Doppler Engine Spring Gas Coil-Over Overhaul

Doppler Engine Spring Gas Coil-Over Overhaul - Peugeot 103

Doppler Engine Spring Gas Coil-Over Overhaul - 103

$67.49

qty:

here's what ya get in this PARTYYY!:

1 of Add-a-Fitting 212mm M6 Threaded Gas Strut - 15lb ($29.99 value!)
1 of flat washers - M6 ($.27) ($0.27 value!)
1 of m6 blk corrosion resistant fender washer ($1.79 value!)
2 of metric nylon lock nuts - M6 - 1.0 ($.25) ($0.50 value!)
1 of Two-Piece Clamping Shaft Collar - 19mm ID ($18.99 value!)
1 of Two-Piece Clamping Shaft Collar - 8mm ID ($17.99 value!)

this is the version that comes with the stuff to overhaul your doppler spring into gas coil over mode and does not include the doppler spring itself

wow wow wow! people have long known the advantages of using a gas spring in addition to your regular engine tension spring on french bikes. it eliminates the "goating" phenomenon, where if your engine tension spring is too light, the motor will bounce off the line, meaning you'll hear the characteristic "bah bah bah" of the goat, robbing your acceleration unless your foot is heavily planted on the launch lever/your pipe/a giant case bolt you left sticking out because you're too cheap to buy a launch lever. but it's always been up to you to figure out how such a shock would mount from your motor to your frame. no longer!

this pack will drop right in place of the M8 stud in the peugeot 103 doppler engine tension spring! The only permanent modification you'll need to make is to cut down the nylon spring guide in order to slide the smaller shaft collar more forward, or else your engine won't be able to swing back and you can't fully variate. this is an easy process, and if you decide to go back to your old doppler spring setup without the gas shock, it's still totally usable! in order to tighten the nylock nuts on either end of the shock, simply tighten the shaft collar to the respective side and keep the hex key inserted to one of the heads on the shaft collar allen screws. while you're at it, might not be the worst idea to put some blue or orange loctite on the shaft collar screws as well!

to adjust preload, loosen the larger shaft collar, and either slide it forward to stiffen or slide it back to lessen the preload, and tighten when preload is at the desired setting. seems to work well with the yellow spring and very little preload, but the doppler springs all fit, so feel free to try another we carry if you like!

***NOTE FOR MBK AND SPX DUDERS***
this setup has only been extensively tested on peugeot 103 motors, so while it should fit on the mbk or spx doppler engine springs, we do not know if they require stiffer gas springs to work well.

taco rating taco rating 3.5 of 5

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buttah smooth	April 30, 2025
taco eater : jp nyc mopeds from BROOKLYN, NY United States

I've got this on a mild+ setup (teknix case & 50 kit, 15 sha, doppler streetcup, er3) and it makes it possible to run a white spring and not get any goating. I still use the launch lever for initial takeoff but this strut really helps smooth out downshifting.

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Ehhhh	November 17, 2022
taco eater : Ryan Nash from New Orleans, LA United States

Might work just fine with a more mild setup but I sheared the rear threads right off of the strut with a red spring and a Derbi airsal kit on my peugeot. It actually made my bike goat when before with the red spring it didn’t lol. I’m not sold on this and will just stick with the red spring.

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