SR4 Weight (loss)

[adma23]

I am under the impression that the wing and the seat on the SR4 are the easiest way to lose a considerable amount of weight.

Anyone knows where to source a lighter seat which will fit the SR4 and possibly a lighter wing structure?

Any assistance/ideas even on what else can be removed/replaced will be super appreciated. Thanks!

[andylaurence]

How about a foam seat? Not sure what the Radical ones weigh, but foam can't be any heavier! DJ Racecars do some nice carbon wings for a reasonable cost. I don't know what your wing weighs, but I had one that weighed 20kg hanging off the back of my car when I bought it. I saved 20kg by replacing it and machining out the mounts!

[adma23]

Problem is I have a double seat. And a foam seat needs another seat to fit in to no?

[BertBert]

If you take out the double seat, you are right there is nothing to locate a foam seat. You'd need the bead kit (indy?) rather than expanding foam though if you could fit a way of locating it.

Could you fit a single seat rather than the double unit? The PR6 seat gets fitted to the SR3.

Bert

[adma23]

BertBert said:

If you take out the double seat, you are right there is nothing to locate a foam seat. You'd need the bead kit (indy?) rather than expanding foam though if you could fit a way of locating it.

Could you fit a single seat rather than the double unit? The PR6 seat gets fitted to the SR3.

Bert

I've thought of going for the PR6 seat. But if i'm paying money to buy a seat better buy light-weight immediately. Anyone knows of a company that manufactures light weight seats for the PR6? I'm thinking of losing weight from the most 'obvious' places first.

[Josh Smith]

Tristan at Arc Angels composites can do a seat for a PR6/SR3.

Also, lithium ion batteries are a good way to drop weight. We have just dropped 10kg off of our car which has a 24V start system.

Greaham at Lanan was very helpful.

[adma23]

Josh Smith said:

Tristan at Arc Angels composites can do a seat for a PR6/SR3.

Also, lithium ion batteries are a good way to drop weight. We have just dropped 10kg off of our car which has a 24V start system.

Greaham at Lanan was very helpful.

Brilliant advice thanks. Mine has a 24v start system, paddle shift and dry sump which apparently all add weight.

[andylaurence]

Unless you regularly take passengers (who will add more weight than all the suggestions put together) then you don't need the double seat. My foam seat sits on the floor and rests against the bulkhead. The belts hold it (and me) in place. When losing weight, look at every component one-by-one and ask yourself "do I need that?" If the answer is not "of course I do" then remove it. If the answer is "of course I do" then ask yourself if you need all of it. Discard anything that doesn't fall into the category of "of course I do" and with the remainder, ask yourself "can I make it lighter or replace it with a lighter option?" That's how I lost 65kg in a year. My splitter is now 8mm ply rather than 15mm ply, the rear wing is lower and lighter, the battery is lithium, parts of the bodywork have been removed and various little bits have been discarded. I've saved tenths getting to the first corner and for a grand total of about £500 for a wing, some endplates, a sheet of ply and a few hacksaw blades.

[adma23]

andylaurence said:

Unless you regularly take passengers (who will add more weight than all the suggestions put together) then you don't need the double seat. My foam seat sits on the floor and rests against the bulkhead. The belts hold it (and me) in place. When losing weight, look at every component one-by-one and ask yourself "do I need that?" If the answer is not "of course I do" then remove it. If the answer is "of course I do" then ask yourself if you need all of it. Discard anything that doesn't fall into the category of "of course I do" and with the remainder, ask yourself "can I make it lighter or replace it with a lighter option?" That's how I lost 65kg in a year. My splitter is now 8mm ply rather than 15mm ply, the rear wing is lower and lighter, the battery is lithium, parts of the bodywork have been removed and various little bits have been discarded. I've saved tenths getting to the first corner and for a grand total of about £500 for a wing, some endplates, a sheet of ply and a few hacksaw blades.

This is exactly the way I need to approach it thanks. Where did you source the wing from please? and does anyone manufacture the front splitter or do you suggest I fabricate it myself?

[dunc_sx]

BertBert said:

You'd need the bead kit (indy?) rather than expanding foam though if you could fit a way of locating it.

BertBert's hit the nail on the head, the best upgrade you can make to a Radical imo:-

http://www.ebay.co.uk/itm/Wooden-Beaded-Seat-Cover...

Dunc.

[andylaurence]

adma23 said:

This is exactly the way I need to approach it thanks. Where did you source the wing from please? and does anyone manufacture the front splitter or do you suggest I fabricate it myself?

A wing needs to be the right shape. I'd go for one from DJ as they have the knowledge to advise you and the wings are of high quality. Finding a used one is cheaper, but it might take you a while!

My splitter is completely flat, so manufacture consisted of cutting the right shape with a jigsaw and bolting it to the bottom of the front crash structure. To retain some strength and stiffness, it was laminated on either side with a single layer of fibreglass weave. It's fixed to the front clamshell at the leading edge and fore of the front wheels, so flex isn't a huge consideration. The front diffuser isn't made yet, but that's just a sheet of aluminium cut to size, folded and riveted. I don't have an SR4, so I dont know whether that'll help you.

[splitpin]

dunc_sx said:

BertBert's hit the nail on the head, the best upgrade you can make to a Radical imo:-

http://www.ebay.co.uk/itm/Wooden-Beaded-Seat-Cover...

Dunc.

Shape a bit of backing foam bought off the market, couple of bits of gardeners string to tether it and away you go boyo

[BioBa]

Also have a look at FUEL Exhaust http://www.fuelexhausts.com/range-detail.cfm?id=9&... . They do a 1.7 kg titanium race muffler for under GBP 157 inclusive VAT. Contact them to get the muffler only without any specific motorcycle exhaust piping for even lower price. Mine saved me over 2.5 kg and sounds much better.

[BertBert]

I think we've been here before!

splitpin said:

dunc_sx said:

BertBert's hit the nail on the head, the best upgrade you can make to a Radical imo:-
http://www.ebay.co.uk/itm/Wooden-Beaded-Seat-Cover...
Dunc.

Shape a bit of backing foam bought off the market, couple of bits of gardeners string to tether it and away you go boyo

[andylaurence]

BioBa said:

Also have a look at FUEL Exhaust http://www.fuelexhausts.com/range-detail.cfm?id=9&... . They do a 1.7 kg titanium race muffler for under GBP 157 inclusive VAT. Contact them to get the muffler only without any specific motorcycle exhaust piping for even lower price. Mine saved me over 2.5 kg and sounds much better.

That's nicely lightweight. What are they like on noise? I have to comply with 105dB at some venues, rather than the usual 110dB.

[BioBa]

I purchased the maxi street legal muffler. It has a removable baffle. Without the baffle they call it "race muffler". Even with the baffle removed I passed the 95dB noise test at my track! It sometimes depends how they measure noise (rpm, distance and who knows what).