175 con rod

Why has the 175 bantam con rod to be 125mm?

ATG has machining faclities that can machine barrel and crankcases.

Paul

Hi Paul Thanks for email I replied but had it returned?! Don't know of the kwak con rod ? Have a look a 175 spinter bit in Tuning info on this site. Just a reminder the crank determines the stroke , not the rod so any length rod will do as long as the machining of cases and barrel remain within the rules ..... See you on sunday

Paul Brown wrote:

Why has the 175 bantam con rod to be 125mm?

ATG has machining faclities that can machine barrel and crankcases.

Paul

Hi Paul I'm sure you've seen this already but here's the link if you haven't

http://www.bsabantamracing.co.uk/bikes/build175.html

No machining is allowed on the crank cases (175s) also not a lot of meat on the bottom of the barrel/inlet port. So rod 125mm btc is what almost everyone is using. The maico rod situation is being sorted also alternatives are out there.

pm me your number and I'll call you and have a chat if you like

Tony

ps I won't be at mallory, off the road at present

I've had 10mm machined from the base of the barrel, excluding the inlet stub area, to suit a 115mm conrod. The crankcase remains externally unaltered - as per 175cc rules.
Chris

Paul

Couldn't reply to your email, so sent you a PM and mail from this site

Chris is this with a BTW barrel? didn't seem that much meat on my 175 barrels/inlet, be interested to see how it runs

Tony
Its a cast iron barrel, D7 I think, with 60mm stud cts. A 10mm skim off the base takes it to the next fin up where there is a decent mating face and easier access to the transfer ports. A little gymnastics required at the inlet via some internal crankcase cutting but otherwise it fits well and remains within the 175 formula.
Under the formula, BTW barrels have to remain externally unaltered anyway.
First outing is either Croft or Anglesey.
Chris

bennion wrote:

Tony
Its a cast iron barrel, D7 I think, with 60mm stud cts. A 10mm skim off the base takes it to the next fin up where there is a decent mating face and easier access to the transfer ports. A little gymnastics required at the inlet via some internal crankcase cutting but otherwise it fits well and remains within the 175 formula.
Under the formula, BTW barrels have to remain externally unaltered anyway.
First outing is either Croft or Anglesey.
Chris

Thanks for clearing that up Chris, knew you can't take much off the BTW without breaking through. If your devolopments work it gives 175ers another option.

Variety the spice of life

ps Chris how much did Maxtons charge to do your forks?

Tony
To shorten the forks and replace the springs and bushes was about £125 from memory. Ouch yes - but lots better than a few very scary looking projections threatening to get stuck up yer nose!
Chris