Optimizing the design of the TRX

[gregs656]

why would they put the V-Max against those?

I haven't actually seen one on the road yet.

[Kayla]

Dunno. I think probably because it was a test of powerful naked bikes and the VMAX doesn't really fit into any category- it's a naked cruisery muscle bike thinger. They liked it but laughed at the price.

[lenny]

I wish Triumph had made a 21st century Bonneville instead of those fugly retro pieces of crap.With their long tradition of sports twins and their bravery of making unusual bikes like the 675 and Rocket,I hoped it would happen.From an engineering and packaging viewpoint the parallel twin makes a lot of sense. Imagine if Ducati had spent as much time and money developing a parallel twin as it has its "fashionable" V twin.It would kick a 1198's arse.

[arrivisto]

I wish Triumph had made a 21st century Bonneville instead of those fugly retro pieces of crap.With their long tradition of sports twins and their bravery of making unusual bikes like the 675 and Rocket,I hoped it would happen.From an engineering and packaging viewpoint the parallel twin makes a lot of sense. Imagine if Ducati had spent as much time and money developing a parallel twin as it has its "fashionable" V twin.It would kick a 1198's arse.

Although Yamaha continue to refuse to produce a Mk II TRX, it is unlikely that Triumph will give us what we're looking for. The new Bonnie is not so much a rebirth of the original, as a response to the cheek of Kawasaki's W650! The BMW F800 360-degree twin is unremarkable apart from its third "vestigial" conrod to act as a counterbalance. The Wikipedia article on parallel twins - http://en.wikipedia.org/wiki/Parallel_twin - makes some good points, but there is still more to say.

In my view, Yamaha got it right with the TRX. The 270-crank with balance shafts is the way to go, and I suspect it may become the norm. Kevin Ash in this week's MCN points out that an engine with balance shafts should actually reduce the overall weight of a bike, by allowing a lighter and more effective frame, with an absence of down-tubes. The TRX's 190kg weight is remarkably low for an 850cc twin; especially given its heavy stock silencers and and absence of emphasis on weight-saving.

V-twins are great. I've had Dukes, a Guzzi and a Hesketh (!) and they all had their good points. But look at it in context. After the iconic 1969 CB750, motorcycling had decades of UJM ("Universal Japanese Motorcycle") fours. The current V-twin fad looks as if it is here to stay. Parallel twins are struggling. Even Triumph are having limited success with their twins; and MZ caught a cold with the 1000S.

One needs only to look at the classic British bikes to see the advantages of a parallel twin over a V-twin. It's cheaper to make, with one cylinder head and block, not two. It's much lighter, for the same reason. The carb(s)/fuel injection are easy to position, with logical access to an aircleaner. The twin exhausts exit at the front of the engine, in the blast of cold air. (Of course, in an air-cooled engine, the front forks and wheel severely interrupt the flow of air for cooling; not a problem for a liquid cooled engine). A parallel twin can have sensible exhaust pipes runs, whereas this is never the case with a V-twin. In fact, the rear cylinder on a V-twin is just a menace! It's in the wrong place and gets in the way of the rear suspension. Of course, you can avoid these problems with a Guzzi-style V-twin, but then you end up with handling seriously compromised by the engine's torque reaction!

As I say, Yamaha got it right with the TRX. Nice and light, with the CG low and well forward. The 79bhp output (more like 75!) is nothing special these days, but it's enough for most people. My Guzzi 750 Strada had 48bhp, and while I suppose it was OK, it was just too gutless and boring. The new Bonneville is similarly underpowered. 50bhp is only fine for a real lightweight like an MZ Skorpion. (Even better, the delicious 60bhp MZ Skorpion Replica; there's a mint one on ebay for £4,500!).

Back to the Yamaha: it is perhaps surprising that a 10-valve 850cc bike engine produces only 75 bhp; and the TRX could probably cope nicely with 85 or even 95 bhp. But though it's nice to have lots of power (I've had a VFR750 with 100bhp; a Triumph Sprint 900S with 112, and a Ducati ST4, with 115) there is a law of diminishing returns. More power means more weight, more expense, bigger and more expensive tyres and chains .. the list goes on.

Then there's the issue of one's riding ability - I'm not sure these days that I want more than, say, 90bhp. I'm older than I was! I'll be 60 soon; and although in the past I changed bikes regularly (I've had 42 bikes!), the TRX suits me and I reckon I'm going to stay with it!

[Trixz]

All things together.....

