I have a Fuji Track bike. The chainline was slightly off from new - the chainring is further outboard than the sprocket by about 2mm. This is enough of a difference to prevent use of a bushed chain, which crackles in protest, and a bushless KMC chain still chatters slightly, which is getting annoying and presumably won't do the chainring, chain and sprocket much good.
I've measured the chainline as 37.6mm front and 35.6mm rear, both of which seem rather low compared to a "standard" 42mm. The sprocket (EAI at the moment) *is* a long way from the rear dropout and the chainring is mounted on the inside of the spider, presumably to compensate for the small chainline at the rear. In fact, the spider on the crank cannot take a ring on the outside - there are no "flats".
The rear hub is a cheap Quando - are these known for having a duff chainline? I'm reluctant to respace the wheel to get the chainline right because I will then need to dish it (making it weaker). Presumably the cheap solution is a shorter BB, and the expensive solution is to rebuild the wheel with a proper track hub and then use a longer BB?
I've measured the chainline as 37.6mm front and 35.6mm rear, both of which seem rather low compared to a "standard" 42mm.
Put a 2 mm. spacer (the kind used for shimming bottom bracket fixed cups or freewheels) between the hubshell and the sprocket. That'll reconcile the difference you measured without having to make further modification.
------------------------------- John Dacey Business Cycles, Miami, Florida Since 1983 Comprehensive catalogue of track equipment: online since 1996. http://www.businesscycles.com
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"Defendit numerus" - Anonymous
Zog The Undeniable said:
I've measured the chainline as 37.6mm front and 35.6mm rear, both of which seem rather low compared to a "standard" 42mm.
Put a 2 mm. spacer (the kind used for shimming bottom bracket fixed cups or freewheels) between the hubshell and the sprocket. That'll reconcile the difference you measured without having to make further modification.
------------------------------- John Dacey Business Cycles, Miami, Florida Since 1983 Comprehensive catalogue of track equipment: online since 1996. http://www.businesscycles.com
Just curious, how did you measure 35.6mm for the rear? -tom
"John Dacey" <[email hidden]> wrote in message news:[email hidden]...
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Zog The Undeniable said:
I've measured the chainline as 37.6mm front and 35.6mm rear, both of which seem rather low compared to a "standard" 42mm.
Put a 2 mm. spacer (the kind used for shimming bottom bracket fixed cups or freewheels) between the hubshell and the sprocket. That'll reconcile the difference you measured without having to make further modification.
Quoted message said:
Just curious, how did you measure 35.6mm for the rear? -tom
I didn't measure them: those were the numbers provided by the OP. Although they seem rather closer to the bike's centerline than the common chainline rendered using premium track-specific cranks and hubs, I'm neither sufficiently familiar with either the subject Fuji bike nor its components to challenge his findings.
------------------------------- John Dacey Business Cycles, Miami, Florida Since 1983 Comprehensive catalogue of track equipment: online since 1996. http://www.businesscycles.com
I didn't measure them: those were the numbers provided by the OP. Although they seem rather closer to the bike's centerline than the common chainline rendered using premium track-specific cranks and hubs, I'm neither sufficiently familiar with either the subject Fuji bike nor its components to challenge his findings.
Vernier calipers. Thinking on this a bit, it may be a hub originally designed for 110mm OLN, with extra spacers and a longer axle. That would account for the weird chainline.
I'll try freewheel spacers under the sprocket but the practicality of this will depend on whether the lockring still engages. I already have a 1mm thick Campag spacer in the toolbox so I'll try that first.
