they might start to be as 29ers get more popular. There is no particular advantage to the larger wheel once you have a motor. Also motor windings are matched to the wheel size, and the ideal winding to use on the 29 inch wheel is not always avaliable from the vendor.

Some do offer slower winding choices, The crystalyte HT model would be good on 29 for instance.

 

[mat h physics]

It's my understanding the rim will be 622cm, which is a 700c/29" tire. Though some here have used a 26" back wheel to increase the head rake geometry for higher speed stability. You should be able to replace the rear indexer w/ a 7 speed, dogman is correct on just adjusting the max index. As mentioned on this board alot, Sheldon Brown has great info on bicycle basics. Hope things go together well on your build.

 

[The Mighty Volt]

My advice , sincerely, is that 26" wheels are the biggest wheels anyone should use on an ebike. The smaller the wheel the better. Its easier on the controller, it is more fun too.

 

[tidelipop]

Thanks for your answer, but I think I didn't make myself totally clear about my current bike. There is no place to mount a derailleur on the frame at all, so it does only work with wheels that got the gears inside the hub.

Anyway, I went down to the store again, just because I'm such a nerd about ebikes now so I don't have much else in the head. I looked a little closer and the wheels and on the rim it reads ETRTO 622*21 DIN ALLOY 700C / DOUBLE WALL / M. Then I guess it's 700C I have to order? Is it always the same width of rims? Or is it something else to consider?

Actually I found another bike there I liked better, it was a little more expensive but it had disc brakes and a better front shock absorber, it was lockable, 100mm and a nicer frame + hydralic brakes and the brakes and gear shifters where separated. 27 speeds. One thing I think would be a problem with this bike and the motor I have looked at (MAC 10T) is the width of the caliper for the rear disc brake. I think it's to wide to fit, so maybe that caliper has to be changed. Is that expensive and difficult to switch to another thinner caliper (hydralic), can you recommend one?

Besides the ebike-kit, I will also have to change the saddle, it was too hard for my taste and I want to rise the handlebar so I can ride the bike a little more upright. I also will have to change tires, because I do want it be more comfortable riding on asphalt + a couple of fenders, then it will be perfect I think/hope!

Should I go for LIPO-batteries or what do you think? 10AH.

 

[Drunkskunk]

29" is the same rim size as 700C, road bike wheels. 29" is just the name for the rim size when used with mountian bike tires. Confusing, right?


Nothing wrong with 29ers. I've built 2 of them. On smooth ground they feel like they'll roll for ever. But I prefer 26" wheels.

 

[tidelipop]

Yes, rim sizes is confusing... anyway, here are a couple of photos I shoot in the store:
https://plus.google.com/photos/102682238132947537962/albums/5721245828485705185?authkey=CMe37Z-A6--eUw

Since I know nothing about the qualities of the Shimano model this bike got, what do you say about it?
Is it cheap crap or ok?

 

[Russell]

Yeah bicycle wheel/tire sizing is completely screwed-up, the victim of marketing. What you always want to look at is the bead to bead diameter stamped or on a sticker on the wheel.

Road bikes with skinny tires generally use the "700C" wheel size which is 622mm

29'ers are also 622mm (700C), they're just wider rims to handle bigger tires. The marketing folks call'um 29" because the overall diameter of the big tires used is around 29 inches.

You'll also see the 700C size sometimes referred to as 28" when the tire isn't quite big enough to justify calling it a "29'er"

But don't get that confused with an actual 28" wheel (yes there is such a thing) that was used in some parts of the world. A "real" 28" wheel has a bead to bead diameter of 635mm

Oh and just to throw this in, if you remember back to the days of road bikes with 27" wheels, those wheels are 630mm.

If you want more info on tire sizing see these links;


http://sheldonbrown.com/tire-sizing.html

http://www.schwalbetires.com/tech_info/tire_dimensions


Oh and though 700C/29" motor kits aren't nearly as popular as 26" kits there's no reason not to motorize a 29'er. All of my ebikes to date, save for one, has used 700C wheels. In my case 700C is the size I've ridden most so that's the bike I had available to convert. If you're starting fresh then use either. My next bike will be a 26'er because I just got a good deal on a motor/wheel in that size.

Have fun

-R

 

[MadRhino]

What is important first, is to know what kind of power and speed that you need. Your actual bike could be used with a rear motor and single freewheel, most won't shift anyway since the motor does the torque job and one can accelerate from a stop on the high gear. This is if it has the required 135mm dropout width to mount the motor, because many of those bikes with dog shift hubs have narrower dropout.

Else, if you buy a bike, your best choice is an MTB with 26in wheels and disc brake mounts front and rear. The bike doesn't have to be new, better spend the money on quality components to build your Ebike. The more power that you plan, the less important it is that the bike is in good condition, for you will want to modify and upgrade it anyway, and a good frame that is suitable for your goal is what to look for.

 

[cassschr1]

You might also want to get full suspension........unless you want to build again....which is fun also!

 

[tidelipop]

I would like full suspension if it wasn't so expensive. This bike on the photos would cost me $519 and that is ok for a new bike with this equipment I think.

I want the bike to do about 25Mph on the flats and to do moderate hills without much problem.

 

[Russell]

Nice bike for the money.

Some thoughts:

Rear brake caliper doesn't look like it will clear a motor.

Many rear motors will handle a 7-speed freewheel so getting a bike with 7 or 8 speed shifters is advisable since they have the same cog to cog spacing. An 8 speed shifter can therefore be used with a 7 speed freewheel by simply adusting either the high or low stops on the rear derailleur. 9 speed cog spacing in narrower so while you can set it up to work kinda ok, it's not the best way to go. You can get a 9 speed freewheel but you have to then spread the rear dropouts with a spacer.

Like many bikes nowadays that one appears to have shallow rear dropouts which definitely need one or two torque arms.

The bike has disc specific wheels and if you order a kit you'll likely get a wheel with machined sides for rim brakes. It's an aesthetic issue that may or may not bug you.

Knobbies are not the best for high speed road use

Use the simulator at ebikes.ca to find a motor/battery combination which will yield your desired cruising speed

http://www.ebikes.ca/simulator/

-R

PS, here's my cheap 29'er turned "hybrid" street bike



http://endless-sphere.com/forums/viewtopic.php?f=6&t=34102

 

[dogman dan]

A fine bike, and quite a good price. However, 9 speed rear clusters do not index at all with a 7 speed screw on freewheel. So it's not such a good candidate. At the very least, you will have to get a new chain, and new shifter, and possibly even a new front crank.

Keep hunting for a good bike. 21 speed is perfect, 24 tolerable. Perhaps later on, you can take stuff off your first cheaper bike, and install it on a really nice 28 speed. But for now keep it a bit easier so you can ride, instead of troubleshoot your new bike.

For many, the best bike to use for that first ebike is a relatively cheap steel frame with front shocks. Perhaps disk only on the front. Usually 21 speed, and the steel makes it easier to make any modifications, like spreading the rear stays to get disks to line up without rubbing a caliper, etc. Trek 820 and similar Specialized models work great.

 

[tidelipop]

I very much appreciate your answers, thanks!

If I really like this bike, what do I need to do to make it work?
1. Buy a 7 speed freewheel that fits my ebike-wheel-kit, if it doesn't have one from the start.
2. Change the shifter at the handlebar to a 7 speed-shifter. Does any type work? If I prefer the type where you make a twist with your hand, is that ok?
3. The front crank, is that the one that moves the chain onto the front gears? Why do I have to change that one and the chain?
4. Does any motor fit with a disc brake and my caliper? Or how would you have solved that?
5. I need a pair of torque arms.
6. If I don't change the brakes on my handle bar. When I brake and release the throttle, will that also completely cut the power to the motor? Or can I somehow use my current brakes and cut the power to the motor when I use them?
7. Have I forgotten something?

 

[Russell]

1) Yes, buy a 7 speed FREEWHEEL (not cassette). Most, but not all motors will accept them without having to use spacers. Many folks like to get a wide range unit with an 11T small gear for high speed.

2) Yes, buy a 7 speed shifter. What model you buy depends on your rear derailleur. If you have a Shimano or Shimano compatible (2:1) derailleur then any Shimano shifter will work. SRAM makes Shimano compatible twist shifters and they also make 1:1 pull shifters which work with their X.0 series of rear derailleurs.

3) You don't need to change the front derailleur, all of them are 1:1 pull and you don't need to change the 9-speed crank or chainrings. You also probably don't need to change the chain since most modern rear cogs are slender enough to work with a narrow 9-speed chain. Try it and if if everything spins freely you're golden. If the chain "sticks" to cogs then you'll need a slightly wider 7/8 speed chain. Going to a wider chain however can cause problems with some 9-speed specific rear derailleurs so don't do it unless you get the aforementioned binding.

4) most rear motors have very limited space and it's a crapshoot. The latest Crystalyte motors have the most clearance. You can fudge with spacers to some degree to get things that are close to work.

5) With an aluminum frame and especially with shallow dropouts, you'll probably want two (I'm not using any but I have a low power motor, steel forks, anti-spin washers and tight nuts).

6) you won't be able to use the brake levers with cut-off switches with hydraulic brakes. I've never seen a need for them myself.

7) probably :wink:

-R

 

[tidelipop]

I've heard Crystalyte has hub-motors that can take 9 speed freewheels, where can I find these? ..or any other brand that would fit a 9 speed freewheel?
Thought it would save me alot of trouble if that could fit.

 

[MadRhino]

Where are you? That would help to fill your profile infos.

You can have Clyte H series motors at Ebike.ca, other members could recommend a reseller in Europe

 

[tidelipop]

Oh, I forgot to say... I'm from Sweden.

 

[tidelipop]

If I buy the first bike I saw in that store, then will I have no problem then? It has 24 speeds = 8 speed rear freewheel.
https://plus.google.com/photos/102682238132947537962/albums/5721311665259485873?authkey=CMvv-dP2r6XIPg

 

[rojitor]

http://www.crystalyte-europe.com/home.php

 

[hillzofvalp]

My experience with a 29er has been good. Only real down side is it's harder to reach the ground with your feet. Other efficiency issues I ignore, along with the fact that I took this picture after running out of juice (headwind) after 16 miles with 700Wh. It's a ridiculous ride! HArd to find good tires for it.

I may add that I bought my original 2807 wheel from ebikes.ca. Great place to get stuff, but in general the chinese wheel build quality is lacking. I rebuilt it myself into a better rim with 13/14 spokes.

I'm considering a smaller wheel for my cromotor.. we will see.

 

[ElectricEd]

I very much appreciate your answers, thanks!

If I really like this bike, what do I need to do to make it work?
...
7. Have I forgotten something?

IMHO, make sure that you have reeeaally good brakes. Doing a panic stop on an eBike from 40 KmH (25mph) with all the extra weight is quite an ask for conventional bike brakes. They have to be very beefy otherwise you'll have the lever bottoming onto the handlebar while you cry "O SH--!!!"

 

[biohazardman]

If I really like this bike, what do I need to do to make it work?
1. Buy a 7 speed freewheel that fits my ebike-wheel-kit, if it doesn't have one from the start.
2. Change the shifter at the handlebar to a 7 speed-shifter. Does any type work? If I prefer the type where you make a twist with your hand, is that ok?
3. The front crank, is that the one that moves the chain onto the front gears? Why do I have to change that one and the chain?
4. Does any motor fit with a disc brake and my caliper? Or how would you have solved that?
5. I need a pair of torque arms.
6. If I don't change the brakes on my handle bar. When I brake and release the throttle, will that also completely cut the power to the motor? Or can I somehow use my current brakes and cut the power to the motor when I use them?
7. Have I forgotten something?

1- A 7 speed freewheel is usually good many motors/kits will come with them.
2- Depends on your shifter I have the 9speed Shimano trigger shifter and they index 4 gears, on my 7speed freewheel, just fine I can get more if I want to double click or pull on the triggers but I use only four gears. If you want it to index perfect yes change to your preferred type shifter and match your gears in the rear.
3- Yes the front crank is what you suspect and personally I took my front derailleur off and only use a 53 tooth chain ring there. You do not have change that or the chain although a larger road bike chain ring will help you pedal at the usually faster speeds your bike will travel with a motor. I can pedal at a much slower pace at 20mph and usefully to near 40mph
4- Most motors with the disk brake option fit on the more standard 135mm dropouts. Some are not perfect and require a spacer easily obtainable or made to get things to line up.
5- One torque arm is sufficient unless you are running at very high power levels. I run my BMC v2 at 66V and a 45A controller and have never had a problem with my aluminum dropouts in 5K+ miles. Be sure things fit good and are tight there it's very important.
6- It is a very good idea to have the brake cut off switch installed for your safety as well as the safety of others. You can make your own brake switch work with the levers you have using a reed switch some epoxy and the two wires found on most motors meant for that purpose. I used the reed switch like this others have put it on thier handlbars. It's not that difficult.
http://endless-sphere.com/forums/viewtopic.php?f=3&t=31503&p=456494&hilit=+brake+lever+switch#p456494

7- Nordlock? washers to be sure things stay tight at the motor.

I never had a problem with the cantilever brakes at <25MPH on my 65LB first build. Disks on my current bike have save my buns a couple of time though.

 

[hillzofvalp]

generally speaking disc brakes are almost a necessity with ebikes. I think even if you are going less than 25-30 you will benefit from caliper pads lasting much longer than cantilever pads.

 

[tidelipop]

That's one of the reasons why I like that bike. I got hydralic disc brakes! ..and that to an affordable price.
I thought that must be much better than the brakes on the first bike I saw in that store.

What is Nordlock washers?