Benefit of a light alloy front wheel?

[storkfoot]

Physics "O" level was a long time ago now, and I wasn't too good at it anyway, to be honest

Anyway, I'm making plans in my head for a new Series 2 project and, in particular, the front end. I'm toying with the idea of trying one of these on the front:

http://lambretta.co.uk/catalog/product_ ... ts_id=6343

Engine is a 17bhp GT186. I don't want an outboard disc and I don't want tubeless rims. I'm planning a reverse pull internal disc, Escort dampers, and I'll be trying to find springs mid way between the MB progressive springs, and standard.

I have picked up a set of these alloy rims at a show a few years ago and I was pretty impressed with the quality, and how much lighter they were.

Question is, is there any benefit to fitting a pair on the front and, if so, what is it please?

[bristolmod]

!) lighter items thus slightly less overall for the springs to do to control "rebound" forces
2) Probably run "truer" than steel rims- smoother ride in theory

I'd need to be convinced on overall strength- not saying they are weak- I just don't know.

Need to tell your insurance company to be on the safe side.

Chris

[coaster]

100% agree with Bristl Mod. The advantage would be in the reduction of 'unsprung weight". The lighter the wheel assembly is, the easier it is for the spring to control the spring compression an return the week to the mid position. All of which means that the tyre should be better connected to the road.

[storkfoot]

I heard that one of the racers used a set for a while and had no problems. May try it on the front then out of curiosity.

[warts]

My experience, admittedly on a proper bike.
Came equipped with 300mm cast iron 1 piece discs. When worn out I swapped them for some two piece ones ie solid rotor and alloy spider. The change in weight can't have been all that much, and obviously the spider is in the centre so has less effect on angular momentum but was immediately noticable, even to to a wimpy rider like me.
Biggest benefit was the reduction in the gyroscopic precession ie it turned into bends easier and was lighter steering.

[storkfoot]

http://forums.pelicanparts.com/porsche- ... ies-2.html

This is a long thread but interesting in terms of a simple description of unsprung weight.

Towards the end, one of the contributors mentions cornering on a "washboarded" road and the effect of the flexing of the tyre as it skips along. Now I have, whilst running uprated springs, felt this and noticed that the wear on the front tyre is uneven after a couple of thousand. Would this be an explanation for the tyre wear?

As regards dampers, I have always used escorts.

[grimspeed]

As Bristol mod said ! In my experience with tubless alloy rims I found them to make a massive difference in ride and handeling.
All for the good !

[dapper]

Has anyone ever weighed steel against alloy to see what the difference in weight actually is?

[tea5ive]

dont forget the wheel in question is a split rim, not a tubeless sip/af type

[Andy W]

I have fittd a pr of Sip rims recently and noticed a difference straight away, mainly due to the fact they are straight and round. The ride is smoother on the road and when it was on the rolling road you could see how much truer they are. As for weight difference I think it works out about 1/2 kilo lighter per wheel making a 1 kilo reduction in unsprung weight and 1 kilo less to move or so the theory goes! Andy