Minimizing Step-through Frame Flex

[frostcrystal]

I got my very first e-bike this year! An EasyMotion Evo Street. I got it used in excellent condition for a steal ($700!), so I was thrilled. My work commute involves a hill and I don't own a car, so I was really looking forward to being able to go grocery shopping with it and so on.

Anyway, it has been doing very well for me so far with only one exception - the frame flex is seriously something else. I'm small, about 5'3" and 115lbs, so when I ride it alone it's only slightly jello-y (I notice it only because I know it's there). But when I load up the rear rack with groceries, or if I'm not careful about weight balance, it's nearly unrideable. I once bought a gallon of milk and a big thing of detergent (one in each pannier on each side of the rack) and crashed in the middle of the bike path because I lost control due to the sway at 10-15mph. I can stand next to the bike, shake the handlebars and watch the whole rear end wibble side-to-side.

Now I've switched to using a trailer for heavy goods, but the fact that I can't load up this bike like a beast of burden grates on me. It makes me nervous riding as well knowing that I've crashed once over something that wasn't addressed.

Does anyone have suggestions for minimizing frame flex? My fiancé is in the machinery/engineering sphere and has suggested making an attachable padded 'top tube' that could be screwed on, but that is all I've got. It would be cool to hear from someone who has done something similar or dealt with similar issues.

 

[fooferdoggie]

I think you found out why you got it for 700.00 imagine what its like with a heavy person. try locking out the suspension fork see if that helps. should be a knob on it that you rotate usually on the right side.

 

[indianajo]

The problem is probably not frame flex. One problem is rack shifting from side to side. Another problem is weight on the back lifting the front wheel. Load up the bike, take two platform scales, see what it weighs. My Pacific steel MTB was 120 lb rear 20 lb front. 20 lb won't steer the bike. I had a dog knock the front wheel sideways and throw groceries everywhere. I had the front wheel turn sideways on a speed bump, a ridge of gravel, a stick, a high pavement separator, and the bike threw me on my chin. Cruiser posture puts the rider's weight mostly on the back wheel anyway. Only flat back head down bikes with drop handlebars even out the weight unloaded with groceries.
The only solution for a short frame cruiser bike is to put the groceries in a front basket. That means you have to steer them, which offers its own control problems. Some expensive $5000 bikes like one specialized model have bosses in the frame to hang a front basket that doesn't steer.
Another solution is a cargo bike, with 6" extra between the seat & the back wheel. Moves your weight to the front tire, the groceries on the rear. In 4 years this yuba bodaboda left has not thrown me. Cargo bikes also tend to have the bosses in the frame for a non-steering front basket, as a second solution. You see my battery mounted up there in my avatar in a custom frame. The back rack on my bike is welded to the frame, no shifting side to side. My yuba was $1500 unpowered, I added $840 in electricity later after a 4 mph 6 hour ordeal into a headwind. Another cargo bike with front basket bosses is the radwagon. However, my yuba had real steel spokes, cables, real aluminum rims. No cable adjusments, no free warrenty parts (spokes) to pay somebody to install.
Other stretch frame cargo models with 24" or 26" wheels, blix packa, m2s, magnum, xtracycle, pedego (expensive) reiss & mueller (expensive) . Butchers has a huge front basket and a 20" wheel, which IMHO would only work in a world with perfect pavement. I can't always miss the potholes, sometimes they are under water or snow or the car in front of me at the green light. 20" tires are jaw rattling, IMHO.
Happy riding & maybe shopping.

 

[frostcrystal]

I think you found out why you got it for 700.00 imagine what its like with a heavy person. try locking out the suspension fork see if that helps. should be a knob on it that you rotate usually on the right side.

Haha for real! I'm certainly glad I didn't get it new though as it apparently retailed for $2k. And to be fair to the previous owners, it seemed like they used it primarily for riding and not for hauling. The shake isn't really apparent when it's just me riding it, so I didn't notice when I test-rode before buying.

I'll try locking the suspension fork. I think I've flipped it back and forth a few times before but wasn't sure what it did.

