BBS02 & Motobecane

[MattA]

Hello all,

Wanted to buy a low-cost Motobecane and convert to mid-drive. I read the info on BaFang's website about the way to determine compatibility. Problem is, don't have a bike in front of me to measure. Don't want to buy a bike and then find out I can't install a BBS02. I talked to BikesDirect and another seller about compatibility and neither was able to help.

This is the main bike I was looking at: Motobecane TAZ2.5 Sport EAGLE 29er

http://www.bikesdirect.com/products/...-275-bikes.htm

Anyone know if the BBS02 will fit this?

[73Eldo]

With a reasonable amount of effort I can't find any decent specs for that bike. Every site it comes up on including apparently Motobecanes is a terrible site IMHO. The little I can see it seems possible because of the high chain stay which is usually the first thing that causes clearance issues but I would want to find better specs and pics to have a better guess how well it would fit.

Why the O2 and not an HD? It looks like a pretty decently equipped bike so it doesn't seem like a couple hundred in price would be stopping you? Why not go for the extra power even if you don't plan to use it often it can be nice to have if you do need it otherwise it should last a long time because its not working very hard.

[ncmired]

My "peeking at pictures" guess is that a BBS02 would fit, as the bike has an English 73mm BB, but since the BBS02's spindle is short you'd have to leave the aluminum lockring off (instead, Loctite the steel nut - not an issue with the BBSHD). Also, since the left chain stay veers out quite a bit, you'd likely need an offset left crank arm (probably with the BBS02, possibly not on a BBSHD), like the Lekkie. If using a tray mount battery, I'd add a third aluminum rivet nut / nutsert and not rely on just the two existing bottle bosses.

For the BBS02 motor, to maintain a good chain line I'd recommend the Lekkie 40 tooth ring set. For the BBSHD, I'd recommend the Lekkie 40 set or the Luna Eclipse 2-piece 42 tooth ring.

[MattA]

With a reasonable amount of effort I can't find any decent specs for that bike. Every site it comes up on including apparently Motobecanes is a terrible site IMHO. The little I can see it seems possible because of the high chain stay which is usually the first thing that causes clearance issues but I would want to find better specs and pics to have a better guess how well it would fit.

Why the O2 and not an HD? It looks like a pretty decently equipped bike so it doesn't seem like a couple hundred in price would be stopping you? Why not go for the extra power even if you don't plan to use it often it can be nice to have if you do need it otherwise it should last a long time because its not working very hard.

One of the reasons I like that model is the very high chain stay. Plans were to experiment later on with belt drives and CVT (if possible). I'm just learning so don't have a good handle on what's easily possible ..... yet. The lack of docs may mean going to another brand/model.

I've spent a little time looking at the HD and thinking that would be the way to go for so little extra money.

[MattA]

My "peeking at pictures" guess is that a BBS02 would fit, as the bike has an English 73mm BB, but since the BBS02's spindle is short you'd have to leave the aluminum lockring off (instead, Loctite the steel nut). Also, since the left chain stay veers out quite a bit, you'd likely need an offset left crank arm (on a BBS02, possibly not on a BBSHD), like the Lekkie. If using a tray mount battery, I'd add a third aluminum rivet nut / nutsert and not rely on just the two existing bottle bosses.

For the BBS02 motor, to maintain a good chain line I'd recommend the Lekkie 40 tooth ring set. For the BBSHD, I'd recommend the Lekkie 40 set or the Luna Eclipse 2-piece 42 tooth ring.

Great info. Thanks.

[ncmired]

You mentioned a desire to explore belt drive possibilities - since this bike has a 141 O.L.D. rear triangle, your IGH hub opportunities drop to (I believe) one probably (the Rohloff A12) and two maybe (the Enviolo "Heavy Duty" and Extreme") currently. I'm leaving out the Kindernay models till the numbers/possibilities are better known. A single-speed hub is also a possibility - but why bother?

None of these specialty hubs are widely available. If you're willing to risk tweaking your frame to 135mm, the standard Rohloff series or the Sturmey Archer CS-RK3 can be fitted relatively straightforwardly. Getting the belt line correct with either motor, especially the BBSHD, is challenging and expensive. Moving the gear ratio range up or down is expensive.

AFAIK Gates has not licensed out the components, and their retail pricing is quite high.

You'll also need to configure some sort of belt tensioner, and there's nothing off the shelf to do it that I've seen for your frame style.

[MattA]

You mentioned a desire to explore belt drive possibilities - since this bike has a 141 O.L.D. rear triangle, your IGH hub opportunities drop to (I believe) one probably (the Rohloff A12) and two maybe (the Enviolo "Heavy Duty" and Extreme") currently.

I was hoping at a point in the future to use the Enviolo. Currently, I have no idea what would be involved in tweaking the frame to 135mm. At this knowledge level, perhaps it's an issue best left for later?

