Rear wheel chain tensioner

I've seen a few road bikes with after market chain adjusters on, is there a specific reason for the modification

Handbag said:

I've seen a few road bikes with after market chain adjusters on, is there a specific reason for the modification

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The Lightech's make it both quicker / easier to adjust and to have more accurate settings due to the finer adjustment scales. I've also had Gilles TCA's and found the worm drive adjustment both easy to damage and slow to use.(for info neither were on my S1000RR however they are the same from model to model)

They also make it easy to fit paddock stand brackets if you don't like where the standard cotton reels fit.

I had lightech adjusters on my previous bike and it made lining up the rear axle and getting the chain tension bang on a lot easier than using the oe blocks. Highly recommended.

Chinese copies ... highly unrecommended lol....

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I have R&G ones on mine they seem ok

perkles said:

I have R&G ones on mine they seem ok

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They are a bit different to the Lightechs / TCA's............you can't use them to hold the bike up when you change the back wheel for a start.

+1 Lightechs in blue, very easy to adjust and ensure that the rear wheel is properly in line and I think they they look really good on my Gen 3 Sport

Probably a stupid question but I take it everyone adjusts the chain side to the correct chain tension then just matches the marks on the other adjuster to that one.

I'm wondering as I used the old "string touching of both sides of the back wheel method" and the lightech marks are not the same. I suspect it's probably me.

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Porridgewog said:

Probably a stupid question but I take it everyone adjusts the chain side to the correct chain tension then just matches the marks on the other adjuster to that one.

I'm wondering as I used the old "string touching of both sides of the back wheel method" and the lightech marks are not the same. I suspect it's probably me.

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i hope you double check the tension after adjusting the non chain side to the same markings? Have you ever noticed doing it this way that the tension changes slightly because I?d expect it to, maybe not by much but it will change slightly.

i never use the marks on the adjusters,to far out i find.i just use verniers with the long"prong" to match each side

scooby said:

i never use the marks on the adjusters,to far out i find.i just use verniers with the long"prong" to match each side

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Same as ...

bananaman said:

Same as ...

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third that, that way you?ll always be so close either side that it would be negligible if they were a baw hair out.

Yep, accuracy of chain tensioners/manufacturers markings can be miles out. it's got better over the years. The K67 Gen 4 is very, very accurate because they have machined the tensioner mounting area, so that the axle pivot centre to front machined edge is the same bike to bike. Dead accurate.

The inaccuracy can be introduced by the fact that the aftermarket tensioners inc BMW's own use the back edge of the swinging arm as the clamping area. That edge has a weld that varies massively so that in the numerous bikes I've checked, they've been different side to side. If the front of the tensioner doesn't sit firm against the machined edge at the front of the tensioner area, it'll be miles out.

I found with mine that both sides differed 3mm. I had to 'Dremel' down the weld so that the front face of the BMW M adjuster contacted the machined surface freely then they matched. I also checked the actually chassis with my Maxton Ronometer. Some bikes out of the factory wouldn't pass an MOT. Mostly it's the front wheel not being centred on the axle.

As long as the machining is done after the welding of the swinging arm, it'll be spot on. It's the unintended use of the rear of the swinging arm ie not in the design that introduces the errors.

Hope that helps, J