[rhuturaj]

Hello BHPians,

Need help and advice on dirt bike performance.

I bought a Fiero 2002 model in Jan 2013 to which changes were made to suit the dirt and motocross needs (Listed below) with their purpose, and the problems I still face as I am new to racing and motocross.

Have participated in the MRF 2013 Pune round and Gulf Supercross 2014 Nasik where my results were somewhat satisfactory. Could manage a Bronze in the 4 stroke expert class race at I Land Racing last September. Currently into the top three fastest at this academy.

I request and appreciate YOUR advice for better performance of my bike as I am new to technical aspects.

CHANGES

1. All glass and plastic parts were removed (headlights, blinkers, horn, guards etc.) to make her completely naked. Added Dirt Mud guard, front Rider No. Dye, front fork clamp, broader handle bar, sprocketing and cancelled the battery.

2. Button tyres. MRF Mocross Front & Rear. Both 18 size.

3. Welded footrests for better grip on the foot rest.

4. Suspension. Pulsar fronts (Extended) with disc brakes and Apache RTR rear (Stock) with swing arm (extended).

Purpose: To suit my 6.2 height and to allow me to throw the bikes rear end outside on corners for drifting and fast turns. This was achieved with lots of practice.

Help: For motocross, these sets are working good enough, but need more stability in the front. Also for dirt, which can be the lightest suspension, but still best ones for going faster?

5. Power. Apache head and block with last size bore done. So he says the bike is of 200 to 225 cc.

Purpose: For all FMSCI approved races in India, maximum 260 cc for Indian category. Power helps in race starts and cutting the corners, but requires bigger tracks or it becomes useless on smaller tracks?

Help: How can I understand about making different head and block for different power levels as the tracks are different with National and Local level events. And how can I at least calculate the power and tune the bike? The carb and exhaust add up to more confusions than good results.

Pics for reference:

















Also any more inputs for motocross regarding safety, body gravity or bike positioning will be really helpful.

Regards

Rhuturaj

[GTO]

Mod Note: Thread moved to the Motorbike Section!

Nice to have people like you on board.
Would you please explain why you opted a Fiero. Why not any other Chasis ? I think the Duke's chassis is miles ahead when it comes to rigidity and durability. Fiero's engine is very good but i don't think it can cope up with such kind of races (or am i wrong? ).

What i can suggest is, try to plonk in a Turbo or make it supercharged. for its advantages. But this is extremely difficult for bikes. The cost & expertise to get the job done, additional weight, the perfect tuning might be some of the limiting factors. But done well, you will be riding a supercharged beast which could give you a significant advantage in races.

Regarding, tuning, i am no expert. But to build better head's, you will have to contact people like Joel, DC motors who customize the core components of automobiles
If you can find/make one good friend who works or does engines. you are done.

[GTO]

Originally Posted by gemi_kk

What i can suggest is, try to plonk in a Turbo or make it supercharged. for its advantages.

I think a turbo is a bad idea in situations that require delicate throttle input & control. I've seen how it can mess things up in offroading. The lag or sudden boost lead to loss of traction & control. Plus, as you mentioned, the complexity & cost are deterrents.

I doubt the authorities would allow it either in competition events (unfair advantage).

you will have to contact people like Joel

Seriously awesome advice! A coincidence that he's built a Fiero too

Thread Link

[ebonho]

For those who doubt the credentials of the Fiero as a dirt bike, it bears reminding that TVS has won more national championships with the Fiero than Yamaha has with the RX and then the super highly underrated YBX. The Fiero was also a permanent fixture at the Raid for many years.

[rhuturaj]

@Gemi_kk: Thanks a lot. I chose Fiero for its good performance and track records. Also considering the prices, this bike is bearable upon its regular wear and tear caused during the practice. Weekly costs are around 2-4k for every two practice sessions.

@GTO: Thank you very much for the link. Mr.Joel looks awesome on his Fiero work and I am sure he will be a good help. Problem being he is based in Bangalore.

@ebonho: Yes you are right as the 2009 National Champion (Dirt) from Mumbai used Fiero , he practices with us and I have been lately making up my bike from him.

Tentatively, next month a Local race(GS Dirt Challenge Mumbai) is scheduled on a Dirt track at Wadala and I Land Championships are also declared. MRF rounds should start in April. I am looking at 4stroke Expert class and 2/4 stroke Mix Class. As in both the Categories I would be facing with the same guy, and some other senior racers. What I am worried upon is the power in the bike. I wont mind taking the bike next week to Bangalore if Mr. Joel helps me out in making the bike.

What is a "Supercharged" and "turbo"?

@GTO: What you said is perfectly correct about lag or boost in the throttle leads to loss of traction and control. Have been thrown off the bike many times, its just practice is what I think will be helpful on managing the higher powers.

How can I contact Mr. Joel as I am not able to send a message or a request??

[GTO]

What is a "Supercharged" and "turbo"?

Forced induction. Recommended read. Hope that helps and good luck with racing

[dhaval-mehta]

Hey rhuturaj, where did you source the MRF Mocross 18 inches from? Looking for a set myself but can't seem to find them anywhere!