TRP Spyre 140mm Rotor on Rear ?

jp1970

Looking to upgrading the brakes on my Planet X London Road from the Shimano BR715 to TRP Spyre.

The bike is mainly used for winter commuting, wet weather riding and the odd venture along canal towpaths.

My LBS has advised that'll I shouldn't need 160mm rotor for the rear and that the 140mm will be OK for the rear.... It so happens to be they only have one set of each in stock !!.

I'm not too sure if the advice given is based on that's all they have in stock and they want to make a sales ? The owner did explain that 160mm rotors would be overkill as they would simply lock and that the 160mm at the front will provide the 'stopping power'


Thanks in advance....

boblo

I running Spyres on a CAADX, 140 mm on the rear. I have the disc and adapter to go up to 160 mm but there's really no need. I can lock the back wheel at will as it is.

ravey1981

I have spyres on my px London road with 160mm front and rear. My rear caliper is not attached using any adaptor and fits a 160 disc. Unless they do different calipers (I don't think they do) then 160 is the minimum that will fit anyway. No issues with locking up on mine.

meanredspider

Check the bargains thread in Commuting Chat - there's a great Shimano 685 hydraulic brake deal at Mantel - better than Spyres or HyRd

I've been using 160 front and 140 rear on my Volagi for 5 years in pretty much every scenario you can think of (including nearly 60mph and multiple descents of Alpe D'Huez) - ideal. In fact I'd be wary of 160mm rear. On road, rear disc brakes are almost pointless - on the right slopes, it's possible to lift the rear wheel on cue.

The only road-type bike I'd fit big rear discs to is a gravel/adventure bike where you might use the rear brake preferentially on loose surfaces.

jp1970

thanks for the advice guys... as per your suggestions think I will stick to 140mm on the rear.

Having trawled around a few cycling websites over the last few days there's not really a consensus, the bikes with OEM discs seem to be 160mm F+R, 140mm F+R, then a mixture of 160mm Front/140mm Rear!!!!.