How much of a difference to range does and idler make?

I am in the middle of making my own board using the parts below, but i am curious how much and idler effects range? @AdamE3399 has a dual 6364 build without idlers and he gets around 16km on a 5ah bat so should i expecting to get around 13km or so? here are other questions as well

  • how do you calculate range with and idler?
  • What belt life can i expect?
  • does 15mm belts effect range more than 12mm?
  • should i use better bearings than the one supplied from @Boardnamics to decrease drag/resistance?

Parts used:

*Boardnamics motor mount with idler *Dual flipsky 4.12 v3.4 vescs *dual Tb 6355 190kv motors *Tb 218 trucks *Tb pulley *Micro drop down sector 9 deck with carbon and fiberglass layers *100mm Mbs wheels, green, running bone red bearings *Chines Bms and charger *4 x Turnigy 5000mah 3s batteries *nano remote/unbranded

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an idler doesn’t necesarily make a difference. tightening your belt DOES make some difference but if you don’t tighten it too much you shouldn’t encounter a difference in range

your belt width doesnt affect range. at least not noticeably.

belt life stays about the same

getting a better bearing for the idler doesnt make a difference

TL;DR just get an idler to fight belt slip. it doesnt affect anything else


Thanks :slight_smile:

so would you recommend just getting 15mm belts than 12?

You can run 9mm belts on dual…Ive seen it done but I wouldn’t do it myself. I’m a bigger guy and building a 12s battery pack so I’m going to put thicker belts in there.

I’m using 15mm but most use 12 and call it a day. Main cause of belt breakage I’ve seen is due to debris getting caught in it, not because it was too thin.

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Yea. i know were i can get 10mm belts but i don’t know if i should get them

120kg+ and 12mm belts might slip on braking.

i weight like 73kg so i should be fine

although i am a bit greedy for speed so if i went full throttle instantly would that just shred the belts on 12mm?

depends on your belts and if you tighten them with the right strength

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i have idlers that make the belts tight, to rock solid if i want

that’s not always what you want. think you didn´t got the idea of an idler. its not to tighten the belt as max as possible. it´s to run the belts as lose as possible.

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i know i am just saying that though

get 15 mm belts, run them a little looser and with idler

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the point of idlers is to maximise tooth engagement while allowing the belt to be run as loose as you can get it without slipping. This will stop the belts skipping on accel and braking but reduce the rolling resistance significantly and make the drivetrain more efficient.


So to conclude:

  • Avoids belt skiping (tighten belt)
  • Improves motor efficiency (more engaging pulley teeth)
  • Longer belt life (reduces belt breaking)
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i’m 100 kilo plus and i rode 9mm belts on a dual set up and rocking it, anyway i will recommend 12 mm instead 9 or 15mm

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I don’t have any data on range. BUT, idlers did reduce my top end speed by ~3-4 mph.

Note: my mounts had dual idlers (both sides of the belt).

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running the belt too tight. Should if anything free things up a bit. Much better free rolling.

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Even though idlers make debris harder to get into the pulley, just a thought, wouldn’t it also technically be harder to remove from the pulley without remove the wheel and belt?

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