GSXR 400r head race issue

[SVboy]

I have a 91 gsxr 400r which I am building/having built into a wee track/road fun bike. The bike is currently at Dirt action services in ChCh, having its front and rear suspension overhauled. When ,at my request, they went to service the steering head bearings, they found the bottom headstock[?part of the frame that holds the center steering shaft and bearings] stretched and out of round,so that the lower steering race is loose in the frame.[as the result of a previous prang]. So, what to do? My solution is for the bike to go to and engineering shop, and for them to use a spigot and fly cutter to return the frame bearing holder to round,then to mike it up,machine a spacer back to factory specs[id=lower steering head beering od] and reinstall the lower head race.
So, my questions:
1/Does this sound like a good idea or is there an easier way?
2/Will the bike have to be stripped to its basic frame[real pain invoved here] or should a workshop be able to cope with a frame with motor, tank etc installed? This would involve machining upwards, as inverting the bike would be unrealistic, unless stripped.
3/Can anyone recommend a shop in ChCh to do this work. Coombes is coming out on monday to look at the job.[they built that nice Bulovard trike], and is there technology available for the job to be done onsite?
Your advice appreciated.......

[Shaun]

I have a 91 gsxr 400r which I am building/having built into a wee track/road fun bike. The bike is currently at Dirt action services in ChCh, having its front and rear suspension overhauled. When ,at my request, they went to service the steering head bearings, they found the bottom headstock[?part of the frame that holds the center steering shaft and bearings] stretched and out of round,so that the lower steering race is loose in the frame.[as the result of a previous prang]. So, what to do? My solution is for the bike to go to and engineering shop, and for them to use a spigot and fly cutter to return the frame bearing holder to round,then to mike it up,machine a spacer back to factory specs[id=lower steering head beering od] and reinstall the lower head race.
So, my questions:
1/Does this sound like a good idea or is there an easier way?
2/Will the bike have to be stripped to its basic frame[real pain invoved here] or should a workshop be able to cope with a frame with motor, tank etc installed? This would involve machining upwards, as inverting the bike would be unrealistic, unless stripped.
3/Can anyone recommend a shop in ChCh to do this work. Coombes is coming out on monday to look at the job.[they built that nice Bulovard trike], and is there technology available for the job to be done onsite?
Your advice appreciated.......




Based on what you say here mate, I would guess the stearing head is BENT as well?

[SVboy]

I am hoping not. When I bought the bike, I checked if the steering moved freely both ways,without binding. The vendor was quite frank with me re the biking having a highside resulting in new forks, at some previous stage. Any way of checking for bends while the front end is stripped. Do you think my suggested cure to the distorted bearing seat is feasable? Appreciate your comments.

[Shaun]

I am hoping not. When I bought the bike, I checked if the steering moved freely both ways,without binding. The vendor was quite frank with me re the biking having a highside resulting in new forks, at some previous stage. Any way of checking for bends while the front end is stripped. Do you think my suggested cure to the distorted bearing seat is feasable? Appreciate your comments.




Theories are great, but only theroies mate, CALL STEVE BRIDGE at F1 Engineering in Hamilton 07 8476990 and talk it through with him first!

Sorry, I do not anyone down in CH CH that does work like Steve

OR you could try Glenn Haywood on 03 3662202, he is a good fussy man!

[imdying]

Strip it down ya pussy... even if you can find someone to machine it in situo, they'll charge the crap out of ya :) Take it to someone like Thorpes, they'll fix it up sweet :yes: