How here Even in the area of tires/rims, conventional bicycle technology is not spared from problems. Blistering of tires, clicking of rims, cracks at spoke holes, and spoke breakages have accompanied/are accompanying Stromers.
While the rims used in many models from the Taiwanese manufacturer AlexRims – especially on the rear wheel – repeatedly had problems with cracks at the spoke holes, spoke breaks have increased since switching to the Spanish manufacturer Rodi in the summer of 2023. Stromer was usually accommodating, replacing entire wheels under warranty or covering repair or respoking. However, these solutions were not always sustainable, as could be read in forums and Facebook groups, and the same problems recurred.
How can you escape this hamster wheel?
Resourceful dealers in the large electricity markets of Belgium and Holland have found a solution to repair broken spokes sustainably. The details can be found in the chapter Cracks in spoke bores, broken spokes read more.
According to a Contribution From the stromerforum.ch on September 30, 2025, Stromer has also found a solution after a long time. The Andra 29 from RYDE will be used as a replacement for the Rodi rims (see further down). The rim was designed by the Dutch rim specialist RYDE for cargo bikes and is intended to better handle the forces occurring on the rear wheel.
Besides repairing, re-spoking, or replacing broken spokes, you can also switch to a different rim manufacturer.
Legal basis
When changing to an alternative rim, the question of legality arises. Is such a third-party replacement permissible?
The wheel brand is not explicitly mentioned in the operating permit or the EC certificate of conformity (CoC). Only the dimensions are specified in section 6.18.1.1 of the CoC of the ST3/ST5 mentioned.
In contrast to the tires, which must be ECE-R75 approved, the rims are considered approved with the version installed by the manufacturer.
If you want to use a different brand or a different type of rim, it still gets confusing.
In principle, the (Warranty)-Provisions of myStromer AG. Stromer has used various rim brands across its model range. In newer Stromer models, such as the ST3 Pinion, there was a switch from the Taiwanese manufacturer AlexRims to the Spanish company Rodi starting around mid-2023. The older ST2S and ST5 were delivered with branded (+Stromer-) rims from DT Swiss (H612). The ST5 ABS/Pinion and the ST7, in turn, feature rims without branding.
Alternative rims
Below you will find a few alternatives to the original rims from AlexRims or Rodi.
The information listed is for information purposes only. No legal legitimization can be derived from it!
DT Swiss H 612
The DT Swiss H 612 You can't find it under this designation anywhere on a Stromer. With the "+Stromer-" branding, it was used on the ST2S and ST5, and it's also being used again on the ST7 (without branding).
It is a valid replacement for all bikes with rims from AlexRims or Rodi.
DT Swiss U 683
The DT Swiss U 683 has the same dimensions as the DT Swiss H612 but is reinforced.
DT Swiss writes:
The increased rim wall thickness and the larger cross-section of the U 683 rim ensure a very high overall stiffness. This is particularly important when used on E-Touring bikes, which tend to be ridden with a higher total weight. With an approved maximum system weight of 180 kg, the 27.5″ rim offers a correspondingly high level of robustness and therefore durability.
RYDE Andra 29
The Andra 29 by RYDE is not identical to the rims from AlexRims or Rodi, fits, but is suitable for 650B tires and is specifically designed for hub motors and cargo bikes. It can here be purchased.
Ryde writes:
With an inner width of 29 mm, the Andra 29 is an ideal rim for the latest e-cargo bikes and wide tire trends and can take loads of up to 150 kg. The thick, wide nipple bed allows various drilling patterns, perfect for use with e-hubs. Even 2 mm offset holes are possible
The Andra 29 rim is now also used by Stromer as a replacement for the RODI rim, which has been affected by spoke breakages.
ST5 2023 Pinion | ST5 2021 ABS | ST5 2018 (rear wheel complete)
ST7 (rear wheel complete)
ST7 2022 | ST5 2023 Pinion | ST5 2021 ABS | ST5 2018 | ST3 2022 Pinion | ST3 2018 | ST2 2023 Pinion (rim only)
See auch den Beitrag des Users Bertil vom 30. September 2025 im stromerforum.ch.
Zur Frage ob die Andrea 29 bei Stromer eine Offsetbohrung sowie ein angepasstes Bohrbild aufweist hat der user JeroenST im speedpedelecreview.com bei Ryde nachgefragt:
Um meine eigene Frage zum Lochmuster der Ryde-Felge zu beantworten: Ja, die Löcher für die Speichennippel sind sowohl versetzt als auch schräg angeordnet. Die Speiche und der Speichennippel liegen nun in einer Linie, es gibt keinen Knick wie bei den Alexrims.
RAD15 - Storm33
The RAD15 Storm33-584 STROOP is advertised by the wheel manufacturer Spaakshop BV as a Stromer and Opium replacement. (Alternative link: rohloff.nl)
With the aptly named „Stroop rim“ (STROmer & OPThe Dutch rim manufacturer RAD15 is introducing a special rim (ium) that is intended to solve the wheel problems of various speed pedelec brands. Rohloff.nl writes on its website that these are only slightly due to the quality of workmanship, but are mainly attributable to the use of unsuitable rims. RAD15 has launched the „Storm33-584 STROOP“ specifically for Stromer and Opium speed pedelecs. The special feature of this rim is that the 32 spoke holes on the rear wheel are drilled at a 13° angle. As a result, the spokes are better positioned in the spoke holes towards the hub motor.
Here also the 28-hole version for the front wheel.
Price: The wheel manufacturer Spaakshop writes:
The re-inspection with the STROOP rim and reinforced Sapim Strong spokes and nipples costs approximately €233 including VAT. (Source)
New DT Swiss H 1900 Spline front wheel
If you want to avoid re-spoking with a new rim, you can also replace the whole wheel. After a figure of eight in the front wheel of my ST3, I ride the DT Swiss H 1900 Spline. Straight Pull Line is a technology in which the spokes run straight from the rim to the hub without forming a bend (J-bend) at the hub. The letter H stands for Hybrid, which means that it has been specially developed for use on e-bikes.
Unfortunately, the rim is not available separately. If you want an identical rear wheel, you have to buy two wheels and re-spoke the rear wheel. Please note that the rear has 32 spoke holes!
Spoke calculator / Spoking
General: If other rims are used, the motor/hub must be re-spoked into them. Due to the large diameter of the motor drum, J-bend spokes are usually used for hub motors.
The spoke length, the braiding and the spoke diameter are also decisive for the installation. Due to the large spoke angle of 12° degrees, the braiding on Stromer is single.
Due to the Spoke breakage problem it is recommended Nipple with a length of 14 mm (instead of 12 mm), in brass or aluminum design, and with a specially rounded nipple head. More details on this can here can be read here.
Many hub motors use 14-gauge spokes (ø 2.0 mm), which is perfectly adequate with clean lacing. If you change something here, it must correspond with the spoke holes in the motor flange and the rim. Either you drill the holes larger, use washers, or use butted spokes, which, for example, are 13G (ø 2.3 mm) at the motor flange, but then reduce to 14G to fit the rim. The latter is the case with my ST3. So-called single butted spokes are used.
The Spoke length depends on the rim used, the motor dimensions, how the motor sits in the rear axle (Hub Shift*), and its position relative to the rim center (Dishing Offset*). Stromer rims are symmetrically drilled (Right/Left Offset = 0 mm) and my ST3 has no Hub Shift.
When spoking, the Spoke tension to consider. Only uniform and correct spoke tensions ensure a stable rim. The mechanical design of the rim determines the maximum possible spoke tension. It is often printed on the rim.
Common values for S-pedelec rims are 1100 - 1300 N. For the above-mentioned RYDE Andra 29 the manufacturer specifies a maximum value of 1400 N. With the DT Swiss H 612 and Rodi are 1200 N.
Example: Here are the Calculation and the material used for my ST3 built in 2019:
- Motor: TDCM (specification TDCM IGH, but with 32 holes and 140 mm axle length)
- Rim: DT Swiss H 612, ERD* = 564 mm
- Spokes: Sapim Strong Spokes 13G/14G J-Bend Black, Single butted (from Custom Cut Spokes)
Nipples: Sapim Polyax Brass Nipples – Black – 14G – 14mmfrom Custom Cut Spokes)
*/** Additional information
Entity-Relationship Diagram Effective Rin the Diameter
Dishing Offset = Rim vs. Hub asymmetry.
Hub Shift = Frame Asymmetry (Axle vs. Frame Center).
The hub shift moves the axle position on the frame, and the dishing moves the rim on the axle. Both work together to create a functional system for complex drivetrains (like hub motors).
For rims with aluminum eyelets, it is recommended to use brass nipples because a) cold welding between aluminum and aluminum can occur with aluminum nipples, and b) brass is more corrosion-resistant and therefore suitable for all weather conditions.
Links
Spoke calculator | GRIN Technologies [EN] for rear wheels with hub motor
Explanatory videos
1 - How to use the spoke calculator for hub motors from ebikes.ca
2 - How to measure hubs and rims for perfect spoke lengths, wheel construction for e-bike hub motors
3 - How to mount a hub motor at home like a pro. The single-cross construction
Basic article
There is a good introductory article – „The ABCs of Wheel Building“ here from bike-components.de. Sheldon Brown's website explains exactly and pragmatically how the ERD is determined. here.
Engine repairs
There are various suppliers who repair Stromer hub motors and also fit new rims. Here to the corresponding topic on my website.
You should note the bearing specifications for the bearings in the (ST3 Pinion circa 2024) rear wheel freewheel. They are 6902.
This topic is about alternative rims. Although the ST3 Pinion has a 12 mm thru axle diameter, the freewheel bearings are 6902 (15x28x7mm). The relevant topic can be found Here.
The U683 from DT Swiss recommended here is only approved up to 32 km/h.
My Velomech didn't want to install them on the front wheel of my ST3.
The DT Swiss website confirms this information. However, the weaker H612 from DT Swiss was and is used as the standard rim for the ST2S and ST5 models. If I look at the quality of the Rodi or AlexRim rims, I would have absolutely no concerns here. I myself ride the H612 at the rear of the ST3 and the Spline H 1900 at the front. The H612 was spoked by the repair store without any intervention when the bearings on the hub motor were changed.
However, I expressly refer once again to the disclaimer:
The information listed is for information purposes only. No legal legitimization can be derived from it!