We want to hold on to the original frame, switch or upgrade the engine to 6 gears, more CC's, injection, torque, power, other suspension, other swingarm and front end, lights..... hmmm...

Ok, I do think now that it's time for a new concept exept for the frame

Greetz
Gerben

[Kayla]

We want to hold on to the original frame, switch or upgrade the engine to 6 gears, more CC's, injection, torque, power, other suspension, other swingarm and front end, lights..... hmmm...

Ok, I do think now that it's time for a new concept exept for the frame

Greetz
Gerben

Well, if I could get hold of an FZR400 3TJ frame cheaply I'd like to put the TRX engine into that Failing that, the gearbox is fine with 5 gears, the capacity's fine and so is the torque and power. The suspension does need looking at, but form should follow function- I'd rather have decent RWU forks than USD forks that don't work as well. The swingarm's fine too- why add weight when the bike doesn't need the extra bracing? Lights? Go daytime only (and save a load of weight off the bike at the same time!)

[Trixz]

Lights? Go daytime only (and save a load of weight off the bike at the same time!)

I rather lose some more weight, but in track-mode, you can't ride on public roads too luv'

Greetz
Gerben

[Kayla]

Lights? Go daytime only (and save a load of weight off the bike at the same time!)

I rather lose some more weight, but in track-mode, you can't ride on public roads too luv'

Greetz
Gerben

You can over here!

[Trixz]

You can over here!

Yes you can (probably ), no you may not (I guess due to MOT right )

[Kayla]

You can over here!

Yes you can (probably ), no you may not (I guess due to MOT right )

Yes, you may. You don't need lights on a motorcycle over here, but if you do have lights on your bike they all have to be present and in working order. If the lights aren't present, they can't be tested All you need to get an MOT (apart from the obvious stuff like good bearings, tyres and brakes) is an electric horn and a legal sized numberplate. I've had a couple of bikes (a TZR250 and a WR250) on daytime only Though of course you can't ride the bike at night

[Trixz]

This is really off-topic Mods feel free to move this part of the thread somewhere else

Yes, you may. You don't need lights on a motorcycle over here, but if you do have lights on your bike they all have to be present and in working order. If the lights aren't present, they can't be tested All you need to get an MOT (apart from the obvious stuff like good bearings, tyres and brakes) is an electric horn and a legal sized numberplate. I've had a couple of bikes (a TZR250 and a WR250) on daytime only Though of course you can't ride the bike at night

Really, OMG You must have some exclusion on your registration document then right

The EU regulation (see also @ eur-lex.europa) mentioned it's required.

I found this also, nothing about no lights neccecery (but it's not official I know).

And @ DLVA, I can't find it too, sorry

Anyone who does?

Greetz
Gerben

[trixynut]

Look at:

http://www.motuk.com/bike/1-1.asp

... and click on 'Headlights' and it says:

This inspection applies to: all machines, except those which have neither front nor rear position lamps, or have such lamps permanently disconnected, painted over or masked that are
. only used during daylight hours, and
. not used at times of seriously reduced visibility
If this situation occurs the vehicle presenter should be issued with an advisory notice recording the above and it should also be recorded on the carbon copy of the VT20

This means if you've got lights, they need to work but If you've not got lights, they can't inspect them, and you'll get an 'advisory' note and a daylight-only MOT.

I've put a motocrosser on the road before with no lights or indicators, just a 6v horn fitted and a number plate.

[Kayla]

http://www.motuk.co.uk/mcmanual_120.htm

There you go God bless the idiosyncracies of the UK and EU!

There is lots of heresay and guff on t'internet regarding 'daytime only' MOTs, in reality there is no such thing- it's just recorded on the MOT certificate that the lights are 'not present' and as such an advisory notice is given. Various MOT testers have their own take on the wording of the manual. Some prefer to see a stop/brake light fitted but others have the opinion that it should be all or nothing. Most people who put their bikes through on a daytime only MOT tend to fit a brake light after the MOT as a safety measure more than a legal requirement to do so.

[Trixz]

http://www.motuk.co.uk/mcmanual_120.htm

I would say that it's native or national law then, good for you all!

Greetz
Gerben

[slow codger]

When I put the Husaberg on the road, I didn't get any advisory notes. However if it was originally fitted, i.e. lights then the machine has to have them, but if it is a one off, or was manufactured without them then it doesn't need them. The daylight MOT only specifies that you have to have a single note electric horn. You don't even need a speedo (however its probably a good idea to have one). Hope that helps.

Dave E