 

[frostcrystal]

The problem is probably not frame flex. One problem is rack shifting from side to side. Another problem is weight on the back lifting the front wheel. Load up the bike, take two platform scales, see what it weighs. My Pacific steel MTB was 120 lb rear 20 lb front. 20 lb won't steer the bike. I had a dog knock the front wheel sideways and throw groceries everywhere. I had the front wheel turn sideways on a speed bump, a ridge of gravel, a stick, a high pavement separator, and the bike threw me on my chin. Cruiser posture puts the rider's weight mostly on the back wheel anyway. Only flat back head down bikes with drop handlebars even out the weight unloaded with groceries.
The only solution for a short frame cruiser bike is to put the groceries in a front basket. That means you have to steer them, which offers its own control problems. Some expensive $5000 bikes like one specialized model have bosses in the frame to hang a front basket that doesn't steer.
Another solution is a cargo bike, with 6" extra between the seat & the back wheel. Moves your weight to the front tire, the groceries on the rear. In 4 years this yuba bodaboda left has not thrown me. Cargo bikes also tend to have the bosses in the frame for a non-steering front basket, as a second solution. You see my battery mounted up there in my avatar in a custom frame. The back rack on my bike is welded to the frame, no shifting side to side. My yuba was $1500 unpowered, I added $840 in electricity later after a 4 mph 6 hour ordeal into a headwind. Another cargo bike with front basket bosses is the radwagon. However, my yuba had real steel spokes, cables, real aluminum rims. No cable adjusments, no free warrenty parts (spokes) to pay somebody to install.
Other stretch frame cargo models with 24" or 26" wheels, blix packa, m2s, magnum, xtracycle, pedego (expensive) reiss & mueller (expensive) . Butchers has a huge front basket and a 20" wheel, which IMHO would only work in a world with perfect pavement. I can't always miss the potholes, sometimes they are under water or snow or the car in front of me at the green light. 20" tires are jaw rattling, IMHO.
Happy riding & maybe shopping.

The rack seems also to be welded on, so I'm not sure how much more sturdy it can get (I've tried loading it up and shaking the seat to see if the rack flexes, and it doesn't. The whole rear end flexes a couple inches side to side when shaking from the front stem), but you might be on to something with the front being much lighter than the back. Bike has adjustable handlebars, so the time I got thrown I was sitting cruiser-style with my weight on the back wheel and about 40lbs in my panniers. I usually switch to trailer for that heavy a load, but I was coming home from work. However it should still have been within rack weight limit (25kg).

I'll happily invest in a front basket though! At the very least I could put the heavier stuff in there and it will be another place to balance out the load. I would love a cargo bike but my wallet is too thin, even this one was a carefully considered purchase as my main commuting vehicle. But I managed to get my hands on an old bike trailer which I'll be converting into a cargo trailer this winter, and that will hopefully solve my bulky equipment hauling needs!

 

[6zfshdb]

I agree with Indianajo above. Frame flex may not be the only issue. I would definitely try a handlebar mount bag to carry some of the small, heavy items. Doing so improved the handling of my rear heavy bike which has a rear rack battery.

 

[sc00ter]

I had a non-step thru 26" ebike and I got some flex when loaded down. I think my flex was thru the wheels? I ended up selling the ebike and purchased my RadRunner back. Never felt any concerning flex in. Now, note that handlebar mounted baskets take some getting used to. I have one on my analog beach cruiser and I pay attention to what I'm loading into it. My RadRunner had a frame mounted basket added. I still pay attention to what I'm putting in it but its a tad more sable that my handlebar mounted basket. I've also discovered that 20" wheels are best for my riding style.

Oh, and I'm 220 and around 5'9". Heavy people like me flex everything!

 

[Handlebars]

I got my very first e-bike this year! An EasyMotion Evo Street. I got it used in excellent condition for a steal ($700!), so I was thrilled. My work commute involves a hill and I don't own a car, so I was really looking forward to being able to go grocery shopping with it and so on.

Anyway, it has been doing very well for me so far with only one exception - the frame flex is seriously something else. I'm small, about 5'3" and 115lbs, so when I ride it alone it's only slightly jello-y (I notice it only because I know it's there). But when I load up the rear rack with groceries, or if I'm not careful about weight balance, it's nearly unrideable. I once bought a gallon of milk and a big thing of detergent (one in each pannier on each side of the rack) and crashed in the middle of the bike path because I lost control due to the sway at 10-15mph. I can stand next to the bike, shake the handlebars and watch the whole rear end wibble side-to-side.

Now I've switched to using a trailer for heavy goods, but the fact that I can't load up this bike like a beast of burden grates on me. It makes me nervous riding as well knowing that I've crashed once over something that wasn't addressed.

Does anyone have suggestions for minimizing frame flex? My fiancé is in the machinery/engineering sphere and has suggested making an attachable padded 'top tube' that could be screwed on, but that is all I've got. It would be cool to hear from someone who has done something similar or dealt with similar issues.

I was surprised by the flex with my step-through. I have large box panniers and when filled with heavy chains and locks and groceries if I stand to pedal, it gets a bit wild.
However, I've become so accustomed to my bike that I don't notice it.
And I don't stand on the pedals now, unless to get a view ahead or something. I stand on the pedals to go over big bumps sometimes, but I do not pedal same time. Pedaling might really increase it.
I have no extra weight at the front.
I'm reading what indianaJo has to say about it. He has a lot of experience with hauling stuff. I get tired just reading his travails.

 

[Handlebars]

you might be on to something with the front being much lighter than the back. Bike has adjustable handlebars, so the time I got thrown I was sitting cruiser-style with my weight on the back wheel and about 40lbs in my panniers.

Exactly the setup with me and my bike.
If starting on slight uphill, the front wheel will often lift a little bit. That isn't good, because in certain conditions it could actually flip right over as I had happen on a regular bike.

 

[frostcrystal]

I had a non-step thru 26" ebike and I got some flex when loaded down. I think my flex was thru the wheels? I ended up selling the ebike and purchased my RadRunner back. Never felt any concerning flex in. Now, note that handlebar mounted baskets take some getting used to. I have one on my analog beach cruiser and I pay attention to what I'm loading into it. My RadRunner had a frame mounted basket added. I still pay attention to what I'm putting in it but its a tad more sable that my handlebar mounted basket. I've also discovered that 20" wheels are best for my riding style.

Oh, and I'm 220 and around 5'9". Heavy people like me flex everything!

Were your wheels not in true, or shaky? I'm wondering if front wheel panniers would make a difference in handling as opposed to a handlebar mounted basket.

 

[frostcrystal]

Exactly the setup with me and my bike.
If starting on slight uphill, the front wheel will often lift a little bit. That isn't good, because in certain conditions it could actually flip right over as I had happen on a regular bike.

That's definitely a yikes, haha! I'm definitely still getting used to mine. I'm so used to biking a regular step-over bike that it feels quite disconcerting not to have the top tube there. I keep trying to rest my knee against it when turning/signaling or clamping with my legs to keep the bike upright when at a standstill, only to find nothing there.

Strangely enough, standing on my bike (leaning my weight forward) helps stabilize the bike a bit for me. I dropped the adjustable handlebars after the crash and now I ride it a lot more like a regular MTB than a cruiser.

 

[sc00ter]

My 26"wheels were true on my ebike. I just think the cheap 26" wheels had no business hauling loads, and mine were on the cheaper end. Now my analog beach cruiser is a swing bike and the wheels are super strong on it! Zero flex.

 

[rich c]

I'm also in the engineering field. That's one of the reasons I would never buy a step thru. The other is that I didn't want to look like I was riding a girls bicycle.

 

[tomjasz]

I didn't want to look like I was riding a girls bicycle.

HA! You're old dude, embrace the gender-neutral world in this decade!

 

[indianajo]

I'm also in the engineering field. That's one of the reasons I would never buy a step thru.

At 100 lb load, my step through doesn't flex. I weigh 160 lb. Yuba bodaboda wasn't a cheap bike.

 

[Stefan Mikes]

As indianajo said, it is not the frame flex but heavy load on the rear rack. I have been carrying heavy groceries on rear racks of all bikes and e-bikes I used to own for a long time, and the erratic behaviour of the rear wheel is a norm, regardless of the frame type. I weigh 200 lbs, and experience the bike rear wobble with the superlighweight, diamond frame Vado SL just because it is a lightweight, narrow tire e-bike. If I ride my heavier, step-through Vado, the phenomenon is far less pronounced.

An no, I don't think step-through or low-step are for girls. As we all age, there is time in life when swinging your leg to mount a bike becomes an ordeal.

 

[6zfshdb]

I'm also in the engineering field. That's one of the reasons I would never buy a step thru. The other is that I didn't want to look like I was riding a girls bicycle.

I'm also an engineer and felt the same as you up until about 6 years ago. It came to the point that I either ride a "girls" bike or not ride at all. These days, where I ride, I see more senior men riding step thru's than diamond frame bikes. At some point in life, most cease to care what others think.

Don't take this the wrong way and I say this sincerely. I honestly hope you can stay physically fit, injury free and avoid old age infirmities long enough to avoid having to ride a step thru or give up the sport.

 

[fooferdoggie]

I had more trouble lifting my leg up to get it through a step through then over the normal way. Now you want hard try lifting your leg over the bar on a tandem.

 

[AHicks]

Is there any chance this bike needs to be running a little more air in the tires? If they were low, it would seem to me like they would allow/encourage some flex/sway/bad handling, especially when heavily loaded.

 

[Dewey]

Now you want hard try lifting your leg over the bar on a tandem.

I found out the other day Dutch brand Azor make a step through tandem https://www.amsterdam-bicycle.com/shop/specials/azor-tandem-bicycle/