Can you recommend a decent donor bike around the 1K or lower price point -- any make/model -- to do what I wanted to do with minimal problems? I do like the slanted step over and wheels maxed at 2.5" wide.

[ncmired]

Can you recommend a decent donor bike around the 1K or lower price point -- any make/model -- to do what I wanted to do with minimal problems?

Not if you throw the Gates belt together with the Bafang BBS series motor, and then wideish tires. On top of that, you haven't mentioned your terrain, rolling weight, willingness to pedal, range/max speed desired, etc.

It's the belt that makes a mess of things, mostly - unless the belt is a just gotta-have feature, dropping it drops complexity and cost rather quickly and opens up access to the used mid-nineties MTB bike market. IMO the Gates belt is not for most "buy it & bolt it together" DIYers - i.e. most of us.

[MattA]

On top of that, you haven't mentioned your terrain, rolling weight, willingness to pedal, range/max speed desired, etc.

It's the belt that makes a mess of things, mostly - unless the belt is a just gotta-have feature, dropping it drops complexity and cost rather quickly and opens up access to the used mid-nineties MTB bike market. IMO the Gates belt is not for most "buy it & bolt it together" DIYers - i.e. most of us.

No problem dropping the belt.

I'm in the SE US. Mostly flat, lots of dirt roads, pastures and of course pavement. I weigh 220 and am willing to pedal perhaps 0% to 70% depending on the number of firing neurons at any given moment :-).

I'd like the highest velocity I can get ..... let's say 28+ MPH. They don't make JATO units (jet assisted take off) units for MTB's, do they?

[ncmired]

Ok, now that that belt nonsense is over ....

The Motobecane is nice, and I suspect a fun build fit - I'd get it with 27.5 wheels myself, but that's just my personal preference.

If you go to the build pages here and here, you'll find a variety of "yup, it worked" completed builds, often on older bikes. I'm hoping other posters like 73Eldo jump in here on some of his favorites. I've listed mine in my signature box. I'd pick clean used brand name bikes over new big box store bikes usually, as hopefully the components and the frame construction are better. Bikes with disc brakes either have better high-speed braking or brake systems that can more easily be improved. Flat tire reduction can usually be had via beefier tires and/or sealant. Whatever bike you choose will gain a lot of weight via the motor and battery.

Speaking of batteries, spring for the usually higher-priced batteries from respected U.S./Canadian sources. Hopefully, doing so reduces the risk of a battery fire. Skimp elsewhere if needed.

Oh, and if you really need jet or rocket power, here are two examples - the first being a true pedalable bicycle, the second is just my favorite kind of old crazy guy:

[MattA]

Oh, and if you really need jet or rocket power, here are two examples - the first being a true pedalable bicycle, the second is just my favorite kind of old crazy guy:

Lol. The expression on crazy old guys face is absolutely friggen priceless! :-)


One the more serious side of things, I went to the build pages you suggested. Found a thread titled: " 2020 Schwinn Axum 29'er"

Looks like he managed to install a BB after a few twists and turns.

Looking up my local Walmart, I find I can buy this bike for $228.

https://www.walmart.com/ip/Schwinn-Axum-Mountain-Bike-8-Speeds-Large-19-Inch-Men-s-Style-Frame-29-Inch-Wheels-Black/288838682?fulfillmentIntent=Shipping&athbdg=L1300

Would you personally take a risk on such a machine?

[73Eldo]

Congrats if you manged to make it all the way thorough the Axum tread. It kinda turned into a longer term review and chat between Dishue and I. If you made it through all that you saw that both of us have changed a fair number of bits, I think I have changed more things than he has so far. Things I remember off the top of my head was he was reasonably happy with the stock 8 speed, I didn't give it a ton of miles and never felt I was able to dial it in and keep it in. Kinda the same thing with the brakes, I was able to get them working decent but 100 miles later had to deal with their pain in the butt adjustments again so both of those systems didn't last long before moderate upgrades.

I did see that at least at the moment the Axum's are in stock online and only $228. I think we both paid the full price in 2020 which was $399. It does seem like a pretty decent frame especially if you like aluminum, personally I think I would rather have steel but especially in 2020 there was almost nothing in stock anywhere. An advantage to that model is you know what it takes to make both a 02 and and HD fit. That alone has some value and the fact that if you act fairly quickly you can actually get a good deal on one. Lots of other cool builds on this site but I bet maybe one in 50 is currently available new. Also if you get one for $228 you will feel a lot less bad about doing upgrades early or if you have the same issues we have after a bunch of miles with the hubs starting to wear out.

Personally for a comfortable multi use but mostly mellow cursing E bike I think steel is the way to go. Steel is about the most flexible you can get without having to have the extra complexity and expense of suspension. Flex isn't good if you are looking for maximum efficiency because some your pedal input just flexes the frame vs getting to the road. Steel is also slightly heavier than other materials but on an E bike we really don't care that much about either one of those factors. Surly was kinda the go to for a mid to upper range steel bike and according to their social media they are still alive and selling bikes but try to find a new one in stock anywhere..... If they are making new bikes since 2020 its a tiny fraction of what they used to put out.

I have not really been looking at what is out there now, I'm content with where the Axum is for my 'street' riding and same with my Surly fat bike that I used mostly off road.

[MattA]

Congrats if you manged to make it all the way thorough the Axum tread. It kinda turned into a longer term review and chat between Dishue and I. If you made it through all that you saw that both of us have changed a fair number of bits, I think I have changed more things than he has so far. Things I remember off the top of my head was he was reasonably happy with the stock 8 speed, I didn't give it a ton of miles and never felt I was able to dial it in and keep it in. Kinda the same thing with the brakes, I was able to get them working decent but 100 miles later had to deal with their pain in the butt adjustments again so both of those systems didn't last long before moderate upgrades.

I did see that at least at the moment the Axum's are in stock online and only $228. I think we both paid the full price in 2020 which was $399. It does seem like a pretty decent frame especially if you like aluminum, personally I think I would rather have steel but especially in 2020 there was almost nothing in stock anywhere. An advantage to that model is you know what it takes to make both a 02 and and HD fit. That alone has some value and the fact that if you act fairly quickly you can actually get a good deal on one. Lots of other cool builds on this site but I bet maybe one in 50 is currently available new. Also if you get one for $228 you will feel a lot less bad about doing upgrades early or if you have the same issues we have after a bunch of miles with the hubs starting to wear out.

Personally for a comfortable multi use but mostly mellow cursing E bike I think steel is the way to go. Steel is about the most flexible you can get without having to have the extra complexity and expense of suspension. Flex isn't good if you are looking for maximum efficiency because some your pedal input just flexes the frame vs getting to the road. Steel is also slightly heavier than other materials but on an E bike we really don't care that much about either one of those factors. Surly was kinda the go to for a mid to upper range steel bike and according to their social media they are still alive and selling bikes but try to find a new one in stock anywhere..... If they are making new bikes since 2020 its a tiny fraction of what they used to put out.

I have not really been looking at what is out there now, I'm content with where the Axum is for my 'street' riding and same with my Surly fat bike that I used mostly off road.

Before I found the Axum thread, I went down several threads. I'd look to see what was available on SearchTempest within 250-300 miles (they pipe in sunshine back here in the stix). The used bikes were priced very high and almost always at great distance. Looking over some threads this morning and changing wording has bought in some new results.

Overall, I don't think I'm into that much replacement work with the Axum. I've watched quality of so many products crater or the past 40 years that it just aggravates me. I would not enjoy it so think I'm gonna pass on the Axum. Finding a hit like that sure was exciting tho.

I looked over Surly and whew, those prices are pretty high. Nice but too rich for my blood. Guess I'll keep combing until something shows.

Thanks for the info!

[ncmired]

Well, keep looking as we come into winter. I use the phone/tablet Craigslist app, and good build potential bikes come up all of the time.

I think the Axiom is one of the better bikes at that price point - gotta give it that. But I prefer using steel frame bikes built bit by bit as my finances permit, with high-quality MTB grade silver retro-looking components and IGH rear hubs, and "therein lies madness" money-wise. I laughably try and justify spending what it cost to do so by riding as much as possible for my errands and driving the car as little as possible (less than a tank of gas a month). Two wheels (bicycles and motorcycles) have always been an interest and hobby. And boats.

There are quite a few top-grade American bicycle component manufacturers, primarily offshoots of the early MTB days.

[73Eldo]

Last year I considered a GT Aggressor Pro from Dicks for a friend, quick look now they appear to be available but $600. At the time I remember them being a little more expensive than the Axum but I thought they were maybe worth it at least based on the looks of em in the store. At the moment with the Axum on sale I would say no way but maybe worth a look? I can't remember if anyone did a detailed write up on a BBS build on one or not, seems like it was the usual where someone said they did it with no real details and another person said it wasn't possible again with no real details. Me just eyeballing it thought it looked possible but I never did do it.

Older MTB's (like 20 years) often will take the BBS's fine. Those oldies were all designed for a 3x drive which I think was also what the BBS was made for. They also didn't tend to have very wide tires so the chain lines were pretty mellow. Biggest downside to oldies is no disc brakes but you could end up with a mid to high end bike that had pretty good rim brakes that stops pretty well especially in fair weather. I guess 90's MTB's have gotten pretty 'cool' in the last couple years so the prices have gone up on the decent ones but you could get lucky and find one still. Do you have any friends or family up in the frozen north? If so check in their area, with us coming into winter many people are looking at their winter storage situation and getting rid of things we never used to make space like maybe bikes that were purchased in 2020.