There it was, a Haibike Nduro Pro, size "M" from the end of 2015. 180 mm travel, robust frame and powerful Bosch motor, a classic that Stefan, a Bavarian enduro biker, had been looking for on eBay for weeks ... First owner, in very good condition in the photos. "Almost only city driving to and from work, just SUV :), battery is like new, drive recently renewed," wrote the seller. No sooner said than done, we arranged a meeting and (chargeable) purchase inspection at a local Haibike dealer. Only there did it turn out that the first owner had tampered with the motor contacts (presumably operating with a permanently mounted S-Pedelec dongle). One contact damaged. However, the battery was still in good shape with only 180 full charges according to Bosch system diagnostics, although the 1650 total kilometres deviated slightly from the number of kilometres stated by the first owner. Other defects: cracked headset, brake pads, brake discs, tyre wear. In the end, the price was realistic and fair. Good thing Stefan had done the used bike check!
THE ENGINE
- Engine tuning refers to the unauthorised operation of a pedelec outside the legally stipulated 25 km/h limit using software or hardware (dongle). Although prohibited by law, this is quite common. For example, you may stumble across used e-MTBs with previously tuned motors, but where the tuning has been reversed. Bike dealers cannot diagnose this on site, but manufacturers such as Bosch can in the event of a warranty claim - via a so-called point cloud evaluation of the operating parameters (which the motor logs over its service life). Consequence: loss of warranty. In the event of recourse, the seller must be held responsible. Therefore, if in doubt, ask the seller to confirm in writing that the motor was not operated illegally.
- Listen carefully: A test drive or a comparison drive with a current model shows whether an engine is louder than usual. Alarm signals are grinding noises from the gearbox or if a motor is particularly loud mechanically. However, it must also be said that the latest Bosch Performance CX motors from current production, for example, run much more quietly and smoothly than even new motors from the 2015 and 2016 model years. A lot has been optimised internally here. Nevertheless: a motor that sounds like a coffee grinder? Hands off.
- Salt corrosion: This can be a problem for the motor housing, but also for the plug contacts on the motor towards the wiring harness. This can only be checked by dismantling the manufacturer's covers. A special tool is available for Bosch, Brose and Shimano.
- Support voters: Check whether the motor support selector is working properly, or whether it is stuck or not responding at different levels.
THE ACCU
- Lifetime: After 500 charging cycles, modern Li-ion batteries still have around 60-70% of their original capacity. The diagnostic tool is used by the specialist dealer to read out the charging cycles. It can then be determined whether the battery is at the beginning, middle or end of its service life. The following applies: full charge cycle = sum of the partial charge cycles (e.g. 2 x 50 % = 1 full charge cycle).
- External damage: Check the battery for external damage such as cracks in the housing. Batteries that have been damaged by dropping must be replaced immediately and disposed of via a specialist dealer.
- Storage: How was the battery stored? The service life is extended by storing the battery at 15-20° C with a charge level of between 40-60%. The service life is reduced by storage above 30° C, prolonged storage when full or empty and parking the E-Bike in direct sunlight.
GENERAL WEAR AND TEAR
- Drive: The drivetrain in particular is subject to high wear on E-MTBs. When were the sprocket and chain changed?
- Suspension elements: The fork and shock should be serviced by a specialist once a year. The maintenance intervals are specified by the manufacturer. Ask for proof of maintenance.
- Brake system: The brake fluid should be changed regularly. The maintenance intervals are specified by the manufacturer. Ask for proof of maintenance here too. Assess the function: Do the pistons reset? How is the pressure point, how thick are the discs and brake pads?
- Tyres and wheels: Check the condition of the tyres. Are cracks visible on the tyre casing? Is the tread heavily worn? Check the spoke tension and the general condition of the tyres (e.g. rim punctures).
- Bearing: Check the rear frame and shock mounts for play. Likewise the headset. If you are not sure, the specialist dealer will do this for you.
- Frame: Check the frame for cracks or dents. Also check the paint quality for scratches that go beyond normal use.
