The Cycling Thread

[maviczap]

Isn't the internet a marvellous place for finding obscure solutions to your cycling problems.

[TheRamJam]

Thought I'd resurrect this thread as I have recently started cycling into work again after a near 2 year break when my son was born.

Still using the Giant Defy at moment and I have given it a major service with new gear/brake cables (inner & outer), headset cleaned and re-greased, pedal axles greased, new bar tape, new brake blocks new Vittoria Pro Control tyres.
The bike is shifting great again, however I think the front chain rings are past their best. The chain jumps on the rings when I occasionally set off from a standing start and could do with replacing. Currently its Shimano's RS500 compact chainset in the bike. Do I buy a brand new 105 compact online or opt for a 2nd hand Ultegra unit to match the rest of the components from eBay??

Whats everyones thoughts? New or 2nd hand. Prices for the 105 are around £90 new and 2nd hand Ultegras are going for around the same?

Cheers

Colin

[maviczap]

I'm much of the mind to match groupsets, so all Ultegra for me, even if it isn't the same series.

My new built will have a compact 6870 chainset, but with Ultegra 8070 shifters.

However as the chainset doesn't have any groupset branding, I'd just buy new black chainrings.

I'm sure the inner won't have any wear, it'll just be the Outer.

I presume you've changed the chain and cassette, as its odd for the front to do this.

Maybe the rear mech needs replacing, a bit of corrosion stopping it moving as freely as when it was new. They've caused me more issues than worn front chainrings, especially when used in the winter

[TheRamJam]

Originally Posted by maviczap

I'm much of the mind to match groupsets, so all Ultegra for me, even if it isn't the same series.

My new built will have a compact 6870 chainset, but with Ultegra 8070 shifters.

However as the chainset doesn't have any groupset branding, I'd just buy new black chainrings.

I'm sure the inner won't have any wear, it'll just be the Outer.

I presume you've changed the chain and cassette, as its odd for the front to do this.

Maybe the rear mech needs replacing, a bit of corrosion stopping it moving as freely as when it was new. They've caused me more issues than worn front chainrings, especially when used in the winter

Cheers Mav,

I have mostly 6800 components on the bike STIs, cassette, F&R Derailuers, & calipers. I have slowly upgraded bits as I got a few bargains on ebay when R8000 appeared on the scene. Only thing left to upgrade is the crankset. I will buy a new chain when I go to install said crank. I did check the chain and it does seem ok its not stretched too much as the chain tool doesn't drop in to the gaps.

Watching a few 6800 compacts on eBay all ending in a few days so hopefully get a bargain ;-0

[Adam Ef]

Does it skip forwards in every gear on the back? If so, it's likely the front. Worth trying stamping on the pedals with it in the smaller sprockets in the back, first on the inner front, then on the outer front. You might find it's the smaller ones on the back that are causing the skip forwards as that's the most common. Chain may be ok but smaller rear sprockets might not. Is it the first chain that's been used on that cassette or has it had a couple? Cassettes usually last 3 chains, if chains are changed before they start to wear.

[TheRamJam]

Originally Posted by Adam Ef

Does it skip forwards in every gear on the back? If so, it's likely the front. Worth trying stamping on the pedals with it in the smaller sprockets in the back, first on the inner front, then on the outer front. You might find it's the smaller ones on the back that are causing the skip forwards as that's the most common. Chain may be ok but smaller rear sprockets might not. Is it the first chain that's been used on that cassette or has it had a couple? Cassettes usually last 3 chains, if chains are changed before they start to wear.

Thanks Adam,

I'll give that a go. The sprocket and chain have less that 500 miles on. However when the bike is in its highest gear i can lift the chain off the big ring at the front by about 8mm. The teeth look worn and hooked on the big ring.

[Adam Ef]

Cassette is probably fine then with that little mileage on. If it's obvious visually that the front is worn I'd do it as soon as you can to not put premature wear on the chain. You could just get chainrings instead of the whole chainset, but the amount they cost, it usually makes sense to change the whole chainset.


I'd keep an eye out for a 6800 Ultegra one on eBay. They're on there all the time as there's loads of people chasing the latest and greatest... ie R8000 and selling off perfectly good previous generation components cheap. When I looked into it a while ago most 105 was going for similar prices to Ultegra.