Another R80 sidecar build

Comes down to what you want to use the sidecar for. I have Eddies old R80 & Velorex 562 sidecar. It’s great for gravel roads & moderate off road, with lightness being a major advantage.

But put a heavier passenger in it, & run it on the seal exclusively, & it starts getting to be hard work, & the sidecar frame becomes a little flexi.

The R80 is a mono (ex R80TIC police bike, now sans fairing), repowered with an R100GS engine, but running an R65 final drive.

The mono front end has loads of trail – which makes it a heavy steerer in sidecar applications. I have a revised top triple clamp to assist with this – but it’s still a lot of work, especially if you want to go quick. You’ll also need to revise the suspension – easy enough to do.

I’ve modified the Velorex chair with a much heavier axle (stock is 15mm, which is way too light), & cast wheel. The stock spoked Velorex wheel is reputed to be strong enough, but the chair came to me with a GN125 or 250 wheel, which wasn’t.

The Ural (& clone) chairs are heavier, & more robust, & easier for the passengers to embark & disembark from. But I think my wife actually prefers the more enclosed feel of the Velorex.

I run the Velorex un-ballasted, but wouldn’t let an inexperienced person ride it without this – Eddie is right in terms of it’s tendency to fly the chair. I am used to this, & use it as part of a suite of skills in riding.

Re the subframe, have a look at the design of some of the commercially available ones. The R80 main frame isn’t robust enough for a sidecar, so the subframes primary role is to supplement this.

These things are a huge amount of fun once you get used to them & the way they (don’t) handle. People also react well to them – they are seen as being cool – I’ve had people hanging out of cars on the motorway so they could take a photo.

There seems to be a dearth of left hand sidecar subframe builders who also advertise on the web. It may be a case of doing google image searches & then taking a drawing into your local engineer (or making it yourself if you have the skills).

I saw you’d got that…

My tyre choices are weighted towards the gravel end of the spectrum

I use TW 18 100/90 x 18 fronts – these were going cheap ($30 – $40 ea) as farmers were buying DR200s with road legal tyres & replacing them with more aggressive tyres. The TWs have good grip. I’ve salted a few away as they were too good a price to miss. You would need to check that they don’t interfere with your hard brake lines if you have twin disc though – I’ve replaced those & routed them elsewhere

On the rear I use Heidenau K60 Scouts in 120/90 x 18. More spending, but wear well & have a flatter profile which works well for sidecar use. Bit more spendy at $160 – you’ll go thru rears in 6k kms.

For the tub I look for cast offs from GN125 Sakura 350 x 16 – once again farmers were buying these bikes & the rears were going cheap ($25/tyre). Last well, & it doesn’t matter what is on the tub as long as its round & black, & more importantly – slides. You don’t want a grippy tub tyre.

I look for non directional tyres. The TW18 falls into this category, as does the Shinko SR244. Colemans in Akld (& a vendor in the Wairarapa – but he’s moved on) were selling the TW18’s – might be worth a call.

Both the TW18 & SR244 are technically rear tyres.

I also tried a Golden Boy SR244 clone – but I prefer the TW18s as they have wet weather more grip (the Golden Boys were ‘interesting’ in the wet). Dry weather & off road there didn’t seem to be anything in it

A less aggressive (front only) tyre which I have used before (& that was recommended to me by others in the sidecar community) is the Mitas H06. That’s circa $100 – 120.

I also given a a Metzler 18×400 Block K Sidecar tyre to try. That was too tall for the brake line & front guard set up that I had at the time. The square section dedicated sidecar tyres are supposed to improve / reduce steering effort but note that I was given the tyre because the prior owner didn’t like grip level though, & preferred the Mitas H06.

Should also say that these tyres are all tube type (just in case you hadn’t picked that)

My guess is that you found it very heavy to steer, & frightened yourself when you turned left & the chair got light? And the Velorex is very light.

The heavy steering is a function of trail – the monos had a lot more of that than the earlier twin shocks. You will need to find some way to reduce that eventually. You can live with it in its current set up – there is another owner in Wgtn with a heavier R80 / Sabastian rig with no steering mods & he gets along fine.

You might want to put some ballast in the chair for a while – say 20 Kgs of builders mix from Bunnings in a dry bag (cause the mix makes a mess if a lighter bag splits, eh Eddie).

Oh and find a carpark & practice round some cones. Accelerate left, throttle off or braking right.

I’ve got twin discs, & find the brake good.

You may be able to find wide bars & still keep the fairing.

Looks a very pretty combo.

Sidecar wheel lead might contribute to the low speed wobble. Also tweaking the steering head bearing up a bit tighter than you’d normally run on a solo may help a bit.

Mine runs straight & doesn’t wobble at all, so it is possible to tune it out.

You can use the drive & brakes to drive around the heavy steering. However even with less trail, mine still beats me up going over the Rimutaka (though I don’t go